

683 

WWUS20 KWNS 131740

SEL6

SPC WW 131740

ALZ000-GAZ000-MSZ000-TNZ000-140100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 576

NWS STORM PREDICTION CENTER NORMAN OK

1240 PM CDT MON AUG 13 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN AND CENTRAL ALABAMA

       EXTREME NORTHWEST GEORGIA

       SOUTHEAST MISSISSIPPI

       SOUTHERN MIDDLE TENNESSEE



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 1240 PM UNTIL

800 PM CDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH

NORTHWEST OF CHATTANOOGA TENNESSEE TO 105 MILES SOUTHWEST OF

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



DISCUSSION...STORMS MAY CONTINUE TO STRENGTHEN ALONG OUTFLOW/COLD

POOL SPREADING EAST INTO AN INCREASINGLY UNSTABLE AIRMASS FROM ERN

MS ACROSS AL INTO SRN TN THIS AFTERNOON. STRONGEST STORMS ARE

PRESENTLY NEAR OUTFLOW BOUNDARY INTERSECTION ACROSS NRN AL WITH MORE

LINEAR MODE NOTED TO THE NORTH AND SOUTH OF THIS INTERSECTION.

DIURNAL HEATING HAS BOOSTED CAPE VALUES TO OVER 1000 J PER KG ACROSS

SRN PORTIONS OF THE WATCH...WHILE SHEAR AND STORM ORGANIZATION

APPEARS TO BE A BIT BETTER ACROSS THE NRN HALF OF THE WATCH. GIVEN

TIME OF DAY AND CURRENT TRENDS...EXPECT SOME INCREASE IN DAMAGING

WIND AND PERHAPS SEVERE HAIL AS STORMS DEVELOP EAST ACROSS THE WATCH

AREA THROUGH THE AFTERNOON.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 27025.





...CARBIN

