04/06/05: FCST: Mississipi Valley/Gulf Coast

Outlook Graphic for Wednesday: ]http://www.midwestchase.com/wxforecasts/ap...pril6-1.gif[/b]

Strong surface low will enter southern IL on Wednesday... NAM shows SBCAPE of 1500j/kg across most of Illinois and western Indiana -- being supported by diurnal heating and substantial low-level moisture (Tds >55F in the warm sector) -- with backed surface flow ahead of the low. I'm betting on central IL as of now....

Hopefully not a repeat...maybe with slower storm speeds, and more supercells.

The setup Wednesday will depend a lot on what happens on Tuesday. Current model trends are holding temperatures in Illinois down to the lower 60s, mostly due to precip and cloud cover associated with the previous day's event.

The system has been slowing with each model run, as just a couple days ago it was forecasted out of the area by early Wednesday, but is now holding the cold front/dryline passage until mid afternoon for central IL.

If we can get the previous day's convection out of the state quick enough and allow for some solar heating, we're going to have a shot. If I had to pick an area, based on the current look, I'd say the best area is going to be the eastern half of Illinois, mainly the northeastern portion. Now, as I said, the system slows with each run, so it wouldnt surprise me should this system end up a lot like last Wednesday's, with it being a central Illinois, northern Illinois event.
ATTN MODS - there are two forecast threads for the Gulf coast today.

Already significant tornado damage reports coming in from Rankin MS area. The SVS during the event sure sounded ominous:


Volatile environment remains in place and additional tornadoes appear likely. SPC mesoanalyses show a trailing instability axis with limited cinh, with 0-3 km effective helicities of up to 400 along the eastern edge of the instability.