Holiday Weekend Forecast

Memorial Day weekend usually marks the 'unofficial' start to summer and boy it will feel like it; especially Sunday.  The cold front that passed late Thursday night will lift back north as a warm front late Friday afternoon as low pressure moves northeast from the panhandle of Oklahoma.  A few light showers have developed north of the warm front in Iowa due to warmer air moving in aloft.  As the front lifts north it will draw in moisture from the Gulf of Mexico.  At the same time, the low level jet will increase which will cause thunderstorm activity to increase later today and tonight.  As the front moves closer to the Stateline our rain chances increase and we'll likely be dealing with a few scattered thunderstorms by early Saturday morning.  It's possible that some of the storms that do develop tonight and early Saturday could contain heavier rainfall as well as hail; especially if elevated storms forms.  If thunderstorms continue along the warm front, the cooler pocket of air the storms produce may slow the northward progress of the front on Saturday.  If that's the case, there will be a fairly large temperature gradient from southwest to northeast across southern Wisconsin and northern Illinois where temperatures on the cooler side of the front may only be in the 70s while on the warmer side of the front temperatures sky rocket near 90°.

By Sunday, the warm front should already be moving into Wisconsin leaving us with a fairly capped and hot air mass.  Temperatures during the afternoon will reach the low to mid 90s and when combined with dew points that will be in the 60s, it will be a hot and humid afternoon.  Because of our capped atmosphere any storm activity along an approaching cold front should remain to the west, but as close to us as Cedar Rapids, IA.

By Monday, the bubble of high pressure that was in place across the southern U.S. will have shifted a little further south as an approaching trough of low pressure moves into the Midwest.  This will allow the surface cold front to move east during the late afternoon hours on Monday.  Similar to what happened on Thursday, the main forcing with the system will remain to the north but because we will have built up the heat and now this time the moisture, storms that form along the front would have a greater probability of being on the stronger side, or possibly severe.  In fact, the Storm Prediction Center has part of the area highlighted for possible severe storm activity during the day.  With Monday being Memorial Day be sure to keep a watchful eye and ear to the forecast this weekend.  Updates will continue on the blog with weekend Meteorologist Eric Nefstead.