

963 

WWUS20 KWNS 311746

SEL0

SPC WW 311746

ARZ000-ILZ000-KYZ000-MOZ000-TNZ000-010100-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 770

NWS STORM PREDICTION CENTER NORMAN OK

1145 AM CST FRI DEC 31 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       FAR NORTHEAST ARKANSAS

       SOUTHERN ILLINOIS

       FAR WESTERN KENTUCKY

       SOUTHEAST MISSOURI

       WESTERN TENNESSEE



EFFECTIVE THIS FRIDAY MORNING AND EVENING FROM 1145 AM UNTIL 700

PM CST.



TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS

TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH OF MOUNT VERNON

ILLINOIS TO 40 MILES EAST SOUTHEAST OF WALNUT RIDGE ARKANSAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU0).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 767...WW 768...WW 769...



DISCUSSION...PRE-FRONTAL BAND OF TSTMS FROM STL SWD TO NW OF BVX IS

EXPECTED TO CONTINUE THROUGH THE AFTERNOON AND LIKELY INTENSIFY

WHILE INTERACTING WITH A WARMING/MOISTENING BOUNDARY LAYER WITH

MLCAPE APPROACHING 1500 J/KG /REF. 17Z LZK SOUNDING/.  GIVEN THAT

LLJ AXIS WILL REMAIN ALONG OR JUST E OF MS RIVER THROUGH THE DIURNAL

HEATING CYCLE...MORE THAN SUFFICIENT VERTICAL SHEAR WILL EXIST FOR

EMBEDDED SUPERCELL AND BOWING STRUCTURES CAPABLE OF DAMAGING

WINDS...A FEW TORNADOES...AND PERHAPS SOME HAIL.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND

GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.

MEAN STORM MOTION VECTOR 24035.





...MEAD

