Hot, Humid & Some Sct’d Storms TodayAugust 23rd, 2014 at 11:34 am by Chad Evans under Chad's WLFI Weather Blog
It is very warm & muggy as of 11:45 a.m.
With the temperature already 84 at the station as of 11:50 a.m. with a dew point of 73, 90-93 in the area still seems reasonable today with heat indices near 100 (especially with boundary of really hot air lifting northward toward our area).
In fact, at 10:54 a.m. (an hour ago), it was 81 degrees at Grissom Air Reserve Base. With this, the dew point was 81, giving them 100% relative humidity. Now that is oppressive. The Burlington sensor had a temperature of 83 with a dew point of 80 at 11 a.m. These stations are near transpiring corn/vegetation, with the wet soils, which often leads to localized very high dew points, especially when the wind is light to calm like at the time.
Outflow boundary from storms across southern Indiana last night has moved north & gelled with our old, weak surface stationary front (which is more of a wind shift line now from E & SE to S & SW).
Meanwhile, outflow boundary is surging out from complex of storms in Iowa & northwestern Illinois with its MCV.
There is also a secondary weak surface boundary across Illinois, which is more of a warm front separating the truly dangerous heat from the more typical summer heat.
This boundary is lifting northeastward.
All of this said, with our surface CAPE up to 3000 J/kg & our lower atmosphere uncapped (with a reservoir of 5000 J/kg surface CAPE already in Illinois), a few storms will likely form on any one of these boundaries & affect us this afternoon &/or this evening.
These storms would tend to be pulsey with isolated severe wind/hail potential with an overall coverage of 30% for the area per most recent analysis. We will watch to see if the scattered storms can gell into a cluster & if that line in Illinois can form a good cold pool, expand southeastward with some severe gusts.