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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 487

NWS STORM PREDICTION CENTER NORMAN OK

325 PM CDT THU AUG 8 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  WESTERN OKLAHOMA

  NORTHWEST TEXAS



* EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 325 PM UNTIL

  1000 PM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    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 110

STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH

NORTHEAST OF BORGER TEXAS TO 90 MILES SOUTH SOUTHEAST OF LUBBOCK

TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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.



&&



DISCUSSION...CONVECTIVE DEVELOPMENT IS UNDERWAY WITHIN AN AXIS OF

STRONG SURFACE HEATING ACROSS THE TEXAS SOUTH PLAINS.  THIS ACTIVITY

IS EXPECTED TO INTENSIFY FURTHER DURING THE NEXT FEW HOURS...WITH

ADDITIONAL STORMS FORMING NEAR A WEAK SURFACE LOW...NOW NORTHWEST OF

LUBBOCK.  AS A LOW AMPLITUDE IMPULSE CONTINUES TO MIGRATE AROUND THE

NORTHWESTERN PERIPHERY OF SUBTROPICAL RIDGING...INTO THE SOUTH

CENTRAL HIGH PLAINS LATE THIS AFTERNOON...MODESTLY STRONG CYCLONIC

MID-LEVEL FLOW IS EXPECTED TO CONTRIBUTE TO SUFFICIENT SHEAR FOR

SUPERCELL STRUCTURES.  EVENTUALLY...STORMS PROBABLY WILL CONSOLIDATE

AND EVOLVE INTO AN ORGANIZED MESOSCALE CONVECTIVE

SYSTEM...ACCOMPANIED BY STRONG DOWNBURSTS AND A STRENGTHENING COLD

POOL...WHICH SHOULD ADVANCE EASTWARD INTO PARTS OF WESTERN OKLAHOMA

AND THE REMAINDER OF NORTHWEST TEXAS.



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 27025.





...KERR

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