FXUS65 KCYS 262011
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
111 PM MST THU NOV 26 2009
.SHORT TERM...TONIGHT THROUGH SATURDAY...
HAPPY THANKSGIVING!
A BEAUTIFUL THANKSGIVING DAY WAS IN STORE FOR THE CWA WITH ONLY
SOME HIGH CLOUDS MOVING OVERHEAD FROM THE NORTHWEST. TEMPS ARE
BREACHING THE 60 DEGREE MARK IN THE SOUTHERN NEBRASKA PANHANDLE
WITH 40S AND 50S ELSEWHERE. WEST TO SOUTHWEST WINDS WERE QUITE
BREEZY IN THE VICINITY AND WEST OF THE LARAMIE RANGE WITH
TYPICALLY WINDY LOCALES NEAR BORDEAUX...ARLINGTON AND THE SOUTHERN
LARAMIE FOOTHILLS GUSTING TO 45 MPH AT TIMES. UPPER RIDGE WILL
CONTINUE TO MOVE OVER THE REGION TONIGHT WHICH WILL PUSH THE
CLOUDS FURTHER TO THE EAST AND STRENGTHEN THE SFC HIGH OVER THE
INTERMOUNTAIN WEST. A UPPER LEVEL TROUGH MOVING INTO THE PACIFIC
NORTHWEST WILL ENHANCE BROAD SCALE PRESSURE FALLS OVER THE PLAINS
TONIGHT. THIS WILL EFFECTIVELY TIGHTEN THE LOW LEVEL PRESSURE
GRADIENT ACROSS THE MOUNTAINS SO WILL SEE GUSTY WINDS INCREASE IN
COVERAGE FOR TOMORROW. EXPECT TEMPS TO INCREASE A DEGREE OR TWO AS
RIDGE MOVES ACROSS THE AREA COMBINED WITH WARM DOWNSLOPE WINDS.
WINDS WILL MAINTAIN THROUGH FRIDAY NIGHT AHEAD OF THE PACIFIC
FRONT WHICH WILL MOVE ACROSS THE CWA SATURDAY MORNING. TEMPS WILL
REMAIN ON THE COOL SIDE BEHIND THE FRONT...MODERATING ONLY
SLIGHTLY THROUGH THE AFTERNOON AS HIGH PRESSURE BUILDS AT THE
SURFACE. MODELS SHOW MOISTURE INCREASE THROUGH THE DAY AS THE MAIN
SYSTEM APPROACHES SO WILL SEE AN INCREASE IN SNOW POTENTIAL WITH
STRENGTHENING UPSLOPE FLOW BEHIND THE FRONT. MODELS SHOW FAIRLY
LIGHT QPF MOVING NORTH TO SOUTH THROUGH THE EVENING SO ANY SNOW
THAT ACCUMULATES WILL BE LITTLE...ESPECIALLY WITH THE GROUND BEING
FAIRLY WARM INITIALLY. WINDS WILL BE OUT OF THE NORTH FOR MUCH OF
THE DAY...LESS THAN PREVIOUS DAYS BUT STILL BREEZY.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
THE MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT WITH THE NORTHERN
PORTION OF THE SPLIT FLOW ALOFT BRINGING AN ENERGETIC DISTURBANCE
THROUGH THE AREA SATURDAY NIGHT. THIS FLOW PATTERN WILL LIKELY
RESULT IN WIDESPREAD SNOWFALL ESPECIALLY ALONG THE LARAMIE RANGE. IT
NOW APPEARS WIDESPREAD PRECIPITATION WILL MOVE OUT OF THE AREA BY
MIDDAY SUNDAY WITH JUST SOME OROGRAPHICALLY INDUCED MOUNTAIN SNOW
SHOWERS PERSISTING THROUGH THE AFTERNOON. THEN A DRY PERIOD WITH A
GRADUAL WARMING TREND INTO EARLY IN THE WEEK AFTER SUNDAY BEING THE
COLDEST DAY PRIOR TO A POTENTIAL COLD CANADIAN AIRMASS MOVING INTO
THE AREA WEDNESDAY AND THURSDAY. THE EUROPEAN MODEL REMAINS FAVORED
AND IS THE MUCH COOLER SOLUTION SO FORECAST TEMPERATURES ARE MUCH
COOLER THAN THE CURRENT GUIDANCE VALUES FROM THE GFS MODEL.
&&
.AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH FRIDAY NIGHT.
WESTERLY SURFACE WINDS WILL GUST 30 TO 40 KNOTS AT TIMES ALONG AND
WEST OF THE LARAMIE RANGE THROUGH EARLY SATURDAY.
&&
.FIRE WEATHER...RELATIVELY WARM AND DRY CONDITIONS WILL CONTINUE
THROUGH FRIDAY EVENING. MINIMUM RELATIVE HUMIDITIES WILL DIP INTO
THE UPPER TEENS AND LOW 20S TO THE EAST OF THE LARAMIE RANGE ON
FRIDAY...WITH UPPER 20S AND 30S IN THE HIGHER ELEVATIONS. WINDS WILL
AGAIN BE GUSTY DURING THIS TIME ALONG AND WEST OF THE LARAMIE RANGE
WITH GUSTS 35 TO 45 MPH EXPECTED THROUGH FRIDAY EVENING. RH RECOVERY
WILL BE GOOD TONIGHT AND FRIDAY NIGHT...AND A COLD FRONT WILL MOVE
THROUGH THE REGION SATURDAY MORNING BRINGING SNOW SHOWERS AND MUCH
COOLER TEMPERATURES THROUGH EARLY SUNDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/AVIATION...RJM
LONG TERM...CARPENTER
