1:37 P.M. UpdateAugust 23rd, 2014 at 1:32 pm by Chad Evans under Chad's WLFI Weather Blog
Temperatures & heat indices as of 1:37 p.m. are below (I did not include AWOS/ASOS as that data is not current………….I will in the next update map)………………Dew points are as high as 81!
Despite not good dynamics, pulsey storms could pop out a wet microburst in such CAPE & high precipitable water conditions in our area today-evening. +3.50″ rainfall/hour is possible in the heavier cells. Such high CAPE could also bring some hail, as this makes for very fast updrafts. So 30% coverage of storms along outflow boundary in area & approaching warm frontal zone seems reasonable.
Dynamics are not good, but there is an MCV moving across Iowa & northwest Illinois with complex of storms with front-end bow.
It is extremely unstable in southern & central Illinois with surface CAPE now pushing 7000 J/kg! This makes sense as incredibly humid & hot it is in Illinois.
Our surface CAPE is approaching 4000 J/kg with an extremely humid, hot airmass full of energy.
Bow in Illinois may continue to develop southwestward along outflow boundary with perhaps cells on gravity wave emitting from the storms (storms popping through top of troposphere, which sends out a shockwave through the lower atmosphere), too. All of this may also occur as bow develops a nice, expanding cold pool.
All that said, pulsey storms with wet microburst/hail threat will remain in the forecast (30% coverage), while we will watch that bow to see what transpires with it. If a really good cold pool CAN form, I see no reason as to why it could not get at least part of our area & produce some strong to severe gusts given the very hot, unstable environment around & downstream of it.