3/8/09 FCST: IL/MO/IN

[Skip Talbot]

The sloppy second's from Saturday's setup over KS might yield an opportunity over IL on Sunday. I'm expecting mainly a linear event here. The winds are largely unidirectional, and there will be strong forcing as the cold front sweeps through. However, there is some veering in the low levels, as well as strong directional shear near the warm front. Two advantages this event also has over Saturday is the lack of a capping inversion, and stronger instability. The 12z WRF actually has Cape approaching 2000 east of St. Louis at 21z. With the weak cap and the upper air support already on the scene, I expect storms to fire early in the afternoon in eastern MO, and then to quickly evolve into a fast moving line. Maybe near initiation, or maybe if there are some breaks in the line, there might be some structure to be had with this setup. However, I expect this to be just a good equipment test for the local chasers. Any tornadoes will be far and few between and with storm motions, I doubt they will be catchable.

 

[Adam Lucio]

I see the potential too like we discussed last night. sref wants to put a dry solt type feature in between warm frontal rains and the cold front linear stuff. If this "dry slot" can somehow come with some clearing we may see some more CAPE into central and eastern IL. Last night the NAM kept the best cape into western IL about 1500 j/kg.

Better shear was up north near Chicago where winds back around the low, which looks like it wants to become negatively tilted. However these backed winds were north of the warm front which is helping to boost helicity values in that area, too bad the best instability wont make it there.

I havent had a chance to look at things yet today but its worth keeping an eye on for us locals.

 

[A Newcomb]

I'm thinking this will be first ever mobile spotting opportunity. Will probably leave the metro Indy area and head towards western Hendricks county, possibly farther west/south. Should be a good gear/driving test day, if nothing else. There won't be much CAPE, it has been cloudy with some stray showers all day today. There is a good deal of Shear up in the higher levels, and the winds are gusting stronger close ti the ground. Humidity/DewP have been on the rise here, I'm at 64º with 78% humidity. Thinking the lack of instability should be overcome by some of the dynamics of the shear.