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000 

WWUS20 KWNS 202309

SEL0

SPC WW 202309

ALZ000-FLZ000-MSZ000-210400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 550

NWS STORM PREDICTION CENTER NORMAN OK

610 PM CDT FRI JUL 20 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST ALABAMA

       THE WESTERN FLORIDA PANHANDLE

       CENTRAL AND SOUTHEAST MISSISSIPPI



EFFECTIVE THIS FRIDAY EVENING FROM 610 PM UNTIL 1100 PM CDT.



HAIL TO 1 INCH 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 10 MILES SOUTH

SOUTHWEST OF JACKSON MISSISSIPPI TO 10 MILES NORTHEAST OF

CRESTVIEW FLORIDA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 547...WW 548...WW 549...



DISCUSSION...THUNDERSTORM COVERAGE WILL INCREASE THROUGH THE EVENING

FROM CENTRAL MS SEWD INTO SW AL IN RESPONSE TO MULTIPLE STORM

MERGERS AND INTERACTIONS WITH A COMPOSITE OUTFLOW BOUNDARY MOVING

SWD ACROSS MS/AL.  MODERATE INSTABILITY IS PRESENT S OF THE NRN

OUTFLOW BOUNDARY...AND THERE WILL BE THE POTENTIAL FOR ADDITIONAL

BOUNDARY/STORM MERGERS WITH THE OUTFLOW PROGRESSING NEWD FROM LA

INTO MS...AND AS CONVECTION REACHES THE REMNANT SEA BREEZE BOUNDARY

IN SRN AL.  WET MICROBURSTS WITH DAMAGING WINDS WILL BE THE MAIN

SEVERE THREAT THROUGH LATE EVENING.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

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

VECTOR 32015.





...THOMPSON

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