A couple days ago the the pattern was warm and stormy over the Midwest. That set-up was responsible for the early season severe weather outbreak that produced more than 1,200 reports of severe weather in a 2 day onslaught.
Today finds a much different situation with a cold dry high dominating the eastern U.S. Here's the 500mb jet stream flow that's cut off the warmth, moisture, and storms.
The northwest flow has resulted in a much calmer weather regime. Look how quiet the radars are around the nation on this national composite image.
Not only is it quiet, it's cold as of Thursday evening. Quite a change!
As has been the case the past couple of months, the overall pattern is progressive and the trough that's over the Midwest quickly moves east. By Sunday notice the big difference in the 500mb flow. A new trough develops over the west with a ridge poking into the central U.S.
Once again the warmth is on and by Sunday widespread 60s return with some areas nearing 70 by Monday. Here's the temperature departures the EURO forecasts Monday. Up, up and away.
With the mild air in place and an approaching front, the potential exists for more thunderstorms Monday. Here's the surface pattern at noon Monday. Note the brisk south winds blowing ahead of the advancing cold front entering northwest Iowa.
Moisture is on the increase as evidenced by the dew points which are well into the 50s.
The moisture combined with highs of 65-70 will create enough instability for thunderstorms. Here's the CAPE (convective available potential energy) that's forecast late Monday. That's the area to watch for any strong thunderstorms. Unless dew points can get into the 60s the severe potential should be low with the main threats isolated hail and strong winds.
Whatever their strength, showers and thunderstorms look to advance across the Midwest Late Monday and Monday night. The EURO shows the line at 6:00pm Monday getting set to cross my local area.
Just to recap, the weekend starts chilly but gets better by the day. The warmth peaks Monday with the chance of thunderstorms ahead of a cold front late in the day or at night. Windy and colder conditions follow the front Tuesday. Happy Friday everybody and roll weather...TS