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000
FXUS65 KRIW 032050
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
150 PM MST TUE DEC 3 2013

.SHORT TERM...TONIGHT AND WEDNESDAY
BITTER COLD AIRMASS SETTLING IN ACROSS WRN AND CNTRL WYOMING AS
EXPECTED TODAY. HIGHLIGHTS ARE LOOKING GOOD WITH MOST AREAS ALREADY
SEEING 2 TO 4 INCHES WITH LOCALIZED AMOUNTS OF 5 TO 6 INCHES IN THE
LOWER ELEVATIONS AND MORE IN THE NRN MOUNTAINS. UPPER LOW IS
SPINNING TO OUR NW AND IT SHOULD MOVE/REDEVELOP SWD INTO THIS
EVENING INTO ERN IDAHO BEFORE MOVING ACROSS THE STATE ON WEDNESDAY.
JET AXIS IS RUNNING FROM NRN NV INTO FAR SRN WYO WITH DISTURBANCES
RIDING EWD ON THE CYCLONIC SIDE OF THE JET. THE DIFFLUENT FLOW
ACROSS THE STATE COMBINED WITH THESE DISTURBANCES AND SURFACE
UPSLOPE HAS PRODUCED SOME PERIODS OF MODERATE TO EVEN HEAVY SNOW
TODAY AND I EXPECT THIS TO CONTINUE THROUGH TONIGHT. WE SEE THE MAIN
PUSH OF COLD AIR TONIGHT WITH DECENT PRESSURE RISES AND DEVELOPING QG
FRONTOGENESIS ACROSS THE CENTRAL AREAS THIS EVENING AND THEN
EXPANDING INTO THE SOUTH OVERNIGHT. POSSIBLE LEFT EXIT JET STREAK
DYNAMICS COME INTO PLAY TONIGHT INTO WEDNESDAY MORNING ALSO. WILL BE
INTERESTING TO SEE HOW IT ALL COMES TOGETHER. WE MAY JUST CONTINUE
TO SEE MORE OF THE SAME OR A PERIOD OF HEAVY SNOW COULD DEVELOP IN
CENTRAL WYO BY THIS EVENING AND LAST FOR SEVERAL HOURS. EITHER
WAY...ADVISORIES AND WARNINGS LOOK GOOD. BUFFALO HAS BEEN HIT HARD
BUT SNOW SHOULD BE ON THE DECREASE SHORTLY WITH WIND LINGERING INTO
THE EVENING. TEMPERATURES WILL CONTINUE TO FALL TONIGHT WITH MANY
AREAS EAST OF THE DIVIDE STRUGGLING TO RISE ABOUT ZERO ON WEDNESDAY.
THE MOUNTAINS WILL NOT MAKE IT ABOVE ZERO FOR SURE ON WEDNESDAY AND
MOST OF THE NORTH AND EAST WILL LIKELY SEE AROUND ZERO AT BEST.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
A DIVING WAVE OF LOW PRESSURE WILL KEEP LIGHT SNOWFALL ACROSS
WESTERN WYOMING DURING THE EARLY PORTION OF THE FORECAST PERIOD.
ADDITIONALLY...THIS SYSTEM WILL HELP TO KEEP FRIGID TEMPERATURES
AROUND THE AREA...WITH MANY AREAS BARELY REACHING POSITIVE SINGLE
DIGITS DURING THE DAYTIME HOURS. THIS PATTERN WILL CONTINUE THROUGH
THE REMAINDER OF THE WEEK...THOUGH A BRIEF REPRIEVE OF SNOWFALL WILL
BE POSSIBLE ON THURSDAY ACROSS THE LOWER ELEVATIONS. LIGHT SNOWFALL
TO FLURRIES ARE ANTICIPATED TO REMAIN ACROSS THE HIGHER ELEVATIONS.

ANOTHER...STRONGER WAVE OF LOW PRESSURE WILL MOVE DOWN THE PACIFIC
NORTHWEST COASTLINE FRIDAY AFTERNOON AND EVENING...WITH NEAR ZONAL
FLOW DEVELOPING OVER THE FORECAST AREA. THIS WILL PUMP ADDITIONAL
MOISTURE ACROSS WESTERN WYOMING RESULTING IN ANOTHER ROUND OF
SNOWFALL. THE WAVE OF LOW PRESSURE WILL DIVE SOUTH TO THE DESERT
SOUTHWEST BY SATURDAY AFTERNOON. MODELS HAVE SOME VARIANCE ON
PLACEMENT OF THIS SYSTEM...AND HOW FAR EAST IT WILL SPREAD SNOWFALL
DURING THE LATER HALF OF THE WEEKEND.

AS THE SYSTEM MOVES EAST...IT WILL BRING CONTINUED COOLING
TEMPERATURES ACROSS THE FORECAST AREA WITH SNOWFALL POTENTIALLY
SPREADING ACROSS THE FORECAST AREA. OVERALL...THE COLD PATTERN WILL
CONTINUE INTO EARLY NEXT WEEK WITH SNOWFALL POSSIBLE AT TIMES.

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE:
BITTER COLD SNOWSTORM WILL CONTINUE EAST OF THE DIVIDE THROUGH
WEDNESDAY ALTHOUGH THERE WILL BE SOME IMPROVEMENT IN THE BIG HORN
BASIN AND CODY FOOTHILLS TONIGHT. GENERAL MVFR TO OCCASIONAL IFR
CONDITIONS WILL PREVAIL...ESPECIALLY FOR KLND...KCPR AND KRKS
THROUGH WEDNESDAY. AREAS OF STIFF NORTH TO NORTHEAST WIND WILL
PREVAIL THROUGH MONDAY NIGHT.

WEST OF THE DIVIDE:
SCATTERED AREAS OF LIGHT SNOW WILL PERSIST THROUGH WEDNESDAY WITH
MVFR CONDITIONS DURING THESE PERIODS OF LIGHT SNOW. OTHERWISE...VFR
CONDITIONS BUT WITH STILL CONSIDERABLE CLOUDS AND MOUNTAIN
OBSCURATION. AREAS OF STIFF NORTH TO NORTHEAST WIND WILL PREVAIL.

.FIRE WEATHER...

BITTER COLD AIRMASS TO COVER THE AREA FOR THE FORESEEABLE FUTURE.
SNOW WILL CONTINUE EAST OF THE DIVIDE AND IN THE SOUTHWEST THROUGH
WEDNESDAY WITH SCATTERED AREAS OF LIGHT SNOW AND FLURRIES
ELSEWHERE. GUSTY TO STRONG NORTH TO NORTHEAST WINDS WILL PREVAIL
IN MANY AREAS THROUGH TONIGHT BEFORE DIMINISHING. IT WILL BE
BITTERLY COLD WITH HIGHS REMAIN BELOW ZERO TO SLIGHTLY ABOVE ZERO
AND LOWS RANGING OF 1O TO 30 BELOW ZERO THURSDAY MORNING.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST WEDNESDAY WYZ019-020-022-030.

WINTER WEATHER ADVISORY UNTIL 5 PM MST WEDNESDAY
WYZ008>011-015-017-018-027>029.

WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON WYZ003>007.

&&

$$

SHORT TERM...SKRBAC
LONG TERM...BRANHAM
AVIATION...SKRBAC
FIRE WEATHER...SKRBAC