WATCHES: Severe Thunderstorm Watch Number 681

WWUS20 KWNS 142036
SEL1
SPC WW 142036
OKZ000-TXZ000-150200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 681
NWS STORM PREDICTION CENTER NORMAN OK
230 PM CST FRI DEC 14 2012

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

FAR WESTERN OKLAHOMA
THE TEXAS PANHANDLE AND TEXAS SOUTH PLAINS

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 800
PM CST.

HAIL TO 0.5 INCH 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 90
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 75 MILES WEST OF
PLAINVIEW TEXAS TO 65 MILES NORTHEAST OF CHILDRESS TEXAS. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU1).

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...A LINE OF FORCED...LOW-TOPPED STORMS HAS FORMED ALONG
PACIFIC COLD FRONT OVER FAR ERN NM...AHEAD OF POTENT SHORTWAVE
TROUGH ACCELERATING ENE ACROSS THE FOUR CORNERS REGION. CLEARANCE OF
MID/UPR LVL CLOUD COVER HAS ALLOWED LOW-LVL LAPSE RATES TO
SUFFICIENTLY STEEPEN ALONG A WIDE ENOUGH SWATH TO SUGGEST THAT
CONVECTIVE BAND MAY FURTHER INTENSIFY AS IT CONTINUES RAPIDLY ENE
INTO W TX. IN FURTHER SUPPORT OF STORM STRENGTHENING IS THE NEARLY
SIMULTANEOUS ARRIVAL OF STRONGER DCVA/MID LVL COLD ADVECTION
ASSOCIATED WITH LEADING EDGE OF UPR TROUGH.
GIVEN 40-50 KT MEAN LWR TROPOSPHERIC FLOW AHEAD OF FRONT...AND SOME
STRENGTHENING OF MEAN FLOW EXPECTED ACROSS AREA THROUGH EARLY
EVE...SETUP APPEARS TO SUPPORT AN APPRECIABLE ENOUGH RISK FOR SVR
WIND GUSTS TO WARRANT WW ISSUANCE. THE SVR THREAT SHOULD DIMINISH
LATER THIS EVE AS THE CONVECTIVE LINE MOVES BEYOND REGION OF
GREATEST DIURNAL HEATING...ALTHOUGH STORMS MAY REMAIN ACTIVE NEWD
INTO PARTS OF ERN OK/KS LATER TNGT.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 350. MEAN STORM
MOTION VECTOR 24045.


...CORFIDI

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.