Friday/Mid Afternoon

WEATHER CODE: GREEN ***No hazardous weather expected today***

Focus will be on the potential for severe weather tomorrow...

The Storm Prediction Center has placed the entire region in a SLIGHT RISK for severe weather tomorrow.

SEVERE WEATHER OUTLOOK-Saturday

SEVERE WEATHER PROBABILITY-Saturday

MY DISCUSSION: A pretty good set-up for severe weather is evident tomorrow. Only thing lacking will be potential debris (clouds/rain) and the timing, which for now is expected to be in the late morning and early afternoon hours. Storms will set-up shop by mid morning across Central Illinois and Southwest Indiana. As the morning wears on and we head into the early afternoon hours the atmosphere will begin to become more unstable across Southern Indiana and Kentucky. Main question is obviously the storm mode. The Storm Prediction Center says it could either be line segments or individual supercells with large hail and a few tornadoes. With the very strong jet stream, and vertical shear at about 40 to potentially 60 knots, I expect storms to take on more of a supercelluar nature. It wouldn't suprise me to see both storm modes tomorrow as severe weather variables favor both line segments and supercelluar storms. Storms will be capable of producing hail the size of golf balls, and a few isolated tornadoes are possible. Wind damage is also possible with storms that become more linear in nature. Right now this is NOT expected to be a widespread severe weather event, however if storms come in later than expected (late afternoon and early evening) a much more widespread severe weather event is possible.

SPC SAYS: AN UPPER-LEVEL TROUGH OVER THE CNTRL APPALACHIAN MTNS WILL REMAIN IN PLACE TONIGHT AND SATURDAY AS A 60 TO 75 KT MID-LEVEL JET MOVES SEWD INTO THE BASE OF THE TROUGH. AT THE SFC...A FRONTAL BOUNDARY SHOULD BE LOCATED FROM NRN MO ESEWD ACROSS SRN IL INTO CNTRL KY SATURDAY. GFS/NAM/NAMKF AND SREF MODEL FORECASTS ARE IN FAIRLY GOOD AGREEMENT LATE SATURDAY MORNING WITH A CLUSTER OF THUNDERSTORMS LOCATED ACROSS IL...SRN IND AND WRN KY IN THE RIGHT REAR QUADRANT OF THE MID-LEVEL JET. CONVECTION WITH THIS FEATURE OR NEW STORMS THAT DEVELOP SOUTH OF THE CLUSTER SHOULD MOVE SEWD ALONG THE BOUNDARY ACROSS CNTRL KY DURING THE AFTERNOON. A CONSENSUS OF FORECAST SOUNDINGS IN CNTRL KY AT 21Z SATURDAY SHOW MODERATE INSTABILITY WITH 40 TO 50 KT OF VERTICAL SHEAR SUGGESTING THE ENVIRONMENT WILL BE FAVORABLE FOR A SEVERE THREAT WITH THE CONVECTIVE CLUSTER. AT THIS TIME...CONVECTIVE MODE REMAINS QUESTIONABLE. IF ISOLATED SUPERCELLS CAN ORGANIZE...THEN LARGE HAIL AND A FEW TORNADOES WILL BE POSSIBLE. IF LINE-SEGMENTS ARE FAVORED...THEN THE PREDOMINANT THREAT COULD BE WIND DAMAGE. ANOTHER UNCERTAINTY IS THE TIMING OF THE CONVECTIVE SYSTEM. IF THE TIMING IS LATER IN THE AFTERNOON WHEN INSTABILITY IS MAXIMIZED...THEN THE SEVERE THREAT COULD BE MORE SUBSTANTIAL.