

498 

WWUS20 KWNS 281958

SEL4

SPC WW 281958

KSZ000-OKZ000-TXZ000-290300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 234

NWS STORM PREDICTION CENTER NORMAN OK

255 PM CDT TUE MAY 28 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  SOUTHWEST KANSAS

  NORTHWEST OKLAHOMA INCLUDING THE PANHANDLE

  WEST TEXAS INCLUDING THE PANHANDLE



* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 255 PM UNTIL

  1000 PM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL VERY LARGE HAIL EVENTS TO 2.5 INCHES IN DIAMETER

    POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A FEW TORNADOES POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 80 MILES WEST

SOUTHWEST OF AMARILLO TEXAS TO 30 MILES NORTH NORTHEAST OF

MEDICINE LODGE KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 233...



DISCUSSION...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND

INTENSITY THIS AFTERNOON ALONG RETREATING DRYLINE IN RESPONSE TO

STRENGTHENING LARGE-SCALE FORCING ATTENDANT TO A SHORT-WAVE TROUGH

MOVING INTO THE HIGH PLAINS.  THE 18Z AMA SOUNDING SHOWED THE

PRESENCE OF VERY STEEP LAPSE RATES AND INCREASING LOW-LEVEL

MOISTURE...YIELDING A MODERATELY UNSTABLE AIR MASS.  WHEN COUPLED

WITH A VERTICALLY VEERING WIND PROFILE WITH 35-45 KT OF DEEP-LAYER

SHEAR...THE SETUP WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF VERY

LARGE HAIL AND DAMAGING WINDS.  INITIALLY...TORNADO POTENTIAL WILL

BE LIMITED BY THE HIGH LCL ENVIRONMENT.  THIS THREAT COULD INCREASE

THIS EVENING AS LOW-LEVEL MOISTURE CONTINUES TO INCREASE AND

LOW-LEVEL SHEAR STRENGTHENS...AND AN UPGRADE TO TORNADO MAY BECOME

NECESSARY.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 26020.





...MEAD

