Tuesday, June 8, 2010


Looking like another potentially major day in Illinois tomorrow evening. While this looks like a much more conditional day than Saturday, it holds a more violent potential in my opinion. Looks like the same exact areas under the gun as well. Looking like the Iowa border from near Burlington east towards Peoria tomorrow evening could be a very interesting place to be. Looking like plenty of early day convection along and north of the warm front. Getting into specifics is not worthwhile at this time as a complex convective scenario will prevent many details from being apparent until morning or even well into the afternoon. However, the GFS and RUC (and the NAM, to a lesser extent however) hint at a potentially volatile situation over NW Illinois in that Burlington to Peoria corridor tomorrow evening with extreme June instability and unseasonably strong shear profiles along and near the warm front which should be south of Interstate 80 a tad.

Should this situation unfold, and NW Illinois sees some clearing from early convective debris, prolific tornadic supercells are certainly possible. GFS soundings for Galesburg, Illinois tomorrow evening show surface cape values surging to approximately 3000 j/kg under 0-1 km shear of 30 knots, and 0-1 km helicity values near or surpassing 300 m2/s2 along the warm front.

Again, this is a conditional scenario and could fail to be realized, but is certainly a day that needs very close attention. June 7th 2008 and April 20th 2004 are both days that come to mind when looking at this setup. While they are not carbon copies, they are perfect examples of these late evening warm front situations that may not be realized until very late in the period. Convection thrives for most of the day, but then the area along the warm front sees simply 2-3 hours of heating and a potential tornado outbreak ensues. Of course, there are countless examples when this backfired and a rainy day ruined storm chaser's dreams.

I'll have an update tomorrow morning, hopefully including a continued positive outlook on things. I need a little redemption after Saturday's debacle.

For what it's worth on the topic of Saturday, the NWS ILX confirmed a 300 yard wide tornado from the wall cloud that I photographed near Lincoln, Illinois after dark. I could tell something large was about to develop, but well, night chasing sucks.

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