

206 

WWUS20 KWNS 091949

SEL9

SPC WW 091949

OKZ000-TXZ000-100500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 49

NWS STORM PREDICTION CENTER NORMAN OK

150 PM CST SAT MAR 9 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN OKLAHOMA

       CENTRAL AND NORTH TEXAS



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 150 PM UNTIL

1100 PM CST.



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 70

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

BROWNWOOD TEXAS TO 35 MILES NORTH NORTHEAST OF ARDMORE OKLAHOMA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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...BAND OF TSTMS INVOF SFC COLD FRONT IS INCREASING

GRADUALLY IN INTENSITY AND ORGANIZATION AS FRONTAL ZONE IMPINGES

UPON PROGRESSIVELY MORE MOIST BOUNDARY LAYER...DESTABILIZED BY

NARROW CORRIDOR OF PREFRONTAL SFC DIABATIC HEATING.  FAVORABLE DEEP

SHEAR AND BUOYANCY ARE FCST FOR CONTINUED TSTM ORGANIZATION AND SVR

POTENTIAL INTO AT LEAST EARLY EVENING. QUASI-LINEAR MODE SHOULD

PREDOMINATE WITH BOW/LEWP FORMATIONS OFFERING THREAT OF DAMAGING

GUSTS AND MRGL HAIL.  ANY SUSTAINED SUPERCELLS THAT CAN FORM WITHIN

OR AHEAD OF LINE WILL POSE RISK OF LARGER HAIL AND A TORNADO...BUT

THIS THREAT IS MORE CONDITIONAL.



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 450. MEAN STORM

MOTION VECTOR 23035.





...EDWARDS



071 

WWUS20 KWNS 091949

SEL9

SPC WW 091949

OKZ000-TXZ000-100500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 49

NWS STORM PREDICTION CENTER NORMAN OK

150 PM CST SAT MAR 9 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN OKLAHOMA

       CENTRAL AND NORTH TEXAS



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 150 PM UNTIL

1100 PM CST.



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 70

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

BROWNWOOD TEXAS TO 35 MILES NORTH NORTHEAST OF ARDMORE OKLAHOMA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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...BAND OF TSTMS INVOF SFC COLD FRONT IS INCREASING

GRADUALLY IN INTENSITY AND ORGANIZATION AS FRONTAL ZONE IMPINGES

UPON PROGRESSIVELY MORE MOIST BOUNDARY LAYER...DESTABILIZED BY

NARROW CORRIDOR OF PREFRONTAL SFC DIABATIC HEATING.  FAVORABLE DEEP

SHEAR AND BUOYANCY ARE FCST FOR CONTINUED TSTM ORGANIZATION AND SVR

POTENTIAL INTO AT LEAST EARLY EVENING. QUASI-LINEAR MODE SHOULD

PREDOMINATE WITH BOW/LEWP FORMATIONS OFFERING THREAT OF DAMAGING

GUSTS AND MRGL HAIL.  ANY SUSTAINED SUPERCELLS THAT CAN FORM WITHIN

OR AHEAD OF LINE WILL POSE RISK OF LARGER HAIL AND A TORNADO...BUT

THIS THREAT IS MORE CONDITIONAL.



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 450. MEAN STORM

MOTION VECTOR 23035.





...EDWARDS

