Tuesday, August 19, 2008

Last Week of Summer?!?

Well, maybe not as far as the weather is concerned. But, many students are heading back to school mid-week this week, or are beginning next week, thus this is their last week of summer. Monday was a nice day for the state, seeing highs in the 80s and only some gusty winds to hamper any outdoor activities. Today should see highs in the 80s throughout the state once again, with the winds a little lighter. Lows tonight should be within a degree or two of the 60-degree mark. The skies should stay clear to partly cloudy for Wednesday and Wednesday night, highs expected to be in the 80s once again. Lows overnight should be in the lower to mid 60s as southerly winds pump some increased moisture into the state.

This increased moisture looks to bring in the chance of thunderstorms beginning on Thursday, and continuing into Thursday night. These chances are still fairly small, with them isolated over eastern Iowa during the day Thursday. Thursday night the isolated showers and storms will be possible over mainly the central and eastern thirds of the state. A more widespread and greater chance of showers and thunderstorms are possible on Friday and Friday night as a cold front begins to move into the state. The severe weather chances with any of these thunderstorms risks is unknown at this time, but may be more defined with later updates.

Temperatures during the latter half of the week should be in the lower 80s on Thursday, with the cloudy skies. Overnight lows on Thursday in the mid 60s due to the increased moisture and cloudy skies. Friday's highs will range throughout the 80s across the state, the wider range due to any lingering cloud cover or otherwise sunshine. We enter the weekend with lows on Friday ranging from near 60 in the northwest to the upper 60s in southeast Iowa.

Friday, August 15, 2008

August 14 Storm Images

I was sent a few pictures of the storms that were rolling across portions of central Iowa last night by Rob Wadsworth, from Alta, IA. He managed to grab some nice images of the entire storm that was located over Hamilton county from near Pocahontas, IA. This storm was severe warned for a short while, with the potential to produce nickel sized hail and damaging winds. The only report from this storm was a measured 59 mph gust near Williams, IA.




Images courtesy Rob Wadsworth


I'm glad readers can enjoy the blog, and feel free to send me any stories/pictures that you have of storms while they are near you and you may also be a part of the postings here on the Iowa Chaser blog!

A Few More Storms...

After Wednesdays' development of storms into northwest Iowa, and continuance into central Iowa; more storms developed on Thursday over portions of northern and eastern Iowa. Yesterday's (Thursday's) storms were not as potent, only isolated severe thunderstorm warnings were issued for mainly marginally severe hail. Some brief funnels were possible with the storms, however, no reports were received. Nickel sized hail, and a wind gust of 59 mph were the only severe weather reports listed over the state of Iowa yesterday. The hail report coming from Tama county, more specifically 8 miles southwest of Tama, IA. The wind report was measured by an RWIS station near Williams, IA in Hamilton county.

Another note on the storms that occurred on Wednesday, the there will officially be a tornado in Iowa. A portion of a hog barn was destroyed around 6:08 PM, 2 miles northeast of Lake Park. This hog barn, and associated crop damage downstream, along with radar imagery of the low level rotation that was occurring at this time did confirm that this may have been a tornado. It will be confirmed as an EF0 tornado. I went back to the GPS logs, and at this time we were approximately 5 miles south of the tornado's location. The very wet RFD forced us to move south to have any view whatsoever of the storm.

Back to the current weather, dense fog is occurring over a majority of the state this morning. Some areas may be quite dense, leading to visibilities of less than a quarter of a mile. This fog should begin to lift as the sun rises and begins to warm us up, however, the fog should be prominent up until 9 AM in most areas. Highs today should range from the upper 70s to lower 80s, under partly to mostly cloudy skies. A few more isolated thunderstorms are possible this evening and into the early overnight hours, mainly for central and eastern Iowa. Lows tonight should be in the mid to upper 50s across the state as we head into the weekend.

Highs over the weekend look to range from the upper 70s to mid 80s from east to west. Lows overnight on Saturday should be in the mid and upper 50s; Sunday overnight in the upper 50s to lower 60s. A few isolated showers and storms are possible Saturday in the eastern quarter of the state. Otherwise mainly dry over the weekend as our next system moves into the state early next week.

Wednesday, August 13, 2008

August 13 Chase Account

Traveled a total of 96 miles this evening from my home, north just across into Minnesota, and then back south to Spencer, IA before returning home. Only a total of two and a half hours actually on the road, with nearly all of it spent with a storm in sight. Arrived on the severe warned supercell as it was pushing southward towards the Iowa border, saw a lowering with the storm that was coincidentally located near the strong inflow notch that was now showing on radar.




Continued to get just ahead of the storm, finally had a place to stop just north of Lake Park, IA and watch this lowering as it slowly rotated. This rotation eventually was one of the reasons behind the tornado warning issued for Dickinson county.




Followed the storm as it went south towards the Great Lakes area of Spirit Lake and Milford. The visibility of the storm deteriorated quickly as a very wet RFD cut into the storm. Continued to drift south in front of the storm as some outflow took over, this created a unique feature with some smoke as it was pulled into the storm.



Ran into some hail 6 miles west of Milford, IA; approximately penny sized with some of the larger stones. Also ran into more hail around pea to dime sized west of Spencer around 5 miles. Didn't try to find the hail, as there was the potential for some pretty good sizes; up to 2 inches in diameter was reported in Lake Park.

You can view the entire album of pictures online: August 13 Album
Wasn't pleased with the turn-out of the images tonight, will have to review and see if some setting was off as it was a fairly rushed chase this evening. Can't say I was disappointed in the chase though, getting on a tornado warned storm and seeing some fairly nice rotation with the storm only 30 miles away from home!

Severe Weather & Chase - August 13

7:30 PM Update: Have called it a chase as the storms have lined up into a large bow echo that is now beginning to gain speed as it moves southeast. Ended up with some nice images of the broad rotation along the Dickinson/Jackson county borders just as the tornado warning was issued. Beyond that time frame it was a large rainy mess... Do have a cool picture of a 'smokenado' as well that occurred near Milford, IA as smoke from a ditch fire was lifted into the storm. Hopefully will have some nice images as these storms move to the southeast out of my area and as sunset arrives. Pictures and other updates are possible after the drive home, and some food!!

---------------------------------------------------------------------------------------

5:15 PM Update: Storms have continued to move southward, with additional development ahead of a now congealing line in southwest Minnesota. Have taken off to head north into Jackson county Minnesota in hopes of some severe weather action!

---------------------------------------------------------------------------------------

4:45 PM Update: Some thunderstorms occurred earlier this afternoon across northern Iowa, dropping mainly rain throughout its' path. Additional thunderstorms have developed in southwestern Minnesota, many have become severe and tornado warned within the past hour. Although only reports received have been for large hail, the continued threat of severe weather as the storms slowly move south/southeastward has prompted the SPC to issue a severe thunderstorm watch that will go until 10 PM and will cover a large portion of northwest Iowa. For more details on this watch, please check the WW#826 page. These thunderstorms should begin to cross the IA/MN borders around 6 PM or potentially sooner if additional development can occur.

---------------------------------------------------------------------------------------

Thunderstorm chances are in the forecast throughout the state this afternoon and evening in response to good thermodynamics (instability). Portions of the plains, including northwest Iowa, will be in a favorable area where strengthening mid level winds and continued sufficient instability/shear. Thus, the area of northwest Iowa has been placed in a slight risk area by the SPC with the potential for isolated large hail and damaging winds to occur with the thunderstorms. Otherwise, partly cloudy skies should give way to highs in the upper 70s to mid 80s throughout the state today.

More details on the severe weather risk may be available this afternoon.

Monday, August 11, 2008

Thunderstorms

Thunderstorms, some severe and tornadic, are occurring over portions of the Dakotas and Nebraska this evening. Other general thunderstorms are also ongoing over Minnesota, and western Iowa. With a weak cold front oriented north/south through the Dakotas and Nebraska, and associated weak low in South Dakota, the thunderstorms west of the state should slowly move east/southeast into western Iowa during the overnight hours. The cold front will make its' way into the state during the morning hours tomorrow and continue to travel slowly eastward. Thunderstorms are a good chance throughout the day, with the storms moving into mainly eastern Iowa for the early overnight Tuesday. Rainfall totals should range from a quarter to three-quarters of an inch with some higher amounts with the stronger thunderstorms.

Lows overnight tonight should be in the upper 50s to mid 60s from northeast to southwest. Highs tomorrow under some cloudy and rainy skies should only reach the mid 70s to mid 80s from northeast to southwest once again. Mid 50s to lower 60s lows on Tuesday night from northwest Iowa to the southeast portion of the state. Wednesday highs are expected to be near 80 in the northeast, gradually rising as you cross southwestward through the state; reaching the mid 80s in southwest Iowa. Overnight Wednesday lows should be within a few degrees of the 60-mark throughout the state.

The next storm system to enter the pictures looks to do so for the latter half of the week, Thursday night may begin some of the thunderstorms chances. But, the main show may come later on Friday and potentially into the weekend. More details on this storm system in later updates towards mid-week.

Sunday, August 10, 2008

August 9 - Tornado near Clare, IA

Unique situation occurred yesterday over portions of northwest Iowa, with several small thunderstorms developing along a weak cold frontal boundary that was draped over that portion of the state. The thunderstorms that developed were fairly weak, no hail or damaging winds were expected, and they remained fairly low-topped (image below). The very steep lapse rates that were noted throughout the low levels, did create the unique situation in which it allowed the fast stretching of the column of air. This stretching combined with some low level shear, allowed for several funnels to form with these thunderstorms. Areas around Mason City had a thunderstorm with several funnels reported around 4:30 PM yesterday. Other storms developed after 5 PM, with additional funnels being reported near Lake Park, IA and the Spirit Lake, IA area around 6 PM.

The highlight of the day came with another storm, developing after 6 PM and being isolated to the northwest of Fort Dodge. This storm had enough stretching and good enough updraft to sustain this funnel, and allowed for a few brief touchdowns. This did prompt a tornado warning for portions of Webster county, as the tornado was reported by several sources, including a pilot who as on his way to land at the Fort Dodge airport.

Being a Saturday afternoon, it seemed like everybody had their camera with them and snapping pictures of this funnel near Clare, IA and Barnum, IA. You supposedly could see this funnel and storm from nearly 30 miles away as it was quite isolated. To view the entire list of emails and pictures with all of the funnels yesterday, take a look at the case file from the Iowa Environmental Mesonet.

I've also uploaded a few pictures from the Clare, Barnum, and Fort Dodge area for you to enjoy to look at.


Image taken by Jim Gargano, near Clare, IA just after 7 PM.


Image taken by Mark Phillips, from the Deer Creek Golf Course.


Image by Lois Shimon, taken just after 7 PM near Fort Dodge, IA.


Image taken by Michael Larsen; Funnel/rainbow located near Manson, IA.

Wednesday, August 6, 2008

Some Showers

A weak wave of energy off to our north, combined with trough of low pressure, allowed for some showers to move into the state this morning. These showers have continued to stick around into the afternoon hours over portions of the state. A large area of cloud cover has accompanied these showers, leaving some areas lingering around the 70-mark for temperatures through the early afternoon. While others in the sunshine have rose nicely into the 80s under their sunny skies. Expect a few showers to linger here and there over the state, but sun should be on its' way for a majority of the state this evening as the weak wave and energy move beyond the state. Highs as mentioned should range from the mid 70s to the mid 80s dependent upon the amount of sun/clouds your area receives.

Lows tonight should range from the upper 50s to lower 60s, under partly cloudy skies. Highs tomorrow under these same partly cloudy skies should reach the lower to mid 80s, northerly 5-15 mph winds. Mid 50s to near 60 for lows on Thursday night; with highs on Friday reaching into the 80s throughout the state. Friday night lows in the mid 50s to lower 60s over the state, as winds slowly shift back to the south/southeast by the weekend. This change to southerly winds will increase the moisture, just in time for the next system to work into the forecast for Saturday night into next week.

Monday, August 4, 2008

Severe Weather: August 4

7:30 PM Update: Storms have moved out of the state of Iowa, and the state should stay clear of any strong storms for the remainder of the evening and into the overnight. The thunderstorms that previously began to develop over extreme eastern Iowa have since moved into northern Illinois. This line is currently a strong bow echo capable of 80 mph winds, and has also shown strong rotation on the northern bow of this storm. Warnings have been posted for the city of Chicago, and their entire metro area as this storm continues to track eastward at nearly 60 mph. Significant damage is possible from this storm as it moves into a very populous area, with plenty of people I'm sure unaware of the situation. Surprisingly the Cubs game which is on ESPN currently has also stated nothing about the storms moving in, which is going to impact the stadium within the next 45 minutes.

-------------------------------------------------------------------------------------

5:00 PM Update: A severe thunderstorm watch has been issued for portions of eastern Iowa and will continue to be in effect until Midnight tonight. Currently a cluster of thunderstorms that is severe warned exists over portions of Delaware, Jones, Dubuque, and Jackson counties. These storms are capable of both large hail and damaging winds, and are moving to the east generally around 35 mph.

-------------------------------------------------------------------------------------

8:15 AM Update: The line of thunderstorms has begun to fall apart, likely given an increasing amount of inhibition for this morning. As it began to fall apart in the western edge, it developed on the eastern edge of the previous line. This has led to a cell, or another small line to form and move mainly eastward that is capable of small hail and gusty winds. This is currently located along the Kossuth and Humboldt, and Hancock and Wright county lines. Movement is eastward at approximately 50 mph, although a severe warning does exist for this cell, there has been nothing more than pea sized hail and upwards of 30 mph gusts reported.

-------------------------------------------------------------------------------------

6:50 AM Update: A line of severe thunderstorms has developed this morning, as is moving northeastward at this time. This line is located approximately from near Marcus, IA eastward to near Aurelia, IA. The warning is currently in effect for Buena Vista, Cherokee, and Plymouth counties until 7:30 this morning. Both large hail up to quarter-sized in diameter, and damaging winds in excess of 60 mph are possible with this storm. Expect this storm to enter portions of O'Brien, Clay and Palo Alto counties around 7:30 as it continues in northeastward movement around 30 mph.

-------------------------------------------------------------------------------------

We will start the day with severe weather ongoing over portions of the state, northwest Iowa has scattered thunderstorms and a line of severe thunderstorms that extend from near the SD/IA border eastward to just to the north of Storm Lake. These thunderstorms are warned as they have the ability to produce quarter sized hail and damaging winds in excess of 60 mph. These storms are moving northeast at around 30 mph, and are expected to sustain themselves through the morning hours.

After this mornings' round of thunderstorms, expect sunny conditions to resume allowing the temperatures to rocket once again into the upper 80s and lower 90s across the state. This combined with dew points around the 70 degree mark will allow for a setup capable of severe thunderstorms this afternoon across the state. A surface boundary is expected to extend from west to east across the state of Iowa, as well as surrounding states this afternoon. This is expected to be in the vicinity of a line from Sioux City through Davenport across Iowa. Thunderstorms should develop along this surface boundary this afternoon, given good lift and strong instability that is in place. Other thunderstorms are expected to the west in Nebraska and South Dakota, which may also mean another round of thunderstorms for portions of the state during the later nighttime hours tonight.

Updates are likely throughout the day if any changes occur to the forecast, as well as when any watches/warnings are issued for the area.

Sunday, August 3, 2008

Severe Weather to Begin August?

Just a quick update to the forecast for Iowa and surrounding areas, sorry for the lack of posts lately. Several shortwaves and a lingering surface boundary is in place today over the northern plains, this could lead to several rounds of thunderstorms over the Dakotas, Minnesota, and Wisconsin; as well as surrounding areas. The highest risk of severe weather is likely over southern Minnesota, where the best thermodynamics are in place. Shear is sufficient to warrant supercell thunderstorms capable of very large hail, damaging winds, and even isolated tornadoes this afternoon/evening. Currently, the latest outlooks have this enhanced threat of severe weather along the Iowa/Minnesota borders and points northward.

Thunderstorms are possible this afternoon/evening, mainly across the northern third of the state. Some of these storms may be severe, with the threat of hail and wind the main threat. However, dependent upon the location of the surface boundary, the enhanced risk that is currently over southern Minnesota may be a factor in the Iowa thunderstorms and thus increase the risk for this evening.

Another round of severe weather is more likely across the entire state tomorrow, Monday, August 4th. As a small trough begins to move into the plains states, a cold front is likely to begin to form and propagate southeastward. This cold front will overtake the lingering surface boundary from today, thus providing a fairly complex situation for severe weather. Although the SPC only has minimal slight risk in place for the state, they have mentioned as well as some model forecasts support, a fairly impressive risk for severe weather. Although mainly large hail and damaging winds will be possible, this may be fairly widespread across the state of Iowa. Another update is possible tomorrow afternoon or potentially early morning if the risk does look to be increased across the state...