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WWUS20 KWNS 020109

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ARZ000-MOZ000-MSZ000-TNZ000-020900-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 127

NWS STORM PREDICTION CENTER NORMAN OK

805 PM CDT SAT MAY 1 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EAST CENTRAL AND NORTHEAST ARKANSAS

       THE MISSOURI BOOTHEEL

       NORTHERN MISSISSIPPI

       WESTERN TENNESSEE



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 805 PM

UNTIL 400 AM CDT.



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



DESTRUCTIVE TORNADOES...LARGE HAIL TO 2.5 INCHES IN DIAMETER...

THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE

POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE

MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH OF DYERSBURG

TENNESSEE TO 35 MILES SOUTHWEST OF OXFORD MISSISSIPPI.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU7).



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 125...WW 126...



DISCUSSION...DISCRETE SUPERCELLS NOW MOVING INTO ERN AR WILL PERSIST

OVERNIGHT WHILE MOVING NEWD TOWARD NE AR...WRN TN...AND NW MS...IN

ADVANCE OF AN EJECTING MIDLEVEL TROUGH AND SURFACE LOW.  THE

SUPERCELLS WILL MOVE INTO AN ENVIRONMENT OF STRONGER LOW-LEVEL SHEAR

COMPARED TO FARTHER W IN AR...AND VERTICAL SHEAR WILL FURTHER

INCREASE TONIGHT WITH A STRENGTHENING LLJ.  MEANWHILE...THE LOW

LEVELS ARE DESTABILIZING ACROSS MS/WRN TN IN THE WAKE OF EARLIER

CONVECTION...SETTING THE STAGE FOR SURFACE-BASED STORMS WELL INTO

THE NIGHT WITHIN A VERY MOIST AND STRONGLY SHEARED ENVIRONMENT.  THE

NET RESULT WILL BE THE POTENTIAL FOR SEVERAL LONG-TRACK SUPERCELLS

CAPABLE OF PRODUCING STRONG TORNADOES.  FARTHER E/SE INTO TN/NE

MS...THE TORNADO THREAT WILL BE SOMEWHAT LESS THAN AREAS NEAR THE MS

RIVER...THOUGH SUPERCELLS AND COUPLE OF TORNADOES WILL BE POSSIBLE

AS CONVECTION FORMS ALONG THE RETREATING OUTFLOW BOUNDARY.



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

SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE

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

500. MEAN STORM MOTION VECTOR 24040.





...THOMPSON

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