

180 

WWUS20 KWNS 151946

SEL4

SPC WW 151946

LAZ000-MSZ000-CWZ000-160300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 144

NWS STORM PREDICTION CENTER NORMAN OK

240 PM CDT FRI APR 15 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND EASTERN LOUISIANA

       CENTRAL AND SOUTHERN MISSISSIPPI

       COASTAL WATERS



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 240 PM UNTIL

1000 PM CDT.



TORNADOES...HAIL TO 2 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 75 STATUTE

MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH NORTHEAST OF

COLUMBUS MISSISSIPPI TO 15 MILES SOUTHEAST OF LAFAYETTE

LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 140...WW 141...WW

142...WW 143...



DISCUSSION...PRE-FRONTAL CLUSTER OF TORNADIC SUPERCELLS OVER

PORTIONS OF CNTRL MS WILL PROGRESS EWD TOWARD THE AL BORDER WITH

ADDITIONAL STORMS INTENSIFYING THIS AFTERNOON ALONG COLD

FRONT/DRYLINE FROM WRN MS INTO CNTRL LA.  AMBIENT WARM SECTOR AIR

MASS IS WARM AND QUITE MOIST WITH MLCAPE VALUES OF 1000-2000 J/KG.

THE STRONGEST LOW-LEVEL SHEAR AND RESULTANT GREATEST SIGNIFICANT

TORNADO THREAT WILL EXIST FROM JUST E OF JAN TO MEI WHERE AMBIENT

STREAMWISE VORTICITY IS BEING AUGMENTED BY A DIFFERENTIAL

HEATING/OUTFLOW BOUNDARY.  ELSEWHERE THE COMBINATION OF EFFECTIVE

BULK SHEAR OF 50-60 KT AND EFFECTIVE SRH OF 150-300 M2/S2 WILL BE

SUPPORTIVE OF SUPERCELLS CAPABLE OF TORNADOES...LARGE HAIL AND

DAMAGING WINDS.



AVIATION...TORNADOES AND 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 26035.





...MEAD

