

927 

WWUS20 KWNS 190504

SEL9

SPC WW 190504

ARZ000-KSZ000-MOZ000-OKZ000-191000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 789

NWS STORM PREDICTION CENTER NORMAN OK

1205 AM CDT FRI AUG 19 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST AND NORTH CENTRAL ARKANSAS

       SOUTHEAST KANSAS

       SOUTHWEST AND SOUTH CENTRAL MISSOURI

       NORTHEAST OKLAHOMA



EFFECTIVE THIS FRIDAY MORNING FROM 1205 AM UNTIL 500 AM CDT.



HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 95

STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH

NORTHEAST OF JOPLIN MISSOURI TO 35 MILES SOUTH SOUTHWEST OF

HARRISON ARKANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 787...WW 788...



DISCUSSION...INTENSE BOW ECHO SYSTEM IS EXPECTED TO CONTINUE MOVING

SEWD 30-35 KT DURING THE EARLY MORNING HOURS INTO MODERATELY

UNSTABLE AIR MASS WITH CAPE TO 2500 J/KG.  VEERING LOW LEVEL FLOW

ASSOCIATED WITH A NOCTURNAL LOW LEVEL JET BENEATH STRONG NWLY FLOW

IN THE MID/UPPER LEVELS WILL MAINTAIN FAVORABLE DEEP LAYER SHEAR TO

SUPPORT QLCS PROPAGATION.  DAMAGING WIND GUSTS AND OCCASIONAL HAIL

WILL BE THE PRIMARY THREATS.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

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

MOTION VECTOR 31030.





...WEISS

