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000 

WWUS20 KWNS 032220

SEL1

SPC WW 032220

COZ000-040600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 221

NWS STORM PREDICTION CENTER NORMAN OK

415 PM MDT THU MAY 3 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST COLORADO



EFFECTIVE THIS THURSDAY AFTERNOON FROM 415 PM UNTIL MIDNIGHT 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 EAST AND WEST OF A LINE FROM 55 MILES NORTHEAST OF

FORT COLLINS COLORADO TO 30 MILES SOUTHEAST OF LIMON COLORADO.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 218...WW 219...WW 220...



DISCUSSION...TSTMS/POSSIBLE SUPERCELLS EXPECTED TO DEVELOP S/SE FROM

THE N CNTRL CO MOUNTAINS AS HEATING CONTINUES DOWNSTREAM FROM

NEGATIVELY TILTED ERN UT UPR TROUGH.  AMPLE DEEP SHEAR WILL BE

PRESENT FOR SUSTAINED SUPERCELLS.  PREDOMINANT STORM MODE...HOWEVER

...IS IN QUESTION ATTM GIVEN SURGE OF LOW LEVEL COOL AIR HEADING EWD

ACROSS THE N CNTRL PART OF THE STATE AND FAIRLY LARGE T/TD SPREADS.

PRIMARY SVR THREATS SHOULD BE HAIL/LOCALLY DAMAGING WIND...ALTHOUGH

POTENTIAL WILL EXIST FOR A TORNADO OR TWO WITH ANY MORE DISCRETE

STORMS.



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 24035.





...CORFIDI

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