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000 

WWUS20 KWNS 072050

SEL0

SPC WW 072050

ALZ000-080100-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 490

NWS STORM PREDICTION CENTER NORMAN OK

350 PM CDT SAT JUL 7 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EAST CENTRAL ALABAMA



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 350 PM UNTIL

800 PM CDT.



TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 60 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 35 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTH SOUTHEAST OF

AUBURN ALABAMA TO 30 MILES WEST OF MONTGOMERY ALABAMA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU0).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



DISCUSSION...A MID LEVEL AND ASSOCIATED SURFACE LOW ARE MOVING EWD

FROM MS TO WRN AL.  IN ADVANCE OF THIS SYSTEM...RAINFALL HAS

MAINTAINED AN E-W RAIN-COOLED BOUNDARY/WARM FRONT NEAR MGM.

LOW-LEVEL SHEAR /EFFECTIVE SRH OF 100-200 M2/S2/ IS MAXIMIZED ALONG

AND N OF THIS BOUNDARY PER THE BMX AND MXX VWP/S...AND DEEP LAYER

SHEAR IS AT LEAST MARGINALLY FAVORABLE FOR SUSTAINED SUPERCELLS

ALONG THIS SAME CORRIDOR.  GIVEN THE MOIST LOW LEVELS AND MODERATE

INSTABILITY...STORMS INTERACTING WITH THE BOUNDARY MAY PRODUCE A

COUPLE OF TORNADOES FOR THE REMAINDER OF THE AFTERNOON AND INTO THIS

EVENING.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 50 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 25020.





...THOMPSON

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