SEL9
   
   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 499
   NWS STORM PREDICTION CENTER NORMAN OK
   115 PM MDT SUN JUN 20 2004
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          EASTERN COLORADO
   
   EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 115 PM UNTIL 800
   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 ALONG AND 80 STATUTE MILES
   EAST AND WEST OF A LINE FROM 55 MILES NORTH NORTHWEST OF AKRON
   COLORADO TO 45 MILES EAST SOUTHEAST OF TRINIDAD COLORADO.
   
   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...SCATTERED SEVERE STORMS WILL DEVELOP THIS AFTERNOON
   ALONG THE CO FRONT RANGE...WITH THE MOST FOCUSED/INITIAL DEVELOPMENT
   EXPECTED WHERE AN E-W ORIENTED OUTFLOW BOUNDARY INTERSECTS THE FRONT
   RANGE N OF COLORADO SPRINGS.  THE LOW LEVELS CONTINUE TO DESTABILIZE
   ACROSS ERN CO...WITH MLCAPE VALUES EXPECTED TO INCREASE TO 1500-2000
   J/KG BY LATE AFTERNOON AS SURFACE TEMPERATURES WARM INTO THE MID 70S
   WITH DEWPOINTS IN THE UPPER 50S.  THE COMBINATION OF MODERATE
   INSTABILITY AND 0-6 KM SHEAR OF 30-40 KT WILL SUPPORT
   SUPERCELLS...WITH LARGE HAIL THE PRIMARY THREAT FOR THE NEXT FEW
   HOURS. LATER THIS EVENING AS CONVECTION BECOMES MORE
   WIDESPREAD...THE THREAT FOR A FEW DAMAGING GUSTS WILL INCREASE
   ACROSS ERN CO. THOUGH THE LOW-LEVEL SHEAR IS NOT PARTICULARLY
   STRONG...AN ISOLATED TORNADO MAY OCCUR INVOF THE E-W OUTFLOW
   BOUNDARY.
   
   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 29020.
   
   
   ...THOMPSON