Severe Weather Update #2 - May 31

A few severe thunderstorms, and even one tornado warning, was issued this evening across southeast Nebraska and southeast South Dakota. Warnings are still ongoing across parts of central/eastern Nebraska along the cold front, however, these storms are only capable of large hail at the moment. Other storms along the cold front in southern South Dakota and Minnesota are only capable of heavy rains and maybe some small hail currently. Although the low level jet should begin to ramp up, these storms do not look like they will be well-above severe limits tonight.

Enjoy the rain, maybe some small hail, and otherwise rumbles of thunder overnight...

Another update is likely early tomorrow with a quick discussion about the warm front across the central/southern thirds of the state tomorrow.

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Severe Weather Update - May 31

A broken line of thunderstorms has erupted along the cold front across eastern/central South Dakota and into northern Nebraska. With surface winds from the southwest along the cold front, low level shear is pretty weak; combined with high LCL's due to only mid 50s dew points and you are left with fairly high based storms capable of mainly large hail. These storms should continue to develop and move southeast through the evening and into the overnight hours.

While additional thunderstorms may be able to develop during sunset along the warm front in eastern Nebraska, the most likely scenario will be for the storms along the cold front to evolve into a more linear system. These storms may be capable of damaging winds and isolated large hail as they move into northwest Iowa and adjacent areas. Additional updates are possible as storms continue to develop and move into/nearby Iowa...

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Severe Weather - May 31

With the lack of an update last night and early this morning, you may have been able to tell that I am not too excited about the severe weather threat today. A warm front will likely push east/northeast through the afternoon into western Iowa by this evening. A cold front will also be located over portions of western Minnesota and across central/eastern Dakotas which will also be a trigger for thunderstorms this afternoon. Today is a combination of favorable shear and weak instability, and then strong instability and weak shear further south along the warm front. Chasers are torn between where to target, where storms are likely but not the greatest tornado chance; or where storms are not so likely but if something were to occur it would likely be the show of the day.

Thunderstorms should develop in the eastern half of South Dakota this afternoon, with the chance of a tornado or two as well as large hail and damaging winds. Forecasts appear to support the development of an MCS, which would likely be capable of damaging winds as it moves into southern Minnesota and northern Iowa tonight. Additional updates as storms form and congeal is likely...

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Severe Weather Potential - May 31

It would appear that surface features and upper air parameters will come into play for tomorrow and allow one of the better risks of severe weather across the plains in nearly two weeks! While surface moisture will still be fairly meager across the northern plains with surface dew points only in the 50s, upper air dynamics will be fairly strong and hopefully be able to overcome the lack of moisture. A shortwave will likely move across the new, more westerly, flow at 500hPa and combine with favorable low level flow to give sufficient shear values across much of western Minnesota and adjacent areas of extreme eastern Dakotas.

With sufficient shear values and modest instability present given meager dew point values for the last day of May we should see the initial development of supercells along the cold front and potentially in the warm sector over eastern SD and western MN. While initially the storms may be favorable for large hail and a tornado or two, it appears that with a strengthening low level jet during the evening and into the overnight that the development of an MCS is likely. This MCS would likely move southeast through southern Minnesota and potentially into extreme northern Iowa with the greatest threat being damaging winds. Expect additional updates on the severe weather threat later this evening and early tomorrow... While I currently do not have any chase plans, if significant severe weather does appear to be likely I may have a chase update as well.

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Severe Weather Threat - May 29 (Update)

The latest SPC outlook for severe thunderstorms has greatly limited the potential for severe weather across the state this evening and overnight. This is likely due to the lack of convergence along the quasi-stationary front that is now over northern Missouri. With this front located that far south, and the lack of convergence along and especially north of the front it looks as if the likelihood of strong/severe storms anywhere in Iowa is going to be limited to extreme southern Iowa if any areas at all. A few scattered thunderstorms are still possible across portions of Iowa this evening/tonight, however, these should not be severe in nature.

Areas that may see severe weather this afternoon would be areas of the eastern Dakotas and extreme western Minnesota; as well as northern Missouri into Illinois along the stationary boundary. Marginally severe hail, and damaging wind gusts will be the main threats with the evening/overnight storms.

With today's severe weather threat becoming minimal if not obsolete, we'll look towards Sunday as the first day that Iowa can see severe weather since oh so long ago...

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Severe Weather Threat - May 29

A weak cold front is positioned across northern Iowa this morning, and should slowly push southward through the morning hours to be positioned near/along the I-80 corridor by this afternoon. Areas along and south of this front will be in position to see strong/severe thunderstorms this afternoon and overnight. While some storm development along the front is possible during the evening hours, storms that develop across central NE/SD are likely to congeal into some form of MCS or cluster of storms. These clusters of storms should follow along/south of the cold front and be capable of damaging winds and/or large hail through the overnight hours across southern Iowa and northern Missouri.

Additional updates are possible this afternoon if development does occur this afternoon across Iowa, otherwise expect an update during the evening hours on the thunderstorm development across Nebraska/Dakotas and how those storms may evolve across Iowa overnight.

Otherwise expect partly cloudy to clear skies across the state, with temperatures in the mid 70s to upper 80s across the state. Additional strong/severe thunderstorms will once again be in the forecast for Sunday afternoon/evening...

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Feels like May!

After yesterday's high temperatures across the state in the 50s and 60s, along with cloudy and rainy skies, today is much of a relief for those wishing it would actually feel like May. Morning lows were on the chilly side in the mid 40s in the northwest, to the mid 50s across much of the southern tiers of the state. With clear skies overhead today, and only light northerly winds the temperatures will soar into the lower 80s across the western portions of the state and near 70 along the Mississippi River. Temperatures will only get warmer as we continue into the weekend, and the return of southerly flow will allow increased moisture as well. We'll see only partly cloudy skies through the rest of the week, leading to a wonderful start of the weekend.

Low temperatures tonight in the lower to mid 50s across the state, setting us up for highs on Friday from the mid 70s across the northeast quarter to the mid 80s across the southwest. Friday night lows from the lower 50s to upper 50s from north to south are expected as light southerly winds begin to pull in moisture from the south. Highs for the start of the weekend on Saturday will range from the upper 70s to upper 80s from east to west across the state. Lows overnight from the lower 50s to lower 60s from northeast to southwest... Previous forecasts had indicated the potential for thunderstorms on Saturday evening across parts of southern Iowa, however, current model trends continue to push the forecasted low pressure system and associated fronts further south into Missouri. If this model trend holds true then only a slight chance of a thunderstorm or two would see possible across southern Iowa.

Sunday should hold a different story, with a cold front beginning to work down from the northwest and warm/moist temperatures finally in place ahead of the front would lead to strong and potentially severe thunderstorm development during the afternoon/evening hours. Sunday's highs from near 80 to near 90 appears likely from east to west, with dew points approaching 60 across much of the state.

Thunderstorms would be likely along the cold front as it sweeps into northwest Iowa by the evening hours, and continued development would be likely across the state as the front continues to move southeast through the overnight hours. Moderate instability would appear to be present given warm temperatures and modest dew point values, however dew points would still appear to be too low to support strong surface-based development. For this reason it would appear that damaging winds be the main threat with storms along the cold front, with large hail being a secondary threat with any of the stronger storms. More updates on the potential for severe weather for this weekend and next week in later updates!

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Return of Severe Weather?!?

A small area of 'See Text' as issued by the Storm Prediction Center covers extreme southeast Iowa today for the risk of an isolated brief tornado. This is in regards to a weak warm core low that has spun across Missouri the past two days, and is continuing to move northward near the Iowa/Missouri border by late this afternoon. The previous two days with this low have brought tornado warnings and even a couple of reports of tornadoes in extreme southeast Missouri on Sunday. Instability and shear are slightly weaker, thus we don't expect anything other than a storm or two that may be able to exhibit rotation across extreme southeast Iowa and adjacent areas. Other areas across the state should see isolated thunderstorms or showers through much of the day as they move northwest with the weak surface low. Temperatures will struggle with the cloudy and rainy conditions, only reaching the the lower 60s to lower 70s from northwest to southeast.

Lingering showers possible across western and central regions tonight, likely over the eastern third of the state. And then isolated showers across the state on Wednesday, and possibly into Wednesday night for the eastern sections of the state. We then look towards clear skies for the remainder of the week, with the only additional chance of thunderstorms coming into the forecast for western Iowa on Saturday. More details on these thunderstorm chances and the return of severe weather being possible for the plains states in later updates...

Wednesday highs in the 60s across the state; Thursday in the mid 70s to lower 80s from east to west; and Friday highs from the mid 70s to mid 80s from east to west as well. Tonight's lows in the from near 50 in the northwest to near 60 in the southeast; overnight lows on Wednesday night from the upper 40s to upper 50s from northwest to southeast. Lows on both Thursday and Friday night will be into the mid to upper 50s across the entire state, as moisture begins to be pushed into the state under stronger southerly winds.

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Severe Weather Drought

Today marked the eighth straight day in which the Storm Prediction Center had not issued a Severe Thunderstorm or Tornado watch over any part of the United States. This is essentially a May record, with eight days of minimal organized severe weather and even one day (May 21) in which not even a single severe weather report was received. For those that are interested in such major projects like VORTEX, this lack of significant severe weather is definitely putting a damper on any hype. At least many are hopeful for a strong start to June, that will hopefully continue through the rest of the month and have mother nature finally give us a good show in the beautiful northern plains states.

Several local chasers/spotters have been using the high plains as chase territory with times like these, minimal moisture is still sufficient at the higher elevations, and low level winds with an easterly component play into good up-slope flow to trigger the convection. A weak/shallow trough is currently over the northern plains, and will create some potential for severe weather across eastern Dakotas and western Minnesota on Memorial Day. However, even with sufficient wind shear over this area, the lack of moisture will likely create high based storms more likely of large hail and some strong wind gusts.

Once this small trough passes through, we'll once again see a ridge in the western half of the CONUS build. Continuing the lack of organized severe weather across the plains states... Forecast models are now beginning to hint at this ridge breaking down towards the last day or two of May and then continuing to support the threat of organized severe weather into the month of June. Once these threats really begin to crank up and enter the forecast, I'll hopefully be able to begin some organized severe weather forecasts for Iowa and adjacent areas.

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Wet Weekend

Memorial Weekend has been fairly wet and cool across northwest Iowa, as a cold front is draped across the state leading to showers/thunderstorms along and north of the boundary. Today's highs over northwest Iowa where rain and cloud cover dominated were only in the mid 60s to lower 70s. Other parts of the state saw plenty of sun and temperatures once again soared into the upper 70s to mid 80s.

These showers and thunderstorms will continue over northwest Iowa tonight, and a few sprinkles are also possible over the rest of western and northern Iowa. Lows from the mid 50s to mid 60s from northwest to southeast are expected. As the cold front works through the rest of the state, we'll see isolated showers over all but the southeast corner of the state on Saturday. High temperatures from the upper 60s in the north, to the lower 80s in the south are forecasted. A few isolated showers are going to be held in the forecast over the western third of the state through the remainder of the weekend; with high temperatures in the 70s through the state on Sunday. Lows on Saturday and Sunday will be in the 50s for the most part, a few 60s also will be seen.

We'll see showers and thunderstorms work back into the forecast for Memorial Day, and through Tuesday. Showers over the southern half of the state during the day on Monday, over the entire state for Monday night and Tuesday, and then over the eastern third on Tuesday night. A few stronger thunderstorms may be possible if moisture can be sufficient, more details on that may be available later this weekend. Look for high temperatures in the mid to upper 70s on Memorial Day for the state; low temperatures in the mid 50s to lower 60s overnight on Monday...

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