Preliminary severe weather reports number 57 from northern Illinois, through southern Lower Michigan to northern & northeastern, eastern & southeastern Indiana to western Ohio today. Tornadoes occurred as close as Onarga, Illinois. Winds were measured as high as 74 mph from storms in the Chicago area.
Measured wind gusts with showers & storms & outside of them were up to 50 mph. The closest severe t'storm gust measured in the area was Lowell with 58 mph gust.
Storms in Illinois are moving north-northeastward. Northwestern counties will be affected & some severe risk continues.
Shear & helicity with strong low-level jet are conducive to isolated severe. CAPE is shallow, however & lapse rates rather poor.
Storms are firing outside of the best tornado probabilites, however. They seem to be occurring along a convergence zone from central Illinois to our northwestern counties.
Isolated severe risk in that zone should continue up to about 2 a.m.
The latest hi-res models shows this set-up well.
We need to watch position & speed of the cold front Wednesday. If it slows down enough, we are going to see some storms fire here around noon-1 p.m. & race east & northeastward. Severe weather risk with wind, hail & tornadoes will accompany them.
It has been a game of just trying to pin down how far west the severe weather risk (whether it be MARGINAL or SLIGHT) needs to be painted. The much higher risk is with eastward extent, but it is still very close.
Here, any severe risk is most likely in the eastern counties, especially along & east of US 31. However, we still need to watch it closely. Any slow-down & we will find ourselves with severe weather in the heart of the area & eastward.
This is looking like a big outbreak of tornadoes, wind & hail from eastern Wisconsin through Lower Michigan, western Ontario to northeastern & eastern Indiana through central & eastern Kentucky, Ohio & parts of West Virginia & Pennsylvania.
MODERATE RISK of severe weather seems likely.
Once this front passes, we will see a dry slot, then considerable cumulus/stratocumulus with much dew points (dropping from 74-79 to 53-58) will pivot in. A few spotty showers are possible.
It will be windy all day with gusts up to 45 mph first from the south-southwest, then southwest to west-southwest.
Thursday still looks good with sun & 80s.
Cold front passes early Friday with a few spotty showers/t'showers with highs 78-85.
Both days look breezy to windy with comfortable humidity levels.
Weekend still looks good with sun, low humidity & 70s to 80 with lows in the upper 40s to mid 50s.