

510 

WWUS20 KWNS 041751

SEL6

SPC WW 041751

OKZ000-050100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 546

NWS STORM PREDICTION CENTER NORMAN OK

1245 PM CDT SAT JUL 4 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST AND SOUTH-CENTRAL OKLAHOMA



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 1245 PM UNTIL

800 PM CDT.



HAIL TO 1.5 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 40

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES EAST

NORTHEAST OF ARDMORE OKLAHOMA TO 45 MILES WEST NORTHWEST OF ALTUS

OKLAHOMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 545...



DISCUSSION...VERY HOT AND UNSTABLE CONDITIONS /95-100F SFC TEMPS AND

DCAPE TO 1500 J PER KG/ HAVE DEVELOPED ALONG AND SOUTH OF

WELL-DEFINED MCS OUTFLOW SITUATED ACROSS SCNTRL OK ATTM. A FEW MORE

HOURS OF HEATING ACROSS THE REGION WILL ESSENTIALLY REMOVE REMAINING

CONVECTIVE INHIBITION AND LEAD TO AN INCREASING CHANCE FOR STORM

DEVELOPMENT NEAR THE RESIDUAL BOUNDARY. DESPITE REACTIVELY WEAK

MID-LEVEL FLOW AND EFFECTIVE SHEAR...BOUNDARY LAYER HEATING WILL

CONTRIBUTE TO A DEEP AND NEARLY DRY ADIABATIC SUB-CLOUD LAYER THAT

SHOULD SUPPORT STRONG TSTM DOWNDRAFTS CAPABLE OF PRODUCING WIND

DAMAGE. RANDOM STORM/OUTFLOW INTERACTIONS MAY FURTHER ENHANCE TSTM

ORGANIZATION AND PERSISTENCE INTO THE EVENING HOURS.



AVIATION...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 28015.





...CARBIN

