12 P.M. UpdateSeptember 1st, 2014 at 11:51 am by Chad Evans under Chad's WLFI Weather Blog
SURFACE COLD FRONT………
Surface cold front runs from Chicago to St. Louis at the moment with lots of low stratus across the area underneath low-level capping (inversion). Outflow boundary is also progressing through area from the severe weather well west of here last night. A few showers/t’showers are possible at any point this afternoon as boundary slowly progresses through area.
CINH & LOW STRATUS CLOUDS………
Thinking this capping will wear off & the sun will appear this afternoon. With already 1000 J/kg of surface CAPE (given current dew points as high as 76!), once the sun appears, this may soar to 2500 J/kg, but it doesn’t look as unstable as it did yesterday (4000 J/kg).
“ISOLATED SEVERE” RATHER THAN “SCATTERED SEVERE”……….
Stronger wind fields aloft will support more organized storms, but I prefer to keep the wording “isolated severe” rather than “scattered severe” due to less instability expected & just so much low cloudiness lingering on into the afternoon.
This said, short, high-resolution models support storm development along cold front.
SOME LOCALLY-HEAVY RAINFALL POSSIBLE (BEST POTENTIAL SOUTH OF U.S. 24)………….
This would tend to occur this evening, followed by considerable t’storm activity north of the front overnight. This could dump locally-heavy rainfall. Given wet soils, some localized flash flooding is possible.
It looks like the best potential of this is south of U.S. 24 where some +2″ rainfall amounts are possible.