

938 

WWUS20 KWNS 121428

SEL4

SPC WW 121428

ARZ000-LAZ000-TXZ000-122100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 144

NWS STORM PREDICTION CENTER NORMAN OK

930 AM CDT SUN APR 12 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF SOUTHERN ARKANSAS

       LARGE PART OF NORTHERN LOUISIANA

       PARTS OF NORTHEAST TEXAS



EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 930 AM UNTIL 400

PM CDT.



HAIL TO 2 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 80

STATUTE MILES EITHER SIDE OF A LINE FROM 25 MILES SOUTH SOUTHWEST

OF LONGVIEW TEXAS TO 55 MILES SOUTHEAST OF EL DORADO ARKANSAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 142...WW 143...



DISCUSSION...LINE OF SEVERE THUNDERSTORMS DEVELOPING RAPIDLY NERN TX

IN RESPONSE TO STRONG ASCENT AHEAD OF MAIN UPPER TROUGH AND

CONTINUED INCREASE IN INSTABILITY ABOVE SHALLOW STABLE BOUNDARY

LAYER.  STORMS EXPECTED TO CONTINUE E/NE ACROSS WATCH WITH PRIMARY

THREAT DAMAGING WINDS AND LARGE HAIL.  DURING AFTERNOON BOUNDARY

LAYER WILL GRADUALLY BECOME MORE UNSTABLE OVER LA AND INCREASE

CONCERN FOR SUPERCELLS AND POSSIBLE TORNADOES.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 24035.





...HALES

