Friday, April 13, 2012

TORNADO WATCH for OKLAHOMA and A SMALL PART OF NORTHWEST TEXAS

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

OKLAHOMA

A SMALL PART OF NORTHWEST TEXAS

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 900

PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES EAST AND WEST OF A LINE FROM 35 MILES WEST OF WICHITA FALLS
TEXAS TO 20 MILES NORTH NORTHWEST OF PONCA CITY OKLAHOMA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.

DISCUSSION...STORMS ARE BEGINNING TO DEVELOP OVER SWRN OK AS THE CAP

HAS WEAKENED WITHIN A STRONGLY UNSTABLE ENVIRONMENT WITH MLCAPE OF
2000-2500 J/KG. ALTHOUGH DYNAMIC FORCING FOR LARGE SCALE ASCENT IS
SUBTLE...NUMERICAL GUIDANCE INDICATES THAT STORMS WILL CONTINUE TO
DEVELOP TOWARD NRN OK THIS AFTERNOON...WITH CONVECTIVE POTENTIAL
ALSO INCREASING ALONG THE NWRN EDGE OF MOISTURE AS IT RETREATS NWWD
LATER THIS AFTERNOON AND EVENING. DEEP LAYER SHEAR OF 40 KT IN THE
LOWEST 6 KM WILL FAVOR FORMATION OF SUPERCELL STRUCTURES...WITH AN
INITIAL THREAT FOR LARGE HAIL AND STRONG WIND GUSTS. WITH
TIME...LOW LEVEL WINDS/SHEAR WILL STRENGTHEN WITH A SUBSEQUENT
INCREASE IN TORNADO POTENTIAL LATER THIS AFTERNOON AND EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 23025. Source