

947 

WWUS20 KWNS 172232

SEL9

SPC WW 172232

NMZ000-TXZ000-180500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 599

NWS STORM PREDICTION CENTER NORMAN OK

430 PM MDT FRI JUL 17 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EAST CENTRAL AND SOUTHEAST NEW MEXICO

       WEST TEXAS



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 430 PM UNTIL

1100 PM MDT.



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 75

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 70 MILES EAST OF

LUBBOCK TEXAS TO 40 MILES WEST OF ROSWELL NEW MEXICO.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU9).



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 594...WW 595...WW

596...WW 597...WW 598...



DISCUSSION...STRONG/SEVERE THUNDERSTORMS ARE CONTINUING TO DEVELOP

AND SPREAD SWD OVER PARTS OF ERN NM AND THE TX PANHANDLE.

CONVECTION IS FORMING WITHIN AN ENVIRONMENT CHARACTERIZED BY A DEEP

MIXED LAYER...STEEP LAPSE RATES...AND SUFFICIENT

MOISTURE/INSTABILITY TO PRODUCE LARGE HAIL AND DAMAGING WIND GUSTS.

IF A SUFFICIENTLY LARGE COOL POOL CAN BE GENERATED BY CURRENT

ACTIVITY...THE STORMS MAY GROW UPSCALE INTO A SWD PROPAGATING SEVERE

MCS THROUGH THE EVENING GIVEN FAVORABLE NORTHERLY COMPONENT TO THE

MID/UPPER LEVEL WINDS.



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 500. MEAN STORM

MOTION VECTOR 35020.





...WEISS

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