Stronger storms possible later this afternoon/evening

HIT REFRESH FOR THE LATEST WEATHER INFORMATION

6:40pm:  Storms continue to move east out of the viewing area this evening.  A few more could redevelop later this evening

A Severe Thunderstorm Warning continues for Rock and Walworth counties until 6:15pm.

A Severe Thunderstorm Warning has been issued for Boone and McHenry counties until 6:30pm

These storms are capable of producing ping pong sized hail and gusty winds.  They're currently moving to the east around 25mph.



3:45pm Update:  The atmosphere remains fairly capped and storms would likely have a hard developing ahead of the cold front that currently sits back in central Iowa.  That's probably why a watch hasn't been issued just yet.  As the front moves southeast the cap should weaken and that should help to get storms to fire.  Keep a watchful eye to the sky heading into this evening because storms should develop within the next couple of hours but should be out of our area by 11pm.

1:00pm Update:  Southern Wisconsin and northern Illinois will likely be placed under a Severe Weather Watch later this afternoon.  Instability continues to build south of the warm front and ahead of a cold front now in central Iowa.  Storms will likely develop ahead of this front within the next couple of hours and move east.

12:00am Update: The slight risk for strong to severe thunderstorms is still there as a cold front moves in from the northwest.  While most of this afternoon will remain dry due to a fairly strong cap in place I do anticipate storms to fire up across west-central Wisconsin around 3pm or so and move southeast with the front.  Because of that I am watching the time frame of 4pm to 9pm for storms to roll through.  There is still a bit of question as to just the exact coverage of the storms, however.  The top image is the NWS WRF weather model at 7pm and it has storms developing across southern Wisconsin during that time.  As the front moves closer the cap along with the CIN (Convective INhibition) is forecast to weaken.

 A couple of outflow boundaries across southern Wisconsin could interact with that cold front and cause a few storms to rotate.  After about 11pm I expect any storms to be east of the Stateline.

The cloud cover from the storms across central Wisconsin earlier this morning will keep our sunshine filtered as we go throughout the day.  The heat and humidity will continue to build across the area behind a warm front currently moving through Wisconsin.  A cold front stretching through western Minnesota will be the focus for our storm development as we go later into the afternoon and evening.

The Storm Prediction Center has the area under a slight risk for strong to severe thunderstorms as that cold front approaches.  Our atmosphere will remain capped (warm air above won't allow air at the surface to rise) through a good portion of the day and it likely won't be until the front moves closer, after 4pm, that we will see storms start to form.  The area that we'll be watching for possible storm development will be across southwest Wisconsin and northeast Iowa ahead of the cold front, but also along any old outflow boundaries.  As storms form they'll move southeast into our area between the 4pm - 8pm time frame.  While the main threat from the storms would be damaging wind gusts, an isolated tornado can't be ruled out given the potential of any interaction between the cold front and those old outflow boundaries.