

137 

WWUS20 KWNS 071936

SEL0

SPC WW 071936

ARZ000-ILZ000-KSZ000-MOZ000-OKZ000-080300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 630

NWS STORM PREDICTION CENTER NORMAN OK

240 PM CDT FRI SEP 7 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME NORTHWEST ARKANSAS

       PARTS OF SOUTHWEST ILLINOIS

       SOUTHEAST KANSAS

       MUCH OF CENTRAL AND SOUTHERN MISSOURI

       NORTHEAST OKLAHOMA



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 240 PM UNTIL

1000 PM CDT.



HAIL TO 1.5 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 75

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES SOUTH

SOUTHWEST OF CHANUTE KANSAS TO 15 MILES EAST OF SCOTT AFB

ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 628...WW 629...



DISCUSSION...STORMS WILL LIKELY INCREASE IN COVERAGE/INTENSITY BOTH

ALONG AND AHEAD OF A COLD FRONT IN THE NEXT FEW HOURS ACROSS SE

KS/NE OK/MO.  INCREASING DEEP-LAYER VERTICAL SHEAR WILL THE APPROACH

OF A MIDLEVEL TROUGH OVER KS...AS WELL AS A DEEP SURFACE-BASED MIXED

LAYER AND MODERATE INSTABILITY...WILL SUPPORT AN INCREASING RISK FOR

DAMAGING WINDS AND LARGE HAIL THROUGH THE AFTERNOON/EVENING.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 29035.





...THOMPSON

