

650 

WWUS20 KWNS 181830

SEL9

SPC WW 181830

COZ000-NMZ000-190300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 709

NWS STORM PREDICTION CENTER NORMAN OK

1230 PM MDT TUE AUG 18 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EASTERN COLORADO

       NORTHEAST NEW MEXICO



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1230 PM UNTIL

900 PM MDT.



HAIL TO 2.5 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 60

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

NORTHWEST OF AKRON COLORADO TO 40 MILES WEST SOUTHWEST OF

TUCUMCARI 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.



DISCUSSION...THUNDERSTORMS WILL LIKELY INCREASE IN

COVERAGE/INTENSITY FROM THE FRONT RANGE EWD THROUGH THE

AFTERNOON...AS SURFACE HEATING COINCIDES WITH THE ARRIVAL OF A MID

LEVEL TROUGH FROM WRN/CENTRAL CO.  THE COMBINATION OF MODERATE

INSTABILITY AND 40-50 KT EFFECTIVE BULK SHEAR WILL SUPPORT

SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.  AN

ISOLATED TORNADO CANNOT BE RULED OUT ACROSS SE CO/NE NM WHERE

LOW-LEVEL MOISTURE IS GREATER AND THERE IS SOME POTENTIAL FOR

LOW-LEVEL FLOW TO BACK TO MORE ELY/SELY LATER THIS AFTERNOON.



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 28020.





...THOMPSON

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