

892 

WWUS20 KWNS 111341

SEL4

SPC WW 111341

TNZ000-111900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 374

NWS STORM PREDICTION CENTER NORMAN OK

840 AM CDT THU JUN 11 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MIDDLE AND EASTERN TENNESSEE



EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 840 AM UNTIL

200 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 55

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

SOUTHWEST OF CLARKSVILLE TENNESSEE TO 40 MILES EAST SOUTHEAST OF

CROSSVILLE TENNESSEE.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 373...



DISCUSSION...A WELL-DEFINED MCV IS MOVING EWD FROM WRN INTO MIDDLE

TN THIS MORNING.  THE 12Z SOUNDING FROM NASHVILLE SHOWED MLCAPE OF

ALMOST 3000 J/KG AND MINIMAL CONVECTIVE INHIBITION...WHILE THE

MEMPHIS VWP REVEALED A 40-50 KT JET AS LOW AS 2 KM AGL IN

ASSOCIATION WITH THE MCV.  THIS COMBINATION OF INGREDIENTS WILL

SUPPORT CONTINUED THUNDERSTORM DEVELOPMENT ACROSS MIDDLE TN AND

SPREADING EWD INTO ERN TN LATER THIS MORNING INTO EARLY

AFTERNOON...WHERE THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING

DAMAGING WINDS AND LARGE HAIL.



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 500. MEAN STORM

MOTION VECTOR 27030.





...THOMPSON

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