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000
FXUS65 KRIW 010911
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
211 AM MST SUN MAR 1 2015

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT

AN INTERESTING FORECAST PERIOD ACROSS WESTERN AND CENTRAL WYOMING. A
FAIRLY QUIET BEGINNING AS LINGER ACTIVITY OTHER SOUTHERN WYOMING
TAPERS OFF THIS MORNING. MORNING INVERSIONS WILL DEVELOP...WITH
PATCHY FOG POSSIBLE ACROSS MUCH OF THE LOW LYING AREAS.

A BRIEF PERIOD OF DRY CONDITIONS ANTICIPATED THROUGH THE OVERNIGHT
HOURS. WHILE THE DRY PERIOD IS ONGOING...AN AREA OF LOW PRESSURE
WILL MOVE SOUTH ALONG THE PACIFIC COASTLINE...FINALLY HEADING INLAND
TOWARDS THE FOUR CORNERS REGION LATE TONIGHT AND INTO MONDAY. AS
THIS SYSTEM PROGRESSES IT WILL SEND SNOWFALL ACROSS THE SOUTHERN
THIRD OF THE FORECAST AREA...ESPECIALLY IMPACTING SOUTHERN
SWEETWATER COUNTY BY MONDAY MORNING. SNOWFALL WILL INCREASE MONDAY
AFTERNOON AND MONDAY NIGHT...AND IS FAVORABLE TO BECOME HEAVY AT
TIMES. SNOWFALL ACCUMULATIONS OF 4 TO 7 INCHES ARE POSSIBLE BY
TUESDAY EVENING...AND ARE SUPPORTED BY NATIONAL CENTERS. SOME
HIGHER AMOUNTS ARE POSSIBLE SOUTH OF INTERSTATE 80. WITH CONCERNS
RELATING TO THIS SYSTEM MOUNTING...HAVE ISSUED A WINTER STORM WATCH
FOR THE COUNTY. INTERSTATE 80 WILL BE IMPACTED...THOUGH AGAIN...THE
GREATEST AREA OF IMPACT LOOKS TO BE SOUTH OF THE
INTERSTATE...ESPECIALLY ALONG THE WYOMING AND COLORADO BORDER.

AS THIS SYSTEM IS IMPACTING THE SOUTHERN PORTION OF THE FORECAST
AREA... A WAVE OF LOW PRESSURE LOOKS TO SEND A CANADIAN SYSTEM INTO
NORTHERN WYOMING BY LATE MONDAY NIGHT. SNOWFALL WITH THIS SYSTEM
WILL ESPECIALLY IMPACT THE NORTHERN MOUNTAINS...AND WILL CONTINUE TO
BE MONITORED. EVENTUALLY...THE NORTHERN SYSTEM LOOKS TO TAKE OVER
THE SOUTHERN SYSTEM...WITH SNOWFALL SPREADING TO INCLUDE THE VAST
MAJORITY OF THE FORECAST AREA DURING THE VERY EARLY MORNING HOURS OF
TUESDAY. ALL SITUATIONS WILL CONTINUE TO BE MONITORED...THOUGH
REGARDLESS EVEN TO AMOUNTS...EXPECT A RETURN TO COOLER WEATHER WITH
SNOWFALL VERY FAVORABLE OVER THE AREA.

.LONG TERM...WEDNESDAY THROUGH SUNDAY

NORTHWEST FLOW IS EXPECTED TO DOMINATE THE EXTENDED WITH AT LEAST
ONE DISTINCT SHORTWAVE TROUGH AND ASSOCIATED WEAK COLD FRONT SLIDING
ACROSS THE AREA IN THE FRIDAY/FRIDAY NIGHT TIME FRAME. OTHERWISE...A
RELATIVELY DRY NORTHWEST FLOW IS EXPECTED. WILL INTRODUCE SLIGHT
MOUNTAIN POPS FOR THIS SYSTEM FRIDAY/FRIDAY NIGHT...BUT KEPT THE
LOWER ELEVATIONS DRY FOR NOW...AS THIS SYSTEM APPEARS TO HAVE
LIMITED AVAILABLE MOISTURE.  CANNOT RULE OUT ISOLATED MOUNTAIN SNOW
SHOWERS ON OTHER DAYS MAINLY OVER THE NORTHWEST/NORTHERN
MOUNTAINS...BUT PREVIOUS FORECASTS WERE DRY...AND MOISTURE IS NOT
EXCITING...THUS HAVE KEPT THE ONGOING DRY FORECAST.

TEMPERATURES ON WEDNESDAY WILL BE 15 TO 25 DEGREES BELOW
AVERAGE...WITH SOME AREAS SEEING HIGHS ABOUT 30 DEGREES BELOW
AVERAGE. A WARMING TREND WILL OCCUR LATE THIS WEEK WITH MOST AREAS
RETURNING TO SEASONAL LEVELS BY FRIDAY. THE EXCEPTION WILL PROBABLY
BE TYPICAL TRAPPED CENTRAL BASINS WHERE MODELS TEND TO WARM THEM UP
TOO QUICKLY. A WEAK COLD FRONT FRIDAY/FRIDAY NIGHT...MIGHT ACTUALLY
HELP MIX OUT THOSE TRAPPED BASINS.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR THROUGH 18Z WITH AREAS OF LOW
CLOUDS AND FLURRIES TO LIGHT SNOW. EXPECT SOME MOUNTAIN OBSCURATION
UNTIL 18Z AS WELL. VFR CONDITIONS WILL PREVAIL BY 21Z AND THEN
THROUGH 12Z MONDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

OVER THE SOUTH UNTIL 15Z VFR TO MVFR CONDITIONS WILL OCCUR DUE TO
LOWER CLOUDS AND AREAS OF LIGHT SNOW. LOW CLOUDS WILL LINGER IN SOME
AREAS UNTIL 19Z. AFTER 22Z VFR CONDITIONS WILL PREVAIL OVER THE
REGION THROUGH 12Z MONDAY.

KPNA...KBPI AND KJAC AIRPORTS WILL SEE VFR CONDITIONS PREVAIL THROUGH
THE FORECAST PERIOD.

&&

.FIRE WEATHER...

ANOTHER RETURN TO WINTER EXPECTED OVER THE NEXT FEW DAYS. GENERALLY
DRY CONDITIONS ANTICIPATED TODAY...WITH MORNING INVERSIONS AND
RELATED PATCHY FOG POSSIBLE. A WINTRY SYSTEM WILL THEN MOVE INTO
SOUTHERN WYOMING MONDAY MORNING...SPREADING SNOWFALL ACROSS
SWEETWATER COUNTY. ANOTHER SYSTEM WILL THEN MOVE INTO NORTHERN
WYOMING MONDAY NIGHT SPREADING SNOWFALL ACROSS THE NORTHERN THIRD OF
THE FORECAST AREA. THESE TWO SYSTEM ARE EXPECTED TO JOIN DURING THE
VERY EARLY MORNING OF TUESDAY...WITH WIDESPREAD SNOWFALL
ANTICIPATED. IT APPEARS AS THOUGH THE GREATEST SNOWFALL AMOUNTS MAY
FALL OVER SOUTHERN WYOMING...WITH A WINTER STORM WATCH ISSUED FOR
THE AREA. STAY TUNED FOR UPDATES TO THIS UPCOMING STORM SYSTEM.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON
WYZ028>030.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...WM
AVIATION...AR
FIRE WEATHER...BRANHAM









000
FXUS65 KRIW 010911
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
211 AM MST SUN MAR 1 2015

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT

AN INTERESTING FORECAST PERIOD ACROSS WESTERN AND CENTRAL WYOMING. A
FAIRLY QUIET BEGINNING AS LINGER ACTIVITY OTHER SOUTHERN WYOMING
TAPERS OFF THIS MORNING. MORNING INVERSIONS WILL DEVELOP...WITH
PATCHY FOG POSSIBLE ACROSS MUCH OF THE LOW LYING AREAS.

A BRIEF PERIOD OF DRY CONDITIONS ANTICIPATED THROUGH THE OVERNIGHT
HOURS. WHILE THE DRY PERIOD IS ONGOING...AN AREA OF LOW PRESSURE
WILL MOVE SOUTH ALONG THE PACIFIC COASTLINE...FINALLY HEADING INLAND
TOWARDS THE FOUR CORNERS REGION LATE TONIGHT AND INTO MONDAY. AS
THIS SYSTEM PROGRESSES IT WILL SEND SNOWFALL ACROSS THE SOUTHERN
THIRD OF THE FORECAST AREA...ESPECIALLY IMPACTING SOUTHERN
SWEETWATER COUNTY BY MONDAY MORNING. SNOWFALL WILL INCREASE MONDAY
AFTERNOON AND MONDAY NIGHT...AND IS FAVORABLE TO BECOME HEAVY AT
TIMES. SNOWFALL ACCUMULATIONS OF 4 TO 7 INCHES ARE POSSIBLE BY
TUESDAY EVENING...AND ARE SUPPORTED BY NATIONAL CENTERS. SOME
HIGHER AMOUNTS ARE POSSIBLE SOUTH OF INTERSTATE 80. WITH CONCERNS
RELATING TO THIS SYSTEM MOUNTING...HAVE ISSUED A WINTER STORM WATCH
FOR THE COUNTY. INTERSTATE 80 WILL BE IMPACTED...THOUGH AGAIN...THE
GREATEST AREA OF IMPACT LOOKS TO BE SOUTH OF THE
INTERSTATE...ESPECIALLY ALONG THE WYOMING AND COLORADO BORDER.

AS THIS SYSTEM IS IMPACTING THE SOUTHERN PORTION OF THE FORECAST
AREA... A WAVE OF LOW PRESSURE LOOKS TO SEND A CANADIAN SYSTEM INTO
NORTHERN WYOMING BY LATE MONDAY NIGHT. SNOWFALL WITH THIS SYSTEM
WILL ESPECIALLY IMPACT THE NORTHERN MOUNTAINS...AND WILL CONTINUE TO
BE MONITORED. EVENTUALLY...THE NORTHERN SYSTEM LOOKS TO TAKE OVER
THE SOUTHERN SYSTEM...WITH SNOWFALL SPREADING TO INCLUDE THE VAST
MAJORITY OF THE FORECAST AREA DURING THE VERY EARLY MORNING HOURS OF
TUESDAY. ALL SITUATIONS WILL CONTINUE TO BE MONITORED...THOUGH
REGARDLESS EVEN TO AMOUNTS...EXPECT A RETURN TO COOLER WEATHER WITH
SNOWFALL VERY FAVORABLE OVER THE AREA.

.LONG TERM...WEDNESDAY THROUGH SUNDAY

NORTHWEST FLOW IS EXPECTED TO DOMINATE THE EXTENDED WITH AT LEAST
ONE DISTINCT SHORTWAVE TROUGH AND ASSOCIATED WEAK COLD FRONT SLIDING
ACROSS THE AREA IN THE FRIDAY/FRIDAY NIGHT TIME FRAME. OTHERWISE...A
RELATIVELY DRY NORTHWEST FLOW IS EXPECTED. WILL INTRODUCE SLIGHT
MOUNTAIN POPS FOR THIS SYSTEM FRIDAY/FRIDAY NIGHT...BUT KEPT THE
LOWER ELEVATIONS DRY FOR NOW...AS THIS SYSTEM APPEARS TO HAVE
LIMITED AVAILABLE MOISTURE.  CANNOT RULE OUT ISOLATED MOUNTAIN SNOW
SHOWERS ON OTHER DAYS MAINLY OVER THE NORTHWEST/NORTHERN
MOUNTAINS...BUT PREVIOUS FORECASTS WERE DRY...AND MOISTURE IS NOT
EXCITING...THUS HAVE KEPT THE ONGOING DRY FORECAST.

TEMPERATURES ON WEDNESDAY WILL BE 15 TO 25 DEGREES BELOW
AVERAGE...WITH SOME AREAS SEEING HIGHS ABOUT 30 DEGREES BELOW
AVERAGE. A WARMING TREND WILL OCCUR LATE THIS WEEK WITH MOST AREAS
RETURNING TO SEASONAL LEVELS BY FRIDAY. THE EXCEPTION WILL PROBABLY
BE TYPICAL TRAPPED CENTRAL BASINS WHERE MODELS TEND TO WARM THEM UP
TOO QUICKLY. A WEAK COLD FRONT FRIDAY/FRIDAY NIGHT...MIGHT ACTUALLY
HELP MIX OUT THOSE TRAPPED BASINS.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR THROUGH 18Z WITH AREAS OF LOW
CLOUDS AND FLURRIES TO LIGHT SNOW. EXPECT SOME MOUNTAIN OBSCURATION
UNTIL 18Z AS WELL. VFR CONDITIONS WILL PREVAIL BY 21Z AND THEN
THROUGH 12Z MONDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

OVER THE SOUTH UNTIL 15Z VFR TO MVFR CONDITIONS WILL OCCUR DUE TO
LOWER CLOUDS AND AREAS OF LIGHT SNOW. LOW CLOUDS WILL LINGER IN SOME
AREAS UNTIL 19Z. AFTER 22Z VFR CONDITIONS WILL PREVAIL OVER THE
REGION THROUGH 12Z MONDAY.

KPNA...KBPI AND KJAC AIRPORTS WILL SEE VFR CONDITIONS PREVAIL THROUGH
THE FORECAST PERIOD.

&&

.FIRE WEATHER...

ANOTHER RETURN TO WINTER EXPECTED OVER THE NEXT FEW DAYS. GENERALLY
DRY CONDITIONS ANTICIPATED TODAY...WITH MORNING INVERSIONS AND
RELATED PATCHY FOG POSSIBLE. A WINTRY SYSTEM WILL THEN MOVE INTO
SOUTHERN WYOMING MONDAY MORNING...SPREADING SNOWFALL ACROSS
SWEETWATER COUNTY. ANOTHER SYSTEM WILL THEN MOVE INTO NORTHERN
WYOMING MONDAY NIGHT SPREADING SNOWFALL ACROSS THE NORTHERN THIRD OF
THE FORECAST AREA. THESE TWO SYSTEM ARE EXPECTED TO JOIN DURING THE
VERY EARLY MORNING OF TUESDAY...WITH WIDESPREAD SNOWFALL
ANTICIPATED. IT APPEARS AS THOUGH THE GREATEST SNOWFALL AMOUNTS MAY
FALL OVER SOUTHERN WYOMING...WITH A WINTER STORM WATCH ISSUED FOR
THE AREA. STAY TUNED FOR UPDATES TO THIS UPCOMING STORM SYSTEM.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON
WYZ028>030.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...WM
AVIATION...AR
FIRE WEATHER...BRANHAM








000
FXUS65 KRIW 010911
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
211 AM MST SUN MAR 1 2015

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT

AN INTERESTING FORECAST PERIOD ACROSS WESTERN AND CENTRAL WYOMING. A
FAIRLY QUIET BEGINNING AS LINGER ACTIVITY OTHER SOUTHERN WYOMING
TAPERS OFF THIS MORNING. MORNING INVERSIONS WILL DEVELOP...WITH
PATCHY FOG POSSIBLE ACROSS MUCH OF THE LOW LYING AREAS.

A BRIEF PERIOD OF DRY CONDITIONS ANTICIPATED THROUGH THE OVERNIGHT
HOURS. WHILE THE DRY PERIOD IS ONGOING...AN AREA OF LOW PRESSURE
WILL MOVE SOUTH ALONG THE PACIFIC COASTLINE...FINALLY HEADING INLAND
TOWARDS THE FOUR CORNERS REGION LATE TONIGHT AND INTO MONDAY. AS
THIS SYSTEM PROGRESSES IT WILL SEND SNOWFALL ACROSS THE SOUTHERN
THIRD OF THE FORECAST AREA...ESPECIALLY IMPACTING SOUTHERN
SWEETWATER COUNTY BY MONDAY MORNING. SNOWFALL WILL INCREASE MONDAY
AFTERNOON AND MONDAY NIGHT...AND IS FAVORABLE TO BECOME HEAVY AT
TIMES. SNOWFALL ACCUMULATIONS OF 4 TO 7 INCHES ARE POSSIBLE BY
TUESDAY EVENING...AND ARE SUPPORTED BY NATIONAL CENTERS. SOME
HIGHER AMOUNTS ARE POSSIBLE SOUTH OF INTERSTATE 80. WITH CONCERNS
RELATING TO THIS SYSTEM MOUNTING...HAVE ISSUED A WINTER STORM WATCH
FOR THE COUNTY. INTERSTATE 80 WILL BE IMPACTED...THOUGH AGAIN...THE
GREATEST AREA OF IMPACT LOOKS TO BE SOUTH OF THE
INTERSTATE...ESPECIALLY ALONG THE WYOMING AND COLORADO BORDER.

AS THIS SYSTEM IS IMPACTING THE SOUTHERN PORTION OF THE FORECAST
AREA... A WAVE OF LOW PRESSURE LOOKS TO SEND A CANADIAN SYSTEM INTO
NORTHERN WYOMING BY LATE MONDAY NIGHT. SNOWFALL WITH THIS SYSTEM
WILL ESPECIALLY IMPACT THE NORTHERN MOUNTAINS...AND WILL CONTINUE TO
BE MONITORED. EVENTUALLY...THE NORTHERN SYSTEM LOOKS TO TAKE OVER
THE SOUTHERN SYSTEM...WITH SNOWFALL SPREADING TO INCLUDE THE VAST
MAJORITY OF THE FORECAST AREA DURING THE VERY EARLY MORNING HOURS OF
TUESDAY. ALL SITUATIONS WILL CONTINUE TO BE MONITORED...THOUGH
REGARDLESS EVEN TO AMOUNTS...EXPECT A RETURN TO COOLER WEATHER WITH
SNOWFALL VERY FAVORABLE OVER THE AREA.

.LONG TERM...WEDNESDAY THROUGH SUNDAY

NORTHWEST FLOW IS EXPECTED TO DOMINATE THE EXTENDED WITH AT LEAST
ONE DISTINCT SHORTWAVE TROUGH AND ASSOCIATED WEAK COLD FRONT SLIDING
ACROSS THE AREA IN THE FRIDAY/FRIDAY NIGHT TIME FRAME. OTHERWISE...A
RELATIVELY DRY NORTHWEST FLOW IS EXPECTED. WILL INTRODUCE SLIGHT
MOUNTAIN POPS FOR THIS SYSTEM FRIDAY/FRIDAY NIGHT...BUT KEPT THE
LOWER ELEVATIONS DRY FOR NOW...AS THIS SYSTEM APPEARS TO HAVE
LIMITED AVAILABLE MOISTURE.  CANNOT RULE OUT ISOLATED MOUNTAIN SNOW
SHOWERS ON OTHER DAYS MAINLY OVER THE NORTHWEST/NORTHERN
MOUNTAINS...BUT PREVIOUS FORECASTS WERE DRY...AND MOISTURE IS NOT
EXCITING...THUS HAVE KEPT THE ONGOING DRY FORECAST.

TEMPERATURES ON WEDNESDAY WILL BE 15 TO 25 DEGREES BELOW
AVERAGE...WITH SOME AREAS SEEING HIGHS ABOUT 30 DEGREES BELOW
AVERAGE. A WARMING TREND WILL OCCUR LATE THIS WEEK WITH MOST AREAS
RETURNING TO SEASONAL LEVELS BY FRIDAY. THE EXCEPTION WILL PROBABLY
BE TYPICAL TRAPPED CENTRAL BASINS WHERE MODELS TEND TO WARM THEM UP
TOO QUICKLY. A WEAK COLD FRONT FRIDAY/FRIDAY NIGHT...MIGHT ACTUALLY
HELP MIX OUT THOSE TRAPPED BASINS.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR THROUGH 18Z WITH AREAS OF LOW
CLOUDS AND FLURRIES TO LIGHT SNOW. EXPECT SOME MOUNTAIN OBSCURATION
UNTIL 18Z AS WELL. VFR CONDITIONS WILL PREVAIL BY 21Z AND THEN
THROUGH 12Z MONDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

OVER THE SOUTH UNTIL 15Z VFR TO MVFR CONDITIONS WILL OCCUR DUE TO
LOWER CLOUDS AND AREAS OF LIGHT SNOW. LOW CLOUDS WILL LINGER IN SOME
AREAS UNTIL 19Z. AFTER 22Z VFR CONDITIONS WILL PREVAIL OVER THE
REGION THROUGH 12Z MONDAY.

KPNA...KBPI AND KJAC AIRPORTS WILL SEE VFR CONDITIONS PREVAIL THROUGH
THE FORECAST PERIOD.

&&

.FIRE WEATHER...

ANOTHER RETURN TO WINTER EXPECTED OVER THE NEXT FEW DAYS. GENERALLY
DRY CONDITIONS ANTICIPATED TODAY...WITH MORNING INVERSIONS AND
RELATED PATCHY FOG POSSIBLE. A WINTRY SYSTEM WILL THEN MOVE INTO
SOUTHERN WYOMING MONDAY MORNING...SPREADING SNOWFALL ACROSS
SWEETWATER COUNTY. ANOTHER SYSTEM WILL THEN MOVE INTO NORTHERN
WYOMING MONDAY NIGHT SPREADING SNOWFALL ACROSS THE NORTHERN THIRD OF
THE FORECAST AREA. THESE TWO SYSTEM ARE EXPECTED TO JOIN DURING THE
VERY EARLY MORNING OF TUESDAY...WITH WIDESPREAD SNOWFALL
ANTICIPATED. IT APPEARS AS THOUGH THE GREATEST SNOWFALL AMOUNTS MAY
FALL OVER SOUTHERN WYOMING...WITH A WINTER STORM WATCH ISSUED FOR
THE AREA. STAY TUNED FOR UPDATES TO THIS UPCOMING STORM SYSTEM.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON
WYZ028>030.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...WM
AVIATION...AR
FIRE WEATHER...BRANHAM









000
FXUS65 KRIW 010911
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
211 AM MST SUN MAR 1 2015

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT

AN INTERESTING FORECAST PERIOD ACROSS WESTERN AND CENTRAL WYOMING. A
FAIRLY QUIET BEGINNING AS LINGER ACTIVITY OTHER SOUTHERN WYOMING
TAPERS OFF THIS MORNING. MORNING INVERSIONS WILL DEVELOP...WITH
PATCHY FOG POSSIBLE ACROSS MUCH OF THE LOW LYING AREAS.

A BRIEF PERIOD OF DRY CONDITIONS ANTICIPATED THROUGH THE OVERNIGHT
HOURS. WHILE THE DRY PERIOD IS ONGOING...AN AREA OF LOW PRESSURE
WILL MOVE SOUTH ALONG THE PACIFIC COASTLINE...FINALLY HEADING INLAND
TOWARDS THE FOUR CORNERS REGION LATE TONIGHT AND INTO MONDAY. AS
THIS SYSTEM PROGRESSES IT WILL SEND SNOWFALL ACROSS THE SOUTHERN
THIRD OF THE FORECAST AREA...ESPECIALLY IMPACTING SOUTHERN
SWEETWATER COUNTY BY MONDAY MORNING. SNOWFALL WILL INCREASE MONDAY
AFTERNOON AND MONDAY NIGHT...AND IS FAVORABLE TO BECOME HEAVY AT
TIMES. SNOWFALL ACCUMULATIONS OF 4 TO 7 INCHES ARE POSSIBLE BY
TUESDAY EVENING...AND ARE SUPPORTED BY NATIONAL CENTERS. SOME
HIGHER AMOUNTS ARE POSSIBLE SOUTH OF INTERSTATE 80. WITH CONCERNS
RELATING TO THIS SYSTEM MOUNTING...HAVE ISSUED A WINTER STORM WATCH
FOR THE COUNTY. INTERSTATE 80 WILL BE IMPACTED...THOUGH AGAIN...THE
GREATEST AREA OF IMPACT LOOKS TO BE SOUTH OF THE
INTERSTATE...ESPECIALLY ALONG THE WYOMING AND COLORADO BORDER.

AS THIS SYSTEM IS IMPACTING THE SOUTHERN PORTION OF THE FORECAST
AREA... A WAVE OF LOW PRESSURE LOOKS TO SEND A CANADIAN SYSTEM INTO
NORTHERN WYOMING BY LATE MONDAY NIGHT. SNOWFALL WITH THIS SYSTEM
WILL ESPECIALLY IMPACT THE NORTHERN MOUNTAINS...AND WILL CONTINUE TO
BE MONITORED. EVENTUALLY...THE NORTHERN SYSTEM LOOKS TO TAKE OVER
THE SOUTHERN SYSTEM...WITH SNOWFALL SPREADING TO INCLUDE THE VAST
MAJORITY OF THE FORECAST AREA DURING THE VERY EARLY MORNING HOURS OF
TUESDAY. ALL SITUATIONS WILL CONTINUE TO BE MONITORED...THOUGH
REGARDLESS EVEN TO AMOUNTS...EXPECT A RETURN TO COOLER WEATHER WITH
SNOWFALL VERY FAVORABLE OVER THE AREA.

.LONG TERM...WEDNESDAY THROUGH SUNDAY

NORTHWEST FLOW IS EXPECTED TO DOMINATE THE EXTENDED WITH AT LEAST
ONE DISTINCT SHORTWAVE TROUGH AND ASSOCIATED WEAK COLD FRONT SLIDING
ACROSS THE AREA IN THE FRIDAY/FRIDAY NIGHT TIME FRAME. OTHERWISE...A
RELATIVELY DRY NORTHWEST FLOW IS EXPECTED. WILL INTRODUCE SLIGHT
MOUNTAIN POPS FOR THIS SYSTEM FRIDAY/FRIDAY NIGHT...BUT KEPT THE
LOWER ELEVATIONS DRY FOR NOW...AS THIS SYSTEM APPEARS TO HAVE
LIMITED AVAILABLE MOISTURE.  CANNOT RULE OUT ISOLATED MOUNTAIN SNOW
SHOWERS ON OTHER DAYS MAINLY OVER THE NORTHWEST/NORTHERN
MOUNTAINS...BUT PREVIOUS FORECASTS WERE DRY...AND MOISTURE IS NOT
EXCITING...THUS HAVE KEPT THE ONGOING DRY FORECAST.

TEMPERATURES ON WEDNESDAY WILL BE 15 TO 25 DEGREES BELOW
AVERAGE...WITH SOME AREAS SEEING HIGHS ABOUT 30 DEGREES BELOW
AVERAGE. A WARMING TREND WILL OCCUR LATE THIS WEEK WITH MOST AREAS
RETURNING TO SEASONAL LEVELS BY FRIDAY. THE EXCEPTION WILL PROBABLY
BE TYPICAL TRAPPED CENTRAL BASINS WHERE MODELS TEND TO WARM THEM UP
TOO QUICKLY. A WEAK COLD FRONT FRIDAY/FRIDAY NIGHT...MIGHT ACTUALLY
HELP MIX OUT THOSE TRAPPED BASINS.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR THROUGH 18Z WITH AREAS OF LOW
CLOUDS AND FLURRIES TO LIGHT SNOW. EXPECT SOME MOUNTAIN OBSCURATION
UNTIL 18Z AS WELL. VFR CONDITIONS WILL PREVAIL BY 21Z AND THEN
THROUGH 12Z MONDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

OVER THE SOUTH UNTIL 15Z VFR TO MVFR CONDITIONS WILL OCCUR DUE TO
LOWER CLOUDS AND AREAS OF LIGHT SNOW. LOW CLOUDS WILL LINGER IN SOME
AREAS UNTIL 19Z. AFTER 22Z VFR CONDITIONS WILL PREVAIL OVER THE
REGION THROUGH 12Z MONDAY.

KPNA...KBPI AND KJAC AIRPORTS WILL SEE VFR CONDITIONS PREVAIL THROUGH
THE FORECAST PERIOD.

&&

.FIRE WEATHER...

ANOTHER RETURN TO WINTER EXPECTED OVER THE NEXT FEW DAYS. GENERALLY
DRY CONDITIONS ANTICIPATED TODAY...WITH MORNING INVERSIONS AND
RELATED PATCHY FOG POSSIBLE. A WINTRY SYSTEM WILL THEN MOVE INTO
SOUTHERN WYOMING MONDAY MORNING...SPREADING SNOWFALL ACROSS
SWEETWATER COUNTY. ANOTHER SYSTEM WILL THEN MOVE INTO NORTHERN
WYOMING MONDAY NIGHT SPREADING SNOWFALL ACROSS THE NORTHERN THIRD OF
THE FORECAST AREA. THESE TWO SYSTEM ARE EXPECTED TO JOIN DURING THE
VERY EARLY MORNING OF TUESDAY...WITH WIDESPREAD SNOWFALL
ANTICIPATED. IT APPEARS AS THOUGH THE GREATEST SNOWFALL AMOUNTS MAY
FALL OVER SOUTHERN WYOMING...WITH A WINTER STORM WATCH ISSUED FOR
THE AREA. STAY TUNED FOR UPDATES TO THIS UPCOMING STORM SYSTEM.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON
WYZ028>030.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...WM
AVIATION...AR
FIRE WEATHER...BRANHAM








000
FXUS65 KRIW 010502
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1002 PM MST SAT FEB 28 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY (ISSUED AT 253 PM MST)

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG.  PARTIAL CLEARING WILL OCCUR ACROSS THE
NORTH SUNDAY AFTERNOON.  TEMPERATURES WILL REMAIN ON THE COLD SIDE.
LOCAL SNOWFALL OF AN INCH WITH VERY LOW DENSITY SNOW CAN BE
EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

AN UPPER LOW RACING DOWN THE BACK SIDE OF A TROUGH DIGGING TO OUR
SOUTHWEST WILL FUJIWHARA THE CLOSED UPPER LOW OVER SOUTHERN
CALIFORNIA...WHIPPING IT UP INTO THE FOUR CORNERS AREA. IT WILL
KICK UP SOME MOISTURE ASSOCIATED WITH THAT LOW FURTHER NORTH AND
EAST AS WELL...THIS COULD REACH OUR FAR SOUTHERN BORDER AREA WITH
COLORADO WITH SOME MODELS EVEN SUGGESTING SOME PRECIPITATION AS FAR
NORTH AS THE WIND RIVER RANGE AND CASPER ON MONDAY. SPREAD THE POPS
THAT FAR NORTH AS A RESULT BUT THE HEAVIER PRECIPITATION IS EXPECTED
TO REMAIN SOUTH OF THE FORECAST AREA THROUGH MONDAY AFTERNOON.

THIS DIGGING TROUGH WILL ALSO BE ACCOMPANIED BY A CYCLONICALLY
CURVING JET THAT WILL SERVE TO ENHANCE A SHORT WAVE MOVING IN MONDAY
NIGHT. THIS WAVE IS ASSOCIATED WITH A VERY COLD ARCTIC LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL CANADA. THIS SOUTHERN PIECE OF THAT
SYSTEM WILL INTERACT WITH THE MOISTURE SUPPLIED BY THE SOUTHERN
STORM...PROVIDING SOME SIGNIFICANT MOISTURE TO WORK WITH FOR THIS
TIME OF YEAR. ADDITIONALLY...THE MODELS ARE SHOWING AN ORGANIZED
BAROCLINIC ZONE WITH THE FRONT AS IT DROPS SOUTH THROUGH THE STATE
MONDAY NIGHT INTO TUESDAY FOLLOWED BY A LONG PERIOD OF UPSLOPE FLOW
FOR AREAS EAST OF THE DIVIDE AS HIGH PRESSURE AT THE SURFACE FILTERS
IN BEHIND THE FRONT. SO THERE WILL BE SEVERAL FEATURES THAT WOULD
SUGGEST SOME AREAS OF SIGNIFICANT SNOW ACCUMULATION WITH THIS
SYSTEM. HOWEVER...IT IS A PRETTY COLD SYSTEM ALOFT SO ONCE THAT
FRONT PASSES BY THE MOISTURE AVAILABLE FOR HEAVY SNOW WILL BE
SQUEEZED OUT AND SHUNTED SOUTH AND EAST. ADDITIONALLY...THERE IS NOT
A LOT OF INSTABILITY ALONG AND BEHIND THE FRONT SO THAT WILL KEEP
MOST OF THE SNOW BANDING AND LOCAL ENHANCEMENTS SOUTH AND WEST OF
THE DIVIDE FOR MONDAY NIGHT INTO TUESDAY.

TUESDAY NIGHT COULD BE A COLD ONE AS WE CLEAR FROM NORTH TO SOUTH.
THERE WILL BE SOME MILDER AIR JUST TO THE EAST IN A HURRY TO MOVE IN
HOWEVER...THIS WILL LIKELY LEAD TO SOME SHARP INVERSIONS AND PATCHY
FOG TUESDAY NIGHT AND WEDNESDAY MORNING BUT GIVEN THE EVER
INCREASING SUN ANGLE AND DEVELOPING LEE SIDE TROUGH ON
WEDNESDAY...THE COLD AIR SHOULD NOT BE TOO STUBBORN WITH AT LEAST
SOME MIXING EXPECTED ON WEDNESDAY IF NOT FULL MIXING BY THURSDAY IN
SOME OF THE SHALLOWER BASINS. AS A RESULT...TEMPERATURES COULD GO
FROM 15 BELOW IN SOME BASINS ON WEDNESDAY MORNING TO HIGHS NEAR 40
ON THURSDAY. THE WARMING TREND CONTINUES INTO FRIDAY AND SATURDAY
WITH NO SIGNIFICANT PRECIPITATION EXPECTED ONCE WE CLEAR OUT ON
TUESDAY.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z SUNDAY
WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE WIDESPREAD
MOUNTAIN OBSCURATIONS THROUGH 18Z SUNDAY. SOME CLEARING WILL OCCUR
OVER THE REGION AFTER 18Z WITH VFR CONDITIONS PREVAILING BY 21Z.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL FOG OVER THE
SOUTH THROUGH 12Z WITH IFR TO MVFR CONDITIONS. CONDITIONS WILL
IMPROVE AFTER 19Z WITH VFR CONDITIONS PREVAILING BY 22Z.

THE REST OF THE REGION WILL HAVE VFR CEILINGS OVERNIGHT INTO SUNDAY
MORNING. CLOUDS WILL DECREASE AROUND 18Z SUNDAY BUT THEN INCREASE
AGAIN SUNDAY NIGHT WITH VFR CEILINGS BY 03Z MONDAY.

KJAC AIRPORT WILL SEE VFR CONDITIONS PREVAIL THROUGH THE FORECAST
PERIOD.

&&

.FIRE WEATHER...

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG. THIS WILL ALSO INCREASE STRONG
TEMPERATURE INVERSIONS PRODUCING STRONG THERMAL BELTS...LOW MIXING
HEIGHTS AND GENERALLY POOR SMOKE DISPERSAL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...ALLEN
AVIATION...AR
FIRE WEATHER...C.BAKER












000
FXUS65 KRIW 010502
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1002 PM MST SAT FEB 28 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY (ISSUED AT 253 PM MST)

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG.  PARTIAL CLEARING WILL OCCUR ACROSS THE
NORTH SUNDAY AFTERNOON.  TEMPERATURES WILL REMAIN ON THE COLD SIDE.
LOCAL SNOWFALL OF AN INCH WITH VERY LOW DENSITY SNOW CAN BE
EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

AN UPPER LOW RACING DOWN THE BACK SIDE OF A TROUGH DIGGING TO OUR
SOUTHWEST WILL FUJIWHARA THE CLOSED UPPER LOW OVER SOUTHERN
CALIFORNIA...WHIPPING IT UP INTO THE FOUR CORNERS AREA. IT WILL
KICK UP SOME MOISTURE ASSOCIATED WITH THAT LOW FURTHER NORTH AND
EAST AS WELL...THIS COULD REACH OUR FAR SOUTHERN BORDER AREA WITH
COLORADO WITH SOME MODELS EVEN SUGGESTING SOME PRECIPITATION AS FAR
NORTH AS THE WIND RIVER RANGE AND CASPER ON MONDAY. SPREAD THE POPS
THAT FAR NORTH AS A RESULT BUT THE HEAVIER PRECIPITATION IS EXPECTED
TO REMAIN SOUTH OF THE FORECAST AREA THROUGH MONDAY AFTERNOON.

THIS DIGGING TROUGH WILL ALSO BE ACCOMPANIED BY A CYCLONICALLY
CURVING JET THAT WILL SERVE TO ENHANCE A SHORT WAVE MOVING IN MONDAY
NIGHT. THIS WAVE IS ASSOCIATED WITH A VERY COLD ARCTIC LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL CANADA. THIS SOUTHERN PIECE OF THAT
SYSTEM WILL INTERACT WITH THE MOISTURE SUPPLIED BY THE SOUTHERN
STORM...PROVIDING SOME SIGNIFICANT MOISTURE TO WORK WITH FOR THIS
TIME OF YEAR. ADDITIONALLY...THE MODELS ARE SHOWING AN ORGANIZED
BAROCLINIC ZONE WITH THE FRONT AS IT DROPS SOUTH THROUGH THE STATE
MONDAY NIGHT INTO TUESDAY FOLLOWED BY A LONG PERIOD OF UPSLOPE FLOW
FOR AREAS EAST OF THE DIVIDE AS HIGH PRESSURE AT THE SURFACE FILTERS
IN BEHIND THE FRONT. SO THERE WILL BE SEVERAL FEATURES THAT WOULD
SUGGEST SOME AREAS OF SIGNIFICANT SNOW ACCUMULATION WITH THIS
SYSTEM. HOWEVER...IT IS A PRETTY COLD SYSTEM ALOFT SO ONCE THAT
FRONT PASSES BY THE MOISTURE AVAILABLE FOR HEAVY SNOW WILL BE
SQUEEZED OUT AND SHUNTED SOUTH AND EAST. ADDITIONALLY...THERE IS NOT
A LOT OF INSTABILITY ALONG AND BEHIND THE FRONT SO THAT WILL KEEP
MOST OF THE SNOW BANDING AND LOCAL ENHANCEMENTS SOUTH AND WEST OF
THE DIVIDE FOR MONDAY NIGHT INTO TUESDAY.

TUESDAY NIGHT COULD BE A COLD ONE AS WE CLEAR FROM NORTH TO SOUTH.
THERE WILL BE SOME MILDER AIR JUST TO THE EAST IN A HURRY TO MOVE IN
HOWEVER...THIS WILL LIKELY LEAD TO SOME SHARP INVERSIONS AND PATCHY
FOG TUESDAY NIGHT AND WEDNESDAY MORNING BUT GIVEN THE EVER
INCREASING SUN ANGLE AND DEVELOPING LEE SIDE TROUGH ON
WEDNESDAY...THE COLD AIR SHOULD NOT BE TOO STUBBORN WITH AT LEAST
SOME MIXING EXPECTED ON WEDNESDAY IF NOT FULL MIXING BY THURSDAY IN
SOME OF THE SHALLOWER BASINS. AS A RESULT...TEMPERATURES COULD GO
FROM 15 BELOW IN SOME BASINS ON WEDNESDAY MORNING TO HIGHS NEAR 40
ON THURSDAY. THE WARMING TREND CONTINUES INTO FRIDAY AND SATURDAY
WITH NO SIGNIFICANT PRECIPITATION EXPECTED ONCE WE CLEAR OUT ON
TUESDAY.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z SUNDAY
WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE WIDESPREAD
MOUNTAIN OBSCURATIONS THROUGH 18Z SUNDAY. SOME CLEARING WILL OCCUR
OVER THE REGION AFTER 18Z WITH VFR CONDITIONS PREVAILING BY 21Z.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL FOG OVER THE
SOUTH THROUGH 12Z WITH IFR TO MVFR CONDITIONS. CONDITIONS WILL
IMPROVE AFTER 19Z WITH VFR CONDITIONS PREVAILING BY 22Z.

THE REST OF THE REGION WILL HAVE VFR CEILINGS OVERNIGHT INTO SUNDAY
MORNING. CLOUDS WILL DECREASE AROUND 18Z SUNDAY BUT THEN INCREASE
AGAIN SUNDAY NIGHT WITH VFR CEILINGS BY 03Z MONDAY.

KJAC AIRPORT WILL SEE VFR CONDITIONS PREVAIL THROUGH THE FORECAST
PERIOD.

&&

.FIRE WEATHER...

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG. THIS WILL ALSO INCREASE STRONG
TEMPERATURE INVERSIONS PRODUCING STRONG THERMAL BELTS...LOW MIXING
HEIGHTS AND GENERALLY POOR SMOKE DISPERSAL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...ALLEN
AVIATION...AR
FIRE WEATHER...C.BAKER













000
FXUS65 KRIW 010502
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1002 PM MST SAT FEB 28 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY (ISSUED AT 253 PM MST)

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG.  PARTIAL CLEARING WILL OCCUR ACROSS THE
NORTH SUNDAY AFTERNOON.  TEMPERATURES WILL REMAIN ON THE COLD SIDE.
LOCAL SNOWFALL OF AN INCH WITH VERY LOW DENSITY SNOW CAN BE
EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

AN UPPER LOW RACING DOWN THE BACK SIDE OF A TROUGH DIGGING TO OUR
SOUTHWEST WILL FUJIWHARA THE CLOSED UPPER LOW OVER SOUTHERN
CALIFORNIA...WHIPPING IT UP INTO THE FOUR CORNERS AREA. IT WILL
KICK UP SOME MOISTURE ASSOCIATED WITH THAT LOW FURTHER NORTH AND
EAST AS WELL...THIS COULD REACH OUR FAR SOUTHERN BORDER AREA WITH
COLORADO WITH SOME MODELS EVEN SUGGESTING SOME PRECIPITATION AS FAR
NORTH AS THE WIND RIVER RANGE AND CASPER ON MONDAY. SPREAD THE POPS
THAT FAR NORTH AS A RESULT BUT THE HEAVIER PRECIPITATION IS EXPECTED
TO REMAIN SOUTH OF THE FORECAST AREA THROUGH MONDAY AFTERNOON.

THIS DIGGING TROUGH WILL ALSO BE ACCOMPANIED BY A CYCLONICALLY
CURVING JET THAT WILL SERVE TO ENHANCE A SHORT WAVE MOVING IN MONDAY
NIGHT. THIS WAVE IS ASSOCIATED WITH A VERY COLD ARCTIC LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL CANADA. THIS SOUTHERN PIECE OF THAT
SYSTEM WILL INTERACT WITH THE MOISTURE SUPPLIED BY THE SOUTHERN
STORM...PROVIDING SOME SIGNIFICANT MOISTURE TO WORK WITH FOR THIS
TIME OF YEAR. ADDITIONALLY...THE MODELS ARE SHOWING AN ORGANIZED
BAROCLINIC ZONE WITH THE FRONT AS IT DROPS SOUTH THROUGH THE STATE
MONDAY NIGHT INTO TUESDAY FOLLOWED BY A LONG PERIOD OF UPSLOPE FLOW
FOR AREAS EAST OF THE DIVIDE AS HIGH PRESSURE AT THE SURFACE FILTERS
IN BEHIND THE FRONT. SO THERE WILL BE SEVERAL FEATURES THAT WOULD
SUGGEST SOME AREAS OF SIGNIFICANT SNOW ACCUMULATION WITH THIS
SYSTEM. HOWEVER...IT IS A PRETTY COLD SYSTEM ALOFT SO ONCE THAT
FRONT PASSES BY THE MOISTURE AVAILABLE FOR HEAVY SNOW WILL BE
SQUEEZED OUT AND SHUNTED SOUTH AND EAST. ADDITIONALLY...THERE IS NOT
A LOT OF INSTABILITY ALONG AND BEHIND THE FRONT SO THAT WILL KEEP
MOST OF THE SNOW BANDING AND LOCAL ENHANCEMENTS SOUTH AND WEST OF
THE DIVIDE FOR MONDAY NIGHT INTO TUESDAY.

TUESDAY NIGHT COULD BE A COLD ONE AS WE CLEAR FROM NORTH TO SOUTH.
THERE WILL BE SOME MILDER AIR JUST TO THE EAST IN A HURRY TO MOVE IN
HOWEVER...THIS WILL LIKELY LEAD TO SOME SHARP INVERSIONS AND PATCHY
FOG TUESDAY NIGHT AND WEDNESDAY MORNING BUT GIVEN THE EVER
INCREASING SUN ANGLE AND DEVELOPING LEE SIDE TROUGH ON
WEDNESDAY...THE COLD AIR SHOULD NOT BE TOO STUBBORN WITH AT LEAST
SOME MIXING EXPECTED ON WEDNESDAY IF NOT FULL MIXING BY THURSDAY IN
SOME OF THE SHALLOWER BASINS. AS A RESULT...TEMPERATURES COULD GO
FROM 15 BELOW IN SOME BASINS ON WEDNESDAY MORNING TO HIGHS NEAR 40
ON THURSDAY. THE WARMING TREND CONTINUES INTO FRIDAY AND SATURDAY
WITH NO SIGNIFICANT PRECIPITATION EXPECTED ONCE WE CLEAR OUT ON
TUESDAY.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z SUNDAY
WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE WIDESPREAD
MOUNTAIN OBSCURATIONS THROUGH 18Z SUNDAY. SOME CLEARING WILL OCCUR
OVER THE REGION AFTER 18Z WITH VFR CONDITIONS PREVAILING BY 21Z.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL FOG OVER THE
SOUTH THROUGH 12Z WITH IFR TO MVFR CONDITIONS. CONDITIONS WILL
IMPROVE AFTER 19Z WITH VFR CONDITIONS PREVAILING BY 22Z.

THE REST OF THE REGION WILL HAVE VFR CEILINGS OVERNIGHT INTO SUNDAY
MORNING. CLOUDS WILL DECREASE AROUND 18Z SUNDAY BUT THEN INCREASE
AGAIN SUNDAY NIGHT WITH VFR CEILINGS BY 03Z MONDAY.

KJAC AIRPORT WILL SEE VFR CONDITIONS PREVAIL THROUGH THE FORECAST
PERIOD.

&&

.FIRE WEATHER...

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG. THIS WILL ALSO INCREASE STRONG
TEMPERATURE INVERSIONS PRODUCING STRONG THERMAL BELTS...LOW MIXING
HEIGHTS AND GENERALLY POOR SMOKE DISPERSAL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...ALLEN
AVIATION...AR
FIRE WEATHER...C.BAKER













000
FXUS65 KRIW 010502
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1002 PM MST SAT FEB 28 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY (ISSUED AT 253 PM MST)

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG.  PARTIAL CLEARING WILL OCCUR ACROSS THE
NORTH SUNDAY AFTERNOON.  TEMPERATURES WILL REMAIN ON THE COLD SIDE.
LOCAL SNOWFALL OF AN INCH WITH VERY LOW DENSITY SNOW CAN BE
EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

AN UPPER LOW RACING DOWN THE BACK SIDE OF A TROUGH DIGGING TO OUR
SOUTHWEST WILL FUJIWHARA THE CLOSED UPPER LOW OVER SOUTHERN
CALIFORNIA...WHIPPING IT UP INTO THE FOUR CORNERS AREA. IT WILL
KICK UP SOME MOISTURE ASSOCIATED WITH THAT LOW FURTHER NORTH AND
EAST AS WELL...THIS COULD REACH OUR FAR SOUTHERN BORDER AREA WITH
COLORADO WITH SOME MODELS EVEN SUGGESTING SOME PRECIPITATION AS FAR
NORTH AS THE WIND RIVER RANGE AND CASPER ON MONDAY. SPREAD THE POPS
THAT FAR NORTH AS A RESULT BUT THE HEAVIER PRECIPITATION IS EXPECTED
TO REMAIN SOUTH OF THE FORECAST AREA THROUGH MONDAY AFTERNOON.

THIS DIGGING TROUGH WILL ALSO BE ACCOMPANIED BY A CYCLONICALLY
CURVING JET THAT WILL SERVE TO ENHANCE A SHORT WAVE MOVING IN MONDAY
NIGHT. THIS WAVE IS ASSOCIATED WITH A VERY COLD ARCTIC LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL CANADA. THIS SOUTHERN PIECE OF THAT
SYSTEM WILL INTERACT WITH THE MOISTURE SUPPLIED BY THE SOUTHERN
STORM...PROVIDING SOME SIGNIFICANT MOISTURE TO WORK WITH FOR THIS
TIME OF YEAR. ADDITIONALLY...THE MODELS ARE SHOWING AN ORGANIZED
BAROCLINIC ZONE WITH THE FRONT AS IT DROPS SOUTH THROUGH THE STATE
MONDAY NIGHT INTO TUESDAY FOLLOWED BY A LONG PERIOD OF UPSLOPE FLOW
FOR AREAS EAST OF THE DIVIDE AS HIGH PRESSURE AT THE SURFACE FILTERS
IN BEHIND THE FRONT. SO THERE WILL BE SEVERAL FEATURES THAT WOULD
SUGGEST SOME AREAS OF SIGNIFICANT SNOW ACCUMULATION WITH THIS
SYSTEM. HOWEVER...IT IS A PRETTY COLD SYSTEM ALOFT SO ONCE THAT
FRONT PASSES BY THE MOISTURE AVAILABLE FOR HEAVY SNOW WILL BE
SQUEEZED OUT AND SHUNTED SOUTH AND EAST. ADDITIONALLY...THERE IS NOT
A LOT OF INSTABILITY ALONG AND BEHIND THE FRONT SO THAT WILL KEEP
MOST OF THE SNOW BANDING AND LOCAL ENHANCEMENTS SOUTH AND WEST OF
THE DIVIDE FOR MONDAY NIGHT INTO TUESDAY.

TUESDAY NIGHT COULD BE A COLD ONE AS WE CLEAR FROM NORTH TO SOUTH.
THERE WILL BE SOME MILDER AIR JUST TO THE EAST IN A HURRY TO MOVE IN
HOWEVER...THIS WILL LIKELY LEAD TO SOME SHARP INVERSIONS AND PATCHY
FOG TUESDAY NIGHT AND WEDNESDAY MORNING BUT GIVEN THE EVER
INCREASING SUN ANGLE AND DEVELOPING LEE SIDE TROUGH ON
WEDNESDAY...THE COLD AIR SHOULD NOT BE TOO STUBBORN WITH AT LEAST
SOME MIXING EXPECTED ON WEDNESDAY IF NOT FULL MIXING BY THURSDAY IN
SOME OF THE SHALLOWER BASINS. AS A RESULT...TEMPERATURES COULD GO
FROM 15 BELOW IN SOME BASINS ON WEDNESDAY MORNING TO HIGHS NEAR 40
ON THURSDAY. THE WARMING TREND CONTINUES INTO FRIDAY AND SATURDAY
WITH NO SIGNIFICANT PRECIPITATION EXPECTED ONCE WE CLEAR OUT ON
TUESDAY.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z SUNDAY
WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE WIDESPREAD
MOUNTAIN OBSCURATIONS THROUGH 18Z SUNDAY. SOME CLEARING WILL OCCUR
OVER THE REGION AFTER 18Z WITH VFR CONDITIONS PREVAILING BY 21Z.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL FOG OVER THE
SOUTH THROUGH 12Z WITH IFR TO MVFR CONDITIONS. CONDITIONS WILL
IMPROVE AFTER 19Z WITH VFR CONDITIONS PREVAILING BY 22Z.

THE REST OF THE REGION WILL HAVE VFR CEILINGS OVERNIGHT INTO SUNDAY
MORNING. CLOUDS WILL DECREASE AROUND 18Z SUNDAY BUT THEN INCREASE
AGAIN SUNDAY NIGHT WITH VFR CEILINGS BY 03Z MONDAY.

KJAC AIRPORT WILL SEE VFR CONDITIONS PREVAIL THROUGH THE FORECAST
PERIOD.

&&

.FIRE WEATHER...

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG. THIS WILL ALSO INCREASE STRONG
TEMPERATURE INVERSIONS PRODUCING STRONG THERMAL BELTS...LOW MIXING
HEIGHTS AND GENERALLY POOR SMOKE DISPERSAL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...C.BAKER
LONG TERM...ALLEN
AVIATION...AR
FIRE WEATHER...C.BAKER












000
FXUS65 KRIW 282153
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
253 PM MST SAT FEB 28 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG.  PARTIAL CLEARING WILL OCCUR ACROSS THE
NORTH SUNDAY AFTERNOON.  TEMPERATURES WILL REMAIN ON THE COLD SIDE.
LOCAL SNOWFALL OF AN INCH WITH VERY LOW DENSITY SNOW CAN BE
EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

AN UPPER LOW RACING DOWN THE BACK SIDE OF A TROUGH DIGGING TO OUR
SOUTHWEST WILL FUJIWHARA THE CLOSED UPPER LOW OVER SOUTHERN
CALIFORNIA...WHIPPING IT UP INTO THE FOUR CORNERS AREA. IT WILL
KICK UP SOME MOISTURE ASSOCIATED WITH THAT LOW FURTHER NORTH AND
EAST AS WELL...THIS COULD REACH OUR FAR SOUTHERN BORDER AREA WITH
COLORADO WITH SOME MODELS EVEN SUGGESTING SOME PRECIPITATION AS FAR
NORTH AS THE WIND RIVER RANGE AND CASPER ON MONDAY. SPREAD THE POPS
THAT FAR NORTH AS A RESULT BUT THE HEAVIER PRECIPITATION IS EXPECTED
TO REMAIN SOUTH OF THE FORECAST AREA THROUGH MONDAY AFTERNOON.

THIS DIGGING TROUGH WILL ALSO BE ACCOMPANIED BY A CYCLONICALLY
CURVING JET THAT WILL SERVE TO ENHANCE A SHORT WAVE MOVING IN MONDAY
NIGHT. THIS WAVE IS ASSOCIATED WITH A VERY COLD ARCTIC LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL CANADA. THIS SOUTHERN PIECE OF THAT
SYSTEM WILL INTERACT WITH THE MOISTURE SUPPLIED BY THE SOUTHERN
STORM...PROVIDING SOME SIGNIFICANT MOISTURE TO WORK WITH FOR THIS
TIME OF YEAR. ADDITIONALLY...THE MODELS ARE SHOWING AN ORGANIZED
BAROCLINIC ZONE WITH THE FRONT AS IT DROPS SOUTH THROUGH THE STATE
MONDAY NIGHT INTO TUESDAY FOLLOWED BY A LONG PERIOD OF UPSLOPE FLOW
FOR AREAS EAST OF THE DIVIDE AS HIGH PRESSURE AT THE SURFACE FILTERS
IN BEHIND THE FRONT. SO THERE WILL BE SEVERAL FEATURES THAT WOULD
SUGGEST SOME AREAS OF SIGNIFICANT SNOW ACCUMULATION WITH THIS
SYSTEM. HOWEVER...IT IS A PRETTY COLD SYSTEM ALOFT SO ONCE THAT
FRONT PASSES BY THE MOISTURE AVAILABLE FOR HEAVY SNOW WILL BE
SQUEEZED OUT AND SHUNTED SOUTH AND EAST. ADDITIONALLY...THERE IS NOT
A LOT OF INSTABILITY ALONG AND BEHIND THE FRONT SO THAT WILL KEEP
MOST OF THE SNOW BANDING AND LOCAL ENHANCEMENTS SOUTH AND WEST OF
THE DIVIDE FOR MONDAY NIGHT INTO TUESDAY.

TUESDAY NIGHT COULD BE A COLD ONE AS WE CLEAR FROM NORTH TO SOUTH.
THERE WILL BE SOME MILDER AIR JUST TO THE EAST IN A HURRY TO MOVE IN
HOWEVER...THIS WILL LIKELY LEAD TO SOME SHARP INVERSIONS AND PATCHY
FOG TUESDAY NIGHT AND WEDNESDAY MORNING BUT GIVEN THE EVER
INCREASING SUN ANGLE AND DEVELOPING LEE SIDE TROUGH ON
WEDNESDAY...THE COLD AIR SHOULD NOT BE TOO STUBBORN WITH AT LEAST
SOME MIXING EXPECTED ON WEDNESDAY IF NOT FULL MIXING BY THURSDAY IN
SOME OF THE SHALLOWER BASINS. AS A RESULT...TEMPERATURES COULD GO
FROM 15 BELOW IN SOME BASINS ON WEDNESDAY MORNING TO HIGHS NEAR 40
ON THURSDAY. THE WARMING TREND CONTINUES INTO FRIDAY AND SATURDAY
WITH NO SIGNIFICANT PRECIPITATION EXPECTED ONCE WE CLEAR OUT ON
TUESDAY.

&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS. PARTIAL CLEARING WILL OCCUR ACROSS
THE NORTH 18Z SUNDAY TO 00Z MONDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS. PARTIAL CLEARING WILL OCCUR ACROSS
THE NORTH 18Z SUNDAY TO 00Z MONDAY.

&&

.FIRE WEATHER...

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG. THIS WILL ALSO INCREASE STRONG
TEMPERATURE INVERSIONS PRODUCING STRONG THERMAL BELTS...LOW MIXING
HEIGHTS AND GENERALLY POOR SMOKE DISPERSAL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...C.BAKER
LONG TERM...ALLEN
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER









000
FXUS65 KRIW 282153
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
253 PM MST SAT FEB 28 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG.  PARTIAL CLEARING WILL OCCUR ACROSS THE
NORTH SUNDAY AFTERNOON.  TEMPERATURES WILL REMAIN ON THE COLD SIDE.
LOCAL SNOWFALL OF AN INCH WITH VERY LOW DENSITY SNOW CAN BE
EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

AN UPPER LOW RACING DOWN THE BACK SIDE OF A TROUGH DIGGING TO OUR
SOUTHWEST WILL FUJIWHARA THE CLOSED UPPER LOW OVER SOUTHERN
CALIFORNIA...WHIPPING IT UP INTO THE FOUR CORNERS AREA. IT WILL
KICK UP SOME MOISTURE ASSOCIATED WITH THAT LOW FURTHER NORTH AND
EAST AS WELL...THIS COULD REACH OUR FAR SOUTHERN BORDER AREA WITH
COLORADO WITH SOME MODELS EVEN SUGGESTING SOME PRECIPITATION AS FAR
NORTH AS THE WIND RIVER RANGE AND CASPER ON MONDAY. SPREAD THE POPS
THAT FAR NORTH AS A RESULT BUT THE HEAVIER PRECIPITATION IS EXPECTED
TO REMAIN SOUTH OF THE FORECAST AREA THROUGH MONDAY AFTERNOON.

THIS DIGGING TROUGH WILL ALSO BE ACCOMPANIED BY A CYCLONICALLY
CURVING JET THAT WILL SERVE TO ENHANCE A SHORT WAVE MOVING IN MONDAY
NIGHT. THIS WAVE IS ASSOCIATED WITH A VERY COLD ARCTIC LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL CANADA. THIS SOUTHERN PIECE OF THAT
SYSTEM WILL INTERACT WITH THE MOISTURE SUPPLIED BY THE SOUTHERN
STORM...PROVIDING SOME SIGNIFICANT MOISTURE TO WORK WITH FOR THIS
TIME OF YEAR. ADDITIONALLY...THE MODELS ARE SHOWING AN ORGANIZED
BAROCLINIC ZONE WITH THE FRONT AS IT DROPS SOUTH THROUGH THE STATE
MONDAY NIGHT INTO TUESDAY FOLLOWED BY A LONG PERIOD OF UPSLOPE FLOW
FOR AREAS EAST OF THE DIVIDE AS HIGH PRESSURE AT THE SURFACE FILTERS
IN BEHIND THE FRONT. SO THERE WILL BE SEVERAL FEATURES THAT WOULD
SUGGEST SOME AREAS OF SIGNIFICANT SNOW ACCUMULATION WITH THIS
SYSTEM. HOWEVER...IT IS A PRETTY COLD SYSTEM ALOFT SO ONCE THAT
FRONT PASSES BY THE MOISTURE AVAILABLE FOR HEAVY SNOW WILL BE
SQUEEZED OUT AND SHUNTED SOUTH AND EAST. ADDITIONALLY...THERE IS NOT
A LOT OF INSTABILITY ALONG AND BEHIND THE FRONT SO THAT WILL KEEP
MOST OF THE SNOW BANDING AND LOCAL ENHANCEMENTS SOUTH AND WEST OF
THE DIVIDE FOR MONDAY NIGHT INTO TUESDAY.

TUESDAY NIGHT COULD BE A COLD ONE AS WE CLEAR FROM NORTH TO SOUTH.
THERE WILL BE SOME MILDER AIR JUST TO THE EAST IN A HURRY TO MOVE IN
HOWEVER...THIS WILL LIKELY LEAD TO SOME SHARP INVERSIONS AND PATCHY
FOG TUESDAY NIGHT AND WEDNESDAY MORNING BUT GIVEN THE EVER
INCREASING SUN ANGLE AND DEVELOPING LEE SIDE TROUGH ON
WEDNESDAY...THE COLD AIR SHOULD NOT BE TOO STUBBORN WITH AT LEAST
SOME MIXING EXPECTED ON WEDNESDAY IF NOT FULL MIXING BY THURSDAY IN
SOME OF THE SHALLOWER BASINS. AS A RESULT...TEMPERATURES COULD GO
FROM 15 BELOW IN SOME BASINS ON WEDNESDAY MORNING TO HIGHS NEAR 40
ON THURSDAY. THE WARMING TREND CONTINUES INTO FRIDAY AND SATURDAY
WITH NO SIGNIFICANT PRECIPITATION EXPECTED ONCE WE CLEAR OUT ON
TUESDAY.

&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS. PARTIAL CLEARING WILL OCCUR ACROSS
THE NORTH 18Z SUNDAY TO 00Z MONDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS. PARTIAL CLEARING WILL OCCUR ACROSS
THE NORTH 18Z SUNDAY TO 00Z MONDAY.

&&

.FIRE WEATHER...

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG. THIS WILL ALSO INCREASE STRONG
TEMPERATURE INVERSIONS PRODUCING STRONG THERMAL BELTS...LOW MIXING
HEIGHTS AND GENERALLY POOR SMOKE DISPERSAL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...C.BAKER
LONG TERM...ALLEN
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER










000
FXUS65 KRIW 282153
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
253 PM MST SAT FEB 28 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG.  PARTIAL CLEARING WILL OCCUR ACROSS THE
NORTH SUNDAY AFTERNOON.  TEMPERATURES WILL REMAIN ON THE COLD SIDE.
LOCAL SNOWFALL OF AN INCH WITH VERY LOW DENSITY SNOW CAN BE
EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

AN UPPER LOW RACING DOWN THE BACK SIDE OF A TROUGH DIGGING TO OUR
SOUTHWEST WILL FUJIWHARA THE CLOSED UPPER LOW OVER SOUTHERN
CALIFORNIA...WHIPPING IT UP INTO THE FOUR CORNERS AREA. IT WILL
KICK UP SOME MOISTURE ASSOCIATED WITH THAT LOW FURTHER NORTH AND
EAST AS WELL...THIS COULD REACH OUR FAR SOUTHERN BORDER AREA WITH
COLORADO WITH SOME MODELS EVEN SUGGESTING SOME PRECIPITATION AS FAR
NORTH AS THE WIND RIVER RANGE AND CASPER ON MONDAY. SPREAD THE POPS
THAT FAR NORTH AS A RESULT BUT THE HEAVIER PRECIPITATION IS EXPECTED
TO REMAIN SOUTH OF THE FORECAST AREA THROUGH MONDAY AFTERNOON.

THIS DIGGING TROUGH WILL ALSO BE ACCOMPANIED BY A CYCLONICALLY
CURVING JET THAT WILL SERVE TO ENHANCE A SHORT WAVE MOVING IN MONDAY
NIGHT. THIS WAVE IS ASSOCIATED WITH A VERY COLD ARCTIC LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL CANADA. THIS SOUTHERN PIECE OF THAT
SYSTEM WILL INTERACT WITH THE MOISTURE SUPPLIED BY THE SOUTHERN
STORM...PROVIDING SOME SIGNIFICANT MOISTURE TO WORK WITH FOR THIS
TIME OF YEAR. ADDITIONALLY...THE MODELS ARE SHOWING AN ORGANIZED
BAROCLINIC ZONE WITH THE FRONT AS IT DROPS SOUTH THROUGH THE STATE
MONDAY NIGHT INTO TUESDAY FOLLOWED BY A LONG PERIOD OF UPSLOPE FLOW
FOR AREAS EAST OF THE DIVIDE AS HIGH PRESSURE AT THE SURFACE FILTERS
IN BEHIND THE FRONT. SO THERE WILL BE SEVERAL FEATURES THAT WOULD
SUGGEST SOME AREAS OF SIGNIFICANT SNOW ACCUMULATION WITH THIS
SYSTEM. HOWEVER...IT IS A PRETTY COLD SYSTEM ALOFT SO ONCE THAT
FRONT PASSES BY THE MOISTURE AVAILABLE FOR HEAVY SNOW WILL BE
SQUEEZED OUT AND SHUNTED SOUTH AND EAST. ADDITIONALLY...THERE IS NOT
A LOT OF INSTABILITY ALONG AND BEHIND THE FRONT SO THAT WILL KEEP
MOST OF THE SNOW BANDING AND LOCAL ENHANCEMENTS SOUTH AND WEST OF
THE DIVIDE FOR MONDAY NIGHT INTO TUESDAY.

TUESDAY NIGHT COULD BE A COLD ONE AS WE CLEAR FROM NORTH TO SOUTH.
THERE WILL BE SOME MILDER AIR JUST TO THE EAST IN A HURRY TO MOVE IN
HOWEVER...THIS WILL LIKELY LEAD TO SOME SHARP INVERSIONS AND PATCHY
FOG TUESDAY NIGHT AND WEDNESDAY MORNING BUT GIVEN THE EVER
INCREASING SUN ANGLE AND DEVELOPING LEE SIDE TROUGH ON
WEDNESDAY...THE COLD AIR SHOULD NOT BE TOO STUBBORN WITH AT LEAST
SOME MIXING EXPECTED ON WEDNESDAY IF NOT FULL MIXING BY THURSDAY IN
SOME OF THE SHALLOWER BASINS. AS A RESULT...TEMPERATURES COULD GO
FROM 15 BELOW IN SOME BASINS ON WEDNESDAY MORNING TO HIGHS NEAR 40
ON THURSDAY. THE WARMING TREND CONTINUES INTO FRIDAY AND SATURDAY
WITH NO SIGNIFICANT PRECIPITATION EXPECTED ONCE WE CLEAR OUT ON
TUESDAY.

&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS. PARTIAL CLEARING WILL OCCUR ACROSS
THE NORTH 18Z SUNDAY TO 00Z MONDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS. PARTIAL CLEARING WILL OCCUR ACROSS
THE NORTH 18Z SUNDAY TO 00Z MONDAY.

&&

.FIRE WEATHER...

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG. THIS WILL ALSO INCREASE STRONG
TEMPERATURE INVERSIONS PRODUCING STRONG THERMAL BELTS...LOW MIXING
HEIGHTS AND GENERALLY POOR SMOKE DISPERSAL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...C.BAKER
LONG TERM...ALLEN
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER









000
FXUS65 KRIW 282153
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
253 PM MST SAT FEB 28 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG.  PARTIAL CLEARING WILL OCCUR ACROSS THE
NORTH SUNDAY AFTERNOON.  TEMPERATURES WILL REMAIN ON THE COLD SIDE.
LOCAL SNOWFALL OF AN INCH WITH VERY LOW DENSITY SNOW CAN BE
EXPECTED.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY

AN UPPER LOW RACING DOWN THE BACK SIDE OF A TROUGH DIGGING TO OUR
SOUTHWEST WILL FUJIWHARA THE CLOSED UPPER LOW OVER SOUTHERN
CALIFORNIA...WHIPPING IT UP INTO THE FOUR CORNERS AREA. IT WILL
KICK UP SOME MOISTURE ASSOCIATED WITH THAT LOW FURTHER NORTH AND
EAST AS WELL...THIS COULD REACH OUR FAR SOUTHERN BORDER AREA WITH
COLORADO WITH SOME MODELS EVEN SUGGESTING SOME PRECIPITATION AS FAR
NORTH AS THE WIND RIVER RANGE AND CASPER ON MONDAY. SPREAD THE POPS
THAT FAR NORTH AS A RESULT BUT THE HEAVIER PRECIPITATION IS EXPECTED
TO REMAIN SOUTH OF THE FORECAST AREA THROUGH MONDAY AFTERNOON.

THIS DIGGING TROUGH WILL ALSO BE ACCOMPANIED BY A CYCLONICALLY
CURVING JET THAT WILL SERVE TO ENHANCE A SHORT WAVE MOVING IN MONDAY
NIGHT. THIS WAVE IS ASSOCIATED WITH A VERY COLD ARCTIC LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL CANADA. THIS SOUTHERN PIECE OF THAT
SYSTEM WILL INTERACT WITH THE MOISTURE SUPPLIED BY THE SOUTHERN
STORM...PROVIDING SOME SIGNIFICANT MOISTURE TO WORK WITH FOR THIS
TIME OF YEAR. ADDITIONALLY...THE MODELS ARE SHOWING AN ORGANIZED
BAROCLINIC ZONE WITH THE FRONT AS IT DROPS SOUTH THROUGH THE STATE
MONDAY NIGHT INTO TUESDAY FOLLOWED BY A LONG PERIOD OF UPSLOPE FLOW
FOR AREAS EAST OF THE DIVIDE AS HIGH PRESSURE AT THE SURFACE FILTERS
IN BEHIND THE FRONT. SO THERE WILL BE SEVERAL FEATURES THAT WOULD
SUGGEST SOME AREAS OF SIGNIFICANT SNOW ACCUMULATION WITH THIS
SYSTEM. HOWEVER...IT IS A PRETTY COLD SYSTEM ALOFT SO ONCE THAT
FRONT PASSES BY THE MOISTURE AVAILABLE FOR HEAVY SNOW WILL BE
SQUEEZED OUT AND SHUNTED SOUTH AND EAST. ADDITIONALLY...THERE IS NOT
A LOT OF INSTABILITY ALONG AND BEHIND THE FRONT SO THAT WILL KEEP
MOST OF THE SNOW BANDING AND LOCAL ENHANCEMENTS SOUTH AND WEST OF
THE DIVIDE FOR MONDAY NIGHT INTO TUESDAY.

TUESDAY NIGHT COULD BE A COLD ONE AS WE CLEAR FROM NORTH TO SOUTH.
THERE WILL BE SOME MILDER AIR JUST TO THE EAST IN A HURRY TO MOVE IN
HOWEVER...THIS WILL LIKELY LEAD TO SOME SHARP INVERSIONS AND PATCHY
FOG TUESDAY NIGHT AND WEDNESDAY MORNING BUT GIVEN THE EVER
INCREASING SUN ANGLE AND DEVELOPING LEE SIDE TROUGH ON
WEDNESDAY...THE COLD AIR SHOULD NOT BE TOO STUBBORN WITH AT LEAST
SOME MIXING EXPECTED ON WEDNESDAY IF NOT FULL MIXING BY THURSDAY IN
SOME OF THE SHALLOWER BASINS. AS A RESULT...TEMPERATURES COULD GO
FROM 15 BELOW IN SOME BASINS ON WEDNESDAY MORNING TO HIGHS NEAR 40
ON THURSDAY. THE WARMING TREND CONTINUES INTO FRIDAY AND SATURDAY
WITH NO SIGNIFICANT PRECIPITATION EXPECTED ONCE WE CLEAR OUT ON
TUESDAY.

&&

.AVIATION.../00Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS. PARTIAL CLEARING WILL OCCUR ACROSS
THE NORTH 18Z SUNDAY TO 00Z MONDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS. PARTIAL CLEARING WILL OCCUR ACROSS
THE NORTH 18Z SUNDAY TO 00Z MONDAY.

&&

.FIRE WEATHER...

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW...WITH LIMITED MOISTURE IN THE MID LEVELS...WILL CONTINUE TO
PRODUCE CONDITIONS FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO
LIGHT SNOW AND LOCAL FOG. THIS WILL ALSO INCREASE STRONG
TEMPERATURE INVERSIONS PRODUCING STRONG THERMAL BELTS...LOW MIXING
HEIGHTS AND GENERALLY POOR SMOKE DISPERSAL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...C.BAKER
LONG TERM...ALLEN
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER










000
FXUS65 KRIW 281813
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1113 AM MST SAT FEB 28 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

A WEAK DISTURBANCE MOVING THROUGH NORTHERN WYOMING WILL BRING SOME
VERY LIGHT SHOWERS ACROSS THE AREA TODAY. THE MORE SIGNIFICANT
SYSTEM IS THE AREA OF LOW PRESSURE MOVING DOWN THE PACIFIC
COASTLINE.

THE NEARBY LOW PRESSURE WILL SEND PUSHES OF MOISTURE ACROSS SOUTHERN
WYOMING BY THIS EVENING...MAINLY IMPACTING THE SOUTHERN HALF OF
SWEETWATER COUNTY. THE SHOWERS WILL WEAKEN LATER TONIGHT AS THE
SYSTEM MOVES NEAR SOUTHERN CALIFORNIA.

THE AREA OF LOW PRESSURE IS THEN EXPECTED TO START MOVING INLAND AND
CONTINUE ON AN EASTERLY TRACK. AS THE SYSTEM REACHES CLOSER TO THE
FOUR CORNERS REGION ON MONDAY EVENING...IT WILL SEND ANOTHER ROUND
OF SHOWER ACTIVITY ACROSS SOUTHERN WYOMING. SIMULTANEOUSLY...A WAVE
OF LOW PRESSURE WILL MOVE INTO NORTHERN WYOMING FROM
CANADA..USHERING COOLING TEMPERATURES ACROSS THE AREA. MODELS
ATTEMPT TO HAVE THESE TWO APPROACHING SYSTEMS MERGE BY LATE MONDAY
NIGHT...RESULTING IN WIDESPREAD PRECIPITATION ACROSS THE FORECAST
AREA. MODELS ARE IN DECENT AGREEMENT WITH THIS SOLUTION...AIDING TO
SOME INCREASED CONFIDENCE IN ITS DEVELOPMENT. HOWEVER...IT IS IN FAR
REACHES OF THE FORECAST PERIOD...SO DID NOT TREND POP FORECAST TOO
HIGH.

.LONG TERM...TUESDAY THROUGH SATURDAY

SYSTEM MOVING TOWARDS WRN ALASKA REMAINS OUR MONDAY NIGHT/TUESDAY
STORM SYSTEM. MODELS CONTINUE TO HAVE VARIATION IN HOW THE ENERGY
DIVES DOWN THE FRONT SIDE OF THE RIDGE AND HOW MANY PIECES THERE MAY
BE. THEY ALL HAVE A DECENT PIECE OF ENERGY THAT DIVES DOWN INTO ERN
IDAHO/WRN WYO LATE MONDAY NIGHT OR TUESDAY MORNING CLOSING OFF A
H7 LOW NEAR JAC. THE GFS/EURO BY 12Z TUE AND THE GEM BY 18Z TUE. BY THE
START OF THIS PERIOD...THE FRONT HAS ALREADY PUSHED THROUGH ALL
BUT THE SW PART OF THE FORECAST AREA. IN ADDITION...THE WEAKENING
UPPER LOW TO THE SOUTH WILL CONTINUE TO STREAM MOISTURE INTO THE
SRN PART OF THE AREA POTENTIALLY OVERRUNNING THE COLD...MOIST DOME
ADVANCING FROM THE NORTH. ACTIVE JET STREAM DYNAMICS START MONDAY
NIGHT AND CARRYOVER JUST SLIGHTLY INTO TUESDAY MORNING IN OUR SERN
ZONES. THE SHORTWAVE TO THE WEST AND JET STREAK PROVIDE SOME
FORCING IN THE W AND THEN SW INTO TUESDAY EVENING. SNOW FOR MANY
AREAS ON TUESDAY WITH TEMPERATURES STEADY OR FALLING. RAN DIURNAL
FROM MOS FOR THE START OF THIS PERIOD TO INDICATE FALLING TEMPS
TUESDAY BEHIND THE FRONT. CLEARING FROM THE NORTH TUESDAY NIGHT WITH
BITTER COLD OVERNIGHT LOWS EXPECTED AS H7 TEMPS PLUMMET TO BETWEEN
-25C AND NEAR -30C IN THE FAR NRN/NERN ZONES POTENTIALLY. CLEARING
SKY COULD RESULT IN RECORD LOWS WEDNESDAY MORNING. THE COLDER
AREAS COULD SEE 10 TO 20 BELOW ZERO WITH COLDER YET IN YNP. ABOUT
THE ONLY THING THAT COULD STOP IT IS SLOWER CLEARING TUESDAY
NIGHT. RAW DAY WEDNESDAY BUT AT LEAST WE COULD SEE SOME DECENT
SUN. RIDGE IS THEN FORECAST TO DEAMPLIFY AND REMAIN TO THE WEST
WITH RAPIDLY MODERATING MID LEVEL TEMPS. SOME LEE TROUGHING
DEVELOPING WEDNESDAY/WED NGT TO MODERATE THE WIND CORRIDOR AND
POSSIBLY CODY FOOTHILLS SOME WITH OTHER AREAS REMAINING QUITE
COLD. HIGHS SHOULD MODERATE THURSDAY INTO FRIDAY AND POSSIBLY
THROUGH SATURDAY AS MARCH SUN PROVIDES SOME ASSISTANCE THAT
WOULDN`T HAVE HELPED MUCH BACK IN DEC/JAN OR EVEN EARLY FEB. SO
20S AND 30S THURSDAY AND THEN 30S AND 40S MOST AREAS FRI AND SAT.

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS.

.FIRE WEATHER...

PERIODS OF LIGHT SNOW AND FOG WILL BE POSSIBLE TODAY. SOUTHERN
WYOMING LOOKS TO TAKE THE BRUNT OF ANY ACTIVITY...THOUGH MODELS
HAVE RELAXED A BIT FROM PREVIOUS FORECASTS. A RELATIVELY QUIET
COUPLE DAYS INTO THE EARLY PORTION OF THE WEEKEND AHEAD OF THE
NEXT WINTRY SYSTEM. SNOWFALL WILL MOVE INTO SOUTHERN WYOMING LATE
MONDAY NIGHT...WHILE A SEPARATE SYSTEM SENDS SNOWFALL ACROSS
NORTHERN WYOMING. THE TWO SYSTEMS ARE EXPECTED TO MERGE LATE
MONDAY NIGHT...POTENTIALLY CREATING WIDESPREAD SNOWFALL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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








000
FXUS65 KRIW 281813
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1113 AM MST SAT FEB 28 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

A WEAK DISTURBANCE MOVING THROUGH NORTHERN WYOMING WILL BRING SOME
VERY LIGHT SHOWERS ACROSS THE AREA TODAY. THE MORE SIGNIFICANT
SYSTEM IS THE AREA OF LOW PRESSURE MOVING DOWN THE PACIFIC
COASTLINE.

THE NEARBY LOW PRESSURE WILL SEND PUSHES OF MOISTURE ACROSS SOUTHERN
WYOMING BY THIS EVENING...MAINLY IMPACTING THE SOUTHERN HALF OF
SWEETWATER COUNTY. THE SHOWERS WILL WEAKEN LATER TONIGHT AS THE
SYSTEM MOVES NEAR SOUTHERN CALIFORNIA.

THE AREA OF LOW PRESSURE IS THEN EXPECTED TO START MOVING INLAND AND
CONTINUE ON AN EASTERLY TRACK. AS THE SYSTEM REACHES CLOSER TO THE
FOUR CORNERS REGION ON MONDAY EVENING...IT WILL SEND ANOTHER ROUND
OF SHOWER ACTIVITY ACROSS SOUTHERN WYOMING. SIMULTANEOUSLY...A WAVE
OF LOW PRESSURE WILL MOVE INTO NORTHERN WYOMING FROM
CANADA..USHERING COOLING TEMPERATURES ACROSS THE AREA. MODELS
ATTEMPT TO HAVE THESE TWO APPROACHING SYSTEMS MERGE BY LATE MONDAY
NIGHT...RESULTING IN WIDESPREAD PRECIPITATION ACROSS THE FORECAST
AREA. MODELS ARE IN DECENT AGREEMENT WITH THIS SOLUTION...AIDING TO
SOME INCREASED CONFIDENCE IN ITS DEVELOPMENT. HOWEVER...IT IS IN FAR
REACHES OF THE FORECAST PERIOD...SO DID NOT TREND POP FORECAST TOO
HIGH.

.LONG TERM...TUESDAY THROUGH SATURDAY

SYSTEM MOVING TOWARDS WRN ALASKA REMAINS OUR MONDAY NIGHT/TUESDAY
STORM SYSTEM. MODELS CONTINUE TO HAVE VARIATION IN HOW THE ENERGY
DIVES DOWN THE FRONT SIDE OF THE RIDGE AND HOW MANY PIECES THERE MAY
BE. THEY ALL HAVE A DECENT PIECE OF ENERGY THAT DIVES DOWN INTO ERN
IDAHO/WRN WYO LATE MONDAY NIGHT OR TUESDAY MORNING CLOSING OFF A
H7 LOW NEAR JAC. THE GFS/EURO BY 12Z TUE AND THE GEM BY 18Z TUE. BY THE
START OF THIS PERIOD...THE FRONT HAS ALREADY PUSHED THROUGH ALL
BUT THE SW PART OF THE FORECAST AREA. IN ADDITION...THE WEAKENING
UPPER LOW TO THE SOUTH WILL CONTINUE TO STREAM MOISTURE INTO THE
SRN PART OF THE AREA POTENTIALLY OVERRUNNING THE COLD...MOIST DOME
ADVANCING FROM THE NORTH. ACTIVE JET STREAM DYNAMICS START MONDAY
NIGHT AND CARRYOVER JUST SLIGHTLY INTO TUESDAY MORNING IN OUR SERN
ZONES. THE SHORTWAVE TO THE WEST AND JET STREAK PROVIDE SOME
FORCING IN THE W AND THEN SW INTO TUESDAY EVENING. SNOW FOR MANY
AREAS ON TUESDAY WITH TEMPERATURES STEADY OR FALLING. RAN DIURNAL
FROM MOS FOR THE START OF THIS PERIOD TO INDICATE FALLING TEMPS
TUESDAY BEHIND THE FRONT. CLEARING FROM THE NORTH TUESDAY NIGHT WITH
BITTER COLD OVERNIGHT LOWS EXPECTED AS H7 TEMPS PLUMMET TO BETWEEN
-25C AND NEAR -30C IN THE FAR NRN/NERN ZONES POTENTIALLY. CLEARING
SKY COULD RESULT IN RECORD LOWS WEDNESDAY MORNING. THE COLDER
AREAS COULD SEE 10 TO 20 BELOW ZERO WITH COLDER YET IN YNP. ABOUT
THE ONLY THING THAT COULD STOP IT IS SLOWER CLEARING TUESDAY
NIGHT. RAW DAY WEDNESDAY BUT AT LEAST WE COULD SEE SOME DECENT
SUN. RIDGE IS THEN FORECAST TO DEAMPLIFY AND REMAIN TO THE WEST
WITH RAPIDLY MODERATING MID LEVEL TEMPS. SOME LEE TROUGHING
DEVELOPING WEDNESDAY/WED NGT TO MODERATE THE WIND CORRIDOR AND
POSSIBLY CODY FOOTHILLS SOME WITH OTHER AREAS REMAINING QUITE
COLD. HIGHS SHOULD MODERATE THURSDAY INTO FRIDAY AND POSSIBLY
THROUGH SATURDAY AS MARCH SUN PROVIDES SOME ASSISTANCE THAT
WOULDN`T HAVE HELPED MUCH BACK IN DEC/JAN OR EVEN EARLY FEB. SO
20S AND 30S THURSDAY AND THEN 30S AND 40S MOST AREAS FRI AND SAT.

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS.

.FIRE WEATHER...

PERIODS OF LIGHT SNOW AND FOG WILL BE POSSIBLE TODAY. SOUTHERN
WYOMING LOOKS TO TAKE THE BRUNT OF ANY ACTIVITY...THOUGH MODELS
HAVE RELAXED A BIT FROM PREVIOUS FORECASTS. A RELATIVELY QUIET
COUPLE DAYS INTO THE EARLY PORTION OF THE WEEKEND AHEAD OF THE
NEXT WINTRY SYSTEM. SNOWFALL WILL MOVE INTO SOUTHERN WYOMING LATE
MONDAY NIGHT...WHILE A SEPARATE SYSTEM SENDS SNOWFALL ACROSS
NORTHERN WYOMING. THE TWO SYSTEMS ARE EXPECTED TO MERGE LATE
MONDAY NIGHT...POTENTIALLY CREATING WIDESPREAD SNOWFALL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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







000
FXUS65 KRIW 281813
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1113 AM MST SAT FEB 28 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

A WEAK DISTURBANCE MOVING THROUGH NORTHERN WYOMING WILL BRING SOME
VERY LIGHT SHOWERS ACROSS THE AREA TODAY. THE MORE SIGNIFICANT
SYSTEM IS THE AREA OF LOW PRESSURE MOVING DOWN THE PACIFIC
COASTLINE.

THE NEARBY LOW PRESSURE WILL SEND PUSHES OF MOISTURE ACROSS SOUTHERN
WYOMING BY THIS EVENING...MAINLY IMPACTING THE SOUTHERN HALF OF
SWEETWATER COUNTY. THE SHOWERS WILL WEAKEN LATER TONIGHT AS THE
SYSTEM MOVES NEAR SOUTHERN CALIFORNIA.

THE AREA OF LOW PRESSURE IS THEN EXPECTED TO START MOVING INLAND AND
CONTINUE ON AN EASTERLY TRACK. AS THE SYSTEM REACHES CLOSER TO THE
FOUR CORNERS REGION ON MONDAY EVENING...IT WILL SEND ANOTHER ROUND
OF SHOWER ACTIVITY ACROSS SOUTHERN WYOMING. SIMULTANEOUSLY...A WAVE
OF LOW PRESSURE WILL MOVE INTO NORTHERN WYOMING FROM
CANADA..USHERING COOLING TEMPERATURES ACROSS THE AREA. MODELS
ATTEMPT TO HAVE THESE TWO APPROACHING SYSTEMS MERGE BY LATE MONDAY
NIGHT...RESULTING IN WIDESPREAD PRECIPITATION ACROSS THE FORECAST
AREA. MODELS ARE IN DECENT AGREEMENT WITH THIS SOLUTION...AIDING TO
SOME INCREASED CONFIDENCE IN ITS DEVELOPMENT. HOWEVER...IT IS IN FAR
REACHES OF THE FORECAST PERIOD...SO DID NOT TREND POP FORECAST TOO
HIGH.

.LONG TERM...TUESDAY THROUGH SATURDAY

SYSTEM MOVING TOWARDS WRN ALASKA REMAINS OUR MONDAY NIGHT/TUESDAY
STORM SYSTEM. MODELS CONTINUE TO HAVE VARIATION IN HOW THE ENERGY
DIVES DOWN THE FRONT SIDE OF THE RIDGE AND HOW MANY PIECES THERE MAY
BE. THEY ALL HAVE A DECENT PIECE OF ENERGY THAT DIVES DOWN INTO ERN
IDAHO/WRN WYO LATE MONDAY NIGHT OR TUESDAY MORNING CLOSING OFF A
H7 LOW NEAR JAC. THE GFS/EURO BY 12Z TUE AND THE GEM BY 18Z TUE. BY THE
START OF THIS PERIOD...THE FRONT HAS ALREADY PUSHED THROUGH ALL
BUT THE SW PART OF THE FORECAST AREA. IN ADDITION...THE WEAKENING
UPPER LOW TO THE SOUTH WILL CONTINUE TO STREAM MOISTURE INTO THE
SRN PART OF THE AREA POTENTIALLY OVERRUNNING THE COLD...MOIST DOME
ADVANCING FROM THE NORTH. ACTIVE JET STREAM DYNAMICS START MONDAY
NIGHT AND CARRYOVER JUST SLIGHTLY INTO TUESDAY MORNING IN OUR SERN
ZONES. THE SHORTWAVE TO THE WEST AND JET STREAK PROVIDE SOME
FORCING IN THE W AND THEN SW INTO TUESDAY EVENING. SNOW FOR MANY
AREAS ON TUESDAY WITH TEMPERATURES STEADY OR FALLING. RAN DIURNAL
FROM MOS FOR THE START OF THIS PERIOD TO INDICATE FALLING TEMPS
TUESDAY BEHIND THE FRONT. CLEARING FROM THE NORTH TUESDAY NIGHT WITH
BITTER COLD OVERNIGHT LOWS EXPECTED AS H7 TEMPS PLUMMET TO BETWEEN
-25C AND NEAR -30C IN THE FAR NRN/NERN ZONES POTENTIALLY. CLEARING
SKY COULD RESULT IN RECORD LOWS WEDNESDAY MORNING. THE COLDER
AREAS COULD SEE 10 TO 20 BELOW ZERO WITH COLDER YET IN YNP. ABOUT
THE ONLY THING THAT COULD STOP IT IS SLOWER CLEARING TUESDAY
NIGHT. RAW DAY WEDNESDAY BUT AT LEAST WE COULD SEE SOME DECENT
SUN. RIDGE IS THEN FORECAST TO DEAMPLIFY AND REMAIN TO THE WEST
WITH RAPIDLY MODERATING MID LEVEL TEMPS. SOME LEE TROUGHING
DEVELOPING WEDNESDAY/WED NGT TO MODERATE THE WIND CORRIDOR AND
POSSIBLY CODY FOOTHILLS SOME WITH OTHER AREAS REMAINING QUITE
COLD. HIGHS SHOULD MODERATE THURSDAY INTO FRIDAY AND POSSIBLY
THROUGH SATURDAY AS MARCH SUN PROVIDES SOME ASSISTANCE THAT
WOULDN`T HAVE HELPED MUCH BACK IN DEC/JAN OR EVEN EARLY FEB. SO
20S AND 30S THURSDAY AND THEN 30S AND 40S MOST AREAS FRI AND SAT.

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS.

.FIRE WEATHER...

PERIODS OF LIGHT SNOW AND FOG WILL BE POSSIBLE TODAY. SOUTHERN
WYOMING LOOKS TO TAKE THE BRUNT OF ANY ACTIVITY...THOUGH MODELS
HAVE RELAXED A BIT FROM PREVIOUS FORECASTS. A RELATIVELY QUIET
COUPLE DAYS INTO THE EARLY PORTION OF THE WEEKEND AHEAD OF THE
NEXT WINTRY SYSTEM. SNOWFALL WILL MOVE INTO SOUTHERN WYOMING LATE
MONDAY NIGHT...WHILE A SEPARATE SYSTEM SENDS SNOWFALL ACROSS
NORTHERN WYOMING. THE TWO SYSTEMS ARE EXPECTED TO MERGE LATE
MONDAY NIGHT...POTENTIALLY CREATING WIDESPREAD SNOWFALL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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








000
FXUS65 KRIW 281813
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1113 AM MST SAT FEB 28 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

A WEAK DISTURBANCE MOVING THROUGH NORTHERN WYOMING WILL BRING SOME
VERY LIGHT SHOWERS ACROSS THE AREA TODAY. THE MORE SIGNIFICANT
SYSTEM IS THE AREA OF LOW PRESSURE MOVING DOWN THE PACIFIC
COASTLINE.

THE NEARBY LOW PRESSURE WILL SEND PUSHES OF MOISTURE ACROSS SOUTHERN
WYOMING BY THIS EVENING...MAINLY IMPACTING THE SOUTHERN HALF OF
SWEETWATER COUNTY. THE SHOWERS WILL WEAKEN LATER TONIGHT AS THE
SYSTEM MOVES NEAR SOUTHERN CALIFORNIA.

THE AREA OF LOW PRESSURE IS THEN EXPECTED TO START MOVING INLAND AND
CONTINUE ON AN EASTERLY TRACK. AS THE SYSTEM REACHES CLOSER TO THE
FOUR CORNERS REGION ON MONDAY EVENING...IT WILL SEND ANOTHER ROUND
OF SHOWER ACTIVITY ACROSS SOUTHERN WYOMING. SIMULTANEOUSLY...A WAVE
OF LOW PRESSURE WILL MOVE INTO NORTHERN WYOMING FROM
CANADA..USHERING COOLING TEMPERATURES ACROSS THE AREA. MODELS
ATTEMPT TO HAVE THESE TWO APPROACHING SYSTEMS MERGE BY LATE MONDAY
NIGHT...RESULTING IN WIDESPREAD PRECIPITATION ACROSS THE FORECAST
AREA. MODELS ARE IN DECENT AGREEMENT WITH THIS SOLUTION...AIDING TO
SOME INCREASED CONFIDENCE IN ITS DEVELOPMENT. HOWEVER...IT IS IN FAR
REACHES OF THE FORECAST PERIOD...SO DID NOT TREND POP FORECAST TOO
HIGH.

.LONG TERM...TUESDAY THROUGH SATURDAY

SYSTEM MOVING TOWARDS WRN ALASKA REMAINS OUR MONDAY NIGHT/TUESDAY
STORM SYSTEM. MODELS CONTINUE TO HAVE VARIATION IN HOW THE ENERGY
DIVES DOWN THE FRONT SIDE OF THE RIDGE AND HOW MANY PIECES THERE MAY
BE. THEY ALL HAVE A DECENT PIECE OF ENERGY THAT DIVES DOWN INTO ERN
IDAHO/WRN WYO LATE MONDAY NIGHT OR TUESDAY MORNING CLOSING OFF A
H7 LOW NEAR JAC. THE GFS/EURO BY 12Z TUE AND THE GEM BY 18Z TUE. BY THE
START OF THIS PERIOD...THE FRONT HAS ALREADY PUSHED THROUGH ALL
BUT THE SW PART OF THE FORECAST AREA. IN ADDITION...THE WEAKENING
UPPER LOW TO THE SOUTH WILL CONTINUE TO STREAM MOISTURE INTO THE
SRN PART OF THE AREA POTENTIALLY OVERRUNNING THE COLD...MOIST DOME
ADVANCING FROM THE NORTH. ACTIVE JET STREAM DYNAMICS START MONDAY
NIGHT AND CARRYOVER JUST SLIGHTLY INTO TUESDAY MORNING IN OUR SERN
ZONES. THE SHORTWAVE TO THE WEST AND JET STREAK PROVIDE SOME
FORCING IN THE W AND THEN SW INTO TUESDAY EVENING. SNOW FOR MANY
AREAS ON TUESDAY WITH TEMPERATURES STEADY OR FALLING. RAN DIURNAL
FROM MOS FOR THE START OF THIS PERIOD TO INDICATE FALLING TEMPS
TUESDAY BEHIND THE FRONT. CLEARING FROM THE NORTH TUESDAY NIGHT WITH
BITTER COLD OVERNIGHT LOWS EXPECTED AS H7 TEMPS PLUMMET TO BETWEEN
-25C AND NEAR -30C IN THE FAR NRN/NERN ZONES POTENTIALLY. CLEARING
SKY COULD RESULT IN RECORD LOWS WEDNESDAY MORNING. THE COLDER
AREAS COULD SEE 10 TO 20 BELOW ZERO WITH COLDER YET IN YNP. ABOUT
THE ONLY THING THAT COULD STOP IT IS SLOWER CLEARING TUESDAY
NIGHT. RAW DAY WEDNESDAY BUT AT LEAST WE COULD SEE SOME DECENT
SUN. RIDGE IS THEN FORECAST TO DEAMPLIFY AND REMAIN TO THE WEST
WITH RAPIDLY MODERATING MID LEVEL TEMPS. SOME LEE TROUGHING
DEVELOPING WEDNESDAY/WED NGT TO MODERATE THE WIND CORRIDOR AND
POSSIBLY CODY FOOTHILLS SOME WITH OTHER AREAS REMAINING QUITE
COLD. HIGHS SHOULD MODERATE THURSDAY INTO FRIDAY AND POSSIBLY
THROUGH SATURDAY AS MARCH SUN PROVIDES SOME ASSISTANCE THAT
WOULDN`T HAVE HELPED MUCH BACK IN DEC/JAN OR EVEN EARLY FEB. SO
20S AND 30S THURSDAY AND THEN 30S AND 40S MOST AREAS FRI AND SAT.

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

COLD NORTH NORTHEAST LOW LEVEL FLOW WITH WEAK WEST OVERRUNNING
FLOW IN THE MID LEVELS WILL CONTINUE TO PRODUCE CONDITIONS
FAVORABLE FOR WIDESPREAD STRATUS...FLURRIES TO LIGHT SNOW AND LOCAL
FOG. IFR TO MVFR CONDITIONS WILL BE RATHER WIDESPREAD THROUGH 18Z
SUNDAY WITH LOCAL VFR CONDITIONS AT TIMES. THIS WILL CAUSE
WIDESPREAD MOUNTAIN OBSCURATIONS.

.FIRE WEATHER...

PERIODS OF LIGHT SNOW AND FOG WILL BE POSSIBLE TODAY. SOUTHERN
WYOMING LOOKS TO TAKE THE BRUNT OF ANY ACTIVITY...THOUGH MODELS
HAVE RELAXED A BIT FROM PREVIOUS FORECASTS. A RELATIVELY QUIET
COUPLE DAYS INTO THE EARLY PORTION OF THE WEEKEND AHEAD OF THE
NEXT WINTRY SYSTEM. SNOWFALL WILL MOVE INTO SOUTHERN WYOMING LATE
MONDAY NIGHT...WHILE A SEPARATE SYSTEM SENDS SNOWFALL ACROSS
NORTHERN WYOMING. THE TWO SYSTEMS ARE EXPECTED TO MERGE LATE
MONDAY NIGHT...POTENTIALLY CREATING WIDESPREAD SNOWFALL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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







000
FXUS65 KRIW 280903
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
203 AM MST SAT FEB 28 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

A WEAK DISTURBANCE MOVING THROUGH NORTHERN WYOMING WILL BRING SOME
VERY LIGHT SHOWERS ACROSS THE AREA TODAY. THE MORE SIGNIFICANT
SYSTEM IS THE AREA OF LOW PRESSURE MOVING DOWN THE PACIFIC
COASTLINE.

THE NEARBY LOW PRESSURE WILL SEND PUSHES OF MOISTURE ACROSS SOUTHERN
WYOMING BY THIS EVENING...MAINLY IMPACTING THE SOUTHERN HALF OF
SWEETWATER COUNTY. THE SHOWERS WILL WEAKEN LATER TONIGHT AS THE
SYSTEM MOVES NEAR SOUTHERN CALIFORNIA.

THE AREA OF LOW PRESSURE IS THEN EXPECTED TO START MOVING INLAND AND
CONTINUE ON AN EASTERLY TRACK. AS THE SYSTEM REACHES CLOSER TO THE
FOUR CORNERS REGION ON MONDAY EVENING...IT WILL SEND ANOTHER ROUND
OF SHOWER ACTIVITY ACROSS SOUTHERN WYOMING. SIMULTANEOUSLY...A WAVE
OF LOW PRESSURE WILL MOVE INTO NORTHERN WYOMING FROM
CANADA..USHERING COOLING TEMPERATURES ACROSS THE AREA. MODELS
ATTEMPT TO HAVE THESE TWO APPROACHING SYSTEMS MERGE BY LATE MONDAY
NIGHT...RESULTING IN WIDESPREAD PRECIPITATION ACROSS THE FORECAST
AREA. MODELS ARE IN DECENT AGREEMENT WITH THIS SOLUTION...AIDING TO
SOME INCREASED CONFIDENCE IN ITS DEVELOPMENT. HOWEVER...IT IS IN FAR
REACHES OF THE FORECAST PERIOD...SO DID NOT TREND POP FORECAST TOO
HIGH.

.LONG TERM...TUESDAY THROUGH SATURDAY

SYSTEM MOVING TOWARDS WRN ALASKA REMAINS OUR MONDAY NIGHT/TUESDAY
STORM SYSTEM. MODELS CONTINUE TO HAVE VARIATION IN HOW THE ENERGY
DIVES DOWN THE FRONT SIDE OF THE RIDGE AND HOW MANY PIECES THERE MAY
BE. THEY ALL HAVE A DECENT PIECE OF ENERGY THAT DIVES DOWN INTO ERN
IDAHO/WRN WYO LATE MONDAY NIGHT OR TUESDAY MORNING CLOSING OFF A
H7 LOW NEAR JAC. THE GFS/EURO BY 12Z TUE AND THE GEM BY 18Z TUE. BY THE
START OF THIS PERIOD...THE FRONT HAS ALREADY PUSHED THROUGH ALL
BUT THE SW PART OF THE FORECAST AREA. IN ADDITION...THE WEAKENING
UPPER LOW TO THE SOUTH WILL CONTINUE TO STREAM MOISTURE INTO THE
SRN PART OF THE AREA POTENTIALLY OVERRUNNING THE COLD...MOIST DOME
ADVANCING FROM THE NORTH. ACTIVE JET STREAM DYNAMICS START MONDAY
NIGHT AND CARRYOVER JUST SLIGHTLY INTO TUESDAY MORNING IN OUR SERN
ZONES. THE SHORTWAVE TO THE WEST AND JET STREAK PROVIDE SOME
FORCING IN THE W AND THEN SW INTO TUESDAY EVENING. SNOW FOR MANY
AREAS ON TUESDAY WITH TEMPERATURES STEADY OR FALLING. RAN DIURNAL
FROM MOS FOR THE START OF THIS PERIOD TO INDICATE FALLING TEMPS
TUESDAY BEHIND THE FRONT. CLEARING FROM THE NORTH TUESDAY NIGHT WITH
BITTER COLD OVERNIGHT LOWS EXPECTED AS H7 TEMPS PLUMMET TO BETWEEN
-25C AND NEAR -30C IN THE FAR NRN/NERN ZONES POTENTIALLY. CLEARING
SKY COULD RESULT IN RECORD LOWS WEDNESDAY MORNING. THE COLDER
AREAS COULD SEE 10 TO 20 BELOW ZERO WITH COLDER YET IN YNP. ABOUT
THE ONLY THING THAT COULD STOP IT IS SLOWER CLEARING TUESDAY
NIGHT. RAW DAY WEDNESDAY BUT AT LEAST WE COULD SEE SOME DECENT
SUN. RIDGE IS THEN FORECAST TO DEAMPLIFY AND REMAIN TO THE WEST
WITH RAPIDLY MODERATING MID LEVEL TEMPS. SOME LEE TROUGHING
DEVELOPING WEDNESDAY/WED NGT TO MODERATE THE WIND CORRIDOR AND
POSSIBLY CODY FOOTHILLS SOME WITH OTHER AREAS REMAINING QUITE
COLD. HIGHS SHOULD MODERATE THURSDAY INTO FRIDAY AND POSSIBLY
THROUGH SATURDAY AS MARCH SUN PROVIDES SOME ASSISTANCE THAT
WOULDN`T HAVE HELPED MUCH BACK IN DEC/JAN OR EVEN EARLY FEB. SO
20S AND 30S THURSDAY AND THEN 30S AND 40S MOST AREAS FRI AND SAT.

&&

.AVIATION.../12Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS WILL OCCUR OVER MOST OF THE REGION
THROUGH 06Z SUNDAY. SOME CLEARING WILL OCCUR OVER NORTHERN WY AFTER
06Z SUNDAY REDUCING SOME OF THE MOUNTAIN OBSCURATION IN THE NORTHERN
MOUNTAINS.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 12Z SUNDAY ACROSS
THE AREA. SOME LIGHT SNOW WILL OCCUR IN PLACES WHICH MAY DROP
VISIBILITY TO MVFR CATEGORY AT TIMES THROUGH THIS EVENING.
IN NORTHERN WY...CONDITIONS WILL IMPROVE TO VFR AS CLOUDS DECREASE
AFTER 06Z SUNDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 12Z SUNDAY ACROSS
THE AREA. AREAS OF LIGHT SNOW WILL OCCUR THROUGH THIS EVENING.
VISIBILITY MAY DROP TO MVFR CATEGORY AT TIMES. GUSTY WIND AT KRKS
AIRPORT MUCH OF TODAY...DECREASING SOME AFTER 06Z SUNDAY.


&&

.FIRE WEATHER...

PERIODS OF SHOWERS WILL BE POSSIBLE TODAY. SOUTHERN WYOMING LOOKS TO
TAKE THE BRUNT OF ANY ACTIVITY...THOUGH MODELS HAVE RELAXED A BIT
FROM PREVIOUS FORECASTS. A RELATIVELY QUIET COUPLE DAYS INTO THE
EARLY PORTION OF THE WEEKEND AHEAD OF THE NEXT WINTRY SYSTEM.
SNOWFALL WILL MOVE INTO SOUTHERN WYOMING LATE MONDAY NIGHT...WHILE A
SEPARATE SYSTEM SENDS SNOWFALL ACROSS NORTHERN WYOMING. THE TWO
SYSTEMS ARE EXPECTED TO MERGE LATE MONDAY NIGHT...POTENTIALLY
CREATING WIDESPREAD SNOWFALL.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...PS
AVIATION...AR
FIRE WEATHER...BRANHAM









000
FXUS65 KRIW 280500
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1000 PM MST FRI FEB 27 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY (ISSUED AT 300 PM MST)

MID-AFTERNOON SATELLITE IMAGERY SHOWING AN UPPER LOW OVER THE
PACIFIC NORTHWEST WHICH WILL BE THE PRIMARY DRIVER OF OUR SENSIBLE
WEATHER THROUGH SATURDAY. ANOTHER VORTICITY CENTER WAS SPINNING EAST
ACROSS EASTERN MONTANA. THE TAIL END OF THIS SYSTEM HAS BEEN
DRAGGING ACROSS THE NORTHWEST PORTION OF THE STATE TODAY. THIS HAS
KEPT LIGHT SNOW ONGOING IN THAT CORNER WITH IR IMAGERY EVEN SHOWING
SOME ENHANCEMENT THE LAST COUPLE OF HOURS. COLDER AIR IN ASSOCIATION
WITH THIS VORTICITY LOBE IS CURRENTLY PUSHING SOUTH THROUGH CENTRAL
MONTANA. SHALLOW COLD DOME WILL BE MOVING IN TO NORTHERN WYOMING
THIS EVENING.

PACIFIC NORTHWEST UPPER LOW WILL MOVE TO THE GREAT BASIN BY SATURDAY
AFTERNOON. THIS WILL KEEP WEAK NORTHWEST FLOW ACROSS THE FORECAST
AREA WITH JUST ENOUGH EMBEDDED MOISTURE TO KEEP LIGHT SNOW GOING IN
THE NORTHWEST MOUNTAINS THROUGH TONIGHT. COLD AIR SURGE WILL BE
PUSHING THROUGH THE BIG HORN BASIN AND JOHNSON COUNTY THIS EVENING.
CLOUD COVER WILL INCREASE BEHIND THIS SURGE BUT LITTLE IS EXPECTED
IN THE WAY OF SNOW. THE COLD AIR WILL WRING OUT WHAT LITTLE MOISTURE
IT CAN...BUT RIGHT NOW HAVE AMOUNTS OF ONE INCH OR LESS. TWEAKED
TEMPERATURES FOR TONIGHT DOWN JUST A HAIR AND DID THE SAME FOR HIGH
TEMPERATURES ON SATURDAY AS SUNSHINE WILL BE LIMITED. SATURDAY
MAXIMUM TEMPERATURES WILL REMAIN WELL BELOW NORMAL...ON THE ORDER OF
15 TO 20 DEGREES...NORTH OF A LANDER TO CASPER LINE. THE SOUTHWEST
WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL. INITIAL GUSTY NORTHERLY
WIND WILL ACCOMPANY THE SURGE OF COLD AIR...BUT PRESSURE RISES DO
NOT APPEAR TO BE THAT IMPRESSIVE. EAST-NORTHEAST WIND WILL BE
STRONGEST ACROSS EASTERN SWEETWATER COUNTY AND NEARBY AREAS. SPEEDS
IN THESE LOCATIONS WILL BE 15 TO 30 MPH. MOISTURE IN WEST-SOUTHWEST
FLOW ALOFT WILL EJECT FROM THE GREAT BASIN LOW AND TRACK TOWARD
SOUTHWEST WYOMING. EARLIER MODEL RUNS...ESPECIALLY THE NAM...HAD
GOOD 850-700MB LAYER FRONTOGENETICAL LIFT SOME POTENTIAL VORTICITY
AND JET ENERGY TO ASSIST SNOWFALL DEVELOPMENT ACROSS SWEETWATER
COUNTY. HOWEVER... NEWEST MODEL RUNS HAVE BEEN BRINGING SURFACE HIGH
FARTHER SOUTH...SO IT LOOKS LESS LIKELY THAT LIGHT SNOW WILL GET AS
FAR NORTH AS I-80 BY 00Z/SUN. TRIED TO INDICATE THIS TREND AS BEST
AS POSSIBLE DURING THE 18Z/SAT-00Z/SUN TIMEFRAME.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

THERE ARE A COUPLE OF CONUNDRUMS IN THE FORECAST TODAY. THE FIRST IS
WHAT WILL HAPPEN SATURDAY NIGHT AND EARLY SUNDAY ALONG THE
INTERSTATE 80 CORRIDOR. THE MODELS CONTINUE TO BE SPLIT. THE GFS AND
THE NEW EUROPEAN SHOW THE COLD FRONT THAT WILL BE THE FOCUS FOR ANY
SNOW PUSHING FAR ENOUGH TO THE SOUTH TO KEEP THE BULK OF THE
PRECIPITATION OVER COLORADO. THE NAM KEEPS THINGS A BIT FARTHER
NORTH. HOWEVER...THE NEW 18Z NAM HAS BACKED OFF AS WELL. AT THIS
TIME...WE TRIMMED POPS AND QPF A LITTLE BUT DID NOT GO ALL THE WAY.
THE EVENING SHIFT SHOULD TAKE ANOTHER LOOK AT THIS TO SEE IF POPS
COULD BE LOWERED SOME MORE. SUNDAY SHOULD FEATURE IMPROVING
CONDITIONS AS THE FRONT SAGS SOUTHWARD OUT OF THE AREA. TEMPERATURES
WILL REMAIN RATHER COLD HOWEVER.

THE NEXT QUESTION IS FOR MONDAY AND INTO TUESDAY. THE QUESTION IS
WHAT WILL HAPPEN WITH THE COLD FRONT DROPPING SOUTHWARD OUT OF
CANADA. THE PREVIOUS SHIFT MENTIONED THAT THE SYSTEM DOES NOT LOOK
AS IMPRESSIVE AND WE AGREE. THERE CONTINUES TO BE NOT GREAT UPPER
LEVEL SUPPORT WITH THE FRONT. THERE IS A BIT OF LEFT FRONT QUAD JET
ENERGY FEEDING THE SYSTEM LATE MONDAY NIGHT INTO TUESDAY MORNING SO
AT THIS TIME THAT LOOKS TO BE THE TIME OF THE WORST CONDITIONS. THE
MODELS ARE ALSO FAIRLY CONSISTENT WITH TIMING. THIS WILL BE A FAIRLY
QUICK HITTER AS WELL WITH MOST OF THE PRECIPITATION OVER BY TUESDAY
EVENING. AND THIS LEADS TO THE NEXT QUESTION...HOW COLD WILL IT GET
TUESDAY NIGHT. THE AIR MASS MOVING INTO THE AREA WILL BE BITTERLY
COLD WITH FLOW COMING STRAIGHT OUT OF THE ARCTIC. IN ADDITION...
FRESH SNOW COVER SHOULD PROVIDE GOOD ALBEDO. 700 MILLIBAR
TEMPERATURES TUESDAY NIGHT LOOK AS COLD AS -25 C. THE WILDCARD IS
HOW MUCH THE SKY WILL CLEAR THOUGH. THE TEMPERATURES IN CONTINUITY
LOOKED REASONABLE SO WE MADE FEW CHANGES. THEY ARE STILL WELL BELOW
THE GUIDANCE WHICH IS SMART SINCE MOS USUALLY DOES A POOR JOB WITH
ARCTIC INTRUSIONS. HIGH TEMPERATURES WILL BE TRICKY FOR THE REST OF
NEXT WEEK AS WELL. WEDNESDAY LOOKS TO BE A COLD DAY DEFINITELY. SOME
MODERATION SHOULD BEGIN THURSDAY AS THE CORE OF THE ARCTIC AIR
RETREATS. THE QUESTION IS INVERSIONS IN THE BASINS AND VALLEYS. IF
IT WAS JANUARY...THEY WOULD HOLD. HOWEVER...WITH THE STRONGER MARCH
SUN THERE IS A BETTER CHANCE OF MIXING OUT. SO...FEW CHANGES WERE
MADE. AS FOR THE POTENTIAL FOR ANOTHER WEATHER MAKER FOR THE END OF
THE WEEK...THE NEW EUROPEAN HAS BACKED OFF OF THE SYSTEM WHILE THE
GFS CONTINUES TO KEEP THINGS DRY. WITH THE GFS CONTINUING TO BE MORE
CONSISTENT...WE KEPT THE FORECAST DRY WITH NEAR NORMAL TEMPERATURES.

&&

.AVIATION.../06Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS WILL OCCUR OVER MOST OF THE REGION
THROUGH 06Z SUNDAY. SOME CLEARING WILL OCCUR OVER NORTHERN WY BY 06Z
SUNDAY REDUCING SOME OF THE MOUNTAIN OBSCURATION IN THE NORTHERN
MOUNTAINS.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 06Z SUNDAY ACROSS
THE AREA. SOME LIGHT SNOW WILL OCCUR IN PLACES WHICH MAY DROP
VISIBILITY TO MVFR CATEGORY AT TIMES THROUGH SATURDAY EVENING.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 06Z SUNDAY ACROSS
THE AREA. AREAS OF LIGHT SNOW WILL OCCUR THROUGH SATURDAY EVENING.
VISIBILITY MAY DROP TO MVFR CATEGORY AT TIMES. GUSTY WIND AT KRKS
AIRPORT MUCH OF SATURDAY...DECREASING SOME BY 06Z SUNDAY.

&&

.FIRE WEATHER...

CONTINUED NORTHWEST FLOW ALOFT WILL ALLOW FOR LIGHT SNOW SHOWERS
ACROSS NORTHWEST WYOMING TONIGHT AND SATURDAY. MOISTURE IS
LIMITED...SO AMOUNTS WILL BE LIGHT. ANOTHER SURGE OF COLDER AIR WILL
PUSH INTO THE NORTHERN BIG HORN BASIN AND JOHNSON COUNTY LATE THIS
EVENING. THIS SURGE WILL REACH CENTRAL WYOMING EARLY SATURDAY AND
SOUTHWEST WYOMING AROUND SUNRISE. EXPECT COLDER TEMPERATURES...MORE
CLOUD COVER...AND VERY LIGHT SNOW WITH THIS AIRMASS. HIGH
TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. DRIER AIR WILL
FILTER INTO THE STATE FROM THE NORTH SATURDAY NIGHT AND SUNDAY. THIS
WILL ALLOW FOR MORE SUNSHINE AND SLIGHTLY WARMER TEMPERATURES...
ALTHOUGH IT WILL REMAIN COLDER THAN NORMAL. THE NEXT CHANCE FOR
WIDESPREAD SNOW COMES TUESDAY AND WEDNESDAY AS ANOTHER COLD SYSTEM
DROPS IN FROM THE NORTH.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...CNJ
LONG TERM...HATTINGS
AVIATION...AR
FIRE WEATHER...CNJ












000
FXUS65 KRIW 280500
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1000 PM MST FRI FEB 27 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY (ISSUED AT 300 PM MST)

MID-AFTERNOON SATELLITE IMAGERY SHOWING AN UPPER LOW OVER THE
PACIFIC NORTHWEST WHICH WILL BE THE PRIMARY DRIVER OF OUR SENSIBLE
WEATHER THROUGH SATURDAY. ANOTHER VORTICITY CENTER WAS SPINNING EAST
ACROSS EASTERN MONTANA. THE TAIL END OF THIS SYSTEM HAS BEEN
DRAGGING ACROSS THE NORTHWEST PORTION OF THE STATE TODAY. THIS HAS
KEPT LIGHT SNOW ONGOING IN THAT CORNER WITH IR IMAGERY EVEN SHOWING
SOME ENHANCEMENT THE LAST COUPLE OF HOURS. COLDER AIR IN ASSOCIATION
WITH THIS VORTICITY LOBE IS CURRENTLY PUSHING SOUTH THROUGH CENTRAL
MONTANA. SHALLOW COLD DOME WILL BE MOVING IN TO NORTHERN WYOMING
THIS EVENING.

PACIFIC NORTHWEST UPPER LOW WILL MOVE TO THE GREAT BASIN BY SATURDAY
AFTERNOON. THIS WILL KEEP WEAK NORTHWEST FLOW ACROSS THE FORECAST
AREA WITH JUST ENOUGH EMBEDDED MOISTURE TO KEEP LIGHT SNOW GOING IN
THE NORTHWEST MOUNTAINS THROUGH TONIGHT. COLD AIR SURGE WILL BE
PUSHING THROUGH THE BIG HORN BASIN AND JOHNSON COUNTY THIS EVENING.
CLOUD COVER WILL INCREASE BEHIND THIS SURGE BUT LITTLE IS EXPECTED
IN THE WAY OF SNOW. THE COLD AIR WILL WRING OUT WHAT LITTLE MOISTURE
IT CAN...BUT RIGHT NOW HAVE AMOUNTS OF ONE INCH OR LESS. TWEAKED
TEMPERATURES FOR TONIGHT DOWN JUST A HAIR AND DID THE SAME FOR HIGH
TEMPERATURES ON SATURDAY AS SUNSHINE WILL BE LIMITED. SATURDAY
MAXIMUM TEMPERATURES WILL REMAIN WELL BELOW NORMAL...ON THE ORDER OF
15 TO 20 DEGREES...NORTH OF A LANDER TO CASPER LINE. THE SOUTHWEST
WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL. INITIAL GUSTY NORTHERLY
WIND WILL ACCOMPANY THE SURGE OF COLD AIR...BUT PRESSURE RISES DO
NOT APPEAR TO BE THAT IMPRESSIVE. EAST-NORTHEAST WIND WILL BE
STRONGEST ACROSS EASTERN SWEETWATER COUNTY AND NEARBY AREAS. SPEEDS
IN THESE LOCATIONS WILL BE 15 TO 30 MPH. MOISTURE IN WEST-SOUTHWEST
FLOW ALOFT WILL EJECT FROM THE GREAT BASIN LOW AND TRACK TOWARD
SOUTHWEST WYOMING. EARLIER MODEL RUNS...ESPECIALLY THE NAM...HAD
GOOD 850-700MB LAYER FRONTOGENETICAL LIFT SOME POTENTIAL VORTICITY
AND JET ENERGY TO ASSIST SNOWFALL DEVELOPMENT ACROSS SWEETWATER
COUNTY. HOWEVER... NEWEST MODEL RUNS HAVE BEEN BRINGING SURFACE HIGH
FARTHER SOUTH...SO IT LOOKS LESS LIKELY THAT LIGHT SNOW WILL GET AS
FAR NORTH AS I-80 BY 00Z/SUN. TRIED TO INDICATE THIS TREND AS BEST
AS POSSIBLE DURING THE 18Z/SAT-00Z/SUN TIMEFRAME.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

THERE ARE A COUPLE OF CONUNDRUMS IN THE FORECAST TODAY. THE FIRST IS
WHAT WILL HAPPEN SATURDAY NIGHT AND EARLY SUNDAY ALONG THE
INTERSTATE 80 CORRIDOR. THE MODELS CONTINUE TO BE SPLIT. THE GFS AND
THE NEW EUROPEAN SHOW THE COLD FRONT THAT WILL BE THE FOCUS FOR ANY
SNOW PUSHING FAR ENOUGH TO THE SOUTH TO KEEP THE BULK OF THE
PRECIPITATION OVER COLORADO. THE NAM KEEPS THINGS A BIT FARTHER
NORTH. HOWEVER...THE NEW 18Z NAM HAS BACKED OFF AS WELL. AT THIS
TIME...WE TRIMMED POPS AND QPF A LITTLE BUT DID NOT GO ALL THE WAY.
THE EVENING SHIFT SHOULD TAKE ANOTHER LOOK AT THIS TO SEE IF POPS
COULD BE LOWERED SOME MORE. SUNDAY SHOULD FEATURE IMPROVING
CONDITIONS AS THE FRONT SAGS SOUTHWARD OUT OF THE AREA. TEMPERATURES
WILL REMAIN RATHER COLD HOWEVER.

THE NEXT QUESTION IS FOR MONDAY AND INTO TUESDAY. THE QUESTION IS
WHAT WILL HAPPEN WITH THE COLD FRONT DROPPING SOUTHWARD OUT OF
CANADA. THE PREVIOUS SHIFT MENTIONED THAT THE SYSTEM DOES NOT LOOK
AS IMPRESSIVE AND WE AGREE. THERE CONTINUES TO BE NOT GREAT UPPER
LEVEL SUPPORT WITH THE FRONT. THERE IS A BIT OF LEFT FRONT QUAD JET
ENERGY FEEDING THE SYSTEM LATE MONDAY NIGHT INTO TUESDAY MORNING SO
AT THIS TIME THAT LOOKS TO BE THE TIME OF THE WORST CONDITIONS. THE
MODELS ARE ALSO FAIRLY CONSISTENT WITH TIMING. THIS WILL BE A FAIRLY
QUICK HITTER AS WELL WITH MOST OF THE PRECIPITATION OVER BY TUESDAY
EVENING. AND THIS LEADS TO THE NEXT QUESTION...HOW COLD WILL IT GET
TUESDAY NIGHT. THE AIR MASS MOVING INTO THE AREA WILL BE BITTERLY
COLD WITH FLOW COMING STRAIGHT OUT OF THE ARCTIC. IN ADDITION...
FRESH SNOW COVER SHOULD PROVIDE GOOD ALBEDO. 700 MILLIBAR
TEMPERATURES TUESDAY NIGHT LOOK AS COLD AS -25 C. THE WILDCARD IS
HOW MUCH THE SKY WILL CLEAR THOUGH. THE TEMPERATURES IN CONTINUITY
LOOKED REASONABLE SO WE MADE FEW CHANGES. THEY ARE STILL WELL BELOW
THE GUIDANCE WHICH IS SMART SINCE MOS USUALLY DOES A POOR JOB WITH
ARCTIC INTRUSIONS. HIGH TEMPERATURES WILL BE TRICKY FOR THE REST OF
NEXT WEEK AS WELL. WEDNESDAY LOOKS TO BE A COLD DAY DEFINITELY. SOME
MODERATION SHOULD BEGIN THURSDAY AS THE CORE OF THE ARCTIC AIR
RETREATS. THE QUESTION IS INVERSIONS IN THE BASINS AND VALLEYS. IF
IT WAS JANUARY...THEY WOULD HOLD. HOWEVER...WITH THE STRONGER MARCH
SUN THERE IS A BETTER CHANCE OF MIXING OUT. SO...FEW CHANGES WERE
MADE. AS FOR THE POTENTIAL FOR ANOTHER WEATHER MAKER FOR THE END OF
THE WEEK...THE NEW EUROPEAN HAS BACKED OFF OF THE SYSTEM WHILE THE
GFS CONTINUES TO KEEP THINGS DRY. WITH THE GFS CONTINUING TO BE MORE
CONSISTENT...WE KEPT THE FORECAST DRY WITH NEAR NORMAL TEMPERATURES.

&&

.AVIATION.../06Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS WILL OCCUR OVER MOST OF THE REGION
THROUGH 06Z SUNDAY. SOME CLEARING WILL OCCUR OVER NORTHERN WY BY 06Z
SUNDAY REDUCING SOME OF THE MOUNTAIN OBSCURATION IN THE NORTHERN
MOUNTAINS.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 06Z SUNDAY ACROSS
THE AREA. SOME LIGHT SNOW WILL OCCUR IN PLACES WHICH MAY DROP
VISIBILITY TO MVFR CATEGORY AT TIMES THROUGH SATURDAY EVENING.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 06Z SUNDAY ACROSS
THE AREA. AREAS OF LIGHT SNOW WILL OCCUR THROUGH SATURDAY EVENING.
VISIBILITY MAY DROP TO MVFR CATEGORY AT TIMES. GUSTY WIND AT KRKS
AIRPORT MUCH OF SATURDAY...DECREASING SOME BY 06Z SUNDAY.

&&

.FIRE WEATHER...

CONTINUED NORTHWEST FLOW ALOFT WILL ALLOW FOR LIGHT SNOW SHOWERS
ACROSS NORTHWEST WYOMING TONIGHT AND SATURDAY. MOISTURE IS
LIMITED...SO AMOUNTS WILL BE LIGHT. ANOTHER SURGE OF COLDER AIR WILL
PUSH INTO THE NORTHERN BIG HORN BASIN AND JOHNSON COUNTY LATE THIS
EVENING. THIS SURGE WILL REACH CENTRAL WYOMING EARLY SATURDAY AND
SOUTHWEST WYOMING AROUND SUNRISE. EXPECT COLDER TEMPERATURES...MORE
CLOUD COVER...AND VERY LIGHT SNOW WITH THIS AIRMASS. HIGH
TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. DRIER AIR WILL
FILTER INTO THE STATE FROM THE NORTH SATURDAY NIGHT AND SUNDAY. THIS
WILL ALLOW FOR MORE SUNSHINE AND SLIGHTLY WARMER TEMPERATURES...
ALTHOUGH IT WILL REMAIN COLDER THAN NORMAL. THE NEXT CHANCE FOR
WIDESPREAD SNOW COMES TUESDAY AND WEDNESDAY AS ANOTHER COLD SYSTEM
DROPS IN FROM THE NORTH.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...CNJ
LONG TERM...HATTINGS
AVIATION...AR
FIRE WEATHER...CNJ













000
FXUS65 KRIW 280500
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1000 PM MST FRI FEB 27 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY (ISSUED AT 300 PM MST)

MID-AFTERNOON SATELLITE IMAGERY SHOWING AN UPPER LOW OVER THE
PACIFIC NORTHWEST WHICH WILL BE THE PRIMARY DRIVER OF OUR SENSIBLE
WEATHER THROUGH SATURDAY. ANOTHER VORTICITY CENTER WAS SPINNING EAST
ACROSS EASTERN MONTANA. THE TAIL END OF THIS SYSTEM HAS BEEN
DRAGGING ACROSS THE NORTHWEST PORTION OF THE STATE TODAY. THIS HAS
KEPT LIGHT SNOW ONGOING IN THAT CORNER WITH IR IMAGERY EVEN SHOWING
SOME ENHANCEMENT THE LAST COUPLE OF HOURS. COLDER AIR IN ASSOCIATION
WITH THIS VORTICITY LOBE IS CURRENTLY PUSHING SOUTH THROUGH CENTRAL
MONTANA. SHALLOW COLD DOME WILL BE MOVING IN TO NORTHERN WYOMING
THIS EVENING.

PACIFIC NORTHWEST UPPER LOW WILL MOVE TO THE GREAT BASIN BY SATURDAY
AFTERNOON. THIS WILL KEEP WEAK NORTHWEST FLOW ACROSS THE FORECAST
AREA WITH JUST ENOUGH EMBEDDED MOISTURE TO KEEP LIGHT SNOW GOING IN
THE NORTHWEST MOUNTAINS THROUGH TONIGHT. COLD AIR SURGE WILL BE
PUSHING THROUGH THE BIG HORN BASIN AND JOHNSON COUNTY THIS EVENING.
CLOUD COVER WILL INCREASE BEHIND THIS SURGE BUT LITTLE IS EXPECTED
IN THE WAY OF SNOW. THE COLD AIR WILL WRING OUT WHAT LITTLE MOISTURE
IT CAN...BUT RIGHT NOW HAVE AMOUNTS OF ONE INCH OR LESS. TWEAKED
TEMPERATURES FOR TONIGHT DOWN JUST A HAIR AND DID THE SAME FOR HIGH
TEMPERATURES ON SATURDAY AS SUNSHINE WILL BE LIMITED. SATURDAY
MAXIMUM TEMPERATURES WILL REMAIN WELL BELOW NORMAL...ON THE ORDER OF
15 TO 20 DEGREES...NORTH OF A LANDER TO CASPER LINE. THE SOUTHWEST
WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL. INITIAL GUSTY NORTHERLY
WIND WILL ACCOMPANY THE SURGE OF COLD AIR...BUT PRESSURE RISES DO
NOT APPEAR TO BE THAT IMPRESSIVE. EAST-NORTHEAST WIND WILL BE
STRONGEST ACROSS EASTERN SWEETWATER COUNTY AND NEARBY AREAS. SPEEDS
IN THESE LOCATIONS WILL BE 15 TO 30 MPH. MOISTURE IN WEST-SOUTHWEST
FLOW ALOFT WILL EJECT FROM THE GREAT BASIN LOW AND TRACK TOWARD
SOUTHWEST WYOMING. EARLIER MODEL RUNS...ESPECIALLY THE NAM...HAD
GOOD 850-700MB LAYER FRONTOGENETICAL LIFT SOME POTENTIAL VORTICITY
AND JET ENERGY TO ASSIST SNOWFALL DEVELOPMENT ACROSS SWEETWATER
COUNTY. HOWEVER... NEWEST MODEL RUNS HAVE BEEN BRINGING SURFACE HIGH
FARTHER SOUTH...SO IT LOOKS LESS LIKELY THAT LIGHT SNOW WILL GET AS
FAR NORTH AS I-80 BY 00Z/SUN. TRIED TO INDICATE THIS TREND AS BEST
AS POSSIBLE DURING THE 18Z/SAT-00Z/SUN TIMEFRAME.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

THERE ARE A COUPLE OF CONUNDRUMS IN THE FORECAST TODAY. THE FIRST IS
WHAT WILL HAPPEN SATURDAY NIGHT AND EARLY SUNDAY ALONG THE
INTERSTATE 80 CORRIDOR. THE MODELS CONTINUE TO BE SPLIT. THE GFS AND
THE NEW EUROPEAN SHOW THE COLD FRONT THAT WILL BE THE FOCUS FOR ANY
SNOW PUSHING FAR ENOUGH TO THE SOUTH TO KEEP THE BULK OF THE
PRECIPITATION OVER COLORADO. THE NAM KEEPS THINGS A BIT FARTHER
NORTH. HOWEVER...THE NEW 18Z NAM HAS BACKED OFF AS WELL. AT THIS
TIME...WE TRIMMED POPS AND QPF A LITTLE BUT DID NOT GO ALL THE WAY.
THE EVENING SHIFT SHOULD TAKE ANOTHER LOOK AT THIS TO SEE IF POPS
COULD BE LOWERED SOME MORE. SUNDAY SHOULD FEATURE IMPROVING
CONDITIONS AS THE FRONT SAGS SOUTHWARD OUT OF THE AREA. TEMPERATURES
WILL REMAIN RATHER COLD HOWEVER.

THE NEXT QUESTION IS FOR MONDAY AND INTO TUESDAY. THE QUESTION IS
WHAT WILL HAPPEN WITH THE COLD FRONT DROPPING SOUTHWARD OUT OF
CANADA. THE PREVIOUS SHIFT MENTIONED THAT THE SYSTEM DOES NOT LOOK
AS IMPRESSIVE AND WE AGREE. THERE CONTINUES TO BE NOT GREAT UPPER
LEVEL SUPPORT WITH THE FRONT. THERE IS A BIT OF LEFT FRONT QUAD JET
ENERGY FEEDING THE SYSTEM LATE MONDAY NIGHT INTO TUESDAY MORNING SO
AT THIS TIME THAT LOOKS TO BE THE TIME OF THE WORST CONDITIONS. THE
MODELS ARE ALSO FAIRLY CONSISTENT WITH TIMING. THIS WILL BE A FAIRLY
QUICK HITTER AS WELL WITH MOST OF THE PRECIPITATION OVER BY TUESDAY
EVENING. AND THIS LEADS TO THE NEXT QUESTION...HOW COLD WILL IT GET
TUESDAY NIGHT. THE AIR MASS MOVING INTO THE AREA WILL BE BITTERLY
COLD WITH FLOW COMING STRAIGHT OUT OF THE ARCTIC. IN ADDITION...
FRESH SNOW COVER SHOULD PROVIDE GOOD ALBEDO. 700 MILLIBAR
TEMPERATURES TUESDAY NIGHT LOOK AS COLD AS -25 C. THE WILDCARD IS
HOW MUCH THE SKY WILL CLEAR THOUGH. THE TEMPERATURES IN CONTINUITY
LOOKED REASONABLE SO WE MADE FEW CHANGES. THEY ARE STILL WELL BELOW
THE GUIDANCE WHICH IS SMART SINCE MOS USUALLY DOES A POOR JOB WITH
ARCTIC INTRUSIONS. HIGH TEMPERATURES WILL BE TRICKY FOR THE REST OF
NEXT WEEK AS WELL. WEDNESDAY LOOKS TO BE A COLD DAY DEFINITELY. SOME
MODERATION SHOULD BEGIN THURSDAY AS THE CORE OF THE ARCTIC AIR
RETREATS. THE QUESTION IS INVERSIONS IN THE BASINS AND VALLEYS. IF
IT WAS JANUARY...THEY WOULD HOLD. HOWEVER...WITH THE STRONGER MARCH
SUN THERE IS A BETTER CHANCE OF MIXING OUT. SO...FEW CHANGES WERE
MADE. AS FOR THE POTENTIAL FOR ANOTHER WEATHER MAKER FOR THE END OF
THE WEEK...THE NEW EUROPEAN HAS BACKED OFF OF THE SYSTEM WHILE THE
GFS CONTINUES TO KEEP THINGS DRY. WITH THE GFS CONTINUING TO BE MORE
CONSISTENT...WE KEPT THE FORECAST DRY WITH NEAR NORMAL TEMPERATURES.

&&

.AVIATION.../06Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS WILL OCCUR OVER MOST OF THE REGION
THROUGH 06Z SUNDAY. SOME CLEARING WILL OCCUR OVER NORTHERN WY BY 06Z
SUNDAY REDUCING SOME OF THE MOUNTAIN OBSCURATION IN THE NORTHERN
MOUNTAINS.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 06Z SUNDAY ACROSS
THE AREA. SOME LIGHT SNOW WILL OCCUR IN PLACES WHICH MAY DROP
VISIBILITY TO MVFR CATEGORY AT TIMES THROUGH SATURDAY EVENING.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 06Z SUNDAY ACROSS
THE AREA. AREAS OF LIGHT SNOW WILL OCCUR THROUGH SATURDAY EVENING.
VISIBILITY MAY DROP TO MVFR CATEGORY AT TIMES. GUSTY WIND AT KRKS
AIRPORT MUCH OF SATURDAY...DECREASING SOME BY 06Z SUNDAY.

&&

.FIRE WEATHER...

CONTINUED NORTHWEST FLOW ALOFT WILL ALLOW FOR LIGHT SNOW SHOWERS
ACROSS NORTHWEST WYOMING TONIGHT AND SATURDAY. MOISTURE IS
LIMITED...SO AMOUNTS WILL BE LIGHT. ANOTHER SURGE OF COLDER AIR WILL
PUSH INTO THE NORTHERN BIG HORN BASIN AND JOHNSON COUNTY LATE THIS
EVENING. THIS SURGE WILL REACH CENTRAL WYOMING EARLY SATURDAY AND
SOUTHWEST WYOMING AROUND SUNRISE. EXPECT COLDER TEMPERATURES...MORE
CLOUD COVER...AND VERY LIGHT SNOW WITH THIS AIRMASS. HIGH
TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. DRIER AIR WILL
FILTER INTO THE STATE FROM THE NORTH SATURDAY NIGHT AND SUNDAY. THIS
WILL ALLOW FOR MORE SUNSHINE AND SLIGHTLY WARMER TEMPERATURES...
ALTHOUGH IT WILL REMAIN COLDER THAN NORMAL. THE NEXT CHANCE FOR
WIDESPREAD SNOW COMES TUESDAY AND WEDNESDAY AS ANOTHER COLD SYSTEM
DROPS IN FROM THE NORTH.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...CNJ
LONG TERM...HATTINGS
AVIATION...AR
FIRE WEATHER...CNJ













000
FXUS65 KRIW 280500
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1000 PM MST FRI FEB 27 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY (ISSUED AT 300 PM MST)

MID-AFTERNOON SATELLITE IMAGERY SHOWING AN UPPER LOW OVER THE
PACIFIC NORTHWEST WHICH WILL BE THE PRIMARY DRIVER OF OUR SENSIBLE
WEATHER THROUGH SATURDAY. ANOTHER VORTICITY CENTER WAS SPINNING EAST
ACROSS EASTERN MONTANA. THE TAIL END OF THIS SYSTEM HAS BEEN
DRAGGING ACROSS THE NORTHWEST PORTION OF THE STATE TODAY. THIS HAS
KEPT LIGHT SNOW ONGOING IN THAT CORNER WITH IR IMAGERY EVEN SHOWING
SOME ENHANCEMENT THE LAST COUPLE OF HOURS. COLDER AIR IN ASSOCIATION
WITH THIS VORTICITY LOBE IS CURRENTLY PUSHING SOUTH THROUGH CENTRAL
MONTANA. SHALLOW COLD DOME WILL BE MOVING IN TO NORTHERN WYOMING
THIS EVENING.

PACIFIC NORTHWEST UPPER LOW WILL MOVE TO THE GREAT BASIN BY SATURDAY
AFTERNOON. THIS WILL KEEP WEAK NORTHWEST FLOW ACROSS THE FORECAST
AREA WITH JUST ENOUGH EMBEDDED MOISTURE TO KEEP LIGHT SNOW GOING IN
THE NORTHWEST MOUNTAINS THROUGH TONIGHT. COLD AIR SURGE WILL BE
PUSHING THROUGH THE BIG HORN BASIN AND JOHNSON COUNTY THIS EVENING.
CLOUD COVER WILL INCREASE BEHIND THIS SURGE BUT LITTLE IS EXPECTED
IN THE WAY OF SNOW. THE COLD AIR WILL WRING OUT WHAT LITTLE MOISTURE
IT CAN...BUT RIGHT NOW HAVE AMOUNTS OF ONE INCH OR LESS. TWEAKED
TEMPERATURES FOR TONIGHT DOWN JUST A HAIR AND DID THE SAME FOR HIGH
TEMPERATURES ON SATURDAY AS SUNSHINE WILL BE LIMITED. SATURDAY
MAXIMUM TEMPERATURES WILL REMAIN WELL BELOW NORMAL...ON THE ORDER OF
15 TO 20 DEGREES...NORTH OF A LANDER TO CASPER LINE. THE SOUTHWEST
WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL. INITIAL GUSTY NORTHERLY
WIND WILL ACCOMPANY THE SURGE OF COLD AIR...BUT PRESSURE RISES DO
NOT APPEAR TO BE THAT IMPRESSIVE. EAST-NORTHEAST WIND WILL BE
STRONGEST ACROSS EASTERN SWEETWATER COUNTY AND NEARBY AREAS. SPEEDS
IN THESE LOCATIONS WILL BE 15 TO 30 MPH. MOISTURE IN WEST-SOUTHWEST
FLOW ALOFT WILL EJECT FROM THE GREAT BASIN LOW AND TRACK TOWARD
SOUTHWEST WYOMING. EARLIER MODEL RUNS...ESPECIALLY THE NAM...HAD
GOOD 850-700MB LAYER FRONTOGENETICAL LIFT SOME POTENTIAL VORTICITY
AND JET ENERGY TO ASSIST SNOWFALL DEVELOPMENT ACROSS SWEETWATER
COUNTY. HOWEVER... NEWEST MODEL RUNS HAVE BEEN BRINGING SURFACE HIGH
FARTHER SOUTH...SO IT LOOKS LESS LIKELY THAT LIGHT SNOW WILL GET AS
FAR NORTH AS I-80 BY 00Z/SUN. TRIED TO INDICATE THIS TREND AS BEST
AS POSSIBLE DURING THE 18Z/SAT-00Z/SUN TIMEFRAME.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

THERE ARE A COUPLE OF CONUNDRUMS IN THE FORECAST TODAY. THE FIRST IS
WHAT WILL HAPPEN SATURDAY NIGHT AND EARLY SUNDAY ALONG THE
INTERSTATE 80 CORRIDOR. THE MODELS CONTINUE TO BE SPLIT. THE GFS AND
THE NEW EUROPEAN SHOW THE COLD FRONT THAT WILL BE THE FOCUS FOR ANY
SNOW PUSHING FAR ENOUGH TO THE SOUTH TO KEEP THE BULK OF THE
PRECIPITATION OVER COLORADO. THE NAM KEEPS THINGS A BIT FARTHER
NORTH. HOWEVER...THE NEW 18Z NAM HAS BACKED OFF AS WELL. AT THIS
TIME...WE TRIMMED POPS AND QPF A LITTLE BUT DID NOT GO ALL THE WAY.
THE EVENING SHIFT SHOULD TAKE ANOTHER LOOK AT THIS TO SEE IF POPS
COULD BE LOWERED SOME MORE. SUNDAY SHOULD FEATURE IMPROVING
CONDITIONS AS THE FRONT SAGS SOUTHWARD OUT OF THE AREA. TEMPERATURES
WILL REMAIN RATHER COLD HOWEVER.

THE NEXT QUESTION IS FOR MONDAY AND INTO TUESDAY. THE QUESTION IS
WHAT WILL HAPPEN WITH THE COLD FRONT DROPPING SOUTHWARD OUT OF
CANADA. THE PREVIOUS SHIFT MENTIONED THAT THE SYSTEM DOES NOT LOOK
AS IMPRESSIVE AND WE AGREE. THERE CONTINUES TO BE NOT GREAT UPPER
LEVEL SUPPORT WITH THE FRONT. THERE IS A BIT OF LEFT FRONT QUAD JET
ENERGY FEEDING THE SYSTEM LATE MONDAY NIGHT INTO TUESDAY MORNING SO
AT THIS TIME THAT LOOKS TO BE THE TIME OF THE WORST CONDITIONS. THE
MODELS ARE ALSO FAIRLY CONSISTENT WITH TIMING. THIS WILL BE A FAIRLY
QUICK HITTER AS WELL WITH MOST OF THE PRECIPITATION OVER BY TUESDAY
EVENING. AND THIS LEADS TO THE NEXT QUESTION...HOW COLD WILL IT GET
TUESDAY NIGHT. THE AIR MASS MOVING INTO THE AREA WILL BE BITTERLY
COLD WITH FLOW COMING STRAIGHT OUT OF THE ARCTIC. IN ADDITION...
FRESH SNOW COVER SHOULD PROVIDE GOOD ALBEDO. 700 MILLIBAR
TEMPERATURES TUESDAY NIGHT LOOK AS COLD AS -25 C. THE WILDCARD IS
HOW MUCH THE SKY WILL CLEAR THOUGH. THE TEMPERATURES IN CONTINUITY
LOOKED REASONABLE SO WE MADE FEW CHANGES. THEY ARE STILL WELL BELOW
THE GUIDANCE WHICH IS SMART SINCE MOS USUALLY DOES A POOR JOB WITH
ARCTIC INTRUSIONS. HIGH TEMPERATURES WILL BE TRICKY FOR THE REST OF
NEXT WEEK AS WELL. WEDNESDAY LOOKS TO BE A COLD DAY DEFINITELY. SOME
MODERATION SHOULD BEGIN THURSDAY AS THE CORE OF THE ARCTIC AIR
RETREATS. THE QUESTION IS INVERSIONS IN THE BASINS AND VALLEYS. IF
IT WAS JANUARY...THEY WOULD HOLD. HOWEVER...WITH THE STRONGER MARCH
SUN THERE IS A BETTER CHANCE OF MIXING OUT. SO...FEW CHANGES WERE
MADE. AS FOR THE POTENTIAL FOR ANOTHER WEATHER MAKER FOR THE END OF
THE WEEK...THE NEW EUROPEAN HAS BACKED OFF OF THE SYSTEM WHILE THE
GFS CONTINUES TO KEEP THINGS DRY. WITH THE GFS CONTINUING TO BE MORE
CONSISTENT...WE KEPT THE FORECAST DRY WITH NEAR NORMAL TEMPERATURES.

&&

.AVIATION.../06Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS WILL OCCUR OVER MOST OF THE REGION
THROUGH 06Z SUNDAY. SOME CLEARING WILL OCCUR OVER NORTHERN WY BY 06Z
SUNDAY REDUCING SOME OF THE MOUNTAIN OBSCURATION IN THE NORTHERN
MOUNTAINS.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 06Z SUNDAY ACROSS
THE AREA. SOME LIGHT SNOW WILL OCCUR IN PLACES WHICH MAY DROP
VISIBILITY TO MVFR CATEGORY AT TIMES THROUGH SATURDAY EVENING.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

LOW VFR OR MVFR CONDITIONS WILL PREVAIL THROUGH 06Z SUNDAY ACROSS
THE AREA. AREAS OF LIGHT SNOW WILL OCCUR THROUGH SATURDAY EVENING.
VISIBILITY MAY DROP TO MVFR CATEGORY AT TIMES. GUSTY WIND AT KRKS
AIRPORT MUCH OF SATURDAY...DECREASING SOME BY 06Z SUNDAY.

&&

.FIRE WEATHER...

CONTINUED NORTHWEST FLOW ALOFT WILL ALLOW FOR LIGHT SNOW SHOWERS
ACROSS NORTHWEST WYOMING TONIGHT AND SATURDAY. MOISTURE IS
LIMITED...SO AMOUNTS WILL BE LIGHT. ANOTHER SURGE OF COLDER AIR WILL
PUSH INTO THE NORTHERN BIG HORN BASIN AND JOHNSON COUNTY LATE THIS
EVENING. THIS SURGE WILL REACH CENTRAL WYOMING EARLY SATURDAY AND
SOUTHWEST WYOMING AROUND SUNRISE. EXPECT COLDER TEMPERATURES...MORE
CLOUD COVER...AND VERY LIGHT SNOW WITH THIS AIRMASS. HIGH
TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. DRIER AIR WILL
FILTER INTO THE STATE FROM THE NORTH SATURDAY NIGHT AND SUNDAY. THIS
WILL ALLOW FOR MORE SUNSHINE AND SLIGHTLY WARMER TEMPERATURES...
ALTHOUGH IT WILL REMAIN COLDER THAN NORMAL. THE NEXT CHANCE FOR
WIDESPREAD SNOW COMES TUESDAY AND WEDNESDAY AS ANOTHER COLD SYSTEM
DROPS IN FROM THE NORTH.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...CNJ
LONG TERM...HATTINGS
AVIATION...AR
FIRE WEATHER...CNJ












000
FXUS65 KRIW 272200
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
300 PM MST FRI FEB 27 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

MID-AFTERNOON SATELLITE IMAGERY SHOWING AN UPPER LOW OVER THE
PACIFIC NORTHWEST WHICH WILL BE THE PRIMARY DRIVER OF OUR SENSIBLE
WEATHER THROUGH SATURDAY. ANOTHER VORTICITY CENTER WAS SPINNING EAST
ACROSS EASTERN MONTANA. THE TAIL END OF THIS SYSTEM HAS BEEN
DRAGGING ACROSS THE NORTHWEST PORTION OF THE STATE TODAY. THIS HAS
KEPT LIGHT SNOW ONGOING IN THAT CORNER WITH IR IMAGERY EVEN SHOWING
SOME ENHANCEMENT THE LAST COUPLE OF HOURS. COLDER AIR IN ASSOCIATION
WITH THIS VORTICITY LOBE IS CURRENTLY PUSHING SOUTH THROUGH CENTRAL
MONTANA. SHALLOW COLD DOME WILL BE MOVING IN TO NORTHERN WYOMING
THIS EVENING.

PACIFIC NORTHWEST UPPER LOW WILL MOVE TO THE GREAT BASIN BY SATURDAY
AFTERNOON. THIS WILL KEEP WEAK NORTHWEST FLOW ACROSS THE FORECAST
AREA WITH JUST ENOUGH EMBEDDED MOISTURE TO KEEP LIGHT SNOW GOING IN
THE NORTHWEST MOUNTAINS THROUGH TONIGHT. COLD AIR SURGE WILL BE
PUSHING THROUGH THE BIG HORN BASIN AND JOHNSON COUNTY THIS EVENING.
CLOUD COVER WILL INCREASE BEHIND THIS SURGE BUT LITTLE IS EXPECTED
IN THE WAY OF SNOW. THE COLD AIR WILL WRING OUT WHAT LITTLE MOISTURE
IT CAN...BUT RIGHT NOW HAVE AMOUNTS OF ONE INCH OR LESS. TWEAKED
TEMPERATURES FOR TONIGHT DOWN JUST A HAIR AND DID THE SAME FOR HIGH
TEMPERATURES ON SATURDAY AS SUNSHINE WILL BE LIMITED. SATURDAY
MAXIMUM TEMPERATURES WILL REMAIN WELL BELOW NORMAL...ON THE ORDER OF
15 TO 20 DEGREES...NORTH OF A LANDER TO CASPER LINE. THE SOUTHWEST
WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL. INITIAL GUSTY NORTHERLY
WIND WILL ACCOMPANY THE SURGE OF COLD AIR...BUT PRESSURE RISES DO
NOT APPEAR TO BE THAT IMPRESSIVE. EAST-NORTHEAST WIND WILL BE
STRONGEST ACROSS EASTERN SWEETWATER COUNTY AND NEARBY AREAS. SPEEDS
IN THESE LOCATIONS WILL BE 15 TO 30 MPH. MOISTURE IN WEST-SOUTHWEST
FLOW ALOFT WILL EJECT FROM THE GREAT BASIN LOW AND TRACK TOWARD
SOUTHWEST WYOMING. EARLIER MODEL RUNS...ESPECIALLY THE NAM...HAD
GOOD 850-700MB LAYER FRONTOGENETICAL LIFT SOME POTENTIAL VORTICITY
AND JET ENERGY TO ASSIST SNOWFALL DEVELOPMENT ACROSS SWEETWATER
COUNTY. HOWEVER... NEWEST MODEL RUNS HAVE BEEN BRINGING SURFACE HIGH
FARTHER SOUTH...SO IT LOOKS LESS LIKELY THAT LIGHT SNOW WILL GET AS
FAR NORTH AS I-80 BY 00Z/SUN. TRIED TO INDICATE THIS TREND AS BEST
AS POSSIBLE DURING THE 18Z/SAT-00Z/SUN TIMEFRAME.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

THERE ARE A COUPLE OF CONUNDRUMS IN THE FORECAST TODAY. THE FIRST IS
WHAT WILL HAPPEN SATURDAY NIGHT AND EARLY SUNDAY ALONG THE
INTERSTATE 80 CORRIDOR. THE MODELS CONTINUE TO BE SPLIT. THE GFS AND
THE NEW EUROPEAN SHOW THE COLD FRONT THAT WILL BE THE FOCUS FOR ANY
SNOW PUSHING FAR ENOUGH TO THE SOUTH TO KEEP THE BULK OF THE
PRECIPITATION OVER COLORADO. THE NAM KEEPS THINGS A BIT FARTHER
NORTH. HOWEVER...THE NEW 18Z NAM HAS BACKED OFF AS WELL. AT THIS
TIME...WE TRIMMED POPS AND QPF A LITTLE BUT DID NOT GO ALL THE WAY.
THE EVENING SHIFT SHOULD TAKE ANOTHER LOOK AT THIS TO SEE IF POPS
COULD BE LOWERED SOME MORE. SUNDAY SHOULD FEATURE IMPROVING
CONDITIONS AS THE FRONT SAGS SOUTHWARD OUT OF THE AREA. TEMPERATURES
WILL REMAIN RATHER COLD HOWEVER.

THE NEXT QUESTION IS FOR MONDAY AND INTO TUESDAY. THE QUESTION IS
WHAT WILL HAPPEN WITH THE COLD FRONT DROPPING SOUTHWARD OUT OF
CANADA. THE PREVIOUS SHIFT MENTIONED THAT THE SYSTEM DOES NOT LOOK
AS IMPRESSIVE AND WE AGREE. THERE CONTINUES TO BE NOT GREAT UPPER
LEVEL SUPPORT WITH THE FRONT. THERE IS A BIT OF LEFT FRONT QUAD JET
ENERGY FEEDING THE SYSTEM LATE MONDAY NIGHT INTO TUESDAY MORNING SO
AT THIS TIME THAT LOOKS TO BE THE TIME OF THE WORST CONDITIONS. THE
MODELS ARE ALSO FAIRLY CONSISTENT WITH TIMING. THIS WILL BE A FAIRLY
QUICK HITTER AS WELL WITH MOST OF THE PRECIPITATION OVER BY TUESDAY
EVENING. AND THIS LEADS TO THE NEXT QUESTION...HOW COLD WILL IT GET
TUESDAY NIGHT. THE AIR MASS MOVING INTO THE AREA WILL BE BITTERLY
COLD WITH FLOW COMING STRAIGHT OUT OF THE ARCTIC. IN ADDITION...
FRESH SNOW COVER SHOULD PROVIDE GOOD ALBEDO. 700 MILLIBAR
TEMPERATURES TUESDAY NIGHT LOOK AS COLD AS -25 C. THE WILDCARD IS
HOW MUCH THE SKY WILL CLEAR THOUGH. THE TEMPERATURES IN CONTINUITY
LOOKED REASONABLE SO WE MADE FEW CHANGES. THEY ARE STILL WELL BELOW
THE GUIDANCE WHICH IS SMART SINCE MOS USUALLY DOES A POOR JOB WITH
ARCTIC INTRUSIONS. HIGH TEMPERATURES WILL BE TRICKY FOR THE REST OF
NEXT WEEK AS WELL. WEDNESDAY LOOKS TO BE A COLD DAY DEFINITELY. SOME
MODERATION SHOULD BEGIN THURSDAY AS THE CORE OF THE ARCTIC AIR
RETREATS. THE QUESTION IS INVERSIONS IN THE BASINS AND VALLEYS. IF
IT WAS JANUARY...THEY WOULD HOLD. HOWEVER...WITH THE STRONGER MARCH
SUN THERE IS A BETTER CHANCE OF MIXING OUT. SO...FEW CHANGES WERE
MADE. AS FOR THE POTENTIAL FOR ANOTHER WEATHER MAKER FOR THE END OF
THE WEEK...THE NEW EUROPEAN HAS BACKED OFF OF THE SYSTEM WHILE THE
GFS CONTINUES TO KEEP THINGS DRY. WITH THE GFS CONTINUING TO BE MORE
CONSISTENT...WE KEPT THE FORECAST DRY WITH NEAR NORMAL TEMPERATURES.

&&

.AVIATION.../00Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS WILL PERSIST ALONG AND WEST OF THE
CONTINENTAL DIVIDE THROUGH THE FORECAST PERIOD. OBSCURATIONS EAST OF
THE CONTINENTAL DIVIDE WILL BECOME MORE WIDESPREAD BEGINNING IN THE
NORTH AROUND 03Z/SAT AND CENTRAL SECTIONS FROM KLND TO KCPR BY
AROUND 09Z/SAT.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

TERMINALS WILL BE VFR THROUGH THIS EVENING. SURGE OF COLDER AIR OVER
CENTRAL MONTANA WILL PUSH INTO THE FAR NORTHERN BIG HORN BASIN BY
03Z/SAT. LOWER CLOUD DECKS OF MVFR OR LOW VFR CEILINGS ALONG WITH
SOME VERY LIGHT SNOW WILL PUSH TO CENTRAL WYOMING BY 06Z-09Z/SAT.
THIS AIRMASS IS FAIRLY DRY SO THE SNOW THAT FALLS WILL JUST BE WRUNG
OUT FROM THE LITTLE BIT OF MOISTURE IN THIS UNSEASONABLY COLD
AIRMASS. KLND MAY BE THE BEST BET FOR A PERIOD OF REDUCED VISIBILITY
LATE TONIGHT DUE TO WEAK UPSLOPE NEAR THE WIND RIVER RANGE.
CONDITIONS MAY IMPROVE SLIGHTLY LATE SATURDAY AFTERNOON.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

THE TAIL END OF AN UPPER LEVEL DISTURBANCE OVER NORTHEAST MONTANA
HAS KEPT LIGHT SNOW GOING ACROSS THE NORTHWEST MOUNTAINS TONIGHT.
LIMITED MOISTURE IN NORTHWEST FLOW WILL DRAG ACROSS NORTHWEST
WYOMING ON SATURDAY. TOUGH TO DISCERN WHEN THERE WOULD BE A
PROLONGED PERIOD OF MVFR IN KJAC. FOR NOW HAVE KEPT CONDITIONS
HOVERING IN THE LOW VFR RANGE THROUGH 00Z/SUN. ELSEWHERE...EXPECT
VFR CONDITIONS AT THE OTHER TERMINALS THROUGH MOST OF THE FORECAST
PERIOD. THERE IS A CHANCE FOR LIGHT SNOW TO BEGIN AROUND KRKS WITH
GUSTY EAST-NORTHEAST WIND AFTER 22Z/SAT. HOWEVER...CONFIDENCE IS NOT
THAT HIGH AND BELIEVE THE BETTER CHANCE COMES AFTER 00Z/SUN.

&&

.FIRE WEATHER...

CONTINUED NORTHWEST FLOW ALOFT WILL ALLOW FOR LIGHT SNOW SHOWERS
ACROSS NORTHWEST WYOMING TONIGHT AND SATURDAY. MOISTURE IS
LIMITED...SO AMOUNTS WILL BE LIGHT. ANOTHER SURGE OF COLDER AIR WILL
PUSH INTO THE NORTHERN BIG HORN BASIN AND JOHNSON COUNTY LATE THIS
EVENING. THIS SURGE WILL REACH CENTRAL WYOMING EARLY SATURDAY AND
SOUTHWEST WYOMING AROUND SUNRISE. EXPECT COLDER TEMPERATURES...MORE
CLOUD COVER...AND VERY LIGHT SNOW WITH THIS AIRMASS. HIGH
TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. DRIER AIR WILL
FILTER INTO THE STATE FROM THE NORTH SATURDAY NIGHT AND SUNDAY. THIS
WILL ALLOW FOR MORE SUNSHINE AND SLIGHTLY WARMER TEMPERATURES...
ALTHOUGH IT WILL REMAIN COLDER THAN NORMAL. THE NEXT CHANCE FOR
WIDESPREAD SNOW COMES TUESDAY AND WEDNESDAY AS ANOTHER COLD SYSTEM
DROPS IN FROM THE NORTH.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...CNJ
LONG TERM...HATTINGS
AVIATION...CNJ
FIRE WEATHER...CNJ










000
FXUS65 KRIW 272200
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
300 PM MST FRI FEB 27 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

MID-AFTERNOON SATELLITE IMAGERY SHOWING AN UPPER LOW OVER THE
PACIFIC NORTHWEST WHICH WILL BE THE PRIMARY DRIVER OF OUR SENSIBLE
WEATHER THROUGH SATURDAY. ANOTHER VORTICITY CENTER WAS SPINNING EAST
ACROSS EASTERN MONTANA. THE TAIL END OF THIS SYSTEM HAS BEEN
DRAGGING ACROSS THE NORTHWEST PORTION OF THE STATE TODAY. THIS HAS
KEPT LIGHT SNOW ONGOING IN THAT CORNER WITH IR IMAGERY EVEN SHOWING
SOME ENHANCEMENT THE LAST COUPLE OF HOURS. COLDER AIR IN ASSOCIATION
WITH THIS VORTICITY LOBE IS CURRENTLY PUSHING SOUTH THROUGH CENTRAL
MONTANA. SHALLOW COLD DOME WILL BE MOVING IN TO NORTHERN WYOMING
THIS EVENING.

PACIFIC NORTHWEST UPPER LOW WILL MOVE TO THE GREAT BASIN BY SATURDAY
AFTERNOON. THIS WILL KEEP WEAK NORTHWEST FLOW ACROSS THE FORECAST
AREA WITH JUST ENOUGH EMBEDDED MOISTURE TO KEEP LIGHT SNOW GOING IN
THE NORTHWEST MOUNTAINS THROUGH TONIGHT. COLD AIR SURGE WILL BE
PUSHING THROUGH THE BIG HORN BASIN AND JOHNSON COUNTY THIS EVENING.
CLOUD COVER WILL INCREASE BEHIND THIS SURGE BUT LITTLE IS EXPECTED
IN THE WAY OF SNOW. THE COLD AIR WILL WRING OUT WHAT LITTLE MOISTURE
IT CAN...BUT RIGHT NOW HAVE AMOUNTS OF ONE INCH OR LESS. TWEAKED
TEMPERATURES FOR TONIGHT DOWN JUST A HAIR AND DID THE SAME FOR HIGH
TEMPERATURES ON SATURDAY AS SUNSHINE WILL BE LIMITED. SATURDAY
MAXIMUM TEMPERATURES WILL REMAIN WELL BELOW NORMAL...ON THE ORDER OF
15 TO 20 DEGREES...NORTH OF A LANDER TO CASPER LINE. THE SOUTHWEST
WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL. INITIAL GUSTY NORTHERLY
WIND WILL ACCOMPANY THE SURGE OF COLD AIR...BUT PRESSURE RISES DO
NOT APPEAR TO BE THAT IMPRESSIVE. EAST-NORTHEAST WIND WILL BE
STRONGEST ACROSS EASTERN SWEETWATER COUNTY AND NEARBY AREAS. SPEEDS
IN THESE LOCATIONS WILL BE 15 TO 30 MPH. MOISTURE IN WEST-SOUTHWEST
FLOW ALOFT WILL EJECT FROM THE GREAT BASIN LOW AND TRACK TOWARD
SOUTHWEST WYOMING. EARLIER MODEL RUNS...ESPECIALLY THE NAM...HAD
GOOD 850-700MB LAYER FRONTOGENETICAL LIFT SOME POTENTIAL VORTICITY
AND JET ENERGY TO ASSIST SNOWFALL DEVELOPMENT ACROSS SWEETWATER
COUNTY. HOWEVER... NEWEST MODEL RUNS HAVE BEEN BRINGING SURFACE HIGH
FARTHER SOUTH...SO IT LOOKS LESS LIKELY THAT LIGHT SNOW WILL GET AS
FAR NORTH AS I-80 BY 00Z/SUN. TRIED TO INDICATE THIS TREND AS BEST
AS POSSIBLE DURING THE 18Z/SAT-00Z/SUN TIMEFRAME.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

THERE ARE A COUPLE OF CONUNDRUMS IN THE FORECAST TODAY. THE FIRST IS
WHAT WILL HAPPEN SATURDAY NIGHT AND EARLY SUNDAY ALONG THE
INTERSTATE 80 CORRIDOR. THE MODELS CONTINUE TO BE SPLIT. THE GFS AND
THE NEW EUROPEAN SHOW THE COLD FRONT THAT WILL BE THE FOCUS FOR ANY
SNOW PUSHING FAR ENOUGH TO THE SOUTH TO KEEP THE BULK OF THE
PRECIPITATION OVER COLORADO. THE NAM KEEPS THINGS A BIT FARTHER
NORTH. HOWEVER...THE NEW 18Z NAM HAS BACKED OFF AS WELL. AT THIS
TIME...WE TRIMMED POPS AND QPF A LITTLE BUT DID NOT GO ALL THE WAY.
THE EVENING SHIFT SHOULD TAKE ANOTHER LOOK AT THIS TO SEE IF POPS
COULD BE LOWERED SOME MORE. SUNDAY SHOULD FEATURE IMPROVING
CONDITIONS AS THE FRONT SAGS SOUTHWARD OUT OF THE AREA. TEMPERATURES
WILL REMAIN RATHER COLD HOWEVER.

THE NEXT QUESTION IS FOR MONDAY AND INTO TUESDAY. THE QUESTION IS
WHAT WILL HAPPEN WITH THE COLD FRONT DROPPING SOUTHWARD OUT OF
CANADA. THE PREVIOUS SHIFT MENTIONED THAT THE SYSTEM DOES NOT LOOK
AS IMPRESSIVE AND WE AGREE. THERE CONTINUES TO BE NOT GREAT UPPER
LEVEL SUPPORT WITH THE FRONT. THERE IS A BIT OF LEFT FRONT QUAD JET
ENERGY FEEDING THE SYSTEM LATE MONDAY NIGHT INTO TUESDAY MORNING SO
AT THIS TIME THAT LOOKS TO BE THE TIME OF THE WORST CONDITIONS. THE
MODELS ARE ALSO FAIRLY CONSISTENT WITH TIMING. THIS WILL BE A FAIRLY
QUICK HITTER AS WELL WITH MOST OF THE PRECIPITATION OVER BY TUESDAY
EVENING. AND THIS LEADS TO THE NEXT QUESTION...HOW COLD WILL IT GET
TUESDAY NIGHT. THE AIR MASS MOVING INTO THE AREA WILL BE BITTERLY
COLD WITH FLOW COMING STRAIGHT OUT OF THE ARCTIC. IN ADDITION...
FRESH SNOW COVER SHOULD PROVIDE GOOD ALBEDO. 700 MILLIBAR
TEMPERATURES TUESDAY NIGHT LOOK AS COLD AS -25 C. THE WILDCARD IS
HOW MUCH THE SKY WILL CLEAR THOUGH. THE TEMPERATURES IN CONTINUITY
LOOKED REASONABLE SO WE MADE FEW CHANGES. THEY ARE STILL WELL BELOW
THE GUIDANCE WHICH IS SMART SINCE MOS USUALLY DOES A POOR JOB WITH
ARCTIC INTRUSIONS. HIGH TEMPERATURES WILL BE TRICKY FOR THE REST OF
NEXT WEEK AS WELL. WEDNESDAY LOOKS TO BE A COLD DAY DEFINITELY. SOME
MODERATION SHOULD BEGIN THURSDAY AS THE CORE OF THE ARCTIC AIR
RETREATS. THE QUESTION IS INVERSIONS IN THE BASINS AND VALLEYS. IF
IT WAS JANUARY...THEY WOULD HOLD. HOWEVER...WITH THE STRONGER MARCH
SUN THERE IS A BETTER CHANCE OF MIXING OUT. SO...FEW CHANGES WERE
MADE. AS FOR THE POTENTIAL FOR ANOTHER WEATHER MAKER FOR THE END OF
THE WEEK...THE NEW EUROPEAN HAS BACKED OFF OF THE SYSTEM WHILE THE
GFS CONTINUES TO KEEP THINGS DRY. WITH THE GFS CONTINUING TO BE MORE
CONSISTENT...WE KEPT THE FORECAST DRY WITH NEAR NORMAL TEMPERATURES.

&&

.AVIATION.../00Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS WILL PERSIST ALONG AND WEST OF THE
CONTINENTAL DIVIDE THROUGH THE FORECAST PERIOD. OBSCURATIONS EAST OF
THE CONTINENTAL DIVIDE WILL BECOME MORE WIDESPREAD BEGINNING IN THE
NORTH AROUND 03Z/SAT AND CENTRAL SECTIONS FROM KLND TO KCPR BY
AROUND 09Z/SAT.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

TERMINALS WILL BE VFR THROUGH THIS EVENING. SURGE OF COLDER AIR OVER
CENTRAL MONTANA WILL PUSH INTO THE FAR NORTHERN BIG HORN BASIN BY
03Z/SAT. LOWER CLOUD DECKS OF MVFR OR LOW VFR CEILINGS ALONG WITH
SOME VERY LIGHT SNOW WILL PUSH TO CENTRAL WYOMING BY 06Z-09Z/SAT.
THIS AIRMASS IS FAIRLY DRY SO THE SNOW THAT FALLS WILL JUST BE WRUNG
OUT FROM THE LITTLE BIT OF MOISTURE IN THIS UNSEASONABLY COLD
AIRMASS. KLND MAY BE THE BEST BET FOR A PERIOD OF REDUCED VISIBILITY
LATE TONIGHT DUE TO WEAK UPSLOPE NEAR THE WIND RIVER RANGE.
CONDITIONS MAY IMPROVE SLIGHTLY LATE SATURDAY AFTERNOON.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

THE TAIL END OF AN UPPER LEVEL DISTURBANCE OVER NORTHEAST MONTANA
HAS KEPT LIGHT SNOW GOING ACROSS THE NORTHWEST MOUNTAINS TONIGHT.
LIMITED MOISTURE IN NORTHWEST FLOW WILL DRAG ACROSS NORTHWEST
WYOMING ON SATURDAY. TOUGH TO DISCERN WHEN THERE WOULD BE A
PROLONGED PERIOD OF MVFR IN KJAC. FOR NOW HAVE KEPT CONDITIONS
HOVERING IN THE LOW VFR RANGE THROUGH 00Z/SUN. ELSEWHERE...EXPECT
VFR CONDITIONS AT THE OTHER TERMINALS THROUGH MOST OF THE FORECAST
PERIOD. THERE IS A CHANCE FOR LIGHT SNOW TO BEGIN AROUND KRKS WITH
GUSTY EAST-NORTHEAST WIND AFTER 22Z/SAT. HOWEVER...CONFIDENCE IS NOT
THAT HIGH AND BELIEVE THE BETTER CHANCE COMES AFTER 00Z/SUN.

&&

.FIRE WEATHER...

CONTINUED NORTHWEST FLOW ALOFT WILL ALLOW FOR LIGHT SNOW SHOWERS
ACROSS NORTHWEST WYOMING TONIGHT AND SATURDAY. MOISTURE IS
LIMITED...SO AMOUNTS WILL BE LIGHT. ANOTHER SURGE OF COLDER AIR WILL
PUSH INTO THE NORTHERN BIG HORN BASIN AND JOHNSON COUNTY LATE THIS
EVENING. THIS SURGE WILL REACH CENTRAL WYOMING EARLY SATURDAY AND
SOUTHWEST WYOMING AROUND SUNRISE. EXPECT COLDER TEMPERATURES...MORE
CLOUD COVER...AND VERY LIGHT SNOW WITH THIS AIRMASS. HIGH
TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL. DRIER AIR WILL
FILTER INTO THE STATE FROM THE NORTH SATURDAY NIGHT AND SUNDAY. THIS
WILL ALLOW FOR MORE SUNSHINE AND SLIGHTLY WARMER TEMPERATURES...
ALTHOUGH IT WILL REMAIN COLDER THAN NORMAL. THE NEXT CHANCE FOR
WIDESPREAD SNOW COMES TUESDAY AND WEDNESDAY AS ANOTHER COLD SYSTEM
DROPS IN FROM THE NORTH.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...CNJ
LONG TERM...HATTINGS
AVIATION...CNJ
FIRE WEATHER...CNJ









000
FXUS65 KRIW 271741
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1041 AM MST FRI FEB 27 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

A PUSH OF MOISTURE MOVING IN THE NORTHWEST FLOW WILL KEEP SOME LIGHT
SHOWER ACTIVITY ACROSS NORTHWESTERN WYOMING TODAY. THE VERY WEAK
DISTURBANCE USHERING THIS MOISTURE PUSH WILL CONTINUE TO MOVE EAST
THROUGH THE FORECAST AREA OVERNIGHT. THE MOISTURE IS EXPECTED TO
INCREASE AND SPREAD ACROSS THE NORTHERN THIRD OF THE FORECAST AREA
BY SATURDAY MORNING. TEMPERATURES WILL BE ABLE TO WARM
SLIGHTLY...THOUGH WILL STILL REMAIN COOL.

AN AREA OF LOW PRESSURE OVER THE PACIFIC NORTHWEST WILL DIVE SOUTH
ON SATURDAY...ARRIVING OVER CALIFORNIA SATURDAY. AS THIS SYSTEM
MOVES SOUTH IT WILL BRING COOLING TEMPERATURES...AND SEND ADDITIONAL
PULSES OF MOISTURE OVER THE FORECAST AREA. THE BEST OF THESE PULSES
IS NOT EXPECTED TO ARRIVE UNTIL LATE SATURDAY AFTERNOON...AND WILL
PRIMARILY IMPACT SOUTHWESTERN WYOMING. THIS SYSTEM WILL CONTINUE TO
MOVE SOUTH THROUGH SUNDAY WITH PRECIPITATION LINGERING OVER SOUTHERN
WYOMING THROUGH SUNDAY AFTERNOON. A BRIEF PERIOD OF DRY CONDITIONS
POSSIBLE SUNDAY NIGHT...THOUGH MODELS DO INDICATE THE POTENTIAL FOR
ADDITIONAL MOISTURE ACROSS SOUTHERN WYOMING DURING THE LATE EVENING
HOURS OF SUNDAY.

.LONG TERM...MONDAY THROUGH FRIDAY

MAIN CHANGE FOR TONIGHT ARE THE MODELS NOT SHOWING AS MUCH ENERGY
DIGGING INTO THE GREAT BASIN/INTER-MOUNTAIN WEST MONDAY NIGHT AND
TUESDAY AS LAST NIGHT. MORE SHEARING OR JUST OVERALL LESS ENERGY.
THE SYSTEM THE MODELS TRACK FROM KAMCHATKA YESTERDAY IS STILL THE
SAME BUT THE END SOLUTION IS JUST DIFFERENT. STILL LOOKS LIKE SNOW
SPREADING S AND SE ACROSS THE AREA MONDAY NIGHT INTO EARLY TUESDAY
AND TURNING SHARPLY COLDER. SOME FAIRLY DECENT QG FORCING MAY
COMBINE WITH SOME INITIAL RRQ JET DYNAMICS MONDAY NIGHT AND THEN
LEFT EXIT REGION ON TUE WITH THE NEXT JET APPROACHING. WITH LESS
ENERGY TO THE WEST...MOVEMENT IS FASTER AND NOW WE MAY ACTUALLY
CLEAR BY WEDNESDAY MORNING LEADING TO SOME BITTER COLD LOWS. A
COLD COUPLE DAYS THOUGH FOR TUE AND WED. ON THE PLUS SIDE...THE
RIDGE FLATTENS MORE QUICKLY WITH A RATHER FAST MODERATION THURSDAY
INTO FRIDAY ON THE GFS. BACK TRACKING A LITTLE...THE WEEKEND
SYSTEM ENERGY LINGERS JUST TO THE SOUTH TO START THIS PERIOD
MONDAY WITH CONTINUED POTENTIAL FOR CLOUDS AND MAYBE EVEN SOME
VERY LIGHT PCPN IN OUR FAR SRN ZONES. OTHERWISE... DETERIORATING
CONDS BEGINNING LATER MONDAY ONWARD WITH OUR AFOREMENTIONED MONDAY
NIGHT/TUE SYSTEM FAST APPROACHING. RIGHT AT THE END OF THE MEDIUM
RANGE PERIOD...THE MODELS DIVERGE AS TO THE HANDLING OF A PIECE OF
ENERGY CURRENTLY COMING OFF THE ASIA COAST. THE GFS BRINGS IT
FURTHER OVER THE RIDGE AND INTO THE NRN PLAINS WHILE THE EURO
BRINGS THIS SHORTWAVE AT A LITTLE LOWER LATITUDE ALLOWING IT TO
DIG SE INTO OUR AREA NEXT FRIDAY NIGHT. KEEPING IT DRY FOR NOW.
THE GFS WOULD HAVE A MUCH NICER DAY ON FRIDAY WHILE THE ECMWF IS
ALREADY DIGGING THE LOW TOWARDS US WITH FALLING TEMPS BEHIND A
COLD FRONT.

&&

.AVIATION.../18Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS ALONG AND WEST OF THE CONTINENTAL
DIVIDE THROUGH THE FORECAST PERIOD. ALSO...FOOTHILL OBSCURATIONS IN
THE VICINITY OF KLND AND KRIW WILL DISSIPATE EARLY THIS AFTERNOON.
EXPECT MORE WIDESPREAD OBSCURATIONS DEVELOPING FROM NORTH TO SOUTH
AFTER 03Z/SAT THROUGH 09Z/SAT.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

IFR/MVFR CONDITIONS WITH LOW STRATUS DECK AT KRIW AND KLND THIS
MORNING. EDGES HAVE BEEN SLOW TO ERODE. HAVE BACKED OFF THE
DISSIPATION OF THE STRATUS UNTIL 19Z-20Z. MORE SUNSHINE HAS BEEN
STARTING TO SHOW THROUGH SINCE 17Z. OTHER TERMINALS WILL BE VFR
THROUGH THIS AFTERNOON. ANOTHER SURGE OF COLD AIR WILL BRING A
RETURN OF LOW CLOUDS AND MVFR OR LOW VFR CEILINGS OVER NORTHERN
WYOMING BETWEEN 00Z-06Z/SAT. THIS AREA OF CLOUDS AND LIGHT SNOW WILL
PUSH SOUTH THROUGH THE NIGHT. KWRL IS THE LEAST LIKELY OF THE
TERMINALS TO SEE AN EXTENDED PERIOD OF LIGHT SNOW. BEST CHANCE FOR
MVFR VISIBILITIES THROUGH 18Z/SAT WILL BE FROM KLND-KCPR WHERE WEAK
UPSLOPE WOULD BE FAVORABLE AFTER THE COLD FRONT PUSHES SOUTH.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

AREAS OF LOW CLOUDS AND LIGHT SNOW ACROSS PORTIONS OF THE FAR WEST
MOUNTAINS AND VALLEYS THIS MORNING. IFR/MVFR CONDITIONS AT KJAC ARE
LIKELY TO HANG ON THROUGH ABOUT 00Z/SAT. EXPECT THAT WHILE
VISIBILITIES WILL IMPROVE CEILINGS WILL BE MVFR OR LOW VFR THROUGH
THE FORECAST PERIOD. MVFR STRATUS DECK WILL LIFT AT KBPI EARLY THIS
AFTERNOON. EXPECT CONDITIONS THERE AND AT KPNA TO REMAIN VFR THROUGH
THE FORECAST PERIOD. SOME PESKY STRATUS AROUND KRKS BUT BELIEVE THE
SUN WILL WIN OUT AND LEAVE VFR THROUGH TODAY. COLD FRONTAL SURGE
WILL BRING GUSTY EAST-NORTHEAST WIND TO KRKS BEGINNING BETWEEN
09Z/SAT AND 12Z/SAT. WHILE CONDITIONS WILL BE VFR THROUGH
18Z/SAT...POSSIBLE RETURN TO MVFR CONDITIONS WITH SNOW/WIND
COMBINATION BY 00Z/SUN OR SHORTLY THEREAFTER. WILL BE ADDRESSING
THIS MORE WITH THE 00Z TAF SET THIS AFTERNOON.

&&

.FIRE WEATHER...

A SOMEWHAT BUSY FORECAST PERIOD ACROSS THE AREA. SHOWER ACTIVITY
WILL REMAIN POSSIBLE OVER THE NORTHERN THIRD OF THE AREA AS A
DISTURBANCES MOVES ACROSS THE AREA IN THE CONTINUED NORTHWEST FLOW.
AFTER A VERY SLIGHT WARMING TODAY...TEMPERATURES WILL AGAIN COOL
SATURDAY AS AN AREA OF LOW PRESSURE MOVES SOUTH ALONG THE PACIFIC
COASTLINE. AS THIS SYSTEM PROGRESSES...IT WILL SPREAD ADDITIONAL
SHOWERS ACROSS SOUTHWESTERN WYOMING...WITH SOUTHERN WYOMING
EXPERIENCING THE BRUNT OF THE SHOWER ACTIVITY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...PS
AVIATION...CNJ
FIRE WEATHER...BRANHAM







000
FXUS65 KRIW 271741
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1041 AM MST FRI FEB 27 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

A PUSH OF MOISTURE MOVING IN THE NORTHWEST FLOW WILL KEEP SOME LIGHT
SHOWER ACTIVITY ACROSS NORTHWESTERN WYOMING TODAY. THE VERY WEAK
DISTURBANCE USHERING THIS MOISTURE PUSH WILL CONTINUE TO MOVE EAST
THROUGH THE FORECAST AREA OVERNIGHT. THE MOISTURE IS EXPECTED TO
INCREASE AND SPREAD ACROSS THE NORTHERN THIRD OF THE FORECAST AREA
BY SATURDAY MORNING. TEMPERATURES WILL BE ABLE TO WARM
SLIGHTLY...THOUGH WILL STILL REMAIN COOL.

AN AREA OF LOW PRESSURE OVER THE PACIFIC NORTHWEST WILL DIVE SOUTH
ON SATURDAY...ARRIVING OVER CALIFORNIA SATURDAY. AS THIS SYSTEM
MOVES SOUTH IT WILL BRING COOLING TEMPERATURES...AND SEND ADDITIONAL
PULSES OF MOISTURE OVER THE FORECAST AREA. THE BEST OF THESE PULSES
IS NOT EXPECTED TO ARRIVE UNTIL LATE SATURDAY AFTERNOON...AND WILL
PRIMARILY IMPACT SOUTHWESTERN WYOMING. THIS SYSTEM WILL CONTINUE TO
MOVE SOUTH THROUGH SUNDAY WITH PRECIPITATION LINGERING OVER SOUTHERN
WYOMING THROUGH SUNDAY AFTERNOON. A BRIEF PERIOD OF DRY CONDITIONS
POSSIBLE SUNDAY NIGHT...THOUGH MODELS DO INDICATE THE POTENTIAL FOR
ADDITIONAL MOISTURE ACROSS SOUTHERN WYOMING DURING THE LATE EVENING
HOURS OF SUNDAY.

.LONG TERM...MONDAY THROUGH FRIDAY

MAIN CHANGE FOR TONIGHT ARE THE MODELS NOT SHOWING AS MUCH ENERGY
DIGGING INTO THE GREAT BASIN/INTER-MOUNTAIN WEST MONDAY NIGHT AND
TUESDAY AS LAST NIGHT. MORE SHEARING OR JUST OVERALL LESS ENERGY.
THE SYSTEM THE MODELS TRACK FROM KAMCHATKA YESTERDAY IS STILL THE
SAME BUT THE END SOLUTION IS JUST DIFFERENT. STILL LOOKS LIKE SNOW
SPREADING S AND SE ACROSS THE AREA MONDAY NIGHT INTO EARLY TUESDAY
AND TURNING SHARPLY COLDER. SOME FAIRLY DECENT QG FORCING MAY
COMBINE WITH SOME INITIAL RRQ JET DYNAMICS MONDAY NIGHT AND THEN
LEFT EXIT REGION ON TUE WITH THE NEXT JET APPROACHING. WITH LESS
ENERGY TO THE WEST...MOVEMENT IS FASTER AND NOW WE MAY ACTUALLY
CLEAR BY WEDNESDAY MORNING LEADING TO SOME BITTER COLD LOWS. A
COLD COUPLE DAYS THOUGH FOR TUE AND WED. ON THE PLUS SIDE...THE
RIDGE FLATTENS MORE QUICKLY WITH A RATHER FAST MODERATION THURSDAY
INTO FRIDAY ON THE GFS. BACK TRACKING A LITTLE...THE WEEKEND
SYSTEM ENERGY LINGERS JUST TO THE SOUTH TO START THIS PERIOD
MONDAY WITH CONTINUED POTENTIAL FOR CLOUDS AND MAYBE EVEN SOME
VERY LIGHT PCPN IN OUR FAR SRN ZONES. OTHERWISE... DETERIORATING
CONDS BEGINNING LATER MONDAY ONWARD WITH OUR AFOREMENTIONED MONDAY
NIGHT/TUE SYSTEM FAST APPROACHING. RIGHT AT THE END OF THE MEDIUM
RANGE PERIOD...THE MODELS DIVERGE AS TO THE HANDLING OF A PIECE OF
ENERGY CURRENTLY COMING OFF THE ASIA COAST. THE GFS BRINGS IT
FURTHER OVER THE RIDGE AND INTO THE NRN PLAINS WHILE THE EURO
BRINGS THIS SHORTWAVE AT A LITTLE LOWER LATITUDE ALLOWING IT TO
DIG SE INTO OUR AREA NEXT FRIDAY NIGHT. KEEPING IT DRY FOR NOW.
THE GFS WOULD HAVE A MUCH NICER DAY ON FRIDAY WHILE THE ECMWF IS
ALREADY DIGGING THE LOW TOWARDS US WITH FALLING TEMPS BEHIND A
COLD FRONT.

&&

.AVIATION.../18Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS ALONG AND WEST OF THE CONTINENTAL
DIVIDE THROUGH THE FORECAST PERIOD. ALSO...FOOTHILL OBSCURATIONS IN
THE VICINITY OF KLND AND KRIW WILL DISSIPATE EARLY THIS AFTERNOON.
EXPECT MORE WIDESPREAD OBSCURATIONS DEVELOPING FROM NORTH TO SOUTH
AFTER 03Z/SAT THROUGH 09Z/SAT.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

IFR/MVFR CONDITIONS WITH LOW STRATUS DECK AT KRIW AND KLND THIS
MORNING. EDGES HAVE BEEN SLOW TO ERODE. HAVE BACKED OFF THE
DISSIPATION OF THE STRATUS UNTIL 19Z-20Z. MORE SUNSHINE HAS BEEN
STARTING TO SHOW THROUGH SINCE 17Z. OTHER TERMINALS WILL BE VFR
THROUGH THIS AFTERNOON. ANOTHER SURGE OF COLD AIR WILL BRING A
RETURN OF LOW CLOUDS AND MVFR OR LOW VFR CEILINGS OVER NORTHERN
WYOMING BETWEEN 00Z-06Z/SAT. THIS AREA OF CLOUDS AND LIGHT SNOW WILL
PUSH SOUTH THROUGH THE NIGHT. KWRL IS THE LEAST LIKELY OF THE
TERMINALS TO SEE AN EXTENDED PERIOD OF LIGHT SNOW. BEST CHANCE FOR
MVFR VISIBILITIES THROUGH 18Z/SAT WILL BE FROM KLND-KCPR WHERE WEAK
UPSLOPE WOULD BE FAVORABLE AFTER THE COLD FRONT PUSHES SOUTH.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

AREAS OF LOW CLOUDS AND LIGHT SNOW ACROSS PORTIONS OF THE FAR WEST
MOUNTAINS AND VALLEYS THIS MORNING. IFR/MVFR CONDITIONS AT KJAC ARE
LIKELY TO HANG ON THROUGH ABOUT 00Z/SAT. EXPECT THAT WHILE
VISIBILITIES WILL IMPROVE CEILINGS WILL BE MVFR OR LOW VFR THROUGH
THE FORECAST PERIOD. MVFR STRATUS DECK WILL LIFT AT KBPI EARLY THIS
AFTERNOON. EXPECT CONDITIONS THERE AND AT KPNA TO REMAIN VFR THROUGH
THE FORECAST PERIOD. SOME PESKY STRATUS AROUND KRKS BUT BELIEVE THE
SUN WILL WIN OUT AND LEAVE VFR THROUGH TODAY. COLD FRONTAL SURGE
WILL BRING GUSTY EAST-NORTHEAST WIND TO KRKS BEGINNING BETWEEN
09Z/SAT AND 12Z/SAT. WHILE CONDITIONS WILL BE VFR THROUGH
18Z/SAT...POSSIBLE RETURN TO MVFR CONDITIONS WITH SNOW/WIND
COMBINATION BY 00Z/SUN OR SHORTLY THEREAFTER. WILL BE ADDRESSING
THIS MORE WITH THE 00Z TAF SET THIS AFTERNOON.

&&

.FIRE WEATHER...

A SOMEWHAT BUSY FORECAST PERIOD ACROSS THE AREA. SHOWER ACTIVITY
WILL REMAIN POSSIBLE OVER THE NORTHERN THIRD OF THE AREA AS A
DISTURBANCES MOVES ACROSS THE AREA IN THE CONTINUED NORTHWEST FLOW.
AFTER A VERY SLIGHT WARMING TODAY...TEMPERATURES WILL AGAIN COOL
SATURDAY AS AN AREA OF LOW PRESSURE MOVES SOUTH ALONG THE PACIFIC
COASTLINE. AS THIS SYSTEM PROGRESSES...IT WILL SPREAD ADDITIONAL
SHOWERS ACROSS SOUTHWESTERN WYOMING...WITH SOUTHERN WYOMING
EXPERIENCING THE BRUNT OF THE SHOWER ACTIVITY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...PS
AVIATION...CNJ
FIRE WEATHER...BRANHAM






000
FXUS65 KRIW 271741
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1041 AM MST FRI FEB 27 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

A PUSH OF MOISTURE MOVING IN THE NORTHWEST FLOW WILL KEEP SOME LIGHT
SHOWER ACTIVITY ACROSS NORTHWESTERN WYOMING TODAY. THE VERY WEAK
DISTURBANCE USHERING THIS MOISTURE PUSH WILL CONTINUE TO MOVE EAST
THROUGH THE FORECAST AREA OVERNIGHT. THE MOISTURE IS EXPECTED TO
INCREASE AND SPREAD ACROSS THE NORTHERN THIRD OF THE FORECAST AREA
BY SATURDAY MORNING. TEMPERATURES WILL BE ABLE TO WARM
SLIGHTLY...THOUGH WILL STILL REMAIN COOL.

AN AREA OF LOW PRESSURE OVER THE PACIFIC NORTHWEST WILL DIVE SOUTH
ON SATURDAY...ARRIVING OVER CALIFORNIA SATURDAY. AS THIS SYSTEM
MOVES SOUTH IT WILL BRING COOLING TEMPERATURES...AND SEND ADDITIONAL
PULSES OF MOISTURE OVER THE FORECAST AREA. THE BEST OF THESE PULSES
IS NOT EXPECTED TO ARRIVE UNTIL LATE SATURDAY AFTERNOON...AND WILL
PRIMARILY IMPACT SOUTHWESTERN WYOMING. THIS SYSTEM WILL CONTINUE TO
MOVE SOUTH THROUGH SUNDAY WITH PRECIPITATION LINGERING OVER SOUTHERN
WYOMING THROUGH SUNDAY AFTERNOON. A BRIEF PERIOD OF DRY CONDITIONS
POSSIBLE SUNDAY NIGHT...THOUGH MODELS DO INDICATE THE POTENTIAL FOR
ADDITIONAL MOISTURE ACROSS SOUTHERN WYOMING DURING THE LATE EVENING
HOURS OF SUNDAY.

.LONG TERM...MONDAY THROUGH FRIDAY

MAIN CHANGE FOR TONIGHT ARE THE MODELS NOT SHOWING AS MUCH ENERGY
DIGGING INTO THE GREAT BASIN/INTER-MOUNTAIN WEST MONDAY NIGHT AND
TUESDAY AS LAST NIGHT. MORE SHEARING OR JUST OVERALL LESS ENERGY.
THE SYSTEM THE MODELS TRACK FROM KAMCHATKA YESTERDAY IS STILL THE
SAME BUT THE END SOLUTION IS JUST DIFFERENT. STILL LOOKS LIKE SNOW
SPREADING S AND SE ACROSS THE AREA MONDAY NIGHT INTO EARLY TUESDAY
AND TURNING SHARPLY COLDER. SOME FAIRLY DECENT QG FORCING MAY
COMBINE WITH SOME INITIAL RRQ JET DYNAMICS MONDAY NIGHT AND THEN
LEFT EXIT REGION ON TUE WITH THE NEXT JET APPROACHING. WITH LESS
ENERGY TO THE WEST...MOVEMENT IS FASTER AND NOW WE MAY ACTUALLY
CLEAR BY WEDNESDAY MORNING LEADING TO SOME BITTER COLD LOWS. A
COLD COUPLE DAYS THOUGH FOR TUE AND WED. ON THE PLUS SIDE...THE
RIDGE FLATTENS MORE QUICKLY WITH A RATHER FAST MODERATION THURSDAY
INTO FRIDAY ON THE GFS. BACK TRACKING A LITTLE...THE WEEKEND
SYSTEM ENERGY LINGERS JUST TO THE SOUTH TO START THIS PERIOD
MONDAY WITH CONTINUED POTENTIAL FOR CLOUDS AND MAYBE EVEN SOME
VERY LIGHT PCPN IN OUR FAR SRN ZONES. OTHERWISE... DETERIORATING
CONDS BEGINNING LATER MONDAY ONWARD WITH OUR AFOREMENTIONED MONDAY
NIGHT/TUE SYSTEM FAST APPROACHING. RIGHT AT THE END OF THE MEDIUM
RANGE PERIOD...THE MODELS DIVERGE AS TO THE HANDLING OF A PIECE OF
ENERGY CURRENTLY COMING OFF THE ASIA COAST. THE GFS BRINGS IT
FURTHER OVER THE RIDGE AND INTO THE NRN PLAINS WHILE THE EURO
BRINGS THIS SHORTWAVE AT A LITTLE LOWER LATITUDE ALLOWING IT TO
DIG SE INTO OUR AREA NEXT FRIDAY NIGHT. KEEPING IT DRY FOR NOW.
THE GFS WOULD HAVE A MUCH NICER DAY ON FRIDAY WHILE THE ECMWF IS
ALREADY DIGGING THE LOW TOWARDS US WITH FALLING TEMPS BEHIND A
COLD FRONT.

&&

.AVIATION.../18Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS ALONG AND WEST OF THE CONTINENTAL
DIVIDE THROUGH THE FORECAST PERIOD. ALSO...FOOTHILL OBSCURATIONS IN
THE VICINITY OF KLND AND KRIW WILL DISSIPATE EARLY THIS AFTERNOON.
EXPECT MORE WIDESPREAD OBSCURATIONS DEVELOPING FROM NORTH TO SOUTH
AFTER 03Z/SAT THROUGH 09Z/SAT.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

IFR/MVFR CONDITIONS WITH LOW STRATUS DECK AT KRIW AND KLND THIS
MORNING. EDGES HAVE BEEN SLOW TO ERODE. HAVE BACKED OFF THE
DISSIPATION OF THE STRATUS UNTIL 19Z-20Z. MORE SUNSHINE HAS BEEN
STARTING TO SHOW THROUGH SINCE 17Z. OTHER TERMINALS WILL BE VFR
THROUGH THIS AFTERNOON. ANOTHER SURGE OF COLD AIR WILL BRING A
RETURN OF LOW CLOUDS AND MVFR OR LOW VFR CEILINGS OVER NORTHERN
WYOMING BETWEEN 00Z-06Z/SAT. THIS AREA OF CLOUDS AND LIGHT SNOW WILL
PUSH SOUTH THROUGH THE NIGHT. KWRL IS THE LEAST LIKELY OF THE
TERMINALS TO SEE AN EXTENDED PERIOD OF LIGHT SNOW. BEST CHANCE FOR
MVFR VISIBILITIES THROUGH 18Z/SAT WILL BE FROM KLND-KCPR WHERE WEAK
UPSLOPE WOULD BE FAVORABLE AFTER THE COLD FRONT PUSHES SOUTH.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

AREAS OF LOW CLOUDS AND LIGHT SNOW ACROSS PORTIONS OF THE FAR WEST
MOUNTAINS AND VALLEYS THIS MORNING. IFR/MVFR CONDITIONS AT KJAC ARE
LIKELY TO HANG ON THROUGH ABOUT 00Z/SAT. EXPECT THAT WHILE
VISIBILITIES WILL IMPROVE CEILINGS WILL BE MVFR OR LOW VFR THROUGH
THE FORECAST PERIOD. MVFR STRATUS DECK WILL LIFT AT KBPI EARLY THIS
AFTERNOON. EXPECT CONDITIONS THERE AND AT KPNA TO REMAIN VFR THROUGH
THE FORECAST PERIOD. SOME PESKY STRATUS AROUND KRKS BUT BELIEVE THE
SUN WILL WIN OUT AND LEAVE VFR THROUGH TODAY. COLD FRONTAL SURGE
WILL BRING GUSTY EAST-NORTHEAST WIND TO KRKS BEGINNING BETWEEN
09Z/SAT AND 12Z/SAT. WHILE CONDITIONS WILL BE VFR THROUGH
18Z/SAT...POSSIBLE RETURN TO MVFR CONDITIONS WITH SNOW/WIND
COMBINATION BY 00Z/SUN OR SHORTLY THEREAFTER. WILL BE ADDRESSING
THIS MORE WITH THE 00Z TAF SET THIS AFTERNOON.

&&

.FIRE WEATHER...

A SOMEWHAT BUSY FORECAST PERIOD ACROSS THE AREA. SHOWER ACTIVITY
WILL REMAIN POSSIBLE OVER THE NORTHERN THIRD OF THE AREA AS A
DISTURBANCES MOVES ACROSS THE AREA IN THE CONTINUED NORTHWEST FLOW.
AFTER A VERY SLIGHT WARMING TODAY...TEMPERATURES WILL AGAIN COOL
SATURDAY AS AN AREA OF LOW PRESSURE MOVES SOUTH ALONG THE PACIFIC
COASTLINE. AS THIS SYSTEM PROGRESSES...IT WILL SPREAD ADDITIONAL
SHOWERS ACROSS SOUTHWESTERN WYOMING...WITH SOUTHERN WYOMING
EXPERIENCING THE BRUNT OF THE SHOWER ACTIVITY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...PS
AVIATION...CNJ
FIRE WEATHER...BRANHAM






000
FXUS65 KRIW 271741
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1041 AM MST FRI FEB 27 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

A PUSH OF MOISTURE MOVING IN THE NORTHWEST FLOW WILL KEEP SOME LIGHT
SHOWER ACTIVITY ACROSS NORTHWESTERN WYOMING TODAY. THE VERY WEAK
DISTURBANCE USHERING THIS MOISTURE PUSH WILL CONTINUE TO MOVE EAST
THROUGH THE FORECAST AREA OVERNIGHT. THE MOISTURE IS EXPECTED TO
INCREASE AND SPREAD ACROSS THE NORTHERN THIRD OF THE FORECAST AREA
BY SATURDAY MORNING. TEMPERATURES WILL BE ABLE TO WARM
SLIGHTLY...THOUGH WILL STILL REMAIN COOL.

AN AREA OF LOW PRESSURE OVER THE PACIFIC NORTHWEST WILL DIVE SOUTH
ON SATURDAY...ARRIVING OVER CALIFORNIA SATURDAY. AS THIS SYSTEM
MOVES SOUTH IT WILL BRING COOLING TEMPERATURES...AND SEND ADDITIONAL
PULSES OF MOISTURE OVER THE FORECAST AREA. THE BEST OF THESE PULSES
IS NOT EXPECTED TO ARRIVE UNTIL LATE SATURDAY AFTERNOON...AND WILL
PRIMARILY IMPACT SOUTHWESTERN WYOMING. THIS SYSTEM WILL CONTINUE TO
MOVE SOUTH THROUGH SUNDAY WITH PRECIPITATION LINGERING OVER SOUTHERN
WYOMING THROUGH SUNDAY AFTERNOON. A BRIEF PERIOD OF DRY CONDITIONS
POSSIBLE SUNDAY NIGHT...THOUGH MODELS DO INDICATE THE POTENTIAL FOR
ADDITIONAL MOISTURE ACROSS SOUTHERN WYOMING DURING THE LATE EVENING
HOURS OF SUNDAY.

.LONG TERM...MONDAY THROUGH FRIDAY

MAIN CHANGE FOR TONIGHT ARE THE MODELS NOT SHOWING AS MUCH ENERGY
DIGGING INTO THE GREAT BASIN/INTER-MOUNTAIN WEST MONDAY NIGHT AND
TUESDAY AS LAST NIGHT. MORE SHEARING OR JUST OVERALL LESS ENERGY.
THE SYSTEM THE MODELS TRACK FROM KAMCHATKA YESTERDAY IS STILL THE
SAME BUT THE END SOLUTION IS JUST DIFFERENT. STILL LOOKS LIKE SNOW
SPREADING S AND SE ACROSS THE AREA MONDAY NIGHT INTO EARLY TUESDAY
AND TURNING SHARPLY COLDER. SOME FAIRLY DECENT QG FORCING MAY
COMBINE WITH SOME INITIAL RRQ JET DYNAMICS MONDAY NIGHT AND THEN
LEFT EXIT REGION ON TUE WITH THE NEXT JET APPROACHING. WITH LESS
ENERGY TO THE WEST...MOVEMENT IS FASTER AND NOW WE MAY ACTUALLY
CLEAR BY WEDNESDAY MORNING LEADING TO SOME BITTER COLD LOWS. A
COLD COUPLE DAYS THOUGH FOR TUE AND WED. ON THE PLUS SIDE...THE
RIDGE FLATTENS MORE QUICKLY WITH A RATHER FAST MODERATION THURSDAY
INTO FRIDAY ON THE GFS. BACK TRACKING A LITTLE...THE WEEKEND
SYSTEM ENERGY LINGERS JUST TO THE SOUTH TO START THIS PERIOD
MONDAY WITH CONTINUED POTENTIAL FOR CLOUDS AND MAYBE EVEN SOME
VERY LIGHT PCPN IN OUR FAR SRN ZONES. OTHERWISE... DETERIORATING
CONDS BEGINNING LATER MONDAY ONWARD WITH OUR AFOREMENTIONED MONDAY
NIGHT/TUE SYSTEM FAST APPROACHING. RIGHT AT THE END OF THE MEDIUM
RANGE PERIOD...THE MODELS DIVERGE AS TO THE HANDLING OF A PIECE OF
ENERGY CURRENTLY COMING OFF THE ASIA COAST. THE GFS BRINGS IT
FURTHER OVER THE RIDGE AND INTO THE NRN PLAINS WHILE THE EURO
BRINGS THIS SHORTWAVE AT A LITTLE LOWER LATITUDE ALLOWING IT TO
DIG SE INTO OUR AREA NEXT FRIDAY NIGHT. KEEPING IT DRY FOR NOW.
THE GFS WOULD HAVE A MUCH NICER DAY ON FRIDAY WHILE THE ECMWF IS
ALREADY DIGGING THE LOW TOWARDS US WITH FALLING TEMPS BEHIND A
COLD FRONT.

&&

.AVIATION.../18Z ISSUANCE/

FREQUENT MOUNTAIN OBSCURATIONS ALONG AND WEST OF THE CONTINENTAL
DIVIDE THROUGH THE FORECAST PERIOD. ALSO...FOOTHILL OBSCURATIONS IN
THE VICINITY OF KLND AND KRIW WILL DISSIPATE EARLY THIS AFTERNOON.
EXPECT MORE WIDESPREAD OBSCURATIONS DEVELOPING FROM NORTH TO SOUTH
AFTER 03Z/SAT THROUGH 09Z/SAT.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

IFR/MVFR CONDITIONS WITH LOW STRATUS DECK AT KRIW AND KLND THIS
MORNING. EDGES HAVE BEEN SLOW TO ERODE. HAVE BACKED OFF THE
DISSIPATION OF THE STRATUS UNTIL 19Z-20Z. MORE SUNSHINE HAS BEEN
STARTING TO SHOW THROUGH SINCE 17Z. OTHER TERMINALS WILL BE VFR
THROUGH THIS AFTERNOON. ANOTHER SURGE OF COLD AIR WILL BRING A
RETURN OF LOW CLOUDS AND MVFR OR LOW VFR CEILINGS OVER NORTHERN
WYOMING BETWEEN 00Z-06Z/SAT. THIS AREA OF CLOUDS AND LIGHT SNOW WILL
PUSH SOUTH THROUGH THE NIGHT. KWRL IS THE LEAST LIKELY OF THE
TERMINALS TO SEE AN EXTENDED PERIOD OF LIGHT SNOW. BEST CHANCE FOR
MVFR VISIBILITIES THROUGH 18Z/SAT WILL BE FROM KLND-KCPR WHERE WEAK
UPSLOPE WOULD BE FAVORABLE AFTER THE COLD FRONT PUSHES SOUTH.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

AREAS OF LOW CLOUDS AND LIGHT SNOW ACROSS PORTIONS OF THE FAR WEST
MOUNTAINS AND VALLEYS THIS MORNING. IFR/MVFR CONDITIONS AT KJAC ARE
LIKELY TO HANG ON THROUGH ABOUT 00Z/SAT. EXPECT THAT WHILE
VISIBILITIES WILL IMPROVE CEILINGS WILL BE MVFR OR LOW VFR THROUGH
THE FORECAST PERIOD. MVFR STRATUS DECK WILL LIFT AT KBPI EARLY THIS
AFTERNOON. EXPECT CONDITIONS THERE AND AT KPNA TO REMAIN VFR THROUGH
THE FORECAST PERIOD. SOME PESKY STRATUS AROUND KRKS BUT BELIEVE THE
SUN WILL WIN OUT AND LEAVE VFR THROUGH TODAY. COLD FRONTAL SURGE
WILL BRING GUSTY EAST-NORTHEAST WIND TO KRKS BEGINNING BETWEEN
09Z/SAT AND 12Z/SAT. WHILE CONDITIONS WILL BE VFR THROUGH
18Z/SAT...POSSIBLE RETURN TO MVFR CONDITIONS WITH SNOW/WIND
COMBINATION BY 00Z/SUN OR SHORTLY THEREAFTER. WILL BE ADDRESSING
THIS MORE WITH THE 00Z TAF SET THIS AFTERNOON.

&&

.FIRE WEATHER...

A SOMEWHAT BUSY FORECAST PERIOD ACROSS THE AREA. SHOWER ACTIVITY
WILL REMAIN POSSIBLE OVER THE NORTHERN THIRD OF THE AREA AS A
DISTURBANCES MOVES ACROSS THE AREA IN THE CONTINUED NORTHWEST FLOW.
AFTER A VERY SLIGHT WARMING TODAY...TEMPERATURES WILL AGAIN COOL
SATURDAY AS AN AREA OF LOW PRESSURE MOVES SOUTH ALONG THE PACIFIC
COASTLINE. AS THIS SYSTEM PROGRESSES...IT WILL SPREAD ADDITIONAL
SHOWERS ACROSS SOUTHWESTERN WYOMING...WITH SOUTHERN WYOMING
EXPERIENCING THE BRUNT OF THE SHOWER ACTIVITY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...PS
AVIATION...CNJ
FIRE WEATHER...BRANHAM







000
FXUS65 KRIW 270932
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
232 AM MST FRI FEB 27 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

A PUSH OF MOISTURE MOVING IN THE NORTHWEST FLOW WILL KEEP SOME LIGHT
SHOWER ACTIVITY ACROSS NORTHWESTERN WYOMING TODAY. THE VERY WEAK
DISTURBANCE USHERING THIS MOISTURE PUSH WILL CONTINUE TO MOVE EAST
THROUGH THE FORECAST AREA OVERNIGHT. THE MOISTURE IS EXPECTED TO
INCREASE AND SPREAD ACROSS THE NORTHERN THIRD OF THE FORECAST AREA
BY SATURDAY MORNING. TEMPERATURES WILL BE ABLE TO WARM
SLIGHTLY...THOUGH WILL STILL REMAIN COOL.

AN AREA OF LOW PRESSURE OVER THE PACIFIC NORTHWEST WILL DIVE SOUTH
ON SATURDAY...ARRIVING OVER CALIFORNIA SATURDAY. AS THIS SYSTEM
MOVES SOUTH IT WILL BRING COOLING TEMPERATURES...AND SEND ADDITIONAL
PULSES OF MOISTURE OVER THE FORECAST AREA. THE BEST OF THESE PULSES
IS NOT EXPECTED TO ARRIVE UNTIL LATE SATURDAY AFTERNOON...AND WILL
PRIMARILY IMPACT SOUTHWESTERN WYOMING. THIS SYSTEM WILL CONTINUE TO
MOVE SOUTH THROUGH SUNDAY WITH PRECIPITATION LINGERING OVER SOUTHERN
WYOMING THROUGH SUNDAY AFTERNOON. A BRIEF PERIOD OF DRY CONDITIONS
POSSIBLE SUNDAY NIGHT...THOUGH MODELS DO INDICATE THE POTENTIAL FOR
ADDITIONAL MOISTURE ACROSS SOUTHERN WYOMING DURING THE LATE EVENING
HOURS OF SUNDAY.

.LONG TERM...MONDAY THROUGH FRIDAY

MAIN CHANGE FOR TONIGHT ARE THE MODELS NOT SHOWING AS MUCH ENERGY
DIGGING INTO THE GREAT BASIN/INTER-MOUNTAIN WEST MONDAY NIGHT AND
TUESDAY AS LAST NIGHT. MORE SHEARING OR JUST OVERALL LESS ENERGY.
THE SYSTEM THE MODELS TRACK FROM KAMCHATKA YESTERDAY IS STILL THE
SAME BUT THE END SOLUTION IS JUST DIFFERENT. STILL LOOKS LIKE SNOW
SPREADING S AND SE ACROSS THE AREA MONDAY NIGHT INTO EARLY TUESDAY
AND TURNING SHARPLY COLDER. SOME FAIRLY DECENT QG FORCING MAY
COMBINE WITH SOME INITIAL RRQ JET DYNAMICS MONDAY NIGHT AND THEN
LEFT EXIT REGION ON TUE WITH THE NEXT JET APPROACHING. WITH LESS
ENERGY TO THE WEST...MOVEMENT IS FASTER AND NOW WE MAY ACTUALLY
CLEAR BY WEDNESDAY MORNING LEADING TO SOME BITTER COLD LOWS. A
COLD COUPLE DAYS THOUGH FOR TUE AND WED. ON THE PLUS SIDE...THE
RIDGE FLATTENS MORE QUICKLY WITH A RATHER FAST MODERATION THURSDAY
INTO FRIDAY ON THE GFS. BACK TRACKING A LITTLE...THE WEEKEND
SYSTEM ENERGY LINGERS JUST TO THE SOUTH TO START THIS PERIOD
MONDAY WITH CONTINUED POTENTIAL FOR CLOUDS AND MAYBE EVEN SOME
VERY LIGHT PCPN IN OUR FAR SRN ZONES. OTHERWISE... DETERIORATING
CONDS BEGINNING LATER MONDAY ONWARD WITH OUR AFOREMENTIONED MONDAY
NIGHT/TUE SYSTEM FAST APPROACHING. RIGHT AT THE END OF THE MEDIUM
RANGE PERIOD...THE MODELS DIVERGE AS TO THE HANDLING OF A PIECE OF
ENERGY CURRENTLY COMING OFF THE ASIA COAST. THE GFS BRINGS IT
FURTHER OVER THE RIDGE AND INTO THE NRN PLAINS WHILE THE EURO
BRINGS THIS SHORTWAVE AT A LITTLE LOWER LATITUDE ALLOWING IT TO
DIG SE INTO OUR AREA NEXT FRIDAY NIGHT. KEEPING IT DRY FOR NOW.
THE GFS WOULD HAVE A MUCH NICER DAY ON FRIDAY WHILE THE ECMWF IS
ALREADY DIGGING THE LOW TOWARDS US WITH FALLING TEMPS BEHIND A
COLD FRONT.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR WITH LINGERING LIGHT SNOW OR
FLURRIES UNTIL 13Z. AFTER 13Z VFR CONDITIONS ARE EXPECTED THROUGH
00Z. CLOUDS WILL LOWER OVER NORTHERN WY AFTER 00Z WITH AREAS OF MVFR
CONDITIONS OCCURRING THROUGH 12Z SATURDAY DUE TO LOW CLOUDS AND
AREAS OF LIGHT SNOW. AFTER 06Z SATURDAY...FROM KLND TO KCPR...AREAS
OF MVFR CONDITIONS WILL OCCUR DUE TO LOW CLOUDS AND AREAS OF LIGHT
SNOW.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

VFR TO MVFR CONDITIONS IN SOUTHWEST WY WHERE LOWER CLOUDS AND
LINGERING LIGHT SNOW OR FLURRIES WILL OCCUR THROUGH 14Z. LOCAL IFR
CONDITIONS ARE POSSIBLE. CONDITIONS IN SOUTHWEST WY WILL IMPROVE TO
VFR BY 17Z AND VFR CONDITIONS WILL PREVAIL UNTIL 06Z SATURDAY. AFTER
06Z SATURDAY AREAS OF MVFR CONDITIONS WILL DEVELOP ALONG WITH SOME
LIGHT SNOW.

FOR THE KJAC TERMINAL SITE VFR CONDITIONS ARE FORECAST THROUGH 16Z.
THEN MVFR CONDITIONS WILL PREVAIL AROUND 18Z THROUGH 08Z SATURDAY AS
LIGHT SNOW DEVELOPS OVER NORTHWEST WY BY 18Z AND CONTINUES THROUGH
09Z SATURDAY. EXPECT MOUNTAIN OBSCURATION AT TIMES IN NW WY THIS
AFTERNOON AND TONIGHT.

&&

.FIRE WEATHER...

A SOMEWHAT BUSY FORECAST PERIOD ACROSS THE AREA. SHOWER ACTIVITY
WILL REMAIN POSSIBLE OVER THE NORTHERN THIRD OF THE AREA AS A
DISTURBANCES MOVES ACROSS THE AREA IN THE CONTINUED NORTHWEST FLOW.
AFTER A VERY SLIGHT WARMING TODAY...TEMPERATURES WILL AGAIN COOL
SATURDAY AS AN AREA OF LOW PRESSURE MOVES SOUTH ALONG THE PACIFIC
COASTLINE. AS THIS SYSTEM PROGRESSES...IT WILL SPREAD ADDITIONAL
SHOWERS ACROSS SOUTHWESTERN WYOMING...WITH SOUTHERN WYOMING
EXPERIENCING THE BRUNT OF THE SHOWER ACTIVITY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...PS
AVIATION...AR
FIRE WEATHER...BRANHAM












000
FXUS65 KRIW 270932
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
232 AM MST FRI FEB 27 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

A PUSH OF MOISTURE MOVING IN THE NORTHWEST FLOW WILL KEEP SOME LIGHT
SHOWER ACTIVITY ACROSS NORTHWESTERN WYOMING TODAY. THE VERY WEAK
DISTURBANCE USHERING THIS MOISTURE PUSH WILL CONTINUE TO MOVE EAST
THROUGH THE FORECAST AREA OVERNIGHT. THE MOISTURE IS EXPECTED TO
INCREASE AND SPREAD ACROSS THE NORTHERN THIRD OF THE FORECAST AREA
BY SATURDAY MORNING. TEMPERATURES WILL BE ABLE TO WARM
SLIGHTLY...THOUGH WILL STILL REMAIN COOL.

AN AREA OF LOW PRESSURE OVER THE PACIFIC NORTHWEST WILL DIVE SOUTH
ON SATURDAY...ARRIVING OVER CALIFORNIA SATURDAY. AS THIS SYSTEM
MOVES SOUTH IT WILL BRING COOLING TEMPERATURES...AND SEND ADDITIONAL
PULSES OF MOISTURE OVER THE FORECAST AREA. THE BEST OF THESE PULSES
IS NOT EXPECTED TO ARRIVE UNTIL LATE SATURDAY AFTERNOON...AND WILL
PRIMARILY IMPACT SOUTHWESTERN WYOMING. THIS SYSTEM WILL CONTINUE TO
MOVE SOUTH THROUGH SUNDAY WITH PRECIPITATION LINGERING OVER SOUTHERN
WYOMING THROUGH SUNDAY AFTERNOON. A BRIEF PERIOD OF DRY CONDITIONS
POSSIBLE SUNDAY NIGHT...THOUGH MODELS DO INDICATE THE POTENTIAL FOR
ADDITIONAL MOISTURE ACROSS SOUTHERN WYOMING DURING THE LATE EVENING
HOURS OF SUNDAY.

.LONG TERM...MONDAY THROUGH FRIDAY

MAIN CHANGE FOR TONIGHT ARE THE MODELS NOT SHOWING AS MUCH ENERGY
DIGGING INTO THE GREAT BASIN/INTER-MOUNTAIN WEST MONDAY NIGHT AND
TUESDAY AS LAST NIGHT. MORE SHEARING OR JUST OVERALL LESS ENERGY.
THE SYSTEM THE MODELS TRACK FROM KAMCHATKA YESTERDAY IS STILL THE
SAME BUT THE END SOLUTION IS JUST DIFFERENT. STILL LOOKS LIKE SNOW
SPREADING S AND SE ACROSS THE AREA MONDAY NIGHT INTO EARLY TUESDAY
AND TURNING SHARPLY COLDER. SOME FAIRLY DECENT QG FORCING MAY
COMBINE WITH SOME INITIAL RRQ JET DYNAMICS MONDAY NIGHT AND THEN
LEFT EXIT REGION ON TUE WITH THE NEXT JET APPROACHING. WITH LESS
ENERGY TO THE WEST...MOVEMENT IS FASTER AND NOW WE MAY ACTUALLY
CLEAR BY WEDNESDAY MORNING LEADING TO SOME BITTER COLD LOWS. A
COLD COUPLE DAYS THOUGH FOR TUE AND WED. ON THE PLUS SIDE...THE
RIDGE FLATTENS MORE QUICKLY WITH A RATHER FAST MODERATION THURSDAY
INTO FRIDAY ON THE GFS. BACK TRACKING A LITTLE...THE WEEKEND
SYSTEM ENERGY LINGERS JUST TO THE SOUTH TO START THIS PERIOD
MONDAY WITH CONTINUED POTENTIAL FOR CLOUDS AND MAYBE EVEN SOME
VERY LIGHT PCPN IN OUR FAR SRN ZONES. OTHERWISE... DETERIORATING
CONDS BEGINNING LATER MONDAY ONWARD WITH OUR AFOREMENTIONED MONDAY
NIGHT/TUE SYSTEM FAST APPROACHING. RIGHT AT THE END OF THE MEDIUM
RANGE PERIOD...THE MODELS DIVERGE AS TO THE HANDLING OF A PIECE OF
ENERGY CURRENTLY COMING OFF THE ASIA COAST. THE GFS BRINGS IT
FURTHER OVER THE RIDGE AND INTO THE NRN PLAINS WHILE THE EURO
BRINGS THIS SHORTWAVE AT A LITTLE LOWER LATITUDE ALLOWING IT TO
DIG SE INTO OUR AREA NEXT FRIDAY NIGHT. KEEPING IT DRY FOR NOW.
THE GFS WOULD HAVE A MUCH NICER DAY ON FRIDAY WHILE THE ECMWF IS
ALREADY DIGGING THE LOW TOWARDS US WITH FALLING TEMPS BEHIND A
COLD FRONT.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR WITH LINGERING LIGHT SNOW OR
FLURRIES UNTIL 13Z. AFTER 13Z VFR CONDITIONS ARE EXPECTED THROUGH
00Z. CLOUDS WILL LOWER OVER NORTHERN WY AFTER 00Z WITH AREAS OF MVFR
CONDITIONS OCCURRING THROUGH 12Z SATURDAY DUE TO LOW CLOUDS AND
AREAS OF LIGHT SNOW. AFTER 06Z SATURDAY...FROM KLND TO KCPR...AREAS
OF MVFR CONDITIONS WILL OCCUR DUE TO LOW CLOUDS AND AREAS OF LIGHT
SNOW.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

VFR TO MVFR CONDITIONS IN SOUTHWEST WY WHERE LOWER CLOUDS AND
LINGERING LIGHT SNOW OR FLURRIES WILL OCCUR THROUGH 14Z. LOCAL IFR
CONDITIONS ARE POSSIBLE. CONDITIONS IN SOUTHWEST WY WILL IMPROVE TO
VFR BY 17Z AND VFR CONDITIONS WILL PREVAIL UNTIL 06Z SATURDAY. AFTER
06Z SATURDAY AREAS OF MVFR CONDITIONS WILL DEVELOP ALONG WITH SOME
LIGHT SNOW.

FOR THE KJAC TERMINAL SITE VFR CONDITIONS ARE FORECAST THROUGH 16Z.
THEN MVFR CONDITIONS WILL PREVAIL AROUND 18Z THROUGH 08Z SATURDAY AS
LIGHT SNOW DEVELOPS OVER NORTHWEST WY BY 18Z AND CONTINUES THROUGH
09Z SATURDAY. EXPECT MOUNTAIN OBSCURATION AT TIMES IN NW WY THIS
AFTERNOON AND TONIGHT.

&&

.FIRE WEATHER...

A SOMEWHAT BUSY FORECAST PERIOD ACROSS THE AREA. SHOWER ACTIVITY
WILL REMAIN POSSIBLE OVER THE NORTHERN THIRD OF THE AREA AS A
DISTURBANCES MOVES ACROSS THE AREA IN THE CONTINUED NORTHWEST FLOW.
AFTER A VERY SLIGHT WARMING TODAY...TEMPERATURES WILL AGAIN COOL
SATURDAY AS AN AREA OF LOW PRESSURE MOVES SOUTH ALONG THE PACIFIC
COASTLINE. AS THIS SYSTEM PROGRESSES...IT WILL SPREAD ADDITIONAL
SHOWERS ACROSS SOUTHWESTERN WYOMING...WITH SOUTHERN WYOMING
EXPERIENCING THE BRUNT OF THE SHOWER ACTIVITY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...BRANHAM
LONG TERM...PS
AVIATION...AR
FIRE WEATHER...BRANHAM











000
FXUS65 KRIW 270501
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1001 PM MST THU FEB 26 2015

.SHORT TERM...TONIGHT THROUGH FRIDAY (ISSUED AT 225 PM MDT)

SURFACE HIGH BUILDS INTO CENTRAL HIGH PLAINS TONIGHT. CHALLENGE
FOR CENTRAL WYOMING WILL BE TIMING OF DECREASING CLOUD COVER. WEAK
LOW LEVEL UPSLOPE FLOW PERSISTS...BUT SURFACE FLOW TO TURN MORE
SOUTHERLY TONIGHT. BEST CONFIDENCE FOR CLEARING WILL BE OVER
NATRONA AND JOHNSON COUNTIES...TO NORTHERN SECTIONS OF FORECAST
AREA. REGARDLESS...IT WILL BE QUITE COLD TONIGHT INTO EARLY FRIDAY.

WEAK FLOW ALOFT SETS UP ON FRIDAY WITH UPPER LEVEL LOW DROPPING INTO
CALIFORNIA. AS A RESULT...LITTLE OR NO ENERGY OVER WYOMING WELL AHEAD
OF THIS TROUGH. COULD STILL SEE A FEW MOUNTAIN SNOW SHOWERS WITH
HEATING OF THE DAY. OTHERWISE...ANOTHER COLD DAY ACROSS WEST
CENTRAL WYOMING WITH MORE SUNSHINE EXPECTED. WITH A VERY LIGHT
SURFACE WIND...IT SHOULD FEEL DECENT OUTDOORS ON FRIDAY.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY

AT THIS TIME...FRIDAY NIGHT LOOKS LIKE A MAINLY QUIET PERIOD WITH
JUST A FEW OROGRAPHIC SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. THE
REST OF THE REGION LOOKS MAINLY DRY WITH BELOW NORMAL TEMPERATURES
FOR THE START OF THE WEEKEND.

THE FIRST OF TWO SYSTEMS OF CONCERN IN THE LONG RANGE WILL START TO
EFFECT THE WEATHER FOR SATURDAY. A PIECE OF ENERGY WILL MOVE OFF A
CUT OFF LOW OVER CALIFORNIA AND MOVE INTO THE ROCKIES. HOWEVER...IT
APPEARS THAT THE BEST UPPER LEVEL SUPPORT WILL REMAIN OVER UTAH AND
COLORADO. AT AS RESULT...RIGHT NOW THIS LOOKS TO MAINLY A NUISANCE
EVENT AND ONLY EFFECT SOUTHERN PORTIONS OF THE COUNTY WARNING AREA
AND MAINLY WEST OF THE DIVIDE. BOTH THE GFS...EUROPEAN AND NAM ARE
IN GOOD AGREEMENT OF THIS. AS A RESULT...WE TRIMMED POPS ACROSS
AREAS NORTH AND EAST OF THE WIND RIVER RANGE FOR SATURDAY AND
SATURDAY NIGHT. EVEN IN AREAS THAT GET SNOW...THIS DOES NOT LOOK
WORTHY OF ANY SORT OF WARNINGS OR ADVISORIES RIGHT NOW. ON
SUNDAY...THERE IS SOME SLIGHT DISAGREEMENT WITH THE GFS KEEPING A
FEW SHOWERS ALONG THE SOUTHERN BORDER AND THE EUROPEAN MAINLY DRY.
WITH THE DIFFERENCES WE MADE FEW CHANGES TO CONTINUITY. MAINLY DRY
BUT CONTINUED CHILLY WEATHER WILL BE THE RULE FOR MONDAY WITH WEAK
SURFACE HIGH PRESSURE IN CONTROL.

THE NEXT AND PROBABLY MORE IMPACTFUL SYSTEM THEN APPROACHES FOR
MONDAY NIGHT AND ESPECIALLY FOR TUESDAY. THIS ONE HAS CHILLY ORIGINS
COMING IN FROM ALASKA.  THE MODELS AGAIN ARE IN FAIRLY GOOD
AGREEMENT WITH SNOW BEGINNING IN THE WEST ON MONDAY NIGHT AND THEN
SPREADING ACROSS ALL AREAS FOR TUESDAY. THE PREVIOUS FORECAST HAD
CHANCE POPS ACROSS MOST AREAS AND THESE LOOK PRETTY GOOD AT THIS
POINT SO FEW CHANGES WERE MADE. SNOWFALL AMOUNTS ARE STILL UNCERTAIN
RIGHT NOW...AS A LOT WILL DEPEND ON THE JET DYNAMICS AND OF COURSE
THE MODELS ARE PERFECT WITH THIS FIVE DAYS OUT...NOTE SARCASM. THERE
IS ALSO MORE AGREEMENT WITH THE END TIME. THE EUROPEAN HAS COME
AROUND TO THE MORE PROGRESSIVE GFS SOLUTION IN KICKING THE SYSTEM TO
THE SOUTH AND EAST DURING WEDNESDAY WITH ALL AREAS DRY AT THAT
POINT. TUESDAY NIGHT AND WEDNESDAY HAVE THE POTENTIAL TO QUITE COLD.
LOWS TUESDAY NIGHT MAY DEPEND ON HOW QUICKLY THE SKY CLEARS THOUGH.
MAINLY DRY BUT COOL WEATHER WILL BE THE RULE FOR WEDNESDAY INTO
THURSDAY WITH DRY NORTHWEST FLOW PREDOMINATING.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR OVERNIGHT WITH LINGERING LIGHT
SNOW OR FLURRIES UNTIL 12Z. AFTER 12Z VFR CONDITIONS ARE EXPECTED
THROUGH 00Z SATURDAY. CLOUDS WILL LOWER OVER NORTHERN WY AFTER 00Z
SATURDAY WITH AREAS OF MVFR CONDITIONS OCCURRING THROUGH 06Z
SATURDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR OVERNIGHT IN SOUTHWEST WY WHERE
LOWER CLOUDS AND LINGERING LIGHT SNOW OR FLURRIES WILL OCCUR THROUGH
12Z. LOCAL IFR CONDITIONS ARE POSSIBLE. CONDITIONS IN SOUTHWEST WY
WILL IMPROVE TO VFR BY 16Z AND VFR CONDITIONS WILL PREVAIL UNTIL 06Z
SATURDAY.

FOR THE KJAC TERMINAL SITE VFR CONDITIONS ARE FORECAST THROUGH 16Z.
THEN MVFR CONDITIONS WILL PREVAIL AROUND 18Z THROUGH 06Z SATURDAY AS
LIGHT SNOW DEVELOPS OVER NORTHWEST WY BY 18Z AND CONTINUES THROUGH
06Z SATURDAY. EXPECT MOUNTAIN OBSCURATION AT TIMES IN NW WY.

&&

.FIRE WEATHER...

NO FIRE WEATHER CONCERNS IN THE SHORT TERM...AS A COLD WEATHER
PATTERN CONTINUES FOR THE ENTIRE DISTRICT. LITTLE OR NO
PRECIPITATION THROUGH THE UPCOMING WEEKEND EAST OF THE DIVIDE...
BUT RELATIVE HUMIDITIES TO REMAIN HIGH.

WEST OF THE DIVIDE...INCREASING CLOUDS CAN BE EXPECTED ON FRIDAY.
A WEAK UPPER LEVEL TROUGH WILL MOVE OVER THE WESTERN MOUNTAINS LATE
FRIDAY TO HELP INITIATE SNOW SHOWERS. AREAS OF LIGHT SNOW WILL
PERSIST FRIDAY NIGHT...POSSIBLY REACHING THE WESTERN VALLEYS OF
WYOMING.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...KPL
LONG TERM...HATTINGS
AVIATION...AR
FIRE WEATHER...KPL








000
FXUS65 KRIW 270501
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1001 PM MST THU FEB 26 2015

.SHORT TERM...TONIGHT THROUGH FRIDAY (ISSUED AT 225 PM MDT)

SURFACE HIGH BUILDS INTO CENTRAL HIGH PLAINS TONIGHT. CHALLENGE
FOR CENTRAL WYOMING WILL BE TIMING OF DECREASING CLOUD COVER. WEAK
LOW LEVEL UPSLOPE FLOW PERSISTS...BUT SURFACE FLOW TO TURN MORE
SOUTHERLY TONIGHT. BEST CONFIDENCE FOR CLEARING WILL BE OVER
NATRONA AND JOHNSON COUNTIES...TO NORTHERN SECTIONS OF FORECAST
AREA. REGARDLESS...IT WILL BE QUITE COLD TONIGHT INTO EARLY FRIDAY.

WEAK FLOW ALOFT SETS UP ON FRIDAY WITH UPPER LEVEL LOW DROPPING INTO
CALIFORNIA. AS A RESULT...LITTLE OR NO ENERGY OVER WYOMING WELL AHEAD
OF THIS TROUGH. COULD STILL SEE A FEW MOUNTAIN SNOW SHOWERS WITH
HEATING OF THE DAY. OTHERWISE...ANOTHER COLD DAY ACROSS WEST
CENTRAL WYOMING WITH MORE SUNSHINE EXPECTED. WITH A VERY LIGHT
SURFACE WIND...IT SHOULD FEEL DECENT OUTDOORS ON FRIDAY.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY

AT THIS TIME...FRIDAY NIGHT LOOKS LIKE A MAINLY QUIET PERIOD WITH
JUST A FEW OROGRAPHIC SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. THE
REST OF THE REGION LOOKS MAINLY DRY WITH BELOW NORMAL TEMPERATURES
FOR THE START OF THE WEEKEND.

THE FIRST OF TWO SYSTEMS OF CONCERN IN THE LONG RANGE WILL START TO
EFFECT THE WEATHER FOR SATURDAY. A PIECE OF ENERGY WILL MOVE OFF A
CUT OFF LOW OVER CALIFORNIA AND MOVE INTO THE ROCKIES. HOWEVER...IT
APPEARS THAT THE BEST UPPER LEVEL SUPPORT WILL REMAIN OVER UTAH AND
COLORADO. AT AS RESULT...RIGHT NOW THIS LOOKS TO MAINLY A NUISANCE
EVENT AND ONLY EFFECT SOUTHERN PORTIONS OF THE COUNTY WARNING AREA
AND MAINLY WEST OF THE DIVIDE. BOTH THE GFS...EUROPEAN AND NAM ARE
IN GOOD AGREEMENT OF THIS. AS A RESULT...WE TRIMMED POPS ACROSS
AREAS NORTH AND EAST OF THE WIND RIVER RANGE FOR SATURDAY AND
SATURDAY NIGHT. EVEN IN AREAS THAT GET SNOW...THIS DOES NOT LOOK
WORTHY OF ANY SORT OF WARNINGS OR ADVISORIES RIGHT NOW. ON
SUNDAY...THERE IS SOME SLIGHT DISAGREEMENT WITH THE GFS KEEPING A
FEW SHOWERS ALONG THE SOUTHERN BORDER AND THE EUROPEAN MAINLY DRY.
WITH THE DIFFERENCES WE MADE FEW CHANGES TO CONTINUITY. MAINLY DRY
BUT CONTINUED CHILLY WEATHER WILL BE THE RULE FOR MONDAY WITH WEAK
SURFACE HIGH PRESSURE IN CONTROL.

THE NEXT AND PROBABLY MORE IMPACTFUL SYSTEM THEN APPROACHES FOR
MONDAY NIGHT AND ESPECIALLY FOR TUESDAY. THIS ONE HAS CHILLY ORIGINS
COMING IN FROM ALASKA.  THE MODELS AGAIN ARE IN FAIRLY GOOD
AGREEMENT WITH SNOW BEGINNING IN THE WEST ON MONDAY NIGHT AND THEN
SPREADING ACROSS ALL AREAS FOR TUESDAY. THE PREVIOUS FORECAST HAD
CHANCE POPS ACROSS MOST AREAS AND THESE LOOK PRETTY GOOD AT THIS
POINT SO FEW CHANGES WERE MADE. SNOWFALL AMOUNTS ARE STILL UNCERTAIN
RIGHT NOW...AS A LOT WILL DEPEND ON THE JET DYNAMICS AND OF COURSE
THE MODELS ARE PERFECT WITH THIS FIVE DAYS OUT...NOTE SARCASM. THERE
IS ALSO MORE AGREEMENT WITH THE END TIME. THE EUROPEAN HAS COME
AROUND TO THE MORE PROGRESSIVE GFS SOLUTION IN KICKING THE SYSTEM TO
THE SOUTH AND EAST DURING WEDNESDAY WITH ALL AREAS DRY AT THAT
POINT. TUESDAY NIGHT AND WEDNESDAY HAVE THE POTENTIAL TO QUITE COLD.
LOWS TUESDAY NIGHT MAY DEPEND ON HOW QUICKLY THE SKY CLEARS THOUGH.
MAINLY DRY BUT COOL WEATHER WILL BE THE RULE FOR WEDNESDAY INTO
THURSDAY WITH DRY NORTHWEST FLOW PREDOMINATING.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR OVERNIGHT WITH LINGERING LIGHT
SNOW OR FLURRIES UNTIL 12Z. AFTER 12Z VFR CONDITIONS ARE EXPECTED
THROUGH 00Z SATURDAY. CLOUDS WILL LOWER OVER NORTHERN WY AFTER 00Z
SATURDAY WITH AREAS OF MVFR CONDITIONS OCCURRING THROUGH 06Z
SATURDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR OVERNIGHT IN SOUTHWEST WY WHERE
LOWER CLOUDS AND LINGERING LIGHT SNOW OR FLURRIES WILL OCCUR THROUGH
12Z. LOCAL IFR CONDITIONS ARE POSSIBLE. CONDITIONS IN SOUTHWEST WY
WILL IMPROVE TO VFR BY 16Z AND VFR CONDITIONS WILL PREVAIL UNTIL 06Z
SATURDAY.

FOR THE KJAC TERMINAL SITE VFR CONDITIONS ARE FORECAST THROUGH 16Z.
THEN MVFR CONDITIONS WILL PREVAIL AROUND 18Z THROUGH 06Z SATURDAY AS
LIGHT SNOW DEVELOPS OVER NORTHWEST WY BY 18Z AND CONTINUES THROUGH
06Z SATURDAY. EXPECT MOUNTAIN OBSCURATION AT TIMES IN NW WY.

&&

.FIRE WEATHER...

NO FIRE WEATHER CONCERNS IN THE SHORT TERM...AS A COLD WEATHER
PATTERN CONTINUES FOR THE ENTIRE DISTRICT. LITTLE OR NO
PRECIPITATION THROUGH THE UPCOMING WEEKEND EAST OF THE DIVIDE...
BUT RELATIVE HUMIDITIES TO REMAIN HIGH.

WEST OF THE DIVIDE...INCREASING CLOUDS CAN BE EXPECTED ON FRIDAY.
A WEAK UPPER LEVEL TROUGH WILL MOVE OVER THE WESTERN MOUNTAINS LATE
FRIDAY TO HELP INITIATE SNOW SHOWERS. AREAS OF LIGHT SNOW WILL
PERSIST FRIDAY NIGHT...POSSIBLY REACHING THE WESTERN VALLEYS OF
WYOMING.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...KPL
LONG TERM...HATTINGS
AVIATION...AR
FIRE WEATHER...KPL









000
FXUS65 KRIW 270501
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1001 PM MST THU FEB 26 2015

.SHORT TERM...TONIGHT THROUGH FRIDAY (ISSUED AT 225 PM MDT)

SURFACE HIGH BUILDS INTO CENTRAL HIGH PLAINS TONIGHT. CHALLENGE
FOR CENTRAL WYOMING WILL BE TIMING OF DECREASING CLOUD COVER. WEAK
LOW LEVEL UPSLOPE FLOW PERSISTS...BUT SURFACE FLOW TO TURN MORE
SOUTHERLY TONIGHT. BEST CONFIDENCE FOR CLEARING WILL BE OVER
NATRONA AND JOHNSON COUNTIES...TO NORTHERN SECTIONS OF FORECAST
AREA. REGARDLESS...IT WILL BE QUITE COLD TONIGHT INTO EARLY FRIDAY.

WEAK FLOW ALOFT SETS UP ON FRIDAY WITH UPPER LEVEL LOW DROPPING INTO
CALIFORNIA. AS A RESULT...LITTLE OR NO ENERGY OVER WYOMING WELL AHEAD
OF THIS TROUGH. COULD STILL SEE A FEW MOUNTAIN SNOW SHOWERS WITH
HEATING OF THE DAY. OTHERWISE...ANOTHER COLD DAY ACROSS WEST
CENTRAL WYOMING WITH MORE SUNSHINE EXPECTED. WITH A VERY LIGHT
SURFACE WIND...IT SHOULD FEEL DECENT OUTDOORS ON FRIDAY.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY

AT THIS TIME...FRIDAY NIGHT LOOKS LIKE A MAINLY QUIET PERIOD WITH
JUST A FEW OROGRAPHIC SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. THE
REST OF THE REGION LOOKS MAINLY DRY WITH BELOW NORMAL TEMPERATURES
FOR THE START OF THE WEEKEND.

THE FIRST OF TWO SYSTEMS OF CONCERN IN THE LONG RANGE WILL START TO
EFFECT THE WEATHER FOR SATURDAY. A PIECE OF ENERGY WILL MOVE OFF A
CUT OFF LOW OVER CALIFORNIA AND MOVE INTO THE ROCKIES. HOWEVER...IT
APPEARS THAT THE BEST UPPER LEVEL SUPPORT WILL REMAIN OVER UTAH AND
COLORADO. AT AS RESULT...RIGHT NOW THIS LOOKS TO MAINLY A NUISANCE
EVENT AND ONLY EFFECT SOUTHERN PORTIONS OF THE COUNTY WARNING AREA
AND MAINLY WEST OF THE DIVIDE. BOTH THE GFS...EUROPEAN AND NAM ARE
IN GOOD AGREEMENT OF THIS. AS A RESULT...WE TRIMMED POPS ACROSS
AREAS NORTH AND EAST OF THE WIND RIVER RANGE FOR SATURDAY AND
SATURDAY NIGHT. EVEN IN AREAS THAT GET SNOW...THIS DOES NOT LOOK
WORTHY OF ANY SORT OF WARNINGS OR ADVISORIES RIGHT NOW. ON
SUNDAY...THERE IS SOME SLIGHT DISAGREEMENT WITH THE GFS KEEPING A
FEW SHOWERS ALONG THE SOUTHERN BORDER AND THE EUROPEAN MAINLY DRY.
WITH THE DIFFERENCES WE MADE FEW CHANGES TO CONTINUITY. MAINLY DRY
BUT CONTINUED CHILLY WEATHER WILL BE THE RULE FOR MONDAY WITH WEAK
SURFACE HIGH PRESSURE IN CONTROL.

THE NEXT AND PROBABLY MORE IMPACTFUL SYSTEM THEN APPROACHES FOR
MONDAY NIGHT AND ESPECIALLY FOR TUESDAY. THIS ONE HAS CHILLY ORIGINS
COMING IN FROM ALASKA.  THE MODELS AGAIN ARE IN FAIRLY GOOD
AGREEMENT WITH SNOW BEGINNING IN THE WEST ON MONDAY NIGHT AND THEN
SPREADING ACROSS ALL AREAS FOR TUESDAY. THE PREVIOUS FORECAST HAD
CHANCE POPS ACROSS MOST AREAS AND THESE LOOK PRETTY GOOD AT THIS
POINT SO FEW CHANGES WERE MADE. SNOWFALL AMOUNTS ARE STILL UNCERTAIN
RIGHT NOW...AS A LOT WILL DEPEND ON THE JET DYNAMICS AND OF COURSE
THE MODELS ARE PERFECT WITH THIS FIVE DAYS OUT...NOTE SARCASM. THERE
IS ALSO MORE AGREEMENT WITH THE END TIME. THE EUROPEAN HAS COME
AROUND TO THE MORE PROGRESSIVE GFS SOLUTION IN KICKING THE SYSTEM TO
THE SOUTH AND EAST DURING WEDNESDAY WITH ALL AREAS DRY AT THAT
POINT. TUESDAY NIGHT AND WEDNESDAY HAVE THE POTENTIAL TO QUITE COLD.
LOWS TUESDAY NIGHT MAY DEPEND ON HOW QUICKLY THE SKY CLEARS THOUGH.
MAINLY DRY BUT COOL WEATHER WILL BE THE RULE FOR WEDNESDAY INTO
THURSDAY WITH DRY NORTHWEST FLOW PREDOMINATING.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR OVERNIGHT WITH LINGERING LIGHT
SNOW OR FLURRIES UNTIL 12Z. AFTER 12Z VFR CONDITIONS ARE EXPECTED
THROUGH 00Z SATURDAY. CLOUDS WILL LOWER OVER NORTHERN WY AFTER 00Z
SATURDAY WITH AREAS OF MVFR CONDITIONS OCCURRING THROUGH 06Z
SATURDAY.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

VFR TO MVFR CONDITIONS WILL OCCUR OVERNIGHT IN SOUTHWEST WY WHERE
LOWER CLOUDS AND LINGERING LIGHT SNOW OR FLURRIES WILL OCCUR THROUGH
12Z. LOCAL IFR CONDITIONS ARE POSSIBLE. CONDITIONS IN SOUTHWEST WY
WILL IMPROVE TO VFR BY 16Z AND VFR CONDITIONS WILL PREVAIL UNTIL 06Z
SATURDAY.

FOR THE KJAC TERMINAL SITE VFR CONDITIONS ARE FORECAST THROUGH 16Z.
THEN MVFR CONDITIONS WILL PREVAIL AROUND 18Z THROUGH 06Z SATURDAY AS
LIGHT SNOW DEVELOPS OVER NORTHWEST WY BY 18Z AND CONTINUES THROUGH
06Z SATURDAY. EXPECT MOUNTAIN OBSCURATION AT TIMES IN NW WY.

&&

.FIRE WEATHER...

NO FIRE WEATHER CONCERNS IN THE SHORT TERM...AS A COLD WEATHER
PATTERN CONTINUES FOR THE ENTIRE DISTRICT. LITTLE OR NO
PRECIPITATION THROUGH THE UPCOMING WEEKEND EAST OF THE DIVIDE...
BUT RELATIVE HUMIDITIES TO REMAIN HIGH.

WEST OF THE DIVIDE...INCREASING CLOUDS CAN BE EXPECTED ON FRIDAY.
A WEAK UPPER LEVEL TROUGH WILL MOVE OVER THE WESTERN MOUNTAINS LATE
FRIDAY TO HELP INITIATE SNOW SHOWERS. AREAS OF LIGHT SNOW WILL
PERSIST FRIDAY NIGHT...POSSIBLY REACHING THE WESTERN VALLEYS OF
WYOMING.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...KPL
LONG TERM...HATTINGS
AVIATION...AR
FIRE WEATHER...KPL









000
FXUS65 KRIW 262125
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
225 PM MST THU FEB 26 2015

.SHORT TERM...TONIGHT THROUGH FRIDAY

SURFACE HIGH BUILDS INTO CENTRAL HIGH PLAINS TONIGHT. CHALLENGE
FOR CENTRAL WYOMING WILL BE TIMING OF DECREASING CLOUD COVER. WEAK
LOW LEVEL UPSLOPE FLOW PERSISTS...BUT SURFACE FLOW TO TURN MORE
SOUTHERLY TONIGHT. BEST CONFIDENCE FOR CLEARING WILL BE OVER
NATRONA AND JOHNSON COUNTIES...TO NORTHERN SECTIONS OF FORECAST
AREA. REGARDLESS...IT WILL BE QUITE COLD TONIGHT INTO EARLY FRIDAY.

WEAK FLOW ALOFT SETS UP ON FRIDAY WITH UPPER LEVEL LOW DROPPING INTO
CALIFORNIA. AS A RESULT...LITTLE OR NO ENERGY OVER WYOMING WELL AHEAD
OF THIS TROUGH. COULD STILL SEE A FEW MOUNTAIN SNOW SHOWERS WITH
HEATING OF THE DAY. OTHERWISE...ANOTHER COLD DAY ACROSS WEST
CENTRAL WYOMING WITH MORE SUNSHINE EXPECTED. WITH A VERY LIGHT
SURFACE WIND...IT SHOULD FEEL DECENT OUTDOORS ON FRIDAY.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY

AT THIS TIME...FRIDAY NIGHT LOOKS LIKE A MAINLY QUIET PERIOD WITH
JUST A FEW OROGRAPHIC SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. THE
REST OF THE REGION LOOKS MAINLY DRY WITH BELOW NORMAL TEMPERATURES
FOR THE START OF THE WEEKEND.

THE FIRST OF TWO SYSTEMS OF CONCERN IN THE LONG RANGE WILL START TO
EFFECT THE WEATHER FOR SATURDAY. A PIECE OF ENERGY WILL MOVE OFF A
CUT OFF LOW OVER CALIFORNIA AND MOVE INTO THE ROCKIES. HOWEVER...IT
APPEARS THAT THE BEST UPPER LEVEL SUPPORT WILL REMAIN OVER UTAH AND
COLORADO. AT AS RESULT...RIGHT NOW THIS LOOKS TO MAINLY A NUISANCE
EVENT AND ONLY EFFECT SOUTHERN PORTIONS OF THE COUNTY WARNING AREA
AND MAINLY WEST OF THE DIVIDE. BOTH THE GFS...EUROPEAN AND NAM ARE
IN GOOD AGREEMENT OF THIS. AS A RESULT...WE TRIMMED POPS ACROSS
AREAS NORTH AND EAST OF THE WIND RIVER RANGE FOR SATURDAY AND
SATURDAY NIGHT. EVEN IN AREAS THAT GET SNOW...THIS DOES NOT LOOK
WORTHY OF ANY SORT OF WARNINGS OR ADVISORIES RIGHT NOW. ON
SUNDAY...THERE IS SOME SLIGHT DISAGREEMENT WITH THE GFS KEEPING A
FEW SHOWERS ALONG THE SOUTHERN BORDER AND THE EUROPEAN MAINLY DRY.
WITH THE DIFFERENCES WE MADE FEW CHANGES TO CONTINUITY. MAINLY DRY
BUT CONTINUED CHILLY WEATHER WILL BE THE RULE FOR MONDAY WITH WEAK
SURFACE HIGH PRESSURE IN CONTROL.

THE NEXT AND PROBABLY MORE IMPACTFUL SYSTEM THEN APPROACHES FOR
MONDAY NIGHT AND ESPECIALLY FOR TUESDAY. THIS ONE HAS CHILLY ORIGINS
COMING IN FROM ALASKA.  THE MODELS AGAIN ARE IN FAIRLY GOOD
AGREEMENT WITH SNOW BEGINNING IN THE WEST ON MONDAY NIGHT AND THEN
SPREADING ACROSS ALL AREAS FOR TUESDAY. THE PREVIOUS FORECAST HAD
CHANCE POPS ACROSS MOST AREAS AND THESE LOOK PRETTY GOOD AT THIS
POINT SO FEW CHANGES WERE MADE. SNOWFALL AMOUNTS ARE STILL UNCERTAIN
RIGHT NOW...AS A LOT WILL DEPEND ON THE JET DYNAMICS AND OF COURSE
THE MODELS ARE PERFECT WITH THIS FIVE DAYS OUT...NOTE SARCASM. THERE
IS ALSO MORE AGREEMENT WITH THE END TIME. THE EUROPEAN HAS COME
AROUND TO THE MORE PROGRESSIVE GFS SOLUTION IN KICKING THE SYSTEM TO
THE SOUTH AND EAST DURING WEDNESDAY WITH ALL AREAS DRY AT THAT
POINT. TUESDAY NIGHT AND WEDNESDAY HAVE THE POTENTIAL TO QUITE COLD.
LOWS TUESDAY NIGHT MAY DEPEND ON HOW QUICKLY THE SKY CLEARS THOUGH.
MAINLY DRY BUT COOL WEATHER WILL BE THE RULE FOR WEDNESDAY INTO
THURSDAY WITH DRY NORTHWEST FLOW PREDOMINATING.

&&

.AVIATION.../00Z ISSUANCE/

CONDITIONS TO BECOME VFR TONIGHT AT ALL AIRPORT LOCATIONS. THIS IS
DUE TO DECREASING CLOUDS EAST OF THE CONTINENTAL DIVIDE. KBYG TO KCPR
EXPECTED TO CLEAR OUT BY LATE EVENING...THEN CENTRAL AND SOUTHWEST
WYOMING TO FOLLOW. HIGH PRESSURE IN CONTROL MOST AREAS ON FRIDAY.

SOME MOUNTAIN FLURRIES OR SNOW SHOWERS ARE STILL POSSIBLE FRIDAY
AFTERNOON AND EVENING. WESTERN MOUNTAIN PEAKS COULD BE OBSCURED
FRIDAY NIGHT INTO EARLY SATURDAY. OTHERWISE...LIGHT SURFACE WIND
AND VFR CONDITIONS CAN BE EXPECTED TO BEGIN THE WEEKEND ON BOTH
SIDES OF THE DIVIDE.

&&

.FIRE WEATHER...

NO FIRE WEATHER CONCERNS IN THE SHORT TERM...AS A COLD WEATHER
PATTERN CONTINUES FOR THE ENTIRE DISTRICT. LITTLE OR NO
PRECIPITATON THROUGH THE UPCOMING WEEKEND EAST OF THE DIVIDE...
BUT RELATIVE HUMIDITIES TO REMAIN HIGH.

WEST OF THE DIVIDE...INCREASING CLOUDS CAN BE EXPECTED ON FRIDAY.
A WEAK UPPER LEVEL TROUGH WILL MOVE OVER THE WESTERN MOUNTAINS LATE
FRIDAY TO HELP INITIATE SNOW SHOWERS. AREAS OF LIGHT SNOW WILL
PERSIST FRIDAY NIGHT...POSSIBLY REACHING THE WESTERN VALLEYS OF
WYOMING.

&&


.RIW WATCHES/WARNINGS/ADVISORIES...NONE.
&&

$$

SHORT TERM...KPL
LONG TERM...HATTINGS
AVIATION...KPL
FIRE WEATHER...KPL





000
FXUS65 KRIW 262125
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
225 PM MST THU FEB 26 2015

.SHORT TERM...TONIGHT THROUGH FRIDAY

SURFACE HIGH BUILDS INTO CENTRAL HIGH PLAINS TONIGHT. CHALLENGE
FOR CENTRAL WYOMING WILL BE TIMING OF DECREASING CLOUD COVER. WEAK
LOW LEVEL UPSLOPE FLOW PERSISTS...BUT SURFACE FLOW TO TURN MORE
SOUTHERLY TONIGHT. BEST CONFIDENCE FOR CLEARING WILL BE OVER
NATRONA AND JOHNSON COUNTIES...TO NORTHERN SECTIONS OF FORECAST
AREA. REGARDLESS...IT WILL BE QUITE COLD TONIGHT INTO EARLY FRIDAY.

WEAK FLOW ALOFT SETS UP ON FRIDAY WITH UPPER LEVEL LOW DROPPING INTO
CALIFORNIA. AS A RESULT...LITTLE OR NO ENERGY OVER WYOMING WELL AHEAD
OF THIS TROUGH. COULD STILL SEE A FEW MOUNTAIN SNOW SHOWERS WITH
HEATING OF THE DAY. OTHERWISE...ANOTHER COLD DAY ACROSS WEST
CENTRAL WYOMING WITH MORE SUNSHINE EXPECTED. WITH A VERY LIGHT
SURFACE WIND...IT SHOULD FEEL DECENT OUTDOORS ON FRIDAY.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY

AT THIS TIME...FRIDAY NIGHT LOOKS LIKE A MAINLY QUIET PERIOD WITH
JUST A FEW OROGRAPHIC SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. THE
REST OF THE REGION LOOKS MAINLY DRY WITH BELOW NORMAL TEMPERATURES
FOR THE START OF THE WEEKEND.

THE FIRST OF TWO SYSTEMS OF CONCERN IN THE LONG RANGE WILL START TO
EFFECT THE WEATHER FOR SATURDAY. A PIECE OF ENERGY WILL MOVE OFF A
CUT OFF LOW OVER CALIFORNIA AND MOVE INTO THE ROCKIES. HOWEVER...IT
APPEARS THAT THE BEST UPPER LEVEL SUPPORT WILL REMAIN OVER UTAH AND
COLORADO. AT AS RESULT...RIGHT NOW THIS LOOKS TO MAINLY A NUISANCE
EVENT AND ONLY EFFECT SOUTHERN PORTIONS OF THE COUNTY WARNING AREA
AND MAINLY WEST OF THE DIVIDE. BOTH THE GFS...EUROPEAN AND NAM ARE
IN GOOD AGREEMENT OF THIS. AS A RESULT...WE TRIMMED POPS ACROSS
AREAS NORTH AND EAST OF THE WIND RIVER RANGE FOR SATURDAY AND
SATURDAY NIGHT. EVEN IN AREAS THAT GET SNOW...THIS DOES NOT LOOK
WORTHY OF ANY SORT OF WARNINGS OR ADVISORIES RIGHT NOW. ON
SUNDAY...THERE IS SOME SLIGHT DISAGREEMENT WITH THE GFS KEEPING A
FEW SHOWERS ALONG THE SOUTHERN BORDER AND THE EUROPEAN MAINLY DRY.
WITH THE DIFFERENCES WE MADE FEW CHANGES TO CONTINUITY. MAINLY DRY
BUT CONTINUED CHILLY WEATHER WILL BE THE RULE FOR MONDAY WITH WEAK
SURFACE HIGH PRESSURE IN CONTROL.

THE NEXT AND PROBABLY MORE IMPACTFUL SYSTEM THEN APPROACHES FOR
MONDAY NIGHT AND ESPECIALLY FOR TUESDAY. THIS ONE HAS CHILLY ORIGINS
COMING IN FROM ALASKA.  THE MODELS AGAIN ARE IN FAIRLY GOOD
AGREEMENT WITH SNOW BEGINNING IN THE WEST ON MONDAY NIGHT AND THEN
SPREADING ACROSS ALL AREAS FOR TUESDAY. THE PREVIOUS FORECAST HAD
CHANCE POPS ACROSS MOST AREAS AND THESE LOOK PRETTY GOOD AT THIS
POINT SO FEW CHANGES WERE MADE. SNOWFALL AMOUNTS ARE STILL UNCERTAIN
RIGHT NOW...AS A LOT WILL DEPEND ON THE JET DYNAMICS AND OF COURSE
THE MODELS ARE PERFECT WITH THIS FIVE DAYS OUT...NOTE SARCASM. THERE
IS ALSO MORE AGREEMENT WITH THE END TIME. THE EUROPEAN HAS COME
AROUND TO THE MORE PROGRESSIVE GFS SOLUTION IN KICKING THE SYSTEM TO
THE SOUTH AND EAST DURING WEDNESDAY WITH ALL AREAS DRY AT THAT
POINT. TUESDAY NIGHT AND WEDNESDAY HAVE THE POTENTIAL TO QUITE COLD.
LOWS TUESDAY NIGHT MAY DEPEND ON HOW QUICKLY THE SKY CLEARS THOUGH.
MAINLY DRY BUT COOL WEATHER WILL BE THE RULE FOR WEDNESDAY INTO
THURSDAY WITH DRY NORTHWEST FLOW PREDOMINATING.

&&

.AVIATION.../00Z ISSUANCE/

CONDITIONS TO BECOME VFR TONIGHT AT ALL AIRPORT LOCATIONS. THIS IS
DUE TO DECREASING CLOUDS EAST OF THE CONTINENTAL DIVIDE. KBYG TO KCPR
EXPECTED TO CLEAR OUT BY LATE EVENING...THEN CENTRAL AND SOUTHWEST
WYOMING TO FOLLOW. HIGH PRESSURE IN CONTROL MOST AREAS ON FRIDAY.

SOME MOUNTAIN FLURRIES OR SNOW SHOWERS ARE STILL POSSIBLE FRIDAY
AFTERNOON AND EVENING. WESTERN MOUNTAIN PEAKS COULD BE OBSCURED
FRIDAY NIGHT INTO EARLY SATURDAY. OTHERWISE...LIGHT SURFACE WIND
AND VFR CONDITIONS CAN BE EXPECTED TO BEGIN THE WEEKEND ON BOTH
SIDES OF THE DIVIDE.

&&

.FIRE WEATHER...

NO FIRE WEATHER CONCERNS IN THE SHORT TERM...AS A COLD WEATHER
PATTERN CONTINUES FOR THE ENTIRE DISTRICT. LITTLE OR NO
PRECIPITATON THROUGH THE UPCOMING WEEKEND EAST OF THE DIVIDE...
BUT RELATIVE HUMIDITIES TO REMAIN HIGH.

WEST OF THE DIVIDE...INCREASING CLOUDS CAN BE EXPECTED ON FRIDAY.
A WEAK UPPER LEVEL TROUGH WILL MOVE OVER THE WESTERN MOUNTAINS LATE
FRIDAY TO HELP INITIATE SNOW SHOWERS. AREAS OF LIGHT SNOW WILL
PERSIST FRIDAY NIGHT...POSSIBLY REACHING THE WESTERN VALLEYS OF
WYOMING.

&&


.RIW WATCHES/WARNINGS/ADVISORIES...NONE.
&&

$$

SHORT TERM...KPL
LONG TERM...HATTINGS
AVIATION...KPL
FIRE WEATHER...KPL






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