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.

The Return of Spring

This past weekends' winter storm left snowfall across all but extreme southern Iowa, with the highest amounts occurring in three different locations (northwest Iowa, extreme west-central Iowa, and central Iowa). The highest snowfall report came from Eldora, IA where a measured 10 inch snowfall was reported, this high snowfall came with some thunder and a total of 1.03" of liquid. For a quick overview of where the snow fell, take a look at the storm total map below:





Temperatures have increased over the past two days, but have been hampered in the areas where significant snowfall was received. With today's warm temperatures, the snowfall across much of the state has disappeared which will allow temperatures to warm even more in the coming days. A quick look at our upcoming high temperatures shows upper 40s to upper 50s from north to south likely on Wednesday. Thursday high temperatures from near 50 to the upper 50s from northwest to southeast; and Friday's high temperatures in the lower to mid 50s throughout the state. Expect some showers to work into the state for Thursday night and continue into Friday which will moderate temperatures some. The weekend looks similar, with another storm system working into the state for the late weekend could bring even more precipitation and some cooler temperatures.

Winter Storm: April 4-5

Another potent storm system is taking shape to impact the state tremendously beginning Saturday evening and continuing into Sunday. The low pressure system is expected to track through southeast Iowa on Sunday, which will likely leave parts of the northern half of the state under a potentially heavy snowband. Many of the models have come into a consensus on the potential of 6-12 inches of snow, with some amounts even over a foot possible within this heavy snowband.

Although models are currently struggling with the exact timing and speed of this low pressure system, which will have an effect on the storm total amounts. The HPC (Hydrometeorological Prediction Center) does seem to have fairly good confidence in this system, as they issued their day 3 outlook with a moderate chance (>40%) of over a foot of snow on a band from south of Sioux City to the northeast through Mason City, etc...

An ironic forecast as the 13th Annual Severe Storms & Doppler Radar Conference got underway this afternoon in West Des Moines. Another update will likely be published tomorrow, good night from West Des Moines!

Light Snow...

Light snow has continued to fall over much of the state this afternoon and into this evening. Here in Ames we began to have a sleet/snow mixture this afternoon, which turned into moderate snowfall through the mid-evening hours. The only places snowfall was sticking to here in Ames seemed to be cars and other very cold surfaces. Other parts of the state have also reported light to moderate snow through the evening, the only accumulations have been limited to northwest Iowa. Sioux Center had a co-op report of ~1 inch, and Sioux City reported a trace or dusting of snow. Expect some light to moderate snow to continue over some parts of the state, however, no accumulation is likely.

Lows tonight from the mid 20s in the northwest, to the lower 30s in the southeast. Highs tomorrow from near 40 in the northwest, to the mid 50s in the southeast; partly cloudy skies and westerly winds nearing 20 mph will likely lead to a chilly feeling through the day. Wednesday night lows from the 20s in the northwest to the 30s in the southeast. We'll see clearing skies for Thursday, with high temperatures in the 40s throughout the state. Thursday night lows in the mid 20s to near 30 from northwest to southeast...

Our next storm system will begin moving into the state on Friday, bringing in a rain/snow mixture for parts of the state. With the low pressure system once again forecasted to come across the state, some parts may see the risk of thunderstorms while some are seeing the chance of snow. More details on this potential storm system later...

Another Winter Storm!!!

After this weekends' winter storm that gave parts of southeast Iowa a few inches of the white stuff, and saw nearly half of the state at least see some snow flurries; we'll up for another winter storm to scrape by the state. Tonight has a strong low developing and slowly moving eastward overnight, with snow to the north and west that will give parts of northwest Iowa anywhere from 1-3" of snow by the end of Tuesday. Other parts of the state will see some light to moderate rain, maybe even a few rumbles of thunder across the central portions of the state tonight. A dry slot will also wrap around the strong low and cut-off much of the precipitation for areas south of Highway 20.

This storm system is just one of many that may move through and affect parts of the state over the next week or so...

The low track over Iowa will spare the state from much of the precip, as the heaviest bands will fall both north and west of the state. Parts of the Dakotas and into Minnesota will be looking at approximately a foot of snow or more by the end of tomorrow. Extreme northwest Iowa has the best chance of accumulation snow, with 1-3" currently forecasted. Just across into parts of SD/MN will have the shot of 3-6" of snowfall, which show how tight of a gradient this storm has; much similar to this past weekends. Light snow and rain will likely move over the northern third of the state through tomorrow, while much of the state south of there will remain dry due to the large expanse of dry air that will wrap-up around the low.

Another update with any of northwest Iowa's snow accumulations and a look ahead at the remainder of the week tomorrow night.

Winter Returns?

Many forecasters as well as I have been following the major storm system that is moving onto the plains this evening, and will track northeastward as we enter the end of the week and into the weekend. This storm system at the beginning of the week was centered or just south of Iowa, leaving much of the state under several inches and even feet of snow! Now as the system gets closer and we have a slightly better idea as to the track it appears that the heaviest snow may fall out into the southern plains of KS/OK/TX over the next 48 hours. Blizzard watches and other advisories are being issued for those areas, where over a foot of snow in areas of TX/OK/KS are appearing likely, not to mention the heavy snows off of the Rockies in CO! The low pressure system is still expected to move northeast once across Kansas/Oklahoma, and portions of southeast Iowa are still in-line to receive some significant snowfall amounts.

Precipitation across much of the southeast half of the state is possible, with a rain/snow mix being the going forecast. However, as the low continues to move northeast the cold air behind the low will quickly rush in and be able to turn the precipitation into snow. By that time it appears that the precipitation will be confined to an area that is southeast of a Lamoni to Oskaloosa to Dubuque line. Areas southeast of this line appear to be looking at 2-5 inches of snowfall, with the possibility of some isolated higher amounts.

Unfortunately, a very busy week at hand will have me deferring you to the local forecasters and National Weather Service for updates on this storm as it nears. For now it does appear that Friday and Saturday may be quite snowy for parts of southeast and eastern Iowa!

And if you're disappointed that you missed out on this one, it appears that we may have the potential for two more strong storms that may bring heavy rain or snow to parts of the state next week! Updates on those likely coming on Sunday!

Winter Storm: Mar 10

Although only a small portion of the state will see winter precipitation, this will still be one of the main highlights of our storm system that is currently effecting the state. While thunderstorms and showers should dominate the forecast for all but northwest Iowa, this will create the potential for additional flooding and overall saturated conditions. Storm total precipitation should range from a few tenths across the diagonal of the state to upwards of a half inch across southeast Iowa. These heavier amounts are likely to come from isolated thunderstorms, some of which over extreme southeast Iowa may be able to reach severe limits with strong winds and large hail. Across northwest Iowa, a mixture of sleet and snow seems likely, along with some freezing rain during the early hours of the event. Snow accumulations should generally only be 1-3 inches for areas that are currently under a Winter Weather Advisory; other parts of the state bordering this advisory will see snowfall but generally no accumulations.

The other part of this storm system will be the cold air funneling in behind the low pressure system, and the strong winds that will move in tomorrow afternoon and overnight. Highs tomorrow will range from near 20 in northwest Iowa as they remain to in the cold air; while southwest Iowa will attempt to reach the 60s in the warm sector of the low pressure system. The cold air moves through the entire state by Tuesday night, bringing lows down into the single digits across northwest Iowa and the upper teens across southeast Iowa. Highs on Wednesday will only reach the teens across the northwest, and the lower 30s across the southeast. We'll look to slowly warm-up through the week, and continue to warm into the weekend.

Severe & Winter Storm: Mar. 7-8 Update #1

While the southern two-thirds of the state continues to see rain and thunderstorms this morning, precipitation is also beginning to move into parts of northwest and northern Iowa where they are expecting winter-type precipitation through this afternoon. While roadways are wet throughout much of the state, there are now reports across northwest Iowa indicating that roadways are beginning to become covered in snow/sleet and are freezing over.

Precipitation is expected to continue across the entire state through the early afternoon hours, with mainly rain expected south of a Onawa to Fort Dodge to Mason City to LaCrosse, WI line. North of that line, a mixture of freezing rain, sleet, and snow is expected. The heaviest snow amounts are expected across northwest Iowa, where 1-3 inches of accumulation may be seen with a mixture of sleet. Other parts of northern and western Iowa are likely to see a combination of precip-types, and a total of 1-2 inches of accumulation by the end of the afternoon.

Expect the low pressure system to move into Illinois by this afternoon, which will begin to pull the precip out of the state. Currently it looks like by mid-afternoon all but the northeast quarter of the state will become dry; northeast Iowa should see an end to the precip by the end of the evening.

Winter Storm: Feb 27-28

Another round of winter weather is likely to effect at least the western half of the state tomorrow evening and overnight. Eastern Iowa will likely be spared, with only flurries and cloudy skies as they head into the weekend. As for the western half, a shortwave in the mid-levels will spark off some additional snow-showers tomorrow afternoon over the Dakotas. These snow-showers will move southeast with time tomorrow, following an axis close to the Missouri River. With cold temperatures in place, this will be an all snow event throughout the northern plains. Snowfall totals should range from 2-4 inches through the eastern half of Nebraska, and much of the western half of Iowa. A few areas may be able to sneak by with a little less, and others a little more (up to 5 inches).

Beyond this storm system, we look to stay dry until late next week...