

370 

WWUS20 KWNS 200838

SEL6

SPC WW 200838

ALZ000-MSZ000-201400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 166

NWS STORM PREDICTION CENTER NORMAN OK

340 AM CDT WED APR 20 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN AND WESTERN ALABAMA

       A SMALL PART OF EASTERN MISSISSIPPI



EFFECTIVE THIS WEDNESDAY MORNING FROM 340 AM UNTIL 900 AM CDT.



HAIL TO 1.5 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 70

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH OF

HUNTSVILLE ALABAMA TO 5 MILES EAST OF TUSCALOOSA ALABAMA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE 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.



OTHER WATCH INFORMATION...CONTINUE...WW 160...WW 161...WW

163...WW 164...WW 165...



DISCUSSION...TSTMS EXPECTED TO CONTINUE MOVING/DEVELOPING ENEWD INTO

NRN AL...WHERE CONVERGENT...INCREASINGLY MOIST LOW-LVL SW FLOW WILL

PERSIST BENEATH LINGERING BAND OF FAST WSWLY UPR FLOW ASSOCIATED

WITH OH VLY TROUGH. SUFFICIENT INSTABILITY SHOULD REMAIN PRESENT TO

SUPPORT A RISK FOR SVR HAIL/LOCALLY DMGG WIND...AND PERHAPS A BRIEF

TORNADO.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 26035.





...CORFIDI

