Saturday, December 26, 2009

Just A Little More...

Our cut-off low pressure system continues to rotate above the northern plains and western great lakes regions, and is making sure it squeezes out as much moisture as possible before it leaves.  Scattered snow showers are rotating across portions of the Dakotas, Minnesota, Nebraska and Iowa at this hour, providing anywhere from a dusting to upwards of 2-3 inches on the ground in heavier bands.  This snow will just be a little top-off by this system before finally leaving the plains...

We'll be left in a cool air mass, with temperatures in the teens and 20s across the northern plains on Sunday.  The Dakotas and northwest Minnesota will see a cool down into the lower 10s for Monday and Tuesday while the remainder of the northern plains will keep high in the teens and 20s.  Lows will have a greater variance, from the single digits below zero the the lower teens from ND to southern Iowa on Sunday night.  Below zero temperatures will be widespread to all but southern Iowa on Monday night and from the teens to near zero from southern Iowa to the Canadian border on Tuesday night ahead of our next clipper storm system.

Our next storm system will not likely bring much in the way of precipitation, but will bring in some reinforced cold air.  Temperatures for the remainder of the week will be below normal with below zero temperatures across much of the northern plains.  More details on this mid-week clipper in the next update...

Winter Storm: Dec. 23-25 Overview

The Christmas Snowstorm/Blizzard of 2009 has came to an end across most of the plains, with some lingering snow left over the Great Lakes region and the far eastern plains states. Widespread blizzard conditions creating major travel delays and cancellations with airport and road closures. These conditions along with a mix of sleet, ice, and snow created power outages across many areas and even more travel concerns. Other areas of the plains were warm enough to escape the winter storm, but saw flooding rains as frozen ground created troublesome run-off.

The Des Moines NWS has issued their event snowfall map for the state of Iowa, which shows a good gradient of snowfall across the state. Keep in mind that there is several reports of greater than 12" in northwest Iowa where isolated amounts of 18-21" have been reported. I've included links to several NWS website stories that have event totals in lists, or in both lists and graphical format below.  I may do another post if I find more NWS sites that do an event summary on the event similar to ones that a few others have done.


Des Moines NWS Map

Omaha NWS Map & List

Sioux Falls NWS List

Kansas City NWS Summary & Maps

Aberdeen NWS List

LaCrosse NWS Summary & List

Friday, December 25, 2009

Winter Storm: Dec. 23-25 Update #6

The Christmas Blizzard and Winter Storm of 2009 has taken its' toll thus far with several roads and interstates becoming closed last evening and continued to be closed this morning.  Much of western Iowa, eastern Dakotas/Nebraska, and southern Minnesota and feeling the brunt of the snow currently.  Expect the snow and winds to continue through the day, making travel near-impossible if not completely impossible.  Refer to the previous post for an updating map on current snowfall totals.  Below is the latest Sioux Falls NWS weather story displaying their current warnings they have issued and the latest expected snowfall forecasts.





Sorry for the short update, but after all it is Christmas morning! Enjoy it inside and don't risk the travel today as conditions are very unforgiving.

Thursday, December 24, 2009

Winter Storm: Dec. 23-25 Update #5

The Christmas Blizzard of 2009 is well underway with the expansion of blizzard warnings to include parts of Iowa, Nebraska, South Dakota and other areas.  Interstates and other major highways are now being closed by the DOT's and other areas are advising no travel.  With winds on the increase throughout the night expect conditions to continue to worsen and remain hazardous through Christmas day.  The combination of ice, snow, and strong winds may also be creating some power outages for the areas affected.

The map below will update automatically throughout the night and Christmas day with the latest snowfall totals, enjoy your Christmas day!

Map removed due to being outdated.

Winter Storm: Dec. 23-25 Update #4

Our first round of snow across the northern plains has came to an end, and we are now looking towards a digging trough in the western plains and its' associated low pressure system that should strengthen and create blizzard or near-blizzard conditions across a large part of the northern plains.  Both the northern and southern streams of the jets will have ample support for a low pressure system and result in rapid intensification of the 500mb low creating a large closed low across the northern high plains.  This will aid in pulling the intensifying surface low from the Mississippi valley region back westward towards the northern plains.  This will prolong the snowfall for much of the plains, and also results in an increased pressure gradient leading towards are high winds expected tonight through Friday.

For today we'll see some scattered snow showers and mixed precipitation across the state of Iowa and adjacent areas, with little accumulations for most areas.  This may give roadway crews time to clear the roads somewhat and make travel a little less hazardous.  However, conditions will deteriorate very quickly this evening as moderate to heavy snow begins to fall and winds continue to increase.  Models continue to forecast the heaviest snowfall across western Iowa, with the potential for 8-12" or more during the overnight hours tonight with snow continue through Christmas day.  Snowfall totals still look to range in the 16-18" with isolated higher amounts throughout western Iowa, Minnesota, the eastern Dakotas and nearby areas.

While afternoon and evening travel may not appear hazardous with the lack of precipitation falling, keep in mind that conditions will deteriorate rapidly this evening as our next storm system begins to impact the area.  Moderate to heavy snowfall will fall throughout the nighttime hours and continue through the day on Christmas.  Here is some of the latest snowfall totals for the past 24 hours at Iowa cooperative observer stations (this should fill in with all of the reports as they are received today):




Wednesday, December 23, 2009

Winter Storm: Dec. 23-25 Update #3

Some hefty snow falling across Iowa currently, with some very large flakes being reported in many areas.  Thus far I currently measure 3.25" of snow, with snow currently falling at a 1"/hour rate.  There is some fairly hefty snow falling across parts of the state currently, with 2"/hour or heavier snow rates likely in the heaviest band.  Latest snowfall reports show widespread 2-4" across northern Iowa with some heavier amounts over north-central Iowa.  Expect the snowfall to continue throughout the night, with total accumulations of 4-8" likely over northern Iowa with perhaps some isolated higher amounts.  Forecasts are still on track for 18"+ for northwest and north-central Iowa; and 10-15" across the remainder of northern Iowa.  Ice accumulations are also becoming a problem across the central portions of the state, with a tenth to over a quarter inch already reported.  Hazardous travel conditions have been ongoing for some time, with reports of multiple cars in ditches in several counties across the state.

We may see some breaks in the snow come tomorrow, but expect travel to continue to be hazardous through Friday and much of the day Saturday.  Snow totals look very impressive with this system, and with winds on the increase and the snow becoming lighter expect drifting to be a big concern as well.  An update in the morning will give the latest snowfall measurement here, and hopefully some graphical representation of the snowfall across the state as well.

Winter Storm: Dec. 23-25 Update #2

A mix of sleet, snow, and freezing rain has fallen today across the plains states.  Areas are now seeing some moderate to heavy snow across northern Iowa and adjacent areas, creating hazardous travel conditions already.  The latest Iowa road conditions indicate that there are roads in north-central Iowa that are completely covered, thus no travel is being advised.  These roads include I-35 from roughly highway 3 northward to the IA/MN border, along with several other major highways in that area.

I did some travel earlier this afternoon, and while most major highways had been graveled/salted to create just wet conditions many of the other county roads were ice/sleet covered.  With moderate snowfall the past hour or two, all of the roads are now becoming covered and thus becoming slick.  The map below shows the latest Iowa road conditions, otherwise check out the website for additional details:  Iowa Road Conditions



The latest NAM forecast run from this afternoon (18z) continues the trend of widespread 18+ inches of snowfall across the northern plains.  Perhaps just a slight eastern movement of the heaviest axis, with the low pressure system over eastern Kansas and continuing to gain strength this afternoon and should continue to do so through the day tomorrow.  The latest water vapor imagery does not indicate any dry punch with this low, thus expect widespread snow to continue unabated through the evening and overnight hours.  Later updates may hopefully have some of the snowfall reports from around the region.

Winter Storm: Dec. 23-25 Update #1

Roadways across northern Iowa and adjacent areas are slick in spots this morning as a layer of ice has fallen during the overnight hours, and may continue to lightly accumulate this morning across parts of the state.  Snow may begin to fall this afternoon across portions of northern Iowa, as well as other areas of eastern KS/NE/SD today.  This snowfall will likely continue through the day on Friday across northern Iowa and other areas of the northern plains, with snow totals reaching well above a foot over a significant part of the Dakotas, Minnesota, Iowa, Nebraska, and a few adjacent areas.  Other areas just south and east of this heaviest snow will see a mix of snow and sleet, and perhaps a few more hundredths to a tenth of ice accumulation as well.  Even further south and east with this system will see several inches of rain on top of the frozen ground, creating flooding hazards in some areas.

Luckily, I find myself in the best probabilities for over a foot of snow as rated by the HPC for both today and tomorrow.  I'll continue to post updates as I can as the snow begins to accumulate over the area.  The next update I'll give later this morning will have the latest model runs and their forecast snow accumulations.  Below is the latest Des Moines weather story, which gives a pretty good summary for the state of Iowa:


Tuesday, December 22, 2009

Winter Storm: Dec. 23-25

A significant winter storm is making its' move at one of the busiest travel times of the year for the central and northern plains.  Not only will significant snowfall accumulations of 10-20 inches be widespread and cause for concern, but ice accumulations of a tenth to over a third of an inch are also possible across parts of KS/NE/IA/MN/WI.  There is also a concern of flooding for areas that will be on the warm side of the system, with significant rainfalls falling on already frozen ground.  For the best details I would look to your local NWS office and local media stations, as this system is just too widespread to try to get all of the details posted.

For the best idea as to what type of precipitation and how much areas will receive, I'll go ahead and post a few model images from this afternoon.  Expect the heaviest snowfall amounts to fall across eastern NE/SD/ND, western Iowa, and southern Minnesota Wednesday night through Thursday; and over western Iowa, Minnesota and western Wisconsin on Thursday night through Friday.  Ice accumulations are also likely to be a concern from eastern KS/NE through Iowa and into portions of MN/WI/IL as well.

Below are the images from this afternoon's model runs of the NAM and GFS, both are snowfall accumulations from today through Friday at Noon.

NAM Accumulated Snowfall










GFS Accumulated Snowfall


Christmas Blizzard?!?!

Another major winter storm is expected to impact the central plains beginning today, and continuing through Friday and perhaps into the weekend for portions of the eastern Plains.  Snowfall accumulations well over a foot are possible across a large area of Kansas, Nebraska, Iowa, South Dakota and Minnesota.  Other areas may see significant accumulations of sleet and ice as well, mainly over parts of Nebraska and Iowa on Wednesday.  With snowfall beginning today over parts of KS/NE/SD, and continuing through Christmas day across areas of IA/MN/WI there is significant travel concerns.  It is likely that a large portion of major highways and interstates over these regions will become too hazardous to travel and may even become closed during the heaviest snowfall.  Winds are expected to increase as the low pressure system responsible for this winter weather strengthens on Friday, with winds nearing blizzard-like conditions over parts of NE/SD/MN/IA being possible on Christmas day.

I returned last night to northwest Iowa from moving a significant portion of my belongings down to Kansas City where I will begin my new job in early January.  Thus, don't have a good hold on how the models have been handling this system as their is some discrepancies in location of the heaviest snow.  Later updates today may hopefully define these areas better, and I will try and include a few quick model images or NWS weather stories for some graphical aids.

I will urge any of those likely do to traveling in this Wednesday through Friday time frame to carefully look at your schedule and your expected route, and either begin your travel today or wait until Saturday or Sunday at the earliest.  I expect their to be a large number of people who do not heed the warnings given on travel conditions and likely will make their Christmas even worse as they end up stuck on the roadways!

Sunday, December 13, 2009

A Light Wintery Mix

A weak low pressure system will move across the plains during the day today and into the overnight, creating a mix of wintery precipitation across the state of Iowa and some decent snowfall amounts across parts of the northern plains.  The state of Iowa will roughly be split in thirds as far as precipitation amount and type goes with this system.  The northern third of the state will see snowfall during the day and overnight hours with accumulations of 1-2 inches possible.  The central third will see a mix of snow and freezing rain, with only light accumulations of each.  The southern third of the state may see a few freezing sprinkles or light showers during the overnight hours, with little accumulations if any expected.  The heaviest snowfall with this systems should fall across central Minnesota, including the metro areas of Minneapolis/St.Paul where 2-4 inches of snow may fall this evening and through the overnight.  For this reason there is a Winter Weather Advisory for many counties across central Minnesota due to this snowfall accumulation.

Beyond tonight weather system, more arctic air will move into the plains states leaving our temperatures in the single digits and teens with lows likely into the single digits above and below zero.  More details on our second arctic outbreak in the next update.

Thursday, December 10, 2009

Arctic Air & Snow Depth Wrap-Up

The blizzard has came to an end across the plains, with many areas are finishing the digging out process today under clear skies and calmer winds.  Storm totals for the state of Iowa were featured in the previous post and final update on the winter storm of Dec. 7 and 8.  As for a wider view of the plains, the attached image below shows the satellite estimated snow depth for the plains as of this morning.  Keep in mind this is an estimate taken by satellite with the aid of more localized observations, thus isolated higher amounts may be missed.  You can really see where the path of the storm dropped the heaviest amounts, and also see some of the lake effect snow that occurred over the UP of Michigan and extreme northern Wisconsin.




With the passing of this system, we are now left under a very cold arctic high pressure system leaving temperatures well below average across much of the plains.  Looking at the state of Iowa for the next few days we'll see a steady increase in the temperatures, however, nothing that will begin to melt any of the snow that we've received thus far this season.  Overnight lows tonight with range from the mid-single digits below zero in the northwest to the mid-single digits above zero in the southeast.  Friday's highs will range from the teens to lower 20s from north to south, with overnight lows in the single digits in the west and south and the single digits below zero in the northeast.  Weekend highs in the 10-20 degree range from northwest to southeast, with overnight lows in the teens to lower 20s.  There is a slight chance of a few snow showers/flurries and even a mix of sleet for Saturday night through Sunday night across the state.  No accumulations are expected...

Wednesday, December 9, 2009

Winter Storm: Dec. 7/8 Update #6

Snowfall has came to an end over much of the central plains, with some snow still falling over the eastern plains and the great lakes regions.  While the snowfall has ended, the winds are continuing to be gusty and blow the light snow creating blizzard-like conditions across a large portion of the plains.  This blowing snow has created hazardous travel conditions as visibilities are reduced to under a mile and snow drifts have made some routes impassable.  The latest update from the Iowa DOT lists at least 5 major highways or interstates that are closed due to being impassable thanks to snow drifts.  Those include I-35 between Des Moines and Ames; portions of US 30 in central Iowa; I-80 between Des Moines and Iowa City; and US 6 near Omaha.  Many other county highways and especially rural roads are also impassable and will likely remain so until tomorrow when the winds begin to subside.

The latest information from the coop observers across the state of Iowa show snowfall varying from 6-8 inches in the northwest, and 4-6 inches in the southeast, to upwards of 16 inches across other parts of southwest, central, and northeast Iowa.  Their latest image is below:


Tuesday, December 8, 2009

Winter Storm: Dec. 7/8 Update #5

A great tool that the Iowa Environmental Mesonet has came up with and is now featuring on their front page.  This is a graphical representation of all the snowfall reports that have came in within the past 4 hours across the state of Iowa, and is updated approximately every 5 minutes.  Be sure to check it out:


Winter Storm: Dec. 7/8 Update #4

The winter storm is in full swing, with blizzard-like conditions beginning to occur across portions of the plains.  Many road departments are now urging to not travel as winds have increased and the snow has begun to drift across roadways, which in nighttime conditions can be very hazardous.  Total snow accumulations vary across the state of Iowa, with 3-5 inches over northwest Iowa and upwards of 6-8 inches over central and southern Iowa.  Expect a few more inches to accumulate yet tonight as the low pressure system finally pushes east of the state.  This movement east, along with its' strengthening, will bring increased winds for the plains with gusts of 40-50 mph likely.  Expect many closings for tomorrow's events and schools with roads becoming impassable during the overnight tonight.  Here is a quick updated graphical forecast from the Sioux Falls National Weather Service:


Winter Storm: Dec. 7/8 Update #3

The morning GFS (12z) model forecast continues the trend to indicate significant snowfall accumulation across the plains states, similar to this mornings NAM model forecast.  Total snowfall accumulations of over a foot are likely across parts of Iowa, Minnesota, Wisconsin, and perhaps even Illinois and other adjacent areas.  Moderate snowfalls are occurring across the area, and accumulations nearing a half foot are already occurring over areas of southern Iowa and nearby areas.  Additional updates are likely later this afternoon as more details on accumulations are given, and if any road conditions warrant a quick update.

Morning (12z) GFS Snow Accumulation Forecast


Winter Storm: Dec. 7/8 Update #2

The National Weather Service in Des Moines, IA has now upgraded much of their region to a Blizzard Warning based upon the latest snowfall forecasts and expected wind speeds.  Their opening line in their issuance is "...AN EPIC AND EXTREMELY DANGEROUS WINTER STORM TODAY THROUGH WEDNESDAY...".  Snow accumulations of 10-14 inches appear likely across much of central Iowa, with snow drifts of 8-15 FEET possible by Wednesday given winds of 25-35 mph and gusts upwards of 50 mph.

I am now located on the western edge of the blizzard warning, and am expecting 8-12" of snowfall by sunrise tomorrow.  However, given such wind speeds I think you'll find quite a variance in snowfall amounts dependent upon where you measure as drifts will definitely be a concern.  Be sure to keep an eye on latest closings, and the latest road conditions which are sure to become 'travel not advised' by this evening and during the overnight.

Winter Storm: Dec. 7/8 Update #1

Snow has begun to fall across much of the plains states, with several inches of accumulation already being reported in some areas where the snow has been falling much of the morning.  Schools and businesses have already begun closing or are already closed for many of these areas, with all nightly activities being canceled and even a few events for Wednesday being postponed as well. 

Snowfall reports have only been light to moderate thus far, but should pick up later this afternoon.  Even with only light to moderate snowfall, several hours of accumulation will be able to make hazardous travel conditions given an increase in wind speeds later this evening with the strengthening low pressure system.  This mornings update will just include a quick look at model guidance once again, this mornings' 40km NAM indicates a slight northward turn to the track of the low pressure system and an actual increase in proposed snowfall accumulations!  Widespread accumulations of at least a foot of snow is forecasted across a significant portion of the plains, with isolated higher amounts.  The forecast image is below, and we'll have to watch how the snowfall and low pressure system evolves as to whether this latest forecast will be accurate.

12z (morning) 40km NAM Snowfall Accumulations


Monday, December 7, 2009

Winter Storm: Dec. 7/8

A significant winter storm is expected to impact much of the plains states beginning tonight and continuing through Tuesday and into Wednesday.  Winter Storm Warnings have been issued as far west as the NE/KS and Colorado borders to the east and northeast to the upper peninsula of Michigan.  Winter Weather Advisories have been posted for many of the areas adjacent to the warnings, with snow accumulations still up to 6 inches in those areas.  As the low pressure system strengthens during the day on Tuesday and into Tuesday night, expect a significant increase in the winds for portions of IA/MN/WI/IL.  For this reason, a blizzard watch and even blizzard warnings have already been posted where conditions are likely to become favorable for significant snowfall accumulations of 1-2" per hour and wind speeds sustained at greater than 35 mph.

Forecast models continue to be consistent in indicating the heaviest snowfall axis from north-central Kansas into Nebraska, Iowa and Minnesota.  Adjacent areas and areas further northeast will also see significant amounts, however not on the same terms of 10-12" that are possible over those areas of KS/NE/IA/MN.  This storm will be a very strong first winter storm for many, meaning that travel conditions will be very treacherous, and likely will result in travel not being advised for a significant portion of the plains.  It will be important to head these warnings, as conditions will likely deteriorate quickly with strong winds, and wind chills will be well below zero for those that do become stranded.  There will be plenty of coverage by local news stations and even national news stations as this event will cover so much of the plains states.

The latest snowfall forecasts by tonight's (00z) model runs are posted below:

00z 40km NAM



00z 5km WRF


 
 
 
Additional updates are likely tomorrow as the storm begins to affect the plains states, however, updates may be scarce as my location is within the warning area.

Sunday, December 6, 2009

A Return to Snow... Lots of Snow...

My wife and I arrived back onto U.S. soil on Saturday morning, at the rainy and unseasonably cold port of Tampa, Florida.  From their we left the airport in the early afternoon and arrived into the cold air of Minneapolis, MN by evening and then continued our drive back into northwest Iowa by the early nighttime hours.  Some light snow was seen over central Minnesota, but a few inches were left on the ground in southern Minnesota and northern Iowa.  This couple of inches are likely to increase quite a bit by midweek as a strong storm system has already forced Winter Storm Watches and Blizzard Watches to be issued.

A low pressure system will come off of the Rockies during the day on Tuesday, and arrive into the western plains states by Tuesday night as it continues to strengthen.  By Wednesday morning the low pressure system should be nearing the Ohio Valley, and has continued to strengthen overnight leaving a very strong pressure gradient across the northern Plains.  This pressure gradient will be responsible for widespread winds of 25-35 mph across the plains, with higher gusts upwards of 50 mph possible near the Mississippi Valley regions of MN/WI/IA/IL.  These winds will be a secondary factor with this system, as snowfall amounts will be significant across a large portion of the plains including portions of KS/NE/IA/MO/MN/WI/IL and perhaps even more areas beyond the Wednesday time frame.

This morning model runs continued with fairly consistent forecast of snowfall amounts for the plains states, and as this system does still have some time to finalize its' details I'll keep this post shorter with just a few map updates regarding snowfall amounts through Wednesday night.  Additional updates tomorrow and Tuesday as the system reaches the plains will contain more specifics regarding timing and snowfall amounts.

12z (morning) NAM Snowfall Accumulations




12z (morning) GFS Snowfall Accumulations


Friday, November 20, 2009

Snow in KC & More...

I spent the day on Monday attempting to forecast the cut-off low pressure system that rolled through Kansas and Missouri, bringing thunderstorms, moderate to heavy rainfall, and some fairly heavy snows to areas along the borders of KS/NE/MO.  This was one very difficult system, with varying temperatures throughout the precipitation bands creating mixes of rain/snow, heavy snow, sleet and just rain.  Parts of northeast Kansas and southeast Nebraska saw as much as 7 inches of snow fall within very short periods of time due to heavy bands of precipitation that were able to rapidly cool the air through evaporative cooling; thus creating conditions prime for a quick heavy snow.  Other areas, such as the Kansas City metro were able to dodge the initial rounds of precipitation and keep mainly rain falling.  Through Monday night however, additional bands created enough cooling to indeed drop a dusting to an inch of snow through the metro area and several inches across additional areas of northeast Kansas and northwest Missouri.  This cut-off low meandered over the central plains for a few more days, creating cloudy and wet conditions for areas of MO/IA/IL and more surrounding states.  Finally the low pressure system was engulfing enough dry air that it began to weaken and has since been picked up by mid-level flow and taken away from the plains.

A shortwave trough is making its' way across the southern plains today, and will bring the threat of thunderstorms and heavy rains to parts of Texas and the Gulf border states over the weekend.  And another trough will work into the plains bringing a passing cold front by Monday, followed by a few additional waves of energy that may likely create a low pressure system on the eastern plains.  This may once again bring a mix of rain and snow for areas of northern Missouri, Iowa, and Illinois; along with a rain/snow mix and perhaps accumulating snow for parts of Minnesota and Wisconsin for early next week.  Beyond this system some portions of the plains may see some very chilly temperatures for mid-week next week as a trough settles into the northern plains and transverses over the northeast by late next week.

Looking out into the guessing land of the models, we look to be flirting with the potential for a large trough for the first week of December which would bring some cold air and perhaps wintery precipitation to the northern and central plains.  Something to keep an eye on for the start of December...

I have better news than the weather though, this past week in Kansas City while I was down for a job interview I was offered and accepted a job in the Kansas City metro area.  Thus, will be relocating to the area sometime late December!  This will make for a busy few weeks as my family not only are in the process of finding a place to live, but the wife and I are going on our cruise from Nov. 30 - Dec. 5 and thus will even be out of the country!

Sunday, November 15, 2009

Rain & Snow for the Plains

A fairly potent storm system is working its' way onto the central plains and will bring significant chances of rain and even snow to areas.  The large trough that will work onto the plains will become cutoff at 500hPa and thus begin to wander the area for a few days until mid-level flow is able to push it off into the Ohio Valley.  While on the plains this system will be able to use all of the moisture available to produce ample amounts of precipitation.  The heaviest precip amounts through Monday morning should be confined to the areas along the cold front passage in the Mississippi Valley regions.  After which the deformation zone along the low pressure system should begin to produce the highest amounts of precipitation.  Interestingly enough, this system does become cold enough to support frozen precipitation over areas of Kansas, Missouri, Nebraska and Iowa on Monday and Tuesday. 

The potential for snowfall and sleet has prompted some Winter Weather Advisories for portions of KS/NE/MO with 3-6 inches of snow being possible across parts of the region.  Other areas may see at least a dusting of snow, and some slick conditions throughout the day on Monday.  You can see a graphical representation of the thoughts from the Kansas City NWS below:




I am currently in Kansas City, MO where I am completing a job interview and some operational forecast testing, thus this event will be very interesting to forecast as I try to show off my forecasting skills.  Nothing like a good cutoff low, mixed precipitation type storm to test on! 

Tuesday, November 10, 2009

Another Week of Sun!

Although not as warm as the previous week that was full of sunny conditions, this week will continue to have a nice fall feel to it with above normal highs through the remainder of the work week.  Under the clear conditions we'll see highs average in the upper 50s across northern Iowa, near 60 across central Iowa, and into the lower 60s and even mid-60s across the southeast and southwest portions of the state.  These conditions won't be completely ideal as we see some gusty winds of 10-20 mph or greater for both Wednesday and Thursday.  If you can deal with the wind, then this week will be another great one for you to enjoy!

The first trough in the mid-levels will work its' way and settle into the west, leaving the plains with favorable southwest flow to allow the potential for rain showers.  A cold front will move through the northern plains late this week, across the state of Iowa on Friday bringing with it the chance for rain showers.  With the passage of the cold front we will see temperatures drop to near-normal temperatures in the upper 40s to mid 50s across the state over the weekend.  Mostly cloudy to partly cloudy skies will also leave us with a bit less sunshine through the weekend...

Beyond the weekend we are looking at the potential for a strong storm system to work its' way onto the plains as the deep trough in the west moves onto the plains and has the potential to become a cutoff low.  This system has the potential to bring some hefty rains, and perhaps some frozen precipitation along the lows path as it moves across the central plains.  More information on this storm system as the week continues and models hopefully begin to come into an agreement.

Friday, November 6, 2009

The Sunshine Continues...

It has been amazing to be able to see the sun for so many consecutive days!  Today will be a bit breezy with southerly winds blowing up warm air at 15-25 mph with some higher gusts possible.  However, temperatures will be pushed up into the 60s and 70s across the state with the aid of this southerly wind.  The cooler temperatures will be confined to the northeast part of the state, where they are a little behind with the temperatures just above the surface.  These temperatures just above the surface will be mixed down today with the aid of those strong winds.  Where the temperatures aloft are cooler, the high temperatures won't be quite as high.  For the portions of western and south-central Iowa, high temperatures in the lower 70s are expected!  The wind will decrease for Saturday, but temperatures will still remain quite nice under the sunshine.  Highs ranging from the mid 60s across a majority of the state, to the upper 60s and near 70 over the southern third.  The latest weather story from the  Des Moines NWS office shows just that, with highs for today and Saturday depicted across the state:




Another sunny day, but once again slightly cooler, will remain for Sunday.  Followed by a chance of showers as a weak cool front blows through the state on Sunday night.  We'll rebound pretty good with sunny skies for a majority of next week, but high temperatures will likely be held in the 50s and lows in the 30s.

Wednesday, November 4, 2009

Enjoy the Day! - New Blog Feature

You can't ask for too much more from a early November day across the state of Iowa.  Temperatures are ranging from the upper 40s to the upper 50s across much of western and central Iowa; with the 40s across the eastern third due to some lingering cloud cover.  We'll likely see a few more days just like this, and likely even warmer, across the state through the remainder of the week.  Clear and sunny skies will give way to temperatures in the 50s and 60s through Saturday this week before our next storm system begins to move in for early next week.  Be sure to get out and enjoy the true fall weather, as October seemed to skip that part.

You'll also notice a new feature on the blog, Twitter Updates!  I recently joined the Twitter world in order to provide a few updates in between blog posts.  This may especially be useful for quick and short updates while on a storm chase, or for general updates on situations.  I'll be sure to note to watch for twitter updates on such occasions, or just be sure to follow me on my twitter page.

Tuesday, November 3, 2009

Light Rainfall

A band of light rain continues to work across portions of western Minnesota and western Iowa, stretching from just northwest of Des Moines, IA to near Fargo, ND.  Typical rainfall values from this line have been less than a tenth of an inch, with only a few isolated spots showing up with greater amounts across southwest Minnesota.  This band of rainfall is occurring ahead of a weak warm front that is working eastward in association with a low pressure system that is located over North Dakota.  Expect this light rainfall to continue to work eastward across portions of Minnesota and Iowa through the evening hours.  Accumulations should continue to be light with only a few hundredths of an inch of rain expected as the rain lasts for only a few hours at most.

Latest Upper Mississippi Radar Image



Sunday, November 1, 2009

A 'Normal' Start to November

After a top ten coldest and wettest month of October across the state of Iowa, and likely so for nearby areas as well, we look to start off the first full week of November in a fairly 'normal' fashion.  Temperatures look to be near normal, likely a few degrees below; and precipitation looks to be intermittent and with total accumulations of a few tenths at most during each of the events.  This sounds much better to those who are wanting to enjoy a little bit of the fall season and is especially helpful for the farmers still wanting to get into the field to complete their harvesting.  Unfortunately, the ground is very wet from the past weeks of rain, and will likely still take several days of dry and sunny weather to dry out the crop.  With light rains potentially in the forecast for this week, we may see the harvesting continue to be delayed by a wet crop.

High temperatures through the week look to range from the lower to upper 50s from roughly north to south on Monday, which will likely be the warmest day of the week.  Continued temperatures ranging from the lower 50s to mid 50s from northeast to southwest across the state through the remainder of the week.  A few locations in northeast Iowa may only see the highs in the upper 40s, as they will remain the cool spot as the upper level trough is steady across the Great Lakes and northeast regions.  Low temperatures will vary a little more, with upper 20s to mid 30s on Monday night from northeast to southwest.  Lower to upper 30s from north to south can be expected on Tuesday and Wednesday night; with a degree or two drop for Thursday and Friday nights' lows.

Precipitation chances enter the forecast due to the passing of two shortwaves that ride the flow across the northern plains on Tuesday and Thursday.  Tuesday's precipitation chances are best throughout the day across the state, higher in the west during the morning hours and in the east during the evening.  Total accumulations expected between a few hundredths to a couple of tenths at most for Tuesday's system.  Thursday's precipitation chances are best during the afternoon and evening hours across the state, with total accumulations of up to a quarter-inch possible.  This is a generalized pattern over the state of Iowa for the week, so you can expect some portions to miss out on these small rainfalls while others may receive the brunt of both systems.

Looking out beyond this week, models are beginning to indicate another large trough to work its' way onto the plains for the time frame of Nov. 9-11.  Precipitation chances are very hard to nail down at this point, and temperatures may see a small window of above normal before likely falling below normal for the remainder of the week (Nov. 12-14) across much of the northern plains.  More details on that system in later updates...

Friday, October 30, 2009

Snow Totals Through Oct. 29

The map below is courtesy of the Interactive Snow Information web page, it shows the latest snow depth information provided at 1AM this morning.  I have switched the views to a high contrast on the image to allow a little better detail, and you can see several locations of 16-20 inches and even isolated higher amounts.  Keep in mind that snow continued to fall through the night across other areas to the north and east, thus an updated map tomorrow may show accumulations in those areas.

The weather pattern seems to go quiet for a period after this system, with only a weak trough settling through the weekend across the northern plains and then a high pressure system working into the forecast for what looks to be the remainder of the week next week.  Our next big storm system appears in the GFS for the time frame of Nov. 10-12 give or take a few days dependent upon your location on the plains.  Check out the map and legend of the snowfall accumulations below:


Wednesday, October 28, 2009

Oct. 28/29 Snowfall

Snow has been falling this morning in the mountain regions of the west, with upwards of 4-6" already being reported in several areas with an additional foot plus still to fall this afternoon and into tonight.  Two bloggers that may be of interest for those of you wanting to keep up with the storm in the Denver area can visit the Tornadoes Kick blog and the Carlson's Blog.  There may be some additional people, so just keep track of the links displayed in the right of the blog to watch for any mentions of snow.

In addition to the snow threat, further east onto the plains states will see the threat of severe weather!  Today's threat extends through the central plains including Oklahoma and Texas, and tomorrows threat is across the Lower Mississippi Valley regions of OK/TX/AR/LA.  Please check out the latest SPC updates and outlooks for more information on the severe weather threats across those aforementioned regions.

In the meantime, you can check out some of the model forecasted snowfall amounts through the next 72 hours across the mountainous west and the high plains of Nebraska and South Dakota.  Needless to say you can see why Winter Storm Warnings have been issued for much of those regions!

00z GFS CONUS Snowfall for 72hrs




00z NAM CONUS Snowfall for 72hrs


Tuesday, October 27, 2009

Oct. 28/29 Storm System

A potent storm system will setup a closed upper-level low over the inter-mountain west during the morning hours tomorrow, that will continue to progress northeastward into the northern plains on Thursday.  This upper level low will evolve into a deep trough as the strong flow aloft pushes the closed low onto the plains.  This storm system will bring moderate to heavy snow across the mountainous west as well as the high plains of western Nebraska and South Dakota.  The system will also produce moderate and locally heavy rainfall across the rest of the central and northern Plains through Friday.  This heavy rainfall across the plains is definitely not a welcome site to most areas that continue to try to harvest crops and finish fall projects that have been hampered by intermittent rains throughout the past month.

Winter Storm Warnings and Winter Weather Advisories have been issued across the mountainous west and high plains as snowfall should begin as early as tonight.  Total snowfall accumulations are likely to be in the 6-12 inch range across the high plains, and even higher in the mountain regions and in localized areas.  Widespread precipitation amounts greater than .25-.50 inches are likely across the plains, with localized areas of an inch or greater across the plains through Thursday.  As the event evolves expect widespread rains to also continue across the lower Mississippi River Valley from Thursday and Friday with amounts well above an inch.  This rainfall in conjunction with a secondary low that will likely form ahead of the continued deep trough.  Severe weather is possible across the central and southern plains as early as tomorrow and continuing through Friday.  Although details are still questionable, widespread damaging winds will likely be the main event given such dynamic and strong winds aloft.  Additional details and updates are possible for portions of the plains states as this system evolves.

Sunday, October 25, 2009

New Blog

I have begun the process of switching over to a new blog, and soon a new website.  Okay, maybe I shouldn't say soon as there may be a good amount of time before a new website is really complete enough to show to the world. 

But, I have imported all of the posts from my previous blog, Iowa Chaser, so as to not lose any of my previous storm chases, meteorological thoughts, and general updates.  I will soon post an update on my previous blog to be sure to let everyone know and to get links transferred over, etc.

In the meantime, I hope to begin to posting more regularly on this blog and keep you updated not only with my current meteorological thoughts, but the on-goings of my life in general.  Here's to more updates!

Friday, October 9, 2009

Been A Long Time...

I kept telling myself that it had been a long time since I had gotten an update on the blog. And I figured as we start to see the first flurries of snow fall across northwest Iowa tonight that this is as good as time as any to give a nice little, welcome snow message.

I've been very busy as of late since my last updates... Been spending lots of time with my now nearly 5-month old son, as well as my new wife (got married last weekend). And trying to find work, applying for jobs, and actually working...

I shall try to get into a better routine now that a few things, like the whole wedding, are now crossed off the list. Hope those across the northwest half of the state can enjoy their snow flurries tonight and into tomorrow morning. Look for a few more shots of snow through the weekend before a warm-up looks to return to the state.

Sunday, August 23, 2009

Fall Already?!?

The past couple of days after a cold front passage have definitely had that fall feeling to them, with highs barely into the 70s for much of the state and lows being down into the 50s and even some 40s there in some portions of Iowa. The cool and calm nights led to some dense fog in low lying areas, but perfect nights for sleeping.

We'll begin to warm up today with high temperatures rising into the mid 80s along the Missouri River; and only into the mid 70s along the Mississippi. Low temperatures tonight ranging from the lower 60s to the mid 50s from west to east marking the increase in moisture ahead of our next storm system. Monday's highs will make it to the 80s throughout the state, from the upper 80s to lower 80s from west to east. Moisture will continue to increase across the state ahead of our next storm system, keeping lows in the upper 60s to lower 60s from west to east. We'll see the cold front push through eastern South Dakota and into western Minnesota during the early morning hours on Tuesday, and likely bring showers and thunderstorms to the northern third of the state through the early afternoon hours on Tuesday. While a few severe storms can't be ruled out given sufficient instability and marginal shear, it does not appear to be much more than a marginal wind/hail threat at this time.

Beyond our cold front passage we'll once again see high temperatures in the mid to upper 70s, and a few 80-marks through the remainder of the week. Low temperatures in the mid to upper 50s will make it a bit cooler than normal, but nothing that most will complain about given the nice sleeping conditions.

Tuesday, August 11, 2009

Much Quieter

After a busy weekend for portions of the state we have set into a much quieter pattern for the remainder of the week, with mostly sunny skies and temperatures in the upper 80s and lower 90s across the state. A weak ridge to zonal flow will be in place across much of the western two-thirds of the US through the end of the week. This is what will be leaving Iowa and much of the plains under sunny skies with warm temperatures. As we work into the weekend a trough enters the flow and will begin to affect the northern plains late Friday and continue through Monday. It is still too early to tell the thunderstorm threat, and specifically the severe weather threat with this disturbance.

Enjoy what seems to be the first full week of summer-like temperatures and conditions. Beyond our weekend disturbance long-range forecast models once again bring the jet stream well north and leave the plains in a weak ridge indicative of warm temperatures and mostly sunny afternoons.

A quick look back at Sunday's long lived supercell that progressed along highway 20 throughout the state, the Des Moines NWS has a nice page that shows a radar loop with storm reports. There is also a few pictures that were provided by the Fort Dodge Amateur Radio Association, you can check them out on the NWS page and below:

NWS Des Moines - August 9 Supercell Page





Sunday, August 9, 2009

August 9 Severe Weather Update #1

A morning supercell is moving through portions of central Iowa, currently just west of Fort Dodge capable of producing 1" to 3" diameter hail and damaging winds in excess of 60 mph. This storm has been severe for quite some time this morning, beginning near the Iowa/Nebraska border and moving east/northeast approximately 40 mph.

This storm has a history of producing 1" to 2" diameter hail and damaging winds, creating some blowing hail that has blown out windows of a home near Yetter, Iowa. The strongest part of this storm is expected to effect downtown Fort Dodge and may produce significant hail capable of producing damaging to vehicles, homes, and especially people.

Latest report from Callender indicates at least 60 mph winds, and close to 1" diameter hail that has caused roof damage and tree damage in town.

Friday, August 7, 2009

Severe Weather Potential - August 7 Update #3

Despite the hopes for convection before sunset, it does not appear likely as sunset is within an hour or two and there is not even a watch issued for potential development. Some cumulus is occurring in the warm sector, however, temperatures at 700hPa have increased to 14C directly over the most likely area for development. This is suppressing any chance of convection until at least after sundown across the area...

Thunderstorm development is still possible along the front as the low level jet increases slightly and we see the decoupling of the boundary layer. The tornadic threat with this development will be fairly minimal, with a large hail threat, and a more likely damaging wind threat across portions of southeast South Dakota and then across northern Iowa and southern Minnesota. An additional update is possible, but only if development can actually occur.

Once again Iowa has went and gone off to disappoint the severe weather lovers across the northern plains!

Severe Weather Potential - August 7 Update #2

Convective inhibition remains strong, however, confidence has increased that the inhibition will yield to convection during the late afternoon or evening hours across portions of the warm front in South Dakota and Iowa. Thunderstorms that do develop are likely to be supercellular with the threat for very large hail, damaging winds, and tornadoes given good low level shear and strong instability.

Just a short update... Expect to leave for a chase target in vicinity of Storm Lake, IA in approximately an hour. Storm initiation by 7 PM along the warm front in vicinity of prolonged strong low level convergence that is occurring in this area. Storms should follow this warm front, tapping into strong instability and good shear parameters leading to a continued tornado threat through 9 PM. Eventual evolution to a cluster or linear segments is expected beyond 10 PM with more of a damaging wind threat.

Severe Weather Potential - August 7 Update #1

Not much for changes in the going forecast or in the current analysis of things across the plains states. Watching clearing skies across the Dakotas and Nebraska, which should also work into western Iowa during the early afternoon hours. Warm front currently located along and just east of the Missouri River from South Dakota into western Iowa. This front should slowly move a bit northward, currently inhibited due to cold pool left from cloud cover and showers this morning. Strong instability and good inhibition is still in the forecast for the warm sector through this evening. A shortwave currently over eastern Colorado should move over the corner regions of SD/NE/MN/IA during the evening hours and should provide enough support for the formation of isolated thunderstorms.

Thunderstorms forming along the warm front would appear to be supercellular in nature during the evening hours, with the threat of very large hail, damaging winds, and the potential for a tornado given favorable storm motion. Storms should merge in the early nighttime hours, and begin more of a damaging wind threat across northern Iowa and southern Minnesota. This is confirmed with the latest SPC outlook upgrading the probabilities for damaging winds across this region...

Will watch the warm front evolution, as well as the 700hPa temperatures that will be inhibiting development until the Colorado shortwave makes its' way over during the evening hours.

Severe Weather Threat - August 7

Morning convection continues across southwest Iowa, with additional showers/thunderstorms spread throughout the state and spreading eastward at approximately 30-40 mph. These thunderstorms and showers should continue through the morning hours across much of the state, with cloud cover also remaining through 10 AM across the entire state. Look for a gradual decrease in coverage in both showers and cloud cover through the Noon hour and into the afternoon. Skies should begin to clear from west to east through the Noon hour as well, beginning to leave portions of western Iowa under warm and sunny skies by early afternoon. A warm front currently positioned south of the thunderstorm activity this morning should make its' way northward as the lee cyclone moves out of eastern Colorado and into the plains this afternoon. The warm front should become positioned parallel to I90 across southern Minnesota and likely through South Dakota, with a very warm/moist and unstable air mass to its' south.

Instability values should become quite high (3000-4000 j/kg) given surface temperatures near/above 90 degrees and dew point values well into the 60s and perhaps 70s along/south of the warm front. Strong surface convergence as well as theta-e should be taking place along the warm front, with aid from a subtle disturbance in the mid-levels also arriving during the evening hours across northwest Iowa. The combination of strong instability and continued convergence along the boundary may have the potential to break a cap that is likely to be in place throughout the afternoon south of the warm front. Temperatures at 700hPa are likely to be in the 11-13C range, with temperatures at 850hPa above 20C. Despite the warm temperatures aloft, models continue to indicate surface heating is enough to overcome the cap in areas that have this strong convergence along the warm front.

If the cap is overcome within the warm sector across northwest Iowa or South Dakota, expect rapid intensification of updrafts leading to large hail becoming a likely threat. Given strong shear values, especially for the late evening and early nighttime hours as the low level jet begins to aid the low level flow, a tornadic potential will exist with any development. Expect storms to begin to form into somewhat of a cluster or MCS after 10 PM and continue across the state, with perhaps an additional MCS moving out of the Dakotas and into MN/IA during the nighttime hours. An additional update is likely near the Noon hour, and once again through the afternoon and convective inhibition and the location of boundaries, etc. becomes more defined.

Storm Chasing Status: With a conditional threat, I will likely be sitting in the comfortable confines of home through the afternoon. However, with the threat likely evolving within an hours drive will be watching conditions closely. Current four county target area is Lyon and Osceola counties in northwest Iowa, and Nobles and Rock counties in southwest Minnesota.

Thursday, August 6, 2009

A Few Rounds of Storms

Sunday night did bring a few severe weather reports across the state, mainly of marginally severe hail around an inch in diameter and several wind gusts of 60 mph or so. The wind was strong enough to take down a few trees and power poles in a line roughly along Highway 30 from Sioux City towards Fort Dodge. We've held quiet since then, with temperatures still a little below normal for this time of year.

We'll be able to change the temperature aspect and finally feel some good summer heat and humidity for a few days for this weekend. This will also bring us the conditional chance of some thunderstorms during the late afternoon and overnight hours beginning tonight, and likely lasting through the weekend. At this time it is too conditional to really pinpoint any good chances of a round of thunderstorms, but rather good to mention that if thunderstorms do persist or develop into Iowa they are likely to have a chance of some large hail and damaging winds.

Our first chance will be across western Iowa tonight as a potential MCS will swing by the state coming out of the Dakotas. An additional round of storms may also be coming into northern Iowa by the early morning hours as the threat of an additional MCS seems possible. After these rounds of storms have a chance to move through, a good setup will be featured over portions of SD/MN/IA for severe weather. However, the warm air at the surface will also translate into the mid-levels and may keep us capped from thunderstorms. Sunday also appears to have a chance of thunderstorms, with the likelihood of an upgrade of the severe weather risks issued by the SPC in later outlooks.

While dodging the rounds of thunderstorms, enjoy the warm and humid air as temperature soar into the upper 80s and 90s and dew points rise into the upper 60s and even 70s creating the typical miserable summer feel. Additional updates may be given if warranted...

Thursday, July 30, 2009

Cool & Calm July

Iowa has been both on the cool and calm side of the weather for the month of July despite a few events that have hit some parts of the state hard, including a few tornadoes and some very damaging hail across northeast Iowa last Friday. A rough and quick look at the mean temperatures over the month of July indicates that it is likely to be the coolest since 1992. For example, Estherville has a mean temperatures thus far of 66.8 degrees, which is second coolest since 1951!

The final day of the month looks to be just at, or just below normal for the state. We'll also get a good chance of some thunderstorms for the end of the month across at least the western half of the state. The severe weather threat appears minimal at the moment, but some small hail and gusty winds is not out of the question for the western third of the state. An update may be necessary if the potential for severe weather tomorrow night does increase...

We'll clear off and be near or just below normal for high temperatures once again through next week; low temperatures will be just below normal. A chance of thunderstorms and showers will work its' way back into the forecast for mid-week, otherwise it appears dry through the first week of August. The long range forecasts do indicate the possibility of a good ridge building into the central US through the first weeks of August which may finally lead to some above normal temperatures!

Friday, July 24, 2009

Severe Weather Update #1 - July 24

Both a Severe Thunderstorm Watch and Tornado Watch have been issued for portions of the state. Currently the bulk of thunderstorm action is confined to the northeast corner of the state where a supercell is beginning to take on tornadic characteristics and has prompted the tornado watch issuance. This storm has moved through areas of northeast Iowa with hail up to 1.50" in diameter and winds of at least 60 mph causing tree damage and at least one injury in Cresco.

While this storm is currently only severe warned, the latest scans have indicated rotation beginning to tighten and this storm may become tornadic within the next hour. With conditions continuing to become favorable for tornadoes, the SPC has issued a tornado watch for portions of eastern Iowa where this storms path appears to be at this time.

Additional development along the cold front across northern Iowa may occur through mid-afternoon, thus the severe thunderstorm watch continuing in effect until 5 PM for portions of the state.

Thursday, July 23, 2009

Severe Weather - July 24

A strong cold front and associated upper level features will aid in thunderstorm development this afternoon across a majority of the state. Given current forecasts for shear, instability, and the strong support with the cold front it would appear that all modes of severe weather are likely across the risk area including isolated tornadoes, very large hail, and damaging winds.

Strong warm air advection should occur through the morning hours and into the late afternoon, suppressing any convection from occurring. As the cold front continues to dive southeast in the evening it should be able to overcome any inhibition that is in place ahead of it in the warm sector. Initial storm development between 6-8 PM should be supercellular in nature given strong bulk wind shear, and given strong veering winds near the surface a tornado or two is possible. Given the strong forcing along the cold front, thunderstorms should quickly develop along the entire front near sunset. This will promote more of a broken line mode of severe weather, with large hail and damaging winds becoming the main threat for the nighttime hours.


Additional updates are likely this afternoon when mesoscale discussions and eventual watch(es) area issued.

Friday, July 17, 2009

A Quick Recap

Busy days ongoing for me has created a good lack of updates on my part. Just to review back to July 14, the severe weather threat did materialize, although much weaker than initially thought due to only convection along the front firing during the evening hours. Did manage to punch through a severe warned cell between Wallingford and Ringsted on the way back from a playoff baseball game. This cell didn't really back much punch in regards to wind, and no hail was found. A weakly photogenic shelf cloud was noted, but not captured...

After the cold front passed through the state we were left with some below average temperatures that have continued into tonight. Current temperatures early this morning range from the mid 50s to the upper 40s! High temperatures for Friday should range from the upper 60s to the mid 70s across the state from northeast to southwest; lows overnight will drop into the upper 40s to mid 50s across the state once again. The weekend will stay dry with highs in the upper 60s to mid 70s from east to west on Saturday, then from mid 70s to mid 80s by Sunday. Low to mid 50s for Saturday night temperatures, and mid 50s to lower 60s from east to west for lows on Sunday night.

We'll return to chances of thunderstorms and showers for the work week, with the best chances on Monday night in the west; Tuesday and Tuesday night for the central and eastern thirds, and the potential for a lingering shower or storm in the east on Wednesday. High temperatures in the upper 70s to mid 80s from east to west for the first half of the work week; with lows in the upper 50s to mid 60s. Look for an update on these chances of thunderstorms come early next week!

Monday, July 13, 2009

Severe Weather Potential - July 14

The potential for a significant severe weather event over portions of the central/northern plains is there for tomorrow, as potent surface features will be supported by strong upper air parameters. Two areas of interest are going to come into play, both of which have some very big question as to its' potential to produce significant severe weather. A lot of the questions may be answered tomorrow morning once the evolution of the MCS(s) from current severe/tornadic convection across SD/NE is known. An update during the overnight hours or during the early morning will hopefully give an idea as to which area of concern is greatest.

The most favorable target will likely be along a reinforced warm front or outflow boundary following tonights' convection that will setup across southeast Nebraska, southwest Iowa and across northern/western Missouri. Strong heating and moisture return will be in place for this area, providing extreme instability and likely strong lift. Upper air features better align with this area of instability and lift, aided by a shortwave that would likely aid in development. As with the case with most late season events with such extreme parameters in place is the capping concerns... Temperatures at 700hPa near the 12C mark will likely cap thing well into the afternoon, however, there is support with the models indicating that this capping inversion will be broken before 00z. A target in this area could come with some significant rewards, or you could end up with nice blue skies as the cap holds.

Another target area will be further north along the cold front which is forecasted to move into western Minnesota and near the SD/NE/IA/MN corners and into eastern Nebraska. Capping will be less of a concern here with a strong mechanism for storm development (cold front) and 700hPa temperatures less than 12C. Development is likely by the evening hours along the cold front throughout western Minnesota and into SD/IA/NE. The problem with the setup here arises with the displacement of instability and shear parameters, with strong instability present along/ahead of the cold front (especially at low levels), but the best shear further ahead of the front. Any development just ahead of the cold front may be able to tap into both instability and shear, thus able to put on a show... This would rely on any outflow boundaries from morning convection...

Additional updates likely within the next 8-12 hours... I will likely favor the secondary target area as it is quite local.

Friday, July 10, 2009

Chase Account - July 9

Several rounds of severe weather swept across portions of northwest Iowa yesterday, from mid-afternoon hail to evening and overnight storms that left hail, winds, and heavy rainfall across parts of the state. I made a trip out to view the storms on two occasions yesterday, once during the mid-afternoon hours between 3:30 and 4:30 PM. This was the initial round of storms that produced some large hail from the SD/IA borders eastward to near Highway 71. Upon arrival to the storms, they were weakening significantly and led to only heavy rains that would obscure your view pretty good. On this trip we would also arrive upon an accident that occurred just west of Ruthven, IA where it appeared a vehicle may have been pulling out of a private lane onto the highway and did not see the cross traffic. A bad scene there as both vehicles were badly damaged, however, have not heard any news about this accident and how either drivers/passengers fared.

The second chase came during the waning daytime hours, from ~8:30 PM to after 10 PM across portions along the Dickinson/Clay county lines and back towards Wallingford in Emmet county. Several occasions of strong lightning strikes, and torrential/blinding rains with the multiple storm cells that we crossed paths with. On the backside of the last cell to be severe warned across these counties we were able to capture several occasions of 3/4" hail and strong east-southeast winds of 40+ mph. Video was captured from the dash cam for the entire trip, however, nothing significant to really note and share... A nice local chase/spot to add on for the year; now we'll wait for some true summer isolated cells to actually have some photogenic quality to the storms!

Wednesday, July 8, 2009

Severe Weather Potential - July 9

A complicated forecast is in the works for the next 36 hours, and perhaps even longer, for Iowa and adjacent areas. A strong wave will initiate thunderstorms this afternoon across the western Dakotas and areas of Montana/Wyoming. These storms should develop into a large MCS, possible derecho, during the evening and overnight hours traversing the Dakotas and moving into western Minnesota by sunrise on Thursday. This MCS will likely be making a right turn throughout the night as the low level jet veers, making the projected path perhaps into northern Iowa between 6-10 AM tomorrow. While the severe weather threat would seem minimal, gusty winds nearing severe criteria is a definite possibility.

As this MCS clears, a stable layer will be left over and likely inhibit additional development until the later afternoon hours. With a cold front and strong disturbance coordinate to create sufficient lift to break and inhibition that will be present across northern Iowa and southern Minnesota. With wind fields increasing in strength throughout the lower and mid-levels, expect deep layer shear to be sufficient for supercells as the initial storm mode with damaging winds, large hail, and isoalted tornadoes all being possible. However, with time and more forcing along the cold front it would appear that the growth of another MCS is likely, yielding a damaging wind threat across the central portions of the state. More details into the forecast will be clear tomorrow morning when the extent of the morning MCS is known... Expect an additional update late tonight and early tomorrow as to the possibilities of severe weather across portions of Iowa.

Severe Weather Recap - July 7

A cluster of thunderstorms developed in eastern South Dakota during the afternoon hours yesterday, and entered into northwest Iowa during the evening hours. These clusters of storms were at times severe warned with the potential for both damaging winds and large hail, estimated 60 mph winds were reported and hail up to 1.5" in diameter also occurred. The severe weather was intermittent at best, with little in the way of damage reported.

I ventured outside of home for a short while as the leading edge of what was a bow echo entered the state in northern Emmet county. Upon arriving outside of Wallingford I did capture very brief video of a gustnado on this leading edge. I estimate the location of this gustnado near Dolliver, IA given its' distance away from me at that time. An otherwise uneventful night as gusty winds and heavy rains were all that occurred...

I will try to get a vidcap of the gustnado up at a later time... Along with a few panoramic images of the shelf as it entered Emmet county.

Tuesday, July 7, 2009

Severe Weather Update #1 - July 7

A Severe Thunderstorm Watch has been issued for portions of South Dakota, Nebraska, Minnesota, and Iowa until 10:00 PM this evening. This watch will cover the four corners of these states, thus including a majority of the counties within the Sioux Falls NWS CWA. Additional thunderstorms have formed outside of this watch area along a warm front/outflow boundary across portions of Iowa. These storms are expected to remain below severe limits, thus no watches or warnings have been issued for this area.

Forecasts and analysis of ongoing convection indicates that the severe weather threat for northwest Iowa will likely not come into play until the evening hours (after 5 PM).

Severe Weather Potential - July 7

A trough of low pressure and possible weak low pressure center should be located over central South Dakota this afternoon. A stationary boundary should extend eastward from this low over parts of eastern South Dakota, southern Minnesota and northern Iowa. This boundary and low pressure center should be the focus for thunderstorm development this afternoon and through the overnight hours, with the potential for severe weather.

While current forecasts indicate that thunderstorms will be more likely to develop in South Dakota, and move into MN/IA/NE during the evening/overnight hours there is potential for development along the frontal boundary during the afternoon and this is supported by a few high-resolution models this morning. Any thunderstorms that do develop this afternoon across the northern plains of SD/NE/IA/MN may be capable of damaging wind gusts and large hail, as well as an associated weak tornado or landspout threat. Storms are likely to congeal into clusters as the evening progresses and move southeastward with time with more of a damaging wind threat through the overnight hours into IA/MN and perhaps northeastern Nebraska.

Additional updates are possible this afternoon as storms develop or initiation becomes more defined...

Wednesday, July 1, 2009

A Few of Natures' Fireworks Possible

With the fourth of July weekend coming up, it looks like mother nature will try to give us some of her own fireworks as we head into the weekend. A storm system will bring the chances of thunderstorms across the state on Friday, and continue through the fourth over a majority of the state. While the chances are fairly small currently, any storms that do develop are likely to be strong and potentially severe with damaging winds and marginally severe hail. These storms would at least cause some problems with any outdoor plans for Friday evening and Saturday across the state. An additional update before this weekend begins may refine any details on the chances for strong/severe thunderstorm across the state...

The forecast otherwise couldn't be too much better for the state... Thursday's highs ranging from the mid 70s to mid 80s from northeast to southwest; overnight lows in the mid 50s to lower 60s. Fridays' highs in the lower to mid 80s across the state will give way to thunderstorms chances across the western half of the state; overnight lows in the lower to mid 60s across the state indicate the increase in moisture across the state. The fourth of July will bring in more cloudy weather across the state, but highs still within a few degrees of 80 across the state. Slight chances of thunderstorms would appear to exist across the entire state during the afternoon, subsiding in the overnight hours. Saturday night lows near 60 across the state will make for an enjoyable overnight. We'll finish off the holiday weekend with highs in the lower 80s and lows in the low to mid 60s leading us back into the workweek.

Friday, June 26, 2009

Severe Squall Line

A mature squall line that continues to be capable of damaging winds in excess of 60 mph and the potential for quarter sized hail is moving swiftly to the east across South Dakota and northeast Nebraska. Current warnings cover the entire length of this line from DeSmet, SD to Pierce, NE...

Along its' current track the line would likely enter southwest Minnesota and northwest Iowa just after 1 AM this morning. Northwest Iowa is most likely to see any damaging winds from this squall line as it enters the state. Those in northwest Iowa should monitor conditions with their weather radio as damaging winds can often cause trees to fall which can produce damage to homes, especially upper levels.

My current plan will be to grab a few hours rest before getting up and heading out ahead of this squall line if it is still in tact as it nears Dickinson/Clay counties. More than likely I will attempt some lightning photography as it nears...

Wednesday, June 24, 2009

Severe Weather Potential - June 24

Quick update from the road today as I am returning from a trip to Ames to visit a few friends. Thunderstorms were widespread yesterday as they continued to move in from NE/SD during the early afternoon hours. Although a few tornado warnings were issued, these tornado warnings were for small vorticies that were confined within the larger line of storms as it moved across the state. No reports were confirmed of a tornado in the state yesterday, but wind damage was widespread through nearly the entire state with wind gusts nearing 80 mph in a few of the stronger storms during the afternoon.

Today's severe weather threat would appear to exist during mainly the late evening and overnight hours as storms once again move out of SD/NE and into western Iowa. A few rogue thunderstorms may develop in localized areas of convergence this evening and have the potential for damaging winds, hail and an isolated tornado. Otherwise it is likely that an MCS will form over eastern SD and continue east/southeast into northwestern Iowa during the early overnight hours. This MCS will likely contain damaging winds and perhaps some small hail as it moves across the state.

Tuesday, June 23, 2009

Welcome Summer...

Apparently summer did not want to show up until it was officially ready, with Sunday being the first day of summer the state sure has heated up since. High temperatures yesterday ranged from the lower to mid 90s across the entire state, with plenty of moisture across a majority of the state to make it feel like temperatures were close to triple digits. Today will be similar, with highs actually getting a few degrees higher than yesterday in most locations. With high continuing in the lower to mid 90s, and even more moisture present today, heat indices will range across the lower 100s. This has prompted a majority of the state to be put under a heat advisory for this afternoons' heat.

Thunderstorms are a possibility across the state tonight and tomorrow, with a chance of a few storms even being near or above severe limits overnight tonight across western and central Iowa. These thunderstorms should be fairly isolated in nature, with marginal hail and damaging winds as the main threats. Temperatures will cool some on Wednesday with the passing of this system, but temperatures should still remain in the 80s across the state. Those temperatures in the 80s should continue through the remainder of the week, with continued high moisture leading to the warm/sticky days and enjoyable nights.

Sunday, June 21, 2009

Severe Weather Potential - June 21

More of a summer-like pattern has pushed into the central plains, with a weak ridge trying to work into the plains states. This has left us with southwest flow aloft through the state of Iowa, and with a low pressure system working off of the high plains and into Nebraska this morning will set us up for a round of severe weather this afternoon. This low pressure system should work into the four corners area of NE/SD/IA/MN by mid-afternoon, with a well defined warm front to its' east/southeast and a trough of lower pressure to its' south/southwest. Along and south of the warm front should have clear skies through the afternoon, with strong heating near 90 and dew points surging into the lower 70s across the area. This should provide us with moderate to strong instability across the state, and with little in the way of inhibition it would likely to see storm initiation fairly early in the afternoon in areas that clear and develop this instability.

Given decent southeasterly flow within the warm sector, low level shear should be sufficient to warrant a tornadic risk. Combined with the very low LCL levels thanks to good heating and moisture present, this tornadic risk seems to be fairly significant. Storms that do develop and move east/southeast nearly parallel to the warm front would have favorable conditions to be tornadic. Thus, would expect areas of northern Iowa, and eastern Iowa where the warm front is more southeast oriented to see the greatest risk of severe weather including tornadoes.

It is Father's Day, thus a lot of people likely enjoying the day outside. It will be important to pay attention to the weather this afternoon due to the risk of severe weather, specifically tornadoes. An additional update near Noon is expected, this will be a brief update in regards to any change in potential.

Friday, June 19, 2009

Iowa Upsets Chasers

Once again the state of Iowa has upset the chasing community with its' lack of cooperation over the past two days. Two straight days of moderate risk, and two straight days of utter disappointment for any storm chaser that was in the state. Both setups featured their own caveats, and both featured the opportunities for greatness, but both days have their caveats win out with no tornado reports and perhaps the highlight of a shelf cloud and some impressive winds this afternoon in southeast Iowa.

Thursday's setup featured a warm front which pushed well north of the state, leaving the state under a heavy capping inhibition between 850 hPa and 700 hPa. With no warm front to help trigger thunderstorms, only a weak remnant outflow boundary had an opportunity for greatness. Although it tried with several cumulus fields attempting to bubble up through the capping inversion, none would ever succeed. Thus, tack a point up for capping inversions with 12C temperatures at 700 hPa over Iowa as a bad chase day.

Today's (Friday) setup finally featured a strong trigger for convection as a cold front moved through the state, and an outflow boundary once again was expected to allow low level winds to remain southeasterly and aid in low level shear. The disappointment would come with winds remaining southwesterly ahead of the cold front, and the lack of a capping inversion allowing the whole cold front to be socked in with showers/storms from Noon onward. At least there were thunderstorms, albeit outflow dominant, that would let you chase something! Wind reports were consistent with at least three separate thunderstorms today, with winds ranging from 60-85 mph across eastern Iowa. Still, a day that would have offered tornado potential for the state would be ruined by a cold front with little inhibition and the lack of cooperation of the surface winds.

If anything can be learned from the past two days, trust instincts that a 12-13C temperature at 700hPa and no strong convergence in the lower levels will lead to nothing but struggling cumulus or blue skies. And, when a cold front comes into the state then you need the 12C temperature at 700hPa along with some southeast if not at least south winds to provide low level shear.

Here's to the hope that the more summer-like thunderstorms can provide some punch for the state with at least some great lightning and supercellular structure!!

Severe Weather Threat - June 19

While yesterday turned out to be another cap bust in Iowa that makes all those out-of-state chasers absolutely hate chasing in Iowa, today will definitely not be the same. Must cooler temperatures just above the surface in the lower levels will provide much less of a capping inversion, and with a must stronger wave in the mid-levels combined with significantly more convergence at the lower levels as well with a cold front moving southeastward. All of this will provide the southeast half of the state to see numerous thunderstorms, many of which may be severe with damaging winds and large hail.

Be sure to pay attention to the latest weather information via TV/Radio as thunderstorms near your area. While the risk of tornadoes is forecasted, it would appear that surface winds quickly turning southwesterly will decrease the low level shear dramatically, thus inhibiting the strong low level shear that was expected to aid in tornadic development.

Thursday, June 18, 2009

Cap Bust??

With 700hPa temperatures in vicinity of the 12C range, the cap over central Iowa is quite strong... And with the ever decreasing convergence along any portion of the state it looks less and less likely that storms will fire before dark. I've decided to slowly work back westward towards home with an eye on the sky/radar if something does try to develop.

For now it appears that the Iowa cap will once again win over another fantastic parameter day in June...

Did manage to meet up with the TWISTEX crew and spend some time chatting with them, and grabbed a few pictures with the TIV2 as they were with the TWISTEX crew today. It was good to see all of them and hope to see you guys again!!

Chasing Live!!

Currently on Highway 18 just east of Cylinder, IA and will likely continue east towards Algona before sitting and waiting for a bit longer. Parameters look amazing, and once the cap is able to go then we should see very explosive development of supercells capable of significant tornadoes and hail.

Be sure to watch the chase live via the spotter network maps, the latest radar update from my laptop, and live video from my dash on the Iowa Chaser Live Chase Page!!

Significant Severe Weather - June 18

The updated SPC Day 1 outlook will continue the moderate risk of severe weather across much of northern Iowa and southern Minnesota. There is a significant risk of damaging winds, very large hail, and tornadoes across the area today. In fact, the updated outlook has increased the probability of tornadoes over northern Iowa and southern Minnesota. The morning thunderstorms will actually help increase the risk of tornadoes this afternoon/evening as the outflow boundary left in its' wake will interact with the warm front to create substantial low level shear. This would appear to once again be a very dangerous and life threatening situation over areas of the plains states today.

I will be chasing today across northwest Iowa, this blog will have the latest updates as I can provide them. As we near the afternoon initiation you may be able to view live video from my vehicle as well as track my location via the Iowa Chaser LIVE Chase Page.

Next update in regards to afternoon chasing and severe weather is expected in the early afternoon hours.

Morning Severe

The SPC has issued a new severe thunderstorm watch for northern Iowa as a line of thunderstorms with a history of large hail and damaging winds is moving across northwest Iowa currently and is expected to remain severe through the morning hours. This watch will be in effect until 11:00 AM and cover the areas shown below: