SPC Severe Thunderstorm Watch 574

WW 574 SEVERE TSTM OK TX 130020Z – 130600Z


URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 574
NWS STORM PREDICTION CENTER NORMAN OK
720 PM CDT SUN AUG 12 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

       EASTERN OKLAHOMA
       NORTHEAST TEXAS

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 720 PM UNTIL
100 AM CDT.

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 40
STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES WEST
NORTHWEST OF POTEAU OKLAHOMA TO 50 MILES SOUTH SOUTHEAST OF PARIS
TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

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 573...

DISCUSSION...TSTMS FORMING ALONG WSW-ENE PRE-FRONTAL CONFLUENCE LINE
NOW NEAR DURANT OK MAY MOVE/DEVELOP E INTO ADJACENT PARTS OF SE OK
AND POSSIBLY NE TX LATER THIS EVE. WHILE LARGE SCALE FORCING FOR
ASCENT WILL REMAIN WEAK...WEAK CONFLUENCE WILL PERSIST WITHIN FAIRLY
MOIST AND UNSTABLE LOW LVL ENVIRONMENT BENEATH 20-25 KT NWLY MID LVL
FLOW.  THIS SETUP MAY FOSTER A FEW DISCRETE STORMS CAPABLE OF DMGG
WIND AND LARGE HAIL.
FARTHER N...ADDITIONAL ISOLD TO PERHAPS WDLY SCTD STORMS MAY FORM
LATER THIS EVE NEAR COLD FRONT AND PREFRONTAL CONFLUENCE LINE IN NE
OK/FAR SE KS...AND/OR ALONG WEAK WARM FRONT IN NW AR/SW MO. LOW
CONFIDENCE IN THIS SCENARIO SUGGESTS THAT A WW IS UNWARRANTED ATTM
...DESPITE PRESENCE OF AMPLE INSTABILITY/SHEAR FOR SVR STORMS.

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 550. MEAN STORM
MOTION VECTOR 30020.


...CORFIDI

via SPC Forecast Products http://www.spc.noaa.gov/products/watch/ww0574.html