Issued by NWS Cheyenne, WY
000 FXUS65 KCYS 110922 AFDCYS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 322 AM MDT MON MAY 11 2009 ..SHORT TERM...TODAY THROUGH TUESDAY NIGHT... AREAS OF FOG WILL CONTINUE THROUGH AROUND 800 AM MDT THIS MORNING NEAR THE LARAMIE RANGE AND TO THE EAST ACROSS THE SOUTHERN NEBRASKA PANHANDLE. GUSTY SOUTH WINDS WILL DEVELOP IN THE NEBRASKA PANHANDLE TODAY AHEAD OF A SURFACE TROUGH MOVING EAST ACROSS THE AREA. ALTHOUGH LOW-LEVEL MOISTURE WILL BE QUITE LIMITED...ENOUGH MID-LEVEL INSTABILITY FROM THE UPPER LEVEL DISTURBANCE OVERHEAD WILL SUPPORT ISOLATED DRY THUNDERSTORMS LATE THIS AFTERNOON AND INTO THE EVENING HOURS. WEST-SOUTHWEST WINDS WILL ALSO BECOME STRONG AND GUSTY IN THE WESTERN PORTION OF THE AREA TODAY. MUCH WARMER TEMPERATURES ARE EXPECTED AND WILL RESULT IN RELATIVE HUMIDITIES DROPPING INTO THE LOWER TEENS ACROSS MOST OF THE LOWER ELEVATIONS OF CARBON COUNTY. ALTHOUGH THESE WINDS AND HUMIDITY VALUES WOULD NORMALLY INDICATE CRITICAL FIRE WEATHER CONDITIONS...FIRE MANAGERS IN THE AREA CONTINUE TO INDICATE THAT THE FUELS ARE NOT FAVORABLE FOR LARGE FIRE GROWTH AT THIS TIME...SO NO FIRE WEATHER HIGHLIGHTS ARE ANTICIPATED FOR TODAY. THE NEXT STRONGER UPPER LEVEL DISTURBANCE WILL QUICKLY MOVE INTO THE PACIFIC NORTHWEST MONDAY NIGHT...AND RESULT IN SURFACE PRESSURE FALLS AND CYCLOGENESIS ACROSS THE CENTRAL ROCKIES. THIS SET-UP WILL LEAD TO ANOTHER DAY OF GUSTY SOUTH WINDS ACROSS THE PANHANDLE...AND GUSTY WEST-SOUTHWEST FLOW ACROSS SOUTHEAST WYOMING. THE WARMING TREND WILL ALSO CONTINUE WITH AFTERNOON HIGH TEMPERATURES GENERALLY AROUND 15 TO 20 DEGREES ABOVE NORMAL. ALTHOUGH SURFACE CONVERGENCE WILL BE PRESENT...THE BEST MOISTURE AVAILABLE WILL BE OVER THE NEBRASKA PANHANDLE AND THE BEST SHEAR WILL BE ACROSS NORTHEAST WYOMING. WILL KEEP A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS THE EASTERN PART OF THE FORECAST AREA AHEAD OF THE COLD FRONTAL PASSAGE DURING THE EVENING. AT THIS TIME THE COLD FRONT WILL MOVE INTO THE NORTHERN PART OF THE AREA DURING THE LATE AFTERNOON HOURS AND OUT OF THE AREA BY AROUND 300 AM MDT WEDNESDAY MORNING. .LONG TERM...WEDNESDAY THROUGH SUNDAY... BREEZY AND MUCH COOLER WEATHER ON TAP FOR WEDNESDAY AS SURFACE HIGH BUILDS INTO THE AREA BEHIND UPPER TROF WHICH WILL BE MOVING INTO THE NORTHERN AND CENTRAL PLAINS. SOME REBOUND IN TEMPERATURES FOR THURSDAY AS A SHORT FLAT RIDGE TRANSLATES ACROSS THE AREA THEN NEXT UPPER TROF WILL ZIP ACROSS ON FRIDAY WITH A LITTLE BETTER CHANCE FOR SOME PCPN TO ACCOMPANY IT BUT RATHER DRY AIRMASS WILL LIMIT OVERALL COVERAGE. MAINLY DRY AND MILD CONDITIONS THEN SET UP FOR THE WEEKEND AS GENERAL NWLY UPPER FLOW DEVELOPS DOWNWIND OF UPPER RIDGING WHICH SHOULD BUILD OVER THE WESTERN CONUS. && .AVIATION... AREAS OF LIFR CEILINGS WILL CONTINUE TO BE OBSERVED SOUTH OF A LINE FROM NEAR KCDR TO KBRX THROUGH AROUND 800 AM MDT. VFR WILL THEN PREVAIL AND GUSTY SOUTH WINDS WILL DEVELOP ACROSS THE NEBRASKA PANHANDLE TODAY. GUSTY WEST-SOUTHWEST WINDS WILL ALSO DEVELOP ACROSS THE WESTERN PORTION OF THE AREA. ISOLATED DRY THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND EARLY THIS EVENING EAST OF THE LARAMIE RANGE...WITH ERRATIC AND GUSTY WINDS POSSIBLE NEAR AREAS OF VIRGA BENEATH ANY THUNDERSTORM ACTIVITY. && .FIRE WEATHER... VERY DRY CONDITIONS AND GUSTY WINDS WILL BE PRESENT IN WYZ293 TODAY AS WEST-SOUTHWEST WINDS WILL ACCOMPANY A SIGNIFICANT WARM-UP FROM CONDITIONS EXPERIENCED ON SUNDAY. FIRE MANAGERS CONTINUE TO INDICATE FUELS IN THIS AREA ARE NOT FAVORABLE FOR LARGE FIRE GROWTH...SO NO FIRE WEATHER HIGHLIGHTS ARE ANTICIPATED FOR THIS AFTERNOON. ISOLATED DRY THUNDERSTORMS CONTINUE TO APPEAR POSSIBLE EAST OF THE LARAMIE RANGE THIS AFTERNOON AND EARLY EVENING. GUSTY SOUTH WINDS WILL ALSO DEVELOP TODAY AND CONTINUE INTO THE EVENING HOURS IN THE NEBRASKA PANHANDLE...BUT THESE WINDS WILL INCREASE LOW-LEVEL MOISTURE IN THESE AREAS AND RESULTING RELATIVE HUMIDITY VALUES SHOULD REMAIN ABOVE CRITICAL VALUES. WILL ADD HEADLINES MENTIONING THESE CONDITIONS TO THE MORNING ISSUANCE OF THE FIRE WEATHER FORECAST. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM/AVIATION...CARPENTER LONG TERM...RE
