Area Forecast Discussion
Issued by NWS Cheyenne, WY

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000
FXUS65 KCYS 271806
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1106 AM MST FRI FEB 27 2015

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 330 AM MST FRI FEB 27 2015

RADAR IMAGERY SHOWS LIGHT SNOW HAS REALLY LET UP ACROSS LARAMIE
COUNTY WITH ONLY VERY LIGHT SNOW OR FLURRIES. CANCELLED THE WINTER
WEATHER ADVISORY A BIT EARLY WITH MINIMAL ADDITIONAL ACCUMULATION
EXPECTED. COLD WIND CHILLS HAVE BEEN OCCURRING OVER THE SOUTHERN
LARAMIE RANGE WITH VALUES IN THE -20 TO -25 RANGE. WITH NOT MUCH
CHANGE IN THE TEMPS OR WINDS THROUGH SUNRISE...SEE NO REASON THAT
WIND CHILLS WILL REACH WARNING CRITERIA(-30)...HOWEVER WILL CONTINUE
TO MONITOR. SOUTHERLY WINDS WILL PERSIST THROUGH THE AFTN ACROSS
THE PLAINS WITH LOW LEVEL UPSLOPE ALONG THE CHEYENNE RIDGE. ALL
MODELS SHOW LOW CLOUDS BEING QUITE PERSISTENT ALONG THE CHEYENNE
RIDGE AND INTO THE SOUTHERN PANHANDLE THROUGH THE EARLY AFTN WHICH
WILL KEEP TEMPS FROM WARMING TOO MUCH COMPARED TO YESTERDAY. OTHER
AREAS WHERE CLEARING OCCURS WILL WARM 5-10 DEGREES...BUT THAT
STILL PUTS US AROUND 20 DEGREES BELOW NORMAL FOR LATE FEB. PRETTY
QUIET WEATHER FROM THIS EVENING THROUGH MIDDAY SATURDAY. WINDS
WILL BE WEAK AND RADIATIONAL COOLING WILL BE BETTER TONIGHT WITH
LESS LOW CLOUDS PRESENT...SO LOWS WILL ONCE AGAIN FALL INTO THE
SINGLE DIGITS.

ANOTHER LIGHT SNOW EVENT APPEARS POSSIBLE FROM MAINLY SAT AFTN
THROUGH SAT NIGHT. THE 00Z EURO HOWEVER CONTINUES TO BE THE OUTLIER
IN SHOWING ALMOST ALL THE QPF TO THE SOUTH OF THE COLORADO BORDER.
THE NAM HAS COME MORE IN LINE WITH THE CONSISTENTLY WETTER GFS...
SHOWING WIDESPREAD 0.1-0.2 INCHES OVER MUCH OF THE CWA. WITH LOW
LEVEL UPSLOPE AND ISENTROPIC LIFT BEING THE PRIMARY FORCING
MECHANISMS... STILL BELIEVE THAT MOST LOCATIONS WILL ONLY PICK UP
A FEW INCHES AND BEING LARGELY SUB-ADVISORY. WITH WINDS LARGELY
REMAINING BELOW 15 KTS...AREAS OF BLOWING SNOW WILL NOT BE A
CONCERN. PRECIP COMES TO AN END BY LATE SUN MORNING WITH ANOTHER
CHILLY DAY IN STORE.

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 AM MST FRI FEB 27 2015

00Z MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT PORTRAYING A SPLIT
FLOW ALOFT WITH A MORE PROGRESSIVE NORTHERN STREAM AND SLOWER
SOUTHERN STREAM. WEST-SOUTHWEST FLOW ALOFT AHEAD OF CA/NV TROUGH
WILL ADVECT ABUNDANT PACIFIC MOISTURE ACROSS THE FOUR CORNERS AND
CENTRAL ROCKIES EARLY NEXT WEEK. POTENT NORTHERN STREAM SHORTWAVE
MOVING ACROSS THE NORTHERN ROCKIES WILL PROPEL A ARCTIC COLD FRONT
SOUTHEAST ACROSS THE CWA BY TUESDAY MORNING. PRIOR TO THE FROPA...
A SURFACE LOW OVER THE FOUR CORNERS TRACKS NORTHEAST TO EAST
THROUGH SOUTHERN COLORADO AND KANSAS. POST-FRONTAL UPSLOPE NORTHEAST
LOW LEVEL FLOW...Q-G LIFT FROM RIGHT REAR QUAD OF UPPER JET AND
OVERRUNNING MOISTURE ACROSS A SHALLOW COLD AIR MASS WILL SET THE
STAGE FOR WIDESPREAD ACCUMULATING SNOW TUESDAY. GUSTY NORTH-NORTHEAST
WINDS WILL CREATE AREAS OF BLOWING/DRIFTING SNOW. IT`S EARLY TO
FORECAST SNOW AMOUNTS...BUT THIS SYSTEM WILL BE PROGRESSIVE WITH
SNOW TAPERING OFF FROM NORTHWEST TO SOUTHEAST TUESDAY NIGHT AS
COLD HIGH PRESSURE BUILDS ACROSS THE REGION. TEMPERATURES WILL BE
MILDER AHEAD OF THE FRONT MONDAY BUT AT LEAST 1O DEGREES BELOW
NORMAL. MUCH COLDER TEMPERATURES RETURN TUESDAY AND LAST THROUGH
MIDWEEK WITH HIGHS IN THE TEENS AND LOWS FROM 10 BELOW TO 10 ABOVE
ZERO. IN THE WAKE OF THE MIDWEEK SYSTEM...FLOW ALOFT BACKS FROM
NORTH- NORTHWEST TO MORE ZONAL THURSDAY. WESTERLY 700MB WINDS
PICK UP TO 40 KT THURSDAY RESULTING IN GUSTY DOWNSLOPE WINDS LEE
OF THE FRONT RANGE PUSHING THE MERCURY INTO THE 30S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1106 AM MST FRI FEB 27 2015

A CHALLENGING AVIATION PERIOD SHAPING UP WITH ONGOING IFR
CIGS/VSBYS AT KCYS AND KSNY LIKELY IMPROVING BACK TO MVFR BY
19-21Z. OTHERWISE SHOULD SEE GENERALLY VFR CONDITIONS ELSEWHERE.
THE ONE TRICKY SPOT WILL BE AT KBFF WHERE CIGS WILL LIKELY BOUNCE
MVFR/VFR THRU THE AFTERNOON. WILL SEE MVFR CIGS RETURN TO
KCYS AND WRN NEBRASKA TERMINALS 00-03Z AS SOUTH/SOUTHEAST WINDS
PERSIST. WINDS WILL TURN TO WESTERLY AT KCYS BY AROUND 08Z WHICH
SHOULD ERODE LOWER CLOUDS BACK TO A VFR BKN060 LAYER. COLD FRONT
WILL BEGIN TO PUSH FROM NORTH TO SOUTH 15-18Z SATURDAY...WHICH
WILL LEAD TO ONCE AGAIN DETERIORATING CONDITIONS AND -SN CHANCES
RETURNING JUST BEYOND THE PERIOD SATURDAY AFTERNOON AND EVENING.

&&

.FIRE WEATHER...
ISSUED AT 245 AM MST FRI FEB 27 2015

NO FIRE WEATHER CONCERNS OVER THE NEXT WEEK. TEMPERATURES WILL
CONTINUE TO REMAIN BELOW NORMAL. WIDESPREAD LIGHT SNOW COULD FALL
SATURDAY AFTERNOON THROUGH THE NIGHT...ESPECIALLY FOR AREAS ALONG
THE COLORADO BORDER.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

SHORT TERM...FINCH
LONG TERM...JAMSKI
AVIATION...CAH
FIRE WEATHER...FINCH



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