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URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 137

NWS STORM PREDICTION CENTER NORMAN OK

640 AM CDT WED APR 24 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* TORNADO WATCH FOR PORTIONS OF

  SOUTHERN AND EASTERN LOUISIANA

  SOUTHERN MISSISSIPPI

  COASTAL WATERS



* EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 640 AM

  UNTIL 100 PM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL TORNADOES POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A FEW LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE

MILES EAST AND WEST OF A LINE FROM 20 MILES WEST NORTHWEST OF MC

COMB MISSISSIPPI TO 40 MILES WEST OF HOUMA LOUISIANA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU7).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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.



&&



DISCUSSION...AN AREA OF TSTMS ALONG SW LA COLD FRONT HAS

STRENGTHENED OVER THE PAST 2 HRS...LIKELY IN RESPONSE TO INCREASING

LARGE SCALE ASCENT/WAA DOWNSTREAM FROM APPROACHING SRN STREAM UPR

IMPULSE. AREA VWP DATA AND SFC OBSERVATIONS SHOW WIND/THERMODYNAMIC

SETUP SUFFICIENT FOR SUSTAINED STORMS/SUPERCELLS GIVEN LOW-LVL

UPLIFT TO OVERCOME CIN. WITH LOW-LVL FLOW FAIRLY CONFLUENT AND

INCREASINGLY MOIST...POTENTIAL WILL EXIST FOR ADDITIONAL

STRENGTHENING OF STORMS...AND POSSIBLY FOR ISOLD DEVELOPMENT AHEAD

OF EXISTING SQLN. LOCALLY DMGG WIND...MARGINALLY SVR HAIL...AND

POSSIBLY A TORNADO OR TWO MAY OCCUR BEFORE UPR IMPULSE SWEEPS E

BEYOND LOW-LVL MOIST AXIS LATER TODAY.



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 24035.





...CORFIDI

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