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WWUS20 KWNS 081952

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SPC WW 081952

ARZ000-OKZ000-TXZ000-090200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 173

NWS STORM PREDICTION CENTER NORMAN OK

250 PM CDT TUE APR 8 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       LARGE PART OF SOUTHERN AND CENTRAL ARKANSAS

       SMALL PART OF SOUTHEAST OKLAHOMA

       PARTS OF NORTHEAST TEXAS



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 250 PM UNTIL

900 PM CDT.



HAIL TO 2.5 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 65 MILES EAST OF

LITTLE ROCK ARKANSAS TO 70 MILES SOUTHWEST OF PARIS TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU3).



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...AIR MASS HAS BECOME MODERATELY UNSTABLE AHEAD OF FRONT

ACROSS NERN TX INTO SWRN AR WITH MLCAPES AOA 2000 J/KG.  WITH LITTLE

REMAINING CINH...THUNDERSTORMS EXPECTED TO INCREASE IN NUMBER AND

INTENSITY ACROSS THE WATCH REMAINDER OF AFTERNOON.  40-50KT OF DEEP

LAYER SHEAR COUPLED WITH INSTABILITY SUPPORT BOTH MULTICELLULAR AND

ISOLATED SUPERCELLS.  PRIMARY THREAT WILL BE LARGE HAIL...WITH WIND

DAMAGE MORE LIKELY WITH DEVELOPMENT OF SHORT LINE SEGMENTS.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 24030.





...HALES

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