6/6/08: NOW: MI/IN/IL/OH

[nickgrillo]

A red box just got issued for much of MI... The convection currently pushing northeast across lake MI should rapidly intensify as it moves onland. On the other hand, all of the strong insolation / sfc diabatic heating that has occured across the area this afternoon has significantly mixed out the moist layer, which is evident per thermodynamic SPC mesoanalysis fields. While low-level / deep-layer shear is intense and supportive of low-level mesocyclones and possible tornadoes, boundary layer thermodynamics aren't particularly supportive. Low-level lapse rates are nearly dry adiabatic given the intense diurnal heating, which has led to intense destabilization (as in SBCAPE >3000j/kg) -- but has also screwed us out of a better chance at tornado development.

It wouldn't surprise me to see a weak tornado report or two today, but much of today's severe weather should come from extensive wind damage, particularly from line segments / bowing structures.

 

[nickgrillo]

Despite tornado warnings out of KGRR and KIWX, much of the convection across the watch area has remained linear and outflow dominant, owing to the shallow moist layer in place across much of the warm sector. With a dry near-sfc layer in place, stronger cold pool generation will occur with much of the convection, precluding tornadogenesis, but also potentially increasing the chances for damaging wind gusts given the steep low-level lapse rates in place across much of central and eastern MI.

 

[Shane Adams]

It'll be interesting to see how many chasers were on the MN tornadoes today. Apparently they caught the SPC off guard, as a glance at reports shows all the tornadoes happened before the watch was issued. This is not a knock on SPC, but rather a chance to see how many chasers were able to nail this one.

Today was a wonderful opportunity for those that bash the SPC to show their quality.

 

[David Draun]

Do my eyes deceive me or is the LFC actually 500 meters LOWER than the LCL around here? How often does that occur?

Ooops, sorry. My bad. One of the isopleths was making a number 1 hard to read.

Storm threat here in N IL seems to be ending. I was in the Mchenry area briefly this afternoon for some nice storm structure. Brilliant white overshooting tops on these storms and with the shear, they titled almost immediately. Still the cold front to the west may initiate a few new cells before sunset.

 

[Von Castor]

Speaking of getting caught off guard, there were a couple 'mini sups' in Oklahoma today and one produced a tornado. It was on the ground for about two minutes, no damage but it was all caught on tape. Location was 4 east of Ft. Gibson. Maybe the mods need to add OK.