Look for a brilliant shade of blue overhead Wednesday as high pressure continues to control the weather over most of the Upper Midwest. Temperatures will be a bit warmer, thanks to a southeasterly breeze that will freshen late in the day. We should top out around 91 in Rockford with 93-95 possible for the Dixon-Sterling/Rock Falls area.
Humidity will not be too terrible either with dewpoints projected to stay in the low to mid 60s.
By the time we get into Thursday, showers and thunderstorms will become quite possible…especially late in the day. And once again, these could be prolific lightning producers. We will have to watch for some severe weather (as always), but it looks like widespread damaging thunderstorms should remain out in Iowa and Minnesota. Temperatures will be highly dependent on cloud cover and the arrival of the thunderstorms. Right now, I am going with a 94 for Thursday with the thinking that the peak heating will be gone and done before the thunderstorms move into the metro. This is also good for any outdoor plans as most of the day should end up being quite dry.
A one-day high pressure event is slated for Thursday which should bring quite a bit of sunshine to our area. There won’t be any forcing mechanism to produce storm activity so will side with a mostly sunny sky. The thermal profiles of the atmosphere will remain quite warm so high temperatures will again be in the lower to middle 90s. The only wild card will be the previous day’s rains. If enough rain falls on Thursday, the dewpoints will be higher on Friday. That scenario has it muggier but a little less hot. If dewpoints get into the lower 70s, we’ll likely only see highs around 90 versus 94 or 95.
Saturday looks to be the most active day weatherwise. A powerful shortwave of low pressure will swing through Minnesota and Wisconsin bringing some dangerous thunderstorms to the Northland. If you’re heading up there this weekend, please be mindful of that. A cool front is expected to swing into Northern Illinois and Southern Wisconsin during the afternoon so I’ve bumped up the storm chance to about 50%. In addition, some severe weather and training thunderstorms will be possible. Any flash flood threat will depend on the amount of rain that falls on Thursday. If we keep that rain under a half inch, there won’t be much trouble soaking in any heavy rain Saturday. Tmemperatures will be warm ahead of the front: in the 90s. We’ll temper things a little with middle 80s Sunday through Tuesday.
Posted under weather
This post was written by Eric Sorensen on July 31, 2012