March 12, 2006 Severe Weather

[Hoosier]

The severe buffs should recognize this day as having a big severe weather outbreak. There were some unusual occurrences - a high risk as far north as I-80, tornadoes with temps in the 40's, a 6 state supercell, and a 107 mph wind gust at Moline, IL in what appeared to be a stable location north of the surface warm front.  Let's focus on that last thing.

The 107 mph wind gust at MLI occurred at 7:48 PM. Here are the obs immediately before and after:

SPECI KMLI 130144Z 08022G32KT 3SM TSRA BR FEW008 BKN013 OVC020 07/06 A2953 RMK AO2 PK WND 08032/0141 WSHFT 0039 LTG DSNT ALQDS P0031

SPECI KMLI 130149Z 16046G93KT 110V240 2 1/2SM R09/6000VP6000FT +TSRA BR SQ FEW008 BKN013 OVC021 08/08 RMK AO2 PK WND 22093/0148 WSHFT 0039 VIS 1 1/2V4 LTG DSNT ALQDS P0033

Besides G93KT, another thing that sticks out is that surface temps were in the mid 40's when this happened. That's right, the mid 40's. The 00z DVN RAOB, which is probably reasonably representative of the environment at MLI around the time of the wind gust, revealed a pretty significant low level inversion extending nearly to 850 mb:

 

Given the low level inversion and the lack of a large dry wedge aloft, I find it amazing that such a strong wind gust was able to occur.

Edited March 6, 2023 by Hoosier