Winter Storm: Feb. 13-14

For the past 36 hours the eyes have been on this upcoming winter storm that will move a low over northern Missouri, putting southern Iowa in the favorable spot for receiving significant snowfall accumulations. Forecast models have continued to show a similar track throughout their latest runs, and continue to show snowfall accumulations of 6-10 inches or greater over southern Iowa. The continued forecast of this significant snow has prompted the NWS to issue a Winter Storm Watch for the entire state south of Highway 30.

As a low pressure system forms over western Kansas/Oklahoma during the nighttime hours on Thursday, the low should move to the northeast through northern Missouri on Friday. Snow should begin along the western borders of Iowa during the early afternoon hours, and spread across the entire state by Midnight on Friday. The snow should begin to taper off over western Iowa by sunrise on Saturday, and end by Noon on Saturday throughout the state. Total accumulations should be in the 6-10 inch range for areas south of Highway 30 to near the IA/MO border, with areas between Highway 30 and Highway 20 also receiving 3-6 inches. Within the heaviest amounts of snow, some isolated heavier amounts in the 10-15 inch range is easily possible. This is due to some elevated instability that will allow for the possibility of thundersnow, with 1+ inch per hour rates becoming up to 2 inches per hour in bands of thundersnow. More updates likely as Friday nears...

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Severe Weather: Feb. 9 Update #2

The strong dry slot that has worked its' way through Kansas, Missouri and not well into Iowa has considerably dampened the possibilities of thunderstorms, let alone severe thunderstorms. The best risk has worked its' way to the north or right along the warm frontal boundary across northern Nebraska and Iowa, this is where despite cooler temperatures at the surface there is still some potential instability present in the lower levels. A few thunderstorms may be able to develop in this area within the next few hours, with the severe threat still fairly minimal.

The remainder of the state will see clear or clearing skies, with temperatures soaring throughout much of the state into the 50s and 60s. Strong winds are also present, a Wind Advisory was issued for the southern half of the state as winds could reach 35-45 mph later this afternoon and evening. Expect warm temperatures and breezy conditions once again tomorrow, with highs near today's or even a few degrees higher in some locations.

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Severe Weather: Feb. 9 Update #1

The severe weather risks for the state of Iowa, and for the entire central plains for that matter, have been dwindling throughout the morning hours. The SPC risk has remained at slight, although the tornado risk and large hail risk were both scaled back in the Noon outlook. Latest radar shows the band of showers wrapping around the low pressure system across northern and eastern Iowa; while a strong dry slot has been working into southwest Iowa bringing in clear skies and surface warming. Further into Kansas this dry slot has mixed down drier air which will diminish the severe weather risk. However, if timing can be nailed down the clear skies will provide instability for parts of southern and western Iowa while the dry air does not have time to mix down. Still a complex situation, but the severe weather risk does seem lower than what was anticipated this morning.

An update is likely near 4 PM...

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Severe Weather: Feb. 9

A low pressure system is currently located over western Nebraska, and should move east-northeast into northern Nebraska by this afternoon. A warm front is currently located from this low and stretches east/southeast across eastern Nebraska, extreme southwest Iowa and into northern Missouri. This warm front should continue to lift north today, bringing increased moisture and a little warming. This combination may yield some instability, mainly in the lower levels, thus creating a situation in which low-topped supercells are a possibility. With strong vorticity maximum working over this same area, and wind speeds being favorable both in speed and direction, rotating storms capable of a few tornadoes are possible. Strong wind gusts are also likely with these storms, especially any that become mainly linear in nature. Some moderate sized hailstones may be possible as well given the cold temperatures aloft throughout the entire state...

Currently the best area that may see these severe thunderstorms capable of damaging winds, moderate hail, and a tornado or two appear to be over southwest Iowa and nearby locations. A line of showers and possibly a thunderstorm will move through southwest Iowa and into other parts of the state this morning, and over eastern Iowa later this afternoon. Behind this line, some clearing may occur which will increase the risk of severe weather for this afternoon. A close eye will be kept on how this clearing evolves, and any changes in the risks for severe weather across Iowa...

You can view updated radar images from my website: www.iowachaser.com
Sorry for the bland view, but I haven't completed all of the things I needed to yet beings I didn't expect to be seeing severe weather in February.

Short updates possible until mid-afternoon, next extensive updates expected by 4 PM.

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Severe Weather Potential: Feb. 9

It is not very often for Iowa that you will be able to get the month of February and severe weather, let alone tornadoes, all in the same sentence. That is the case today as a potent storm system works' its' way up northeast through the central and northern plains. This dynamic system has very strong winds at both the lower and mid-levels which is creating significant speed and directional shear. This shear combined with fairly warm and moist low levels compared to climatology, and the cold air that is located in the mid-levels will allow for some instability. While this instability is expected to be fairly weak (<500 J/kg), it should still be enough for thunderstorms and a few severe ones at that.

With the lack of time, just a few brief notes from tonight's model runs shows good agreement and overlap between the strong shear, good vorticity maximum at 500mb, along with appreciable LI's and good 0-3 km CAPE. This combination may yield low-topped supercells across parts of eastern Kansas, northern Missouri, far eastern Nebraska and into western Iowa. With the chance of clouds and showers previous to the afternoon, the forecast is quite delicate still. However, it does appear that areas in Iowa south of Highway 30 and west of Highway 63 will see the potential for these low-topped supercells. These storms may be capable of strong winds and moderate hail, but will also likely be rotating and may produce tornadoes. Several factors will have to come together for this event, but it is something that parts of the state should keep an eye on.

Other parts of the state may still see thunderstorms, however, with weaker instability these storms are not likely to reach severe limits. Some small hail and gusty winds is still possible throughout much of the state during the afternoon and early evening hours.

Additional severe weather forecast updates are likely in the mid-morning hours...

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Rain & Thunderstorm!?

We will undoubtedly see our first rain of the year across the state on Monday, but a mix of winter weather may be in store for the northern third tonight. And the entire state returns to a chance of winter precipitation for Tuesday night and Wednesday as the next storm system arrives...

The state has seen temperatures in the 40s and 50s, even a few 60s the past couple of days which has allowed a considerable amount of snow melt. This snow melt combined with ice jams has created some flooding concerns across the state, with an increased chance of flooding for early this week as rain moves into the forecast. A storm system will begin to effect the state tonight as moisture moves into the lower and mid-levels. Scattered sprinkles or showers are possible tonight across the state, with the northern third seeing the risk of these showers/sprinkles freezing upon contact with the surfaces as temperatures drop below freezing. Ice accumulations is not likely, especially as any freezing rain should last only a few hours before turning into rain showers. Expect showers to become widespread by the morning hours across much of western Iowa, with these showers and thunderstorms working through the rest of the state by evening. Given the strong dynamic storm system, some instability is expected to combine with strong speed shear and low level wind shear to create the potential for a few severe thunderstorms. The main threats appear to be strong winds and maybe a few hailstones. After lows tonight ranging from 30 to 40 degrees from northeast to southwest, expect highs on Monday from the upper 40s to upper 50s from north to south. The showers and thunderstorms may continue over the northern half of the state Monday night, with lows from the mid 30s to mid 40s from northwest to southeast.

A drastic warm-up on Tuesday just ahead of the next storm system, temperatures should range from the mid 40s to mid 60s from northwest to southeast. Tuesday night lows from the mid 20s in northwest Iowa to near 40 in the southeast corner of the state. The southeast half of the state may also see some rain showers during the overnight. Light precipitation should continue on Wednesday over much of the state, with high temperatures in the mid 30s to mid 40s and falling, some mixed precipitation of rain/snow is possible. We'll see this round of precipitation move out as temperatures fall Wednesday night into the upper teens to upper 20s across the state.

A late night update is possible to address the potential for severe thunderstorms on Monday for Iowa...

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Warm!!

Despite what people felt today around the state, temperatures in the upper teens at best with wind chills ranging from near zero to over 30 degrees below zero. The temperatures should be even colder tonight with lows in the single digits below zero to the negative teens in northern Iowa. The winds should be a little calmer, meaning wind chills will once again only be in the -20 to -30 range across the state tomorrow morning. High temperatures on Wednesday in the west will begin to reflect on what the state has coming for the remainder of the week, while the east stays in this quick cold spell. Highs should range from the mid teens across the northeast, to the lower 30s along the Missouri River. Overnight lows will drop into the single digits for the northeast quarter of the state, the teens northwest and southeast, and the lower 20s for areas along the Missouri and in the southwest. The entire state should see these lows come during the early nighttime hours, with steadily rising temperatures after midnight.

These rising temperatures during the overnight will set the state up for a very nice day on Thursday, Friday, and through the weekend for that matter. Southwest winds of 10-20 mph with clear skies will allow high temperatures from the mid 30s in northeast Iowa to the lower 50s in the southwest. Overnight lows on Thursday will be near 20 in the north, to near 30 in the south. The warm-up continues on Friday with even warmer temperatures, lower 40s across the northeast to the mid 50s in the southwest! The ridge responsible for these warmer temperatures does begin to move out of the state on Friday evening, which will lead to slightly cooler temperatures on Saturday. A look at the weekend forecast, and the potential for thunderstorms early next week in the next update!

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Above Freezing?!?

Another round of snow created hazardous travel conditions across parts of central Iowa this evening. My drive this evening from Ames to Ogden saw over a half-dozen vehicles in the ditch along Highway 30 due to slick conditions and limited visibilities. The snow has tapered off and the winds have begun to subside, this should continue to be the story through the weekend as temperatures continue to rise through Saturday. Another weak system will bring a cold front through and temperatures should fall once again for Sunday afternoon...

Friday highs should range from the upper teens over extreme northeast Iowa to the mid 30s along the Missouri River despite cloud cover. A few more flurries may be possible over central and eastern Iowa during the afternoon and through the evening. Overnight lows heading into the weekend will range from the mid teens to lower 20s over the state. Saturday will be the warmest day of the week as warm air pushes into the state, highs in the mid 30s to mid 40s are likely from northeast to southwest under clear skies and moderate southwesterly winds. A cold front will sweep through during the early morning hours on Sunday, with lows in the lower and mid 20s on Saturday night they will not rise too much on Sunday. Afternoon highs on Sunday will only range from the upper 20s to mid 30s from north to south. Sunday night lows will range from the single digits to mid teens from north to south.

Look for the state to slowly warm a few degrees each day through next week, and no chances of precipitation in the forecast currently. Dry and warm...

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Light Snow

Through today and Tuesday we will see light snow fall throughout the state, leaving parts of southern Iowa with a chance of 2-4 inches of snowfall through that time. Other parts of Iowa will mainly see under 2 inches of the white stuff as we work through the day tomorrow. With light winds and temperatures well below freezing, minimal problems with traveling are expected. Beyond this snowfall, Wednesday night may hold another dusting of snow for the state before we stay dry through the weekend.

Temperatures for the early half of this week will begin below normal, but work their way back up to near normal temperatures. Highs today will only reach the 10-15 degree mark as light snow and cloud cover exist. Tonight's lows won't drop too far thanks to this cloud cover as well, with single digits expected across the state. Tuesday will be a few degrees warmer, with temperatures in the mid-teens throughout; overnight lows once again in the single digits above zero. The skies should finally begin to clear for Wednesday, and with westerly winds will allow temperatures to range from near 20 along the Mississippi to near 30 along the Missouri. Wednesday night lows should remain in the teens...

Temperatures look to continue to rise right on through the weekend, the mid-week update will let you know just how much.

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Welcome Back Cold & Wind...

It has been a couple of days since we've seen the cold and windy conditions across the state, with temperatures yesterday near 30 to near 60 across the state and winds nearly calm it was a brisk change back this morning. Winds across the state are from the northwest at 25-35 mph and some higher gusts, creating blowing snow over areas that still have the large snow-pack left. For those that are along and north of Highway 30 in north-central Iowa you are under a Winter Weather Advisory until 2 PM this afternoon due to the blowing snow creating some drifting and slick conditions on roadways. The northern half of the state will also go under a Wind Chill Advisory beginning tonight at 9 PM and continuing until 9 AM tomorrow morning. This is due to the cold temperatures and gusty winds creating wind chills that are likely to range from -20 to -30 overnight.

High temperatures today are what they are now for the most part, upper teens to mid 20s across most of the state from northwest to southeast. As mentioned the winds will create some localized hazardous conditions, and create wind chills that are well below zero by this evening. Overnight tonight the cold air has a chance to settle in with lows from near -10 in the north to around 5 in the south, the gusty winds will likely continue throughout the overnight.

Winds will die down tomorrow morning, with partly cloudy skies and winds around 10 mph the temperatures will still remain cold. Highs expected to range from the single digits to only the lower teens from northeast to southwest across the state. Saturday night lows will range from near -10 in the northeast, to near 10 above in the southwest. Snow will likely begin to creep into western Iowa during the overnight hours on Saturday. This snow will continue to overspread the southwest half of the state on Sunday, with cloudy skies and fairly light winds the high temperatures will remain in the single digits to upper teens from northeast to southwest across the state. Lows overnight on Sunday will be from the single digits below zero across the north to the upper single digits above in the south. Snow is still possible over the southwest half of the state, likely ending by Monday morning, total accumulations over the weekend should remain around an inch or two.

Next week looks to remain around average as far as temperatures go, slowly warming each day through Wednesday. The best precipitation chances may come mid-week, but current forecast models are pushing a majority of the storms to our south.

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