

000 

WWUS20 KWNS 160009

SEL8

SPC WW 160009

TXZ000-160800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 398

NWS STORM PREDICTION CENTER NORMAN OK

705 PM CDT FRI JUN 15 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF WESTERN AND INTO CENTRAL TEXAS



EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 705 PM

UNTIL 300 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 90

STATUTE MILES EITHER SIDE OF A LINE FROM 45 MILES SOUTHWEST OF

FORT STOCKTON TEXAS TO 45 MILES EAST OF ABILENE TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU8).



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...CONVECTION HAS BEGUN TO INCREASE IN COVERAGE ACROSS THE

WW AREA...AS UPPER VORT MAX ROTATING SWD AROUND LARGER-SCALE SWRN OK

LOW APPROACHES.  STORMS SHOULD INCREASE INVOF THE LINGERING OUTFLOW

BOUNDARY ACROSS THIS AREA...AND LATER NEAR THE HIGHER TERRAIN OF

SERN NM AND W TX AS ESELY LOW-LEVEL JET AND ASSOCIATED UPSLOPE FLOW

COMPONENT INCREASE.

WITH MODERATE INSTABILITY IN PLACE...SOME INCREASE IN NWLY FLOW

ALOFT WITH THE APPROACH OF THE VORT MAX ABOVE LOW-LEVEL ELYS/SELYS

WILL YIELD SHEAR SUPPORTIVE OF SUPERCELLS.  LARGE HAIL SHOULD REMAIN

THE PRIMARY THREAT...THOUGH LOCALLY-DAMAGING WINDS WILL BE POSSIBLE

-- PARTICULARLY IF STORMS MERGE INTO A SSEWD-MOVING MCS LATER THIS

EVENING.



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 33020.





...GOSS

