BY THE HAIR OF OUR CHINNY CHIN CHIN...
A cold front streaked across the Midwest Tuesday and depending on where you were in my area you may have seen a shower or thunderstorm. As we discussed in my previous post, the greatest chances were going to be in the southeast half of the area where the front arrived during the day's peak heating and maximum instability. On the tail end of a short wave, the cap broke in Illinois but further west in southern Iowa it held strong limiting storms there. Here you can see how things lined up on the cold front early in the afternoon/
From far away in space the convection looked like this on the hi-res GOES satellite imagery.
As expected, the best forcing was just northeast of my and that was probably a good thing because severe weather was a force in that region. In fact, a thunderstorm watch was issued for much of the area southeast of the Quad Cities. Most of the action remained just to the east of my counties and the watch was cancelled early.
Parts of Wisconsin and NE Illinois however were pummeled with hail and high winds. Through evening Tuesday SPC indicated 122 reports of severe hail an damaging winds.
Here's another perspective of the days storm reports. 1/2 to 1 inch hail was reported in Whiteside and Carroll counties, both in my area. We missed the worst by the hair of our chinny chin chin!
Some of the largest hail was found around Fond due Lac, Wisconsin where baseball size stones were noted 3 inches in diameter. These images from that region are from the NWS in Milwaukee. That will get your attention!
Below you can see where rain fell by way of the Doppler rainfall estimates. There were likely a few spots just north and northeast of Clinton that may have picked up 1/2 to 3/4 inch totals. In general, most places that picked up rain saw light amounts 1/4 inch or less, mainly in Illinois.
With the rain long gone Wednesday and Thursday we can look forward to outstanding September weather Wednesday and Thursday. Dew points are going to be way down in the 40s and low 50s indicating a very dry air mass. That adds up to cool nights and pleasant days with highs in the low to perhaps mid 70s. Also, with the shortening days the nights are longer allowing colder readings (fall is coming). The 3K NAM has lows well into the 40s Thursday morning. Some of the river valleys and low lying spots north of I-80 could even see low 40s...crisp!
Friday we see a robust return flow of southerly winds develop that sends a quick surge of warm air into the Midwest. Highs in the low to mid 80s are expected initiating a warm-up that could send highs near the 90 degree mark Saturday. The GFS is really excited about that prospect showing highs that look like this. Fortunately moisture is limited and humidity will not be much of a factor.
If we do get another 90 degree day we will add to a total that's pretty significant. My man Steve Gottschalk in Lowden (Cedar County, Iowa) already reports 35 90 degree days this summer, his 4th highest total. For the summer as a whole, he reports it was the 7th warmest and 9th driest in good old Lowden.
There is expected to be a front pass through the region Saturday night but it does not get too far south in Missouri before stalling out. At this point a dry passage is indicated, thanks primarily to limited moisture. Temperatures will be cooler though on Sunday, especially in the north where the EURO indicates some clouds, showers, and storms north of the boundary which is already beginning to inch back towards Iowa. A pretty good temperature gradient may develop with highs around 75 north to the mid 80s south. The GFS is not as cool with readings in the low 80s north to the upper 80s south. It's also dry. This part of the forecast is low confidence and still needs some fine tuning.
It does appear that above normal temperatures could dominate much of next week. The GFS indicates highs well into the 80s, perhaps low 90s next Monday-Wednesday. There is a chance of some widely scattered thunderstorms early in the week but if the warmth is as strong as the GFS indicates, a stout cap is likely that would keep much of the activity further north. The GFS has this for rain totals the next 7 days.
Obviously that is way below normal which is depicted in the departures below.
The EURO is more generous on amounts in my northern counties showing this for totals, most of it occurring in that questionable period Sunday and Sunday night.
Well, that's all I have to say. Enjoy the fall preview that's on the way in today and tomorrow. This is some good stuff and I've already powered the air conditioner down! Make it a good one and roll weather...TS