

734 

WWUS20 KWNS 191657

SEL9

SPC WW 191657

FLZ000-GAZ000-192300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 179

NWS STORM PREDICTION CENTER NORMAN OK

1255 PM EDT SUN MAY 19 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHERN FLORIDA

  CENTRAL AND SOUTHERN GEORGIA



* EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 1255 PM UNTIL

  700 PM EDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS TO 60 MPH POSSIBLE

  A FEW LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHWEST OF

MACON GEORGIA TO 35 MILES EAST SOUTHEAST OF VALDOSTA GEORGIA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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.



&&



DISCUSSION...WEAK TO MODEST DEEP LAYER SHEAR BENEATH NORTHERLY

MID/UPPER FLOW HAS CONTRIBUTED TO THE EVOLUTION OF AN ORGANIZING

MESOSCALE CONVECTIVE SYSTEM TO THE SOUTH OF ATLANTA...WHERE LATEST

VWP DATA INDICATE THE DEVELOPMENT OF A 30-40 KT REAR INFLOW JET.

WITH FURTHER HEATING OF A MOIST BOUNDARY LAYER ACROSS CENTRAL AND

SOUTHERN GEORGIA INTO NORTHERN FLORIDA...ADDITIONAL STORM AND

SURFACE COLD POOL INTENSIFICATION AND SOUTHWARD ACCELERATION IS

EXPECTED THIS AFTERNOON.  SOME HAIL IS POSSIBLE...BUT POTENTIALLY

DAMAGING WIND GUSTS APPEAR THE PRIMARY SEVERE THREAT.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 50 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION

VECTOR 33035.





...KERR

