

993 

WWUS20 KWNS 121639

SEL8

SPC WW 121639

ARZ000-MSZ000-OKZ000-TNZ000-130000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 388

NWS STORM PREDICTION CENTER NORMAN OK

1135 AM CDT FRI JUN 12 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF ARKANSAS

       PARTS OF NORTHERN MISSISSIPPI

       PARTS OF EASTERN OKLAHOMA

       PARTS OF WESTERN TENNESSEE



EFFECTIVE THIS FRIDAY MORNING AND EVENING FROM 1135 AM UNTIL 700

PM CDT.



...THIS IS A PARTICULARLY DANGEROUS SITUATION...



EXTREMELY DAMAGING THUNDERSTORM WIND GUSTS TO 105 MPH...LARGE

HAIL TO 3 INCHES IN DIAMETER...AND DANGEROUS LIGHTNING ARE

POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 100

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES WEST

SOUTHWEST OF MUSKOGEE OKLAHOMA TO 35 MILES SOUTH SOUTHEAST OF

MEMPHIS TENNESSEE.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 387...



DISCUSSION...AN INTENSE BOW ECHO/DERECHO HAS DEVELOPED ACROSS NERN

OK AND WILL CONTINUE RAPIDLY E/ESEWD ACROSS THE WATCH AREA THRU THE

AFTERNOON. WITH A VERY UNSTABLE AIRMASS IN PLACE AND 40-50KT OF DEEP

LAYER SHEAR...A SWATH OF DAMAGING WINDS...POSSIBLY VERY DAMAGING

WILL TRACK EWD ACROSS THE WATCH AREA.  IN ADDITION SEVERE STORMS

EXPECTED TO DEVELOP WITH THE STRONG HEATING OF THE UNSTABLE AIR MASS

AHEAD OF THE DERECHO WITH POTENTIAL FOR LARGE HAIL AS WELL AS WIND

DAMAGE.



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

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 90

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

MOTION VECTOR 28045.





...HALES

