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126 

WWUS20 KWNS 151137

SEL6

SPC WW 151137

ARZ000-KSZ000-MOZ000-OKZ000-151600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 176

NWS STORM PREDICTION CENTER NORMAN OK

640 AM CDT SUN APR 15 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST ARKANSAS

       EXTREME SOUTHEAST KANSAS

       EXTREME SOUTHWEST MISSOURI

       NORTHEAST OKLAHOMA



EFFECTIVE THIS SUNDAY MORNING FROM 640 AM UNTIL 1100 AM 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 45

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH

NORTHEAST OF JOPLIN MISSOURI TO 40 MILES WEST SOUTHWEST OF FORT

SMITH ARKANSAS.  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.



DISCUSSION...WELL-DEVELOPED SQUALL LINE ACROSS NE OK/SE KS WILL

LIKELY PERSIST FOR A FEW MORE HOURS WILL MOVING TOWARD SW MO/NW AR.

DESPITE ONLY WEAK SURFACE-BASED INSTABILITY...A TENDENCY FOR

LOW-LEVEL MOISTENING JUST AHEAD OF THE LINE...AND STRONG LOW-LEVEL

SHEAR...WILL MAINTAIN A RISK FOR ORGANIZED BOWING SEGMENTS WITH A

RISK FOR DAMAGING WINDS.  AN EMBEDDED QLCS MESOVORTEX TORNADO CANNOT

BE RULED OUT, BUT THE WEAK INSTABILITY SUGGESTS THAT DAMAGING WINDS

ARE THE MAIN THREAT.



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 25040.





...THOMPSON

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