695 
FXUS65 KCYS 181201
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
601 AM MDT TUE MAR 18 2014

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 445 AM MDT TUE MAR 18 2014

WATER VAPOR IMAGERY AND EVEN RADAR IMAGERY SHOWS THE DEEPENING LOW
AND MIDLEVEL CYCLONE ACROSS THE NEBRASKA PANHANDLE. THE 00Z MODEL
SUITE CONTINUED THE TREND FROM THE PREVIOUS DAY OF DROPPING THE
LOW CENTER SLIGHTLY FURTHER SOUTH. WIDESPREAD SNOW HAS DEVELOPED
IN THE NORTHWESTERN QUADRANT OF THE SYSTEM FROM LARAMIE NORTHEASTWARD
INTO THE NORTHERN NEBRASKA PANHANDLE. SOME OF THE HEAVIEST SNOW
HAS BEEN ACROSS CONVERSE AND NIOBRARA COUNTIES WHERE INFRARED
IMAGERY SHOWS THE COLDEST CLOUD TOPS. IT IS IN THIS AREA THAT THE
NAM AND GFS SHOW A PRONOUNCED TROWAL FEATURE. THE FACT THAT THIS
SYSTEM HAS DUG FURTHER SOUTH AND WEST MEANS THAT EVEN AREAS ALONG
AND WEST OF THE LARAMIE RANGE ARE EXPERIENCING GOOD SYNOPTIC SCALE
LIFT ON THE WESTERN EDGE OF THIS TROWAL. MODEL SNOWFALL AMOUNTS
NOW SHOW WIDESPREAD 2-5 INCHES THROUGH 18Z ALONG AND WEST OF THE
LARAMIE RANGE AND 2-4 INCHES ALONG INTERSTATE 80 STRETCHING INTO
THE SOUTHERN NEBRASKA PANHANDLE.  

THE OTHER STORY WITH THIS SYSTEM IS THE STRONG NORTHWEST WINDS ON
ITS BACKSIDE. DOUGLAS HAS GUSTED TO 58 MPH OVER THE PAST HOUR AND
THESE STRONG WINDS WILL SPREAD OVER THE REMAINDER OF THE PLAINS
THROUGH THE MORNING. 00Z MOS WINDSPEEDS AT CHEYENNE AND SYDNEY DID
COME DOWN ABOUT 5 KTS...HOWEVER SOUNDINGS STILL SUGGEST THAT GUSTS
TO 50-55 MPH WILL BE COMMON ESPECIALLY ACROSS THE SOUTHERN
PANHANDLE. SINCE SNOW AND BLOWING SNOW HAS EMERGED AS THE DOMINANT
THREAT WITH THIS RAPIDLY EVOLVING SYSTEM...DECIDED TO REPLACE THE
HIGH WIND WARNINGS WITH WINTER STORM HIGHLIGHTS. WENT WITH A
WINTER STORM WARNING ACROSS THE SOUTHERN PANHANDLE SINCE WINDS
WILL LIKELY BE THE STRONGEST HERE WITH SOUNDINGS SHOWING THE
POTENTIAL FOR 50-55 KT GUSTS. ISSUED WINTER WEATHER ADVISORIES FOR
AREAS ALONG INTERSTATE 80 IN SOUTHEAST WYOMING. WHILE SNOWFALL
RATES COULD BECOME MODERATE TO HEAVY AT TIMES THROUGH THIS
MORNING...THE FAST-MOVING NATURE OF THIS SYSTEM WILL LIMIT
SNOWFALL AMOUNTS TO AN EXTENT. SNOW WILL TAPER OFF BY EARLY THIS
AFTN. KEPT THE WINTER STORM WARNING GOING THROUGH 21Z ACROSS THE
SOUTHERN PANHANDLE AS WINDS WILL STAY UP LONGER OUT THERE.

THIS SYSTEM QUICKLY EXITS TO THE EAST INTO THE CENTRAL PLAINS BY
TONIGHT. IT WILL DEFINITELY BE A CHILLY NIGHT WITH SNOW COVER ON
THE GROUND AND WEAKENING WINDS. A WEAK SHORTWAVE IN THE
NORTHWESTERLY FLOW ALOFT MOVES ACROSS THE REGION AND THIS WILL
KEEP A SLIGHT CHANCE OF SNOW SHOWERS GOING. TEMPS BEGIN TO
MODERATE SOME ON WED...ALTHOUGH THE REAL WARMING DOES NOT OCCUR
UNTIL THURS. A LEE TROUGH DEVELOPS LATE IN THE DAY JUST TO THE
EAST OF THE LARAMIE RANGE...SO EXPECT WEST TO SOUTHWEST WINDS TO
INCREASE OVER MAINLY ALONG AND WEST OF THE LARAMIE RANGE.

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY NIGHT)
ISSUED AT 445 AM MDT TUE MAR 18 2014

WEST TO NORTHWEST FLOW WILL REMAIN OVERHEAD THROUGH THE LONG TERM 
PERIOD...WITH EMBEDDED SHORTWAVES MOVING ACROSS THE AREA. 
DRY...MILD...AND WINDY CONDITIONS WILL OCCUR WEDNESDAY NIGHT AND 
THURSDAY AS AN UPPER WAVE MOVES ACROSS THE NORTHERN ROCKIES/HIGH 
PLAINS AND DEEPENS THE LEESIDE PRESSURE TROUGH. COULD SEE SOUTHWEST 
WINDS GUSTING 50 TO 60 MPH ALONG AND WEST OF INTERSTATE 25...WITH 35 
TO 45 MPH FURTHER EAST ACROSS THE PLAINS. THE COLD FRONT ASSOCIATED 
WITH THIS UPPER WAVE WILL SLIDE SOUTH ACROSS THE PLAINS ON THURSDAY 
EVENING...AND WILL BACK WEST THROUGH THE HIGH COUNTRY ON FRIDAY. 
THIS WILL BRING COOLER TEMPS TO THE CWA FOR FRIDAY WITH WINDS 
WEAKENING AND SHIFTING TO THE NORTHEAST ON FRIDAY EVENING. A WEAK 
SHORTWAVE WILL MOVE TOWARDS THE AREA FROM THE WEST AT THIS TIME AS 
WELL...SO LOOKING AT A POSSIBLE OVERRUNNING SNOW EVENT FRIDAY NIGHT 
INTO SATURDAY. MUCH DRIER AIR WILL FILTER IN ON SATURDAY NIGHT AND 
SUNDAY...AND TEMPS WILL WARM BACK UP ON SUNDAY AS HEIGHTS ALOFT RISE 
IN THE WAKE OF THE SHORTWAVE. SUNDAY NIGHT LOOKS TO BE BREEZY AS YET 
ANOTHER SHORTWAVE DIVES IN FROM THE NORTHWEST...AND A COLD FRONT 
WILL MOVE SOUTH ACROSS THE PLAINS. THE FRONT LOOKS TO STALL ALONG 
THE LARAMIE RANGE SUNDAY NIGHT AND MONDAY...AND COULD SEE LIGHT SNOW 
DEVELOP BEHIND THE FRONT THROUGH THIS TIME.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 601 AM MDT TUE MAR 18 2014

WIDESPREAD MODERATE TO HEAVY SNOW AND STRONG NORTH TO NORTHWEST
WINDS WILL CONTINUE AT MOST SITES THIS MORNING AS THE POTENT STORM
SYSTEM CONTINUES TO MOVE SOUTHEAST ACROSS THE FORECAST AREA.
THE WINDS WILL BE STRONGEST OVER THE PLAINS...WITH GUSTS OF 35 TO
45 KTS TO CONTINUE THROUGH AROUND 20Z. IFR TO LIFR CONDITIONS ARE
EXPECTED IN THE SNOW THROUGH AROUND 18Z...WITH CONDITIONS STEADILY
IMPROVE FROM NORTHWEST TO SOUTHEAST THROUGH THE AFTERNOON. WINDS
WILL REMAIN ON THE LIGHTER SIDE TONIGHT WITH A MID CLOUD DECK
MOVING OVERHEAD. SOME MVFR CIGS ARE POSSIBLE AT KRWL EARLY
WEDNESDAY MORNING.

&&

.FIRE WEATHER...
ISSUED AT 445 AM MDT TUE MAR 18 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH WEDNESDAY. WIDESPREAD
SNOWFALL ACCUMULATIONS OF 2-5 INCHES WILL OCCUR TODAY ALONG WITH
GUSTY NORTHWEST WINDS. TEMPERATURES WILL WARM INTO THE 50S AND
LOWER 60S ACROSS THE PLAINS BY THURSDAY AND WEST WINDS WILL ALSO
INCREASE. THERE COULD BE AN ELEVATED FIRE WEATHER THREAT OVER THE
SOUTHERN PANHANDLE BY THURSDAY AFTERNOON AS RELATIVE HUMIDITY
VALUES DROP TO AROUND 20 PERCENT AND GUSTS TO 25-30 MPH WILL BE
POSSIBLE.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL NOON MDT TODAY FOR WYZ101-102-107-108.

     WINTER WEATHER ADVISORY UNTIL NOON MDT TODAY FOR WYZ103>106-109-
     110-112>119.

NE...WINTER STORM WARNING UNTIL NOON MDT TODAY FOR NEZ002-003-095-096.

     WINTER STORM WARNING UNTIL 3 PM MDT THIS AFTERNOON FOR 
     NEZ019>021-054-055.

&&

$$

SHORT TERM...FINCH
LONG TERM...RJM
AVIATION...RJM
FIRE WEATHER...FINCH