

855 

WWUS20 KWNS 310623

SEL2

SPC WW 310623

ALZ000-311200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 542

NWS STORM PREDICTION CENTER NORMAN OK

125 AM CDT TUE JUL 31 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL ALABAMA



EFFECTIVE THIS TUESDAY MORNING FROM 125 AM UNTIL 700 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH

NORTHWEST OF BIRMINGHAM ALABAMA TO 10 MILES SOUTH SOUTHEAST OF

MONTGOMERY ALABAMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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...DEVELOPING MCS SHOULD PERSIST FOR SEVERAL HOURS WHILE

MOVING SEWD ACROSS CENTRAL AL.  THE DAMAGING WIND/HAIL THREAT MAY BE

MAXIMIZED IN THE SHORT TERM NEAR AND W-NW OF BHM...AS STORMS MERGE

WITH A SEPARATE OUTFLOW BOUNDARY APPROACHING FROM THE S.  THE

LONGER-TERM SEVERE THREAT IS A BIT MORE UNCERTAIN GIVEN THE

INFLUENCE OF THE OUTFLOW BOUNDARY...BUT IT APPEARS TO BE RATHER

SHALLOW AND A FEED OF MODERATE-STRONG INSTABILITY FROM THE W SHOULD

MAINTAIN THE STORMS JUST ABOVE THE SHALLOW OUTFLOW THROUGH THE EARLY

MORNING HOURS.



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 550. MEAN STORM

MOTION VECTOR 32035.





...THOMPSON

