MON 7:13 AM - Narrowed the STRONG zone to focus on central WI. Storms will likely cluster up while hitting generally the same areas overnight.
As for severe weather...obviously cannot rule out a strong/severe storm. Latest models have initiation really late but also don't complex it out...favoring more training of cells or small clusters. Probably not a huge deal overall.
Felt confident enough to add a heavy rain threat zone across central WI (see maps). A few places may see upwards of 2.0". If it takes place squarely across central WI then flash flooding threat will be minimized...it's been dry and the sandy soil will soak it right up. We need some rain.
SUN 9:21PM - latest models trending south, more inline with Minneapolis region. Adjusted map to reflect latest developments. This doesn't appear to be a widespread event...scattered storms beginning with cellular development over MN spreading east-SE overnight(weakening probably). Will update tomorrow AM.
SUN 9:21 AM - Strong to severe t-storms are possible within a large STRONG zone across northern Wisconsin Monday night into early Tues AM. Uncertainty regarding the evolution into a complex...perhaps storm coverage remains more scattered? If storm coverage is limited...the threat will be less widespread.
This setup is typical of a complex of storms originating over western WI and pushing across northern WI into northeast WI overnight. Forcing coming from the southern edge of a potent/shallow upper level trough in strengthening & changing upper level pattern. Instability pool builds during the day...warm front laying W->E and thermodynamics are good enough. Initial development likely in the NW WI region likely to be cellular and it wouldn't surprise me if one or two were severe. The question is how will late MON convection evolve overnight as it moves east? I have to assume it will complex out but that doesn't mean it will. Extended the STRONG zone right through NE WI because that's typically how this goes.
Early day isolated t-storm convection possible. NAM high res refires isolated t-storm activity over Door County/extreme northeast WI during the afternoon. Not sure about that as NAM/GFS place greater emphasis on convection moving out of NW WI.
Getting ahead of it now. Low end event still, could be worse. Will see how it looks Monday morning as we get closer to the event.