( A list of Alabama counties will follow shortly…)
WWUS20 KWNS 130132
SEL6
SPC WW 130132
ALZ000-LAZ000-MSZ000-CWZ000-130800-
URGENT – IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 146
NWS STORM PREDICTION CENTER NORMAN OK
830 PM CDT SUN APR 12 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHWEST AND WEST CENTRAL ALABAMA
SOUTHEAST LOUISIANA
SOUTHERN AND EAST CENTRAL MISSISSIPPI
COASTAL WATERS
EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 830 PM UNTIL
300 AM CDT.
TORNADOES…HAIL TO 1.5 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 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH NORTHEAST OF
MERIDIAN MISSISSIPPI TO 15 MILES SOUTH SOUTHWEST OF SLIDELL
LOUISIANA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).
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…THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 145. WATCH NUMBER 145 WILL NOT BE IN EFFECT AFTER
830 PM CDT.
DISCUSSION…AN ORGANIZED BAND OF THUNDERSTORMS WITH EMBEDDED
BOW/SUPERCELL STRUCTURES WILL LIKELY PERSIST AND SPREAD EWD/NEWD
TOWARD WRN/SWRN AL THROUGH THE OVERNIGHT HOURS. THE SURFACE MOIST
SECTOR AND THE WARM FRONT WILL LIFT NWD ACROSS MS/AL IN CONJUNCTION
WITH A SURFACE LOW DEVELOPING NWD FROM NW MS TOWARD WRN TN…AND AT
LEAST WEAK SURFACE-BASED INSTABILITY CAN BE EXPECTED WITH MID-UPPER
60S BOUNDARY LAYER DEWPOINTS. THE N EDGE OF THE WARM SECTOR WILL
COINCIDE WITH A ZONE OF STRONG WAA WHICH WILL HELP MAINTAIN
THUNDERSTORM DEVELOPMENT…WHERE A 50-60 KT LLJ WILL CONTRIBUTE TO
VERY STRONG LOW-LEVEL SHEAR AND AN ASSOCIATED THREAT FOR A COUPLE OF
TORNADOES AND DAMAGING WINDS.
AVIATION…TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24030.
