

048 

WWUS20 KWNS 051932

SEL1

SPC WW 051932

ARZ000-ILZ000-KYZ000-MOZ000-TNZ000-060300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 621

NWS STORM PREDICTION CENTER NORMAN OK

225 PM CDT WED SEP 5 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST ARKANSAS

       SOUTHERN ILLINOIS

       WESTERN KENTUCKY

       SOUTHEAST AND SOUTH CENTRAL MISSOURI

       NORTHWEST TENNESSEE



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 225 PM UNTIL

1000 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 105

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHEAST OF

CAPE GIRARDEAU MISSOURI TO 20 MILES SOUTHEAST OF WALNUT RIDGE

ARKANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 619...WW 620...



DISCUSSION...TSTMS EXPECTED TO INCREASE IN COVERAGE/STRENGTH OVER

THE NEXT SEVERAL HOURS ZONE OF MODEST DEEP WNWLY SHEAR BUT STRONG

SFC-BASED INSTABILITY ALONG THE SRN EDGE OF THE WLYS. LOW-LVL UPLIFT

MAY BE ENHANCED ALONG WNW-ESE OUTFLOW BOUNDARY IN NRN PART OF WW

/LEFT BY IL-IND MCS/. DEEP EML AND RICH LOW-LVL MOISTURE SHOULD

FOSTER DEVELOPMENT OF HAIL/LOCALLY DMGG WIND IN STRONGER

STORMS...WITH THE ACTIVITY POSSIBLY MERGING INTO A SE-MOVING CLUSTER

BY EVE.



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 550. MEAN STORM

MOTION VECTOR 29025.





...CORFIDI

