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000
FXUS65 KCYS 061825
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1125 AM MST THU MAR 6 2014

.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 540 AM MST THU MAR 6 2014

WINDS IN THE WIND PRONE AREAS OUT WEST HAVE STEADILY BEEN
INCREASING OVERNIGHT AS THE LEESIDE PRESSURE TROUGH DEEPENS
IN ADVANCE OF THE SHORTWAVE MOVING ACROSS THE PAC NW. SUSTAINED
WINDS HAVE BEEN AVERAGING 35 TO 45 MPH WITH A FEW GUSTS AROUND 60
MPH SO FAR. STARTED THE WARNING FOR THE SOUTHERN LARAMIE RANGE AND
FOOTHILLS SHORTLY AFTER 4 AM AS WINDS WERE ALREADY FLIRTING WITH
HIGH WIND CRITERIA. OTHERWISE...WILL MAINTAIN THE WARNING AS IS
FOR NOW...ALTHOUGH DO THINK THERE IS A GOOD POSSIBILITY THE DAY
SHIFT WILL BE ABLE TO CANCEL IT EARLY AS THE GRADIENT WILL SLACKEN
EARLY THIS AFTERNOON. SHORTWAVE RIDGING WILL MOVE OVERHEAD TODAY IN
ADVANCE OF THE SHORTWAVE TROUGH...WITH 700 MB TEMPS EXPECTED TO BE
BETWEEN 0 AND 3 C. THESE WARM TEMPS ALOFT COMBINED WITH DOWNSLOPE
WARMING WILL BRING WIDESPREAD 40S AND 50S FOR HIGHS OUT
WEST...WITH 50S AND 60S ACROSS THE EASTERN PLAINS TODAY.

THE UPPER TROUGH WILL MOVE OVER THE FORECAST AREA BEGINNING FRIDAY
MORNING WITH MOIST SOUTHWEST FLOW MOVING OVERHEAD LATE THIS
AFTERNOON AND EVENING AHEAD OF THE TROUGH AXIS. A PRE-TROUGH
SHORTWAVE EMBEDDED IN THIS FLOW WILL MOVE ACROSS THE AREA THROUGH
THIS TIME WITH RAIN AND HIGH ELEVATION SNOW DEVELOPING IN THE
MOUNTAINS AND NEARBY VALLEYS. THE ASSOCIATED PACIFIC COLD FRONT WILL
THEN BEGIN TO SHIFT SOUTH ACROSS FORECAST AREA LATE THIS EVENING
AND LOOKS TO BE WELL THROUGH THE EASTERN PLAINS BY SUNRISE FRIDAY.
SHOULD SEE THE FRONT PUSH THROUGH THE MOUNTAINS BY FRIDAY
AFTERNOON AS WELL. FOR THIS EVENING...THE DIFFLUENT RIGHT ENTRANCE
REGION OF THE UPPER JET WILL OVERRIDE THE SFC BOUNDARY WHICH WILL
INCREASE CHANCES FOR RAIN AND SNOW WITHIN NORTHERN ZONES THIS
EVENING. WILL LIKELY BE MOSTLY RAIN IN THE EVENING WITH A
CHANGEOVER TO SNOW EXPECTED JUST BEFORE MIDNIGHT WHEN CAA
STRENGTHENS BEHIND THE EVER PROGRESSIVE SOUTHWARD MOVING FRONT.
NORTH TO NORTHEAST SFC WINDS SETTING UP BEHIND THE FRONT WILL
INCREASE CHANCES FOR SNOW OVERNIGHT ACROSS SOUTHERN PORTIONS OF
THE CWA AS WELL...ESPECIALLY AS MID AND UPPER LEVEL ENERGY MOVES
OVERHEAD AHEAD OF THE TROUGH AXIS. HOWEVER...THE STRONGEST ENERGY
WILL BE WELL SOUTH INTO COLORADO SO ANTICIPATING A DECENT
COVERAGE OF ONLY LIGHT TO MODERATE SNOW AT TIMES THROUGH FRIDAY
MORNING. EXPECTING ABOUT 4 TO 6 INCHES OF ACCUMULATION IN THE
SNOWY AND SIERRA MADRES...AN INCH OR 2 IN THE LARAMIE RANGE...AND
LESS IN THE LOWER ELEVATIONS. TEMPS FOR FRIDAY WILL BE COOLER AND
WINDS WILL BE RELATIVELY WEAK AND OUT OF A NORTHERLY COMPONENT IN
THE POST FRONTAL ENVIRONMENT. DRIER AIR AND SUBSIDENCE WILL THEN
MOVE IN ON THE BACKSIDE OF THE TROUGH FRIDAY NIGHT WHICH WILL
BRING PRECIP TO AN END FROM NORTH TO SOUTH.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 540 AM MST THU MAR 6 2014

SATURDAY WILL START OFF WITH A RIDGE BUILDING ACROSS THE ROCKIES.
SKIES SHOULD BE CLEAR OR AT LEAST CLEARING FROM WEST TO EAST
SATURDAY MORNING. WITH MOSTLY SUNNY SKIES AND WESTERLY DOWNSLOPE
WIND DEVELOPING WENT ABOVE GUIDANCE ON HIGH TEMPERATURES SATURDAY.
NOT QUITE AS CONFIDENT NEAR THE COLORADO BORDER WHERE IT MAKE TAKE
A BIT OF ENERGY TO MELT SNOW WHICH COULD BE IN PLACE...BUT GIVEN
THE TIME OF YEAR AND ONLY LIGHT AMOUNTS OF SNOW EXPECTED...IT WILL
BE A NICE MILD DAY NONE THE LESS.

UPPER RIDGE TO FOLD OVER SUNDAY BUT HEIGHTS WILL REMAIN NEARLY
STEADY STATE. WESTERLY FLOW WILL STRENGTHEN WHILE THE LOWER
LEVELS OF THE ATMOSPHERE CONTINUE TO WARM AHEAD OF A PUSH OF
COOLER AIR MONDAY. CLEAR SKIES AND DOWNSLOPE WESTERLY FLOW WILL
REMAIN...SO SHOULD WARM UP NICELY. IN FACT IT SHOULD BE THE
WARMEST DAY OF THE YEAR SO FAR FOR MOST OF THE FORECAST AREA...AND
WOULD NOT BE SURPRISED TO SEE SOME MID 70S INTO THE NEBRASKA
PANHANDLE SHOULD THE GFS VERIFY.

INCREASING CLOUDS FOR MONDAY AS THE RIDGE FLATTENS WITH ZONAL FLOW
TAKING OVER. DEPENDING ON TIMING...MONDAY COULD STILL BE A RATHER
WARM DAY. FOR NOW KEPT TEMPERATURES NEAR GUIDANCE...BUT LOW
TEMPERATURES THAT MORNING SHOULD BE ON THE WARM SIDE. INCREASING
CHANCES FOR PRECIPITATION FROM WEST TO EAST LATE MONDAY AFTERNOON
INTO MONDAY NIGHT AS A SHORTWAVE APPROACHES. THE BIG QUESTION IS
HOW THIS SYSTEM EVOLVES TUESDAY AND WEDNESDAY. ECMWF AND GFS
SHOWING BIG DIFFERENCES WITH THE ECMWF WETTER WITH WIDESPREAD
PRECIPITATION LATE MONDAY NIGHT THROUGH TUESDAY MORNING. WILL HAVE
TO WATCH TO SEE HOW THE MODELS HANDLE THIS SYSTEM BUT EITHER WAY
IT WILL BE ON THE COOL SIDE TUESDAY WITH AT LEAST A FEW SHOWERS
AROUND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1052 AM MST THU MAR 6 2014

WYOMING TAFS...VFR THROUGH 00Z WITH STRONG WEST WINDS GUSTING TO
35 KNOTS...WITH MOUNTAIN WAVE TURBULENCE...LEE EDDY EFFECTS AND
ROTOR CLOUD DEVELOPMENT. AFTER 00Z...CEILINGS AND VISIBILITIES
GRADUALLY DECREASING WITH IFR AND MVFR DEVELOPING IN SNOW AND FOG...
ESPECIALLY AFTER 12Z. MOUNTAINS BECOMING OBSCURED TONIGHT AND
FRIDAY.

NEBRASKA TAFS...VFR WITH SCATTERED TO BROKEN CLOUDS AT 0R ABOVE
10000 FEET AGL THROUGH 00Z...THEN CEILINGS LOWERING OVERNIGHT
WITH IFR VISIBILITIES DEVELOPING IN RAIN...FOG AND LOW CLOUDS AFTER
09Z.

&&

.FIRE WEATHER...
ISSUED AT 540 AM MST THU MAR 6 2014

ACTIVE WEATHER PATTERN REMAINS IN PLACE. ANOTHER SHOT OF
PRECIPITATION TONIGHT INTO FRIDAY MAINLY FOR THE MOUNTAINS AND NEAR
THE COLORADO BORDER. MOST PRECIPITATION WILL FALL AS SNOW BUT NOT
EXPECTING MORE THAN A FEW INCHES FOR MOST PLACES. DRY AND WARMER
INTO THE WEEKEND WITH WIDESPREAD 50S AND 60S FOR HIGHS SUNDAY WITH
A FEW 70S POSSIBLE INTO THE NEBRASKA PANHANDLE. BREEZY TO WINDY
BOTH SATURDAY AND SUNDAY ACROSS THE AREA. ANOTHER SHOT OF RAIN AND
SNOW FOR THE MONDAY NIGHT THROUGH TUESDAY NIGHT TIME FRAME.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ106-110-
     116-117.

NE...NONE.
&&

$$

SHORT TERM...RJM
LONG TERM...SML
AVIATION...RUBIN
FIRE WEATHER...SML