03/30/05 NOW: MO, IA, IL, WI, IN

[Nic Wilson]

More news on the supercell that originated southwest of Peoria around 2pm CST this afternoon:

As of 4:28 CST the public reported a tornado on the ground 8 miles west of Morris, IL moving northeast at 45 mph.

Despite being an HP mess and moving into more stable air the supercell continues to have a tornado on the ground. In another 45 minutes it will approach the southwest suburbs of Chicago so this could possibly have a large impact. Latest ob. from LOT is 73 over 48

 

[Jeff Snyder]

I agree... T-td depressions are pretty large, leaving LCLs quite high. In addition, surface winds are so strong that it's reducing helicity / SRH quite a bit. The tornadoes in se MN and ne IA kind of surprised me, but they appeared to be nonsupercell tornadoes. I wish we had a high density surface ob network in IL, as it'd be interesting to see the area near Chicago, which two supercells are currently aiming for (though, they are losing their supercell characteristics pretty quickly as they near the city). Those two particular storms are actually in a pretty marginal supercell environment, with 1000 CAPE and 40-45kt 0-6km shear with little directional shear. The storms farther south near Bloomington look interesting, however.

 

[Kurt Silvey]

I was picking up a nice couplet on this storm until it moved just SE of Morris. Since then it appears the cell may be weakening. If it is still spitting baseballs the damage could be extensive, as it is moving into very populated areas. We should be able to get great reports, as the storm is on target to pass over the NWS office.

 

[Nic Wilson]

The Chicago WFO has gone with a Severe Thunderstorm Warning in DuPage and Will Counties. Golf ball sized hail has been reported 5 miles SW of Plainfield as thankfully the hook echo has disappeared during the past two volume scans. Large hail appears to be the main threat now for the Chicago metro. The cells down south near Bloomington have been dropping nickel sized hail and don't appear that they are losing their tornadic potential.

The cells downstate tracking toward Decatur, IL should be monitored however as they are still in a 1000 J/kg environment with better VGP of ~0.2 with 0-1 SRH Helicity of ~200. They are also near a bullseye of EHI of 2. Hindrance is still LCL's of ~1700 m and Td's of only 54 degrees.