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WWUS20 KWNS 211546
SEL6  
SPC WW 211539
ILZ000-MOZ000-212100-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 136
STORM PREDICTION CENTER NORMAN OK
1039 AM CDT SUN APR 21 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   SOUTHERN ILLINOIS                           
   SOUTHERN AND EASTERN MISSOURI                           

EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 1100 AM UNTIL 400
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 ALONG AND 100 STATUTE MILES
EAST AND WEST OF A LINE FROM 30 MILES SOUTHWEST OF POPLAR BLUFF
MISSOURI TO 40 MILES NORTH OF SALEM ILLINOIS.

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...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 135.  WATCH NUMBER 135 WILL NOT BE
IN EFFECT AFTER 1100 AM CDT.

DISCUSSION...HEATING INTO THE UPPER 70S WILL SUPPORT MODERATE
SURFACE BASED INSTABILITY AHEAD OF COLD FRONT NOW MOVING INTO
CENTRAL MO.  VERY STRONG LOW AND DEEP LAYER SHEAR WILL BE
SUPPORTIVE OF SMALL LINE AND BOW ECHOES ALONG AND JUST AHEAD OF
THIS EWD MOVING FRONT THROUGH THE AFTERNOON.  SUPERCELLS ARE ALSO
POSSIBLE...ESPECIALLY INVOF OUTFLOW BOUNDARY ACROSS SRN IL TO JUST
SOUTH OF STL ATTM.

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 400.  MEAN STORM MOTION
VECTOR 26040.

...EVANS

;362,0923 391,0905 391,0870 362,0890;

699 
WWUS20 KWNS 211546
SEL6  
SPC WW 211539
ILZ000-MOZ000-212100-