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000
FXUS65 KRIW 202210
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
310 PM MST THU NOV 20 2014

.SHORT TERM...TONIGHT THROUGH FRIDAY

WEAK SNOWFALL OVER THE WESTERN MOUNTAINS WILL CONTINUE THIS
EVENING...THOUGH COVERAGE SHOULD WEAKEN A BIT DURING THE OVERNIGHT
HOURS. DEVELOPMENT OF PATCHY FOG WILL BE POSSIBLE ACROSS THE
INVERSION FAVORED LOCATIONS...INCLUDING MUCH OF THE LOWER ELEVATIONS
WEST OF THE CONTINENTAL DIVIDE. FOG DEVELOPMENT IS GENERALLY
EXPECTED TO DISSIPATE DURING THE MID TO LATE MORNING HOURS.

A MORE ZONAL FLOW IS EXPECTED TO DEVELOP OVER THE FORECAST AREA ON
FRIDAY...WITH SOME MOISTURE REMAINING TRAPPED OVER NORTHWESTERN
WYOMING. CONTINUED LIGHT SNOW WILL BE POSSIBLE...WITH GENERALLY
INSIGNIFICANT ACCUMULATION EXPECTED. MODELS DO INDICATE SOME
INCREASED ISENTROPIC LIFT ACROSS MUCH OF THE FORECAST AREA ON
FRIDAY...RESULTING IN SOME ADDITIONAL CLOUD COVER AHEAD OF THE NEXT
WINTER SYSTEM.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY

THE NEXT STORM SYSTEM WILL BE MOVING INTO THE WEST FRIDAY NIGHT.
INITIALLY THE SNOW WILL BEGIN AS THE JET BEGINS TO NOSE INTO THE
REGION CREATING BROAD LIFT AHEAD OF IT...COMBINED WITH SOME MOIST
ISENTROPIC UPGLIDE...THIS SHOULD BE ENOUGH TO GET SOME SNOW
ACCUMULATING AT FIRST BUT THE HEAVIER SNOW WILL NOT ARRIVE UNTIL
EARLY SATURDAY MORNING IF THE CURRENT MODEL SOLUTIONS HAVE THE
TIMING RIGHT. AT THAT TIME...EXPECT SNOW AND WIND TO BEGIN TO FILTER
DOWN INTO THE VALLEYS AS MORE FORCING ARRIVES ALOFT...AND LATER IN
THE DAY AS THE COLD FRONT SWEEPS THROUGH. THERE WILL BE A BIT OF A
BREAK WELL BEHIND THE FRONT SATURDAY NIGHT BUT ANOTHER WAVE WILL BE
QUICKLY NIPPING AT THE HEELS OF THE FIRST. FOR THIS REASON...THE
WINTER STORM WATCH WAS EXTENDED THROUGH THE LULL AND INTO EARLY
SUNDAY MORNING.

EAST OF THE DIVIDE...THE SWIFT WEST TO SOUTHWEST FLOW WILL KEEP
AREAS EAST OF THE DIVIDE ON THE WARM AND WINDY SIDE FOR MUCH OF
SATURDAY. LATER DURING THE DAY SOME OF THAT ISENTROPIC UPGLIDE WILL
BREAK ACROSS THE DIVIDE AND MAY WORK WITH SOME OF THE DYNAMIC
FORCING ALOFT AND STEEP LAPSE RATES TO DRAW SOME SNOW BANDS OUT
...POTENTIALLY MIXED WITH RAIN SHOWERS IN SOME SPOTS DEPENDING UPON
WHEN THE PRECIPITATION ARRIVES. OTHERWISE THERE ARE SOME 60KT WIND
BARBS SHOWING UP AT H6...ALIGNING WITH THE SURFACE FLOW AND THE
EXPECTED MIXING WITH THE RIGHT FRONT QUAD OF THE JET...THESE WINDS
ARE EXPECTED TO MIX DOWN IN FAVORED AREAS IN SOUTHEAST FREMONT AND
ALL OF NATRONA COUNTY ON SATURDAY. THE WINDS WILL SHIFT AFTER THE
FRONT MOVES THROUGH TO A LESS FAVORABLE DIRECTION FOR THESE
AREAS...BRINGING THE WINDS BACK DOWN BELOW HIGHLIGHT CRITERIA BUT
REMAINING GUSTY INTO THE NIGHT.

COOL AND DISTURBED NORTHWEST FLOW WILL KEEP SOME SNOW SHOWERS GOING
ON MONDAY AND TUESDAY...OCCASIONALLY ENHANCED COVERAGE AND INTENSITY
WILL COME ALONG WITH A FEW SHORT WAVES AS THEY RIPPLE BY. ALSO WINDY
CONDITIONS WILL OCCUR IN THIS NORTHWEST FLOW PATTERN...ESPECIALLY
BUFFALO...DUBOIS AND ROCK SPRINGS AREAS.

AFTER TUESDAY THE MODELS ARE A MESS. THE GFS IS ADVERTISING A WARM
AND DRY RIDGE BUILDING IN FOR WEDNESDAY AND THURSDAY WHILE THE
EUROPEAN BOTTOMS OUT A COLD LOW WITH WIDESPREAD SNOW ACROSS THE
REGION. THERE ALMOST A 30 DEGREE DIFFERENCE IN H7 TEMPERATURES AT
SOME POINTS ON THANKSGIVING DAY...A VAST DIFFERENCE. AT THIS TIME
POPS WERE KEPT VERY NON-COMMITAL WITH SLIGHT CHANCES IN THE LOW
ELEVATIONS AND CHANCES IN THE HIGH ELEVATIONS THROUGH MOST OF THE
LONG TERM PERIOD. EVERYTHING ELSE WAS WEIGHTED HEAVILY ON CONTINUITY
WITH THE PREVIOUS FORECAST BUT ACCORDING TO NATIONAL GUIDANCE...THE
LARGE SCALE PATTERN OF THE TIGHTEST CLUSTER OF ENSEMBLE MEAN
SOLUTIONS MOST CLOSELY RESEMBLE THE OPERATIONAL AND PARALLEL GFS
SOLUTIONS...FAVORING A RIDGE...SO AN EVER SO SLIGHT NUDGE WAS GIVEN
TO THE GFS SOLUTION TO BALANCE OUT THE WILD EUROPEAN
SOLUTION...KEEPING IN MIND THAT THE LAST TIME THE MODELS
DISAGREED...THE ECMWF ENDED UP THE VICTOR. HOWEVER...THAT TIME THERE
WERE SOME OTHER CLUES THAT WOULD LEAD YOU TO THE ECMWF SOLUTION
ANYWAY. THIS TIME...NOT SO MUCH. SO TO SUM IT UP...PEOPLE TRAVELING
FOR THANKSGIVING HOLIDAY WILL NEED TO KEEP AN EYE ON THIS SYSTEM AS
HOPEFULLY THE MODELS COME TOGETHER AS THE TIME DRAWS NEAR.

&&

.AVIATION.../00Z DISCUSSION/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
RELATIVELY BENIGN FORECAST PERIOD FOR AREAS EAST OF THE DIVIDE. VFR
CONDITIONS GENERALLY EXPECTED THROUGH THE EVENING...WITH GUSTY WIND
EXPECTED AT KCPR THROUGH THE PERIOD. SOME PATCHY FOG WILL BE POSSIBLE
AFTER 08Z THIS EVENING...MAINLY IMPACTING THE WIND RIVER BASIN AND
THE BIG HORN BASIN. CONFIDENCE...THOUGH NOT OVERLY HIGH...IS HIGHEST
FOR DEVELOPMENT AROUND KWRL AND KGEY. ANY FOG DEVELOPMENT ACROSS THE
AREA WILL LIFT BY 18Z.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A WAVE OF LOW PRESSURE MOVING THROUGH THE AREA WILL LEAVE SOME WEAK
SNOWFALL OVER THE WESTERN MOUNTAINS TONIGHT. MOUNTAIN OBSCURATION
WILL BE POSSIBLE WITH ONGOING SNOWFALL AND LOWERED CEILINGS. SOME
PATCHY FOG WILL BE POSSIBLE ACROSS MOST TERMINALS. VCFG HAS BEEN
INCLUDED WITH MOST TERMINALS SOMETIME THROUGH AROUND 18Z. LOWERED
CEILINGS WILL LINGER THROUGH THE AFTERNOON...THOUGH SNOWFALL SHOULD
STILL REMAIN CONFINED TO THE WESTERN MOUNTAINS.

&&

.FIRE WEATHER...

GUSTY WIND WILL REMAIN OVER AREAS OF EASTERN WYOMING OVERNIGHT AND
INTO FRIDAY. LIGHT SNOWFALL MAY OCCUR OVER THE WESTERN
MOUNTAINS...WHICH COULD PERSIST THROUGH FRIDAY AFTERNOON.
ADDITIONALLY...SOME PATCHY MORNING FOG IS POSSIBLE ACROSS THE LOWER
ELEVATIONS DUE TO MORNING INVERSIONS. ANY FOG DEVELOPMENT SHOULD
DISSIPATE BY THE MID TO LATE MORNING HOURS. OVERALL... FIRE WEATHER
CONCERNS ARE GENERALLY EXPECTED TO BE LOW. A BRIEF INCREASE IN SMOKE
DISPERSAL MAY OCCUR FRIDAY AFTERNOON...AND WILL BE GENERALLY
CO-LOCATED WITH ONGOING SNOWFALL. OTHERWISE POOR TO FAIR CONDITIONS
WILL BE WIDESPREAD THROUGH FRIDAY AFTERNOON.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY
NIGHT WYZ001-012-013-023>025.

HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING
WYZ019-020.

&&

$$

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






000
FXUS65 KRIW 202210
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
310 PM MST THU NOV 20 2014

.SHORT TERM...TONIGHT THROUGH FRIDAY

WEAK SNOWFALL OVER THE WESTERN MOUNTAINS WILL CONTINUE THIS
EVENING...THOUGH COVERAGE SHOULD WEAKEN A BIT DURING THE OVERNIGHT
HOURS. DEVELOPMENT OF PATCHY FOG WILL BE POSSIBLE ACROSS THE
INVERSION FAVORED LOCATIONS...INCLUDING MUCH OF THE LOWER ELEVATIONS
WEST OF THE CONTINENTAL DIVIDE. FOG DEVELOPMENT IS GENERALLY
EXPECTED TO DISSIPATE DURING THE MID TO LATE MORNING HOURS.

A MORE ZONAL FLOW IS EXPECTED TO DEVELOP OVER THE FORECAST AREA ON
FRIDAY...WITH SOME MOISTURE REMAINING TRAPPED OVER NORTHWESTERN
WYOMING. CONTINUED LIGHT SNOW WILL BE POSSIBLE...WITH GENERALLY
INSIGNIFICANT ACCUMULATION EXPECTED. MODELS DO INDICATE SOME
INCREASED ISENTROPIC LIFT ACROSS MUCH OF THE FORECAST AREA ON
FRIDAY...RESULTING IN SOME ADDITIONAL CLOUD COVER AHEAD OF THE NEXT
WINTER SYSTEM.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY

THE NEXT STORM SYSTEM WILL BE MOVING INTO THE WEST FRIDAY NIGHT.
INITIALLY THE SNOW WILL BEGIN AS THE JET BEGINS TO NOSE INTO THE
REGION CREATING BROAD LIFT AHEAD OF IT...COMBINED WITH SOME MOIST
ISENTROPIC UPGLIDE...THIS SHOULD BE ENOUGH TO GET SOME SNOW
ACCUMULATING AT FIRST BUT THE HEAVIER SNOW WILL NOT ARRIVE UNTIL
EARLY SATURDAY MORNING IF THE CURRENT MODEL SOLUTIONS HAVE THE
TIMING RIGHT. AT THAT TIME...EXPECT SNOW AND WIND TO BEGIN TO FILTER
DOWN INTO THE VALLEYS AS MORE FORCING ARRIVES ALOFT...AND LATER IN
THE DAY AS THE COLD FRONT SWEEPS THROUGH. THERE WILL BE A BIT OF A
BREAK WELL BEHIND THE FRONT SATURDAY NIGHT BUT ANOTHER WAVE WILL BE
QUICKLY NIPPING AT THE HEELS OF THE FIRST. FOR THIS REASON...THE
WINTER STORM WATCH WAS EXTENDED THROUGH THE LULL AND INTO EARLY
SUNDAY MORNING.

EAST OF THE DIVIDE...THE SWIFT WEST TO SOUTHWEST FLOW WILL KEEP
AREAS EAST OF THE DIVIDE ON THE WARM AND WINDY SIDE FOR MUCH OF
SATURDAY. LATER DURING THE DAY SOME OF THAT ISENTROPIC UPGLIDE WILL
BREAK ACROSS THE DIVIDE AND MAY WORK WITH SOME OF THE DYNAMIC
FORCING ALOFT AND STEEP LAPSE RATES TO DRAW SOME SNOW BANDS OUT
...POTENTIALLY MIXED WITH RAIN SHOWERS IN SOME SPOTS DEPENDING UPON
WHEN THE PRECIPITATION ARRIVES. OTHERWISE THERE ARE SOME 60KT WIND
BARBS SHOWING UP AT H6...ALIGNING WITH THE SURFACE FLOW AND THE
EXPECTED MIXING WITH THE RIGHT FRONT QUAD OF THE JET...THESE WINDS
ARE EXPECTED TO MIX DOWN IN FAVORED AREAS IN SOUTHEAST FREMONT AND
ALL OF NATRONA COUNTY ON SATURDAY. THE WINDS WILL SHIFT AFTER THE
FRONT MOVES THROUGH TO A LESS FAVORABLE DIRECTION FOR THESE
AREAS...BRINGING THE WINDS BACK DOWN BELOW HIGHLIGHT CRITERIA BUT
REMAINING GUSTY INTO THE NIGHT.

COOL AND DISTURBED NORTHWEST FLOW WILL KEEP SOME SNOW SHOWERS GOING
ON MONDAY AND TUESDAY...OCCASIONALLY ENHANCED COVERAGE AND INTENSITY
WILL COME ALONG WITH A FEW SHORT WAVES AS THEY RIPPLE BY. ALSO WINDY
CONDITIONS WILL OCCUR IN THIS NORTHWEST FLOW PATTERN...ESPECIALLY
BUFFALO...DUBOIS AND ROCK SPRINGS AREAS.

AFTER TUESDAY THE MODELS ARE A MESS. THE GFS IS ADVERTISING A WARM
AND DRY RIDGE BUILDING IN FOR WEDNESDAY AND THURSDAY WHILE THE
EUROPEAN BOTTOMS OUT A COLD LOW WITH WIDESPREAD SNOW ACROSS THE
REGION. THERE ALMOST A 30 DEGREE DIFFERENCE IN H7 TEMPERATURES AT
SOME POINTS ON THANKSGIVING DAY...A VAST DIFFERENCE. AT THIS TIME
POPS WERE KEPT VERY NON-COMMITAL WITH SLIGHT CHANCES IN THE LOW
ELEVATIONS AND CHANCES IN THE HIGH ELEVATIONS THROUGH MOST OF THE
LONG TERM PERIOD. EVERYTHING ELSE WAS WEIGHTED HEAVILY ON CONTINUITY
WITH THE PREVIOUS FORECAST BUT ACCORDING TO NATIONAL GUIDANCE...THE
LARGE SCALE PATTERN OF THE TIGHTEST CLUSTER OF ENSEMBLE MEAN
SOLUTIONS MOST CLOSELY RESEMBLE THE OPERATIONAL AND PARALLEL GFS
SOLUTIONS...FAVORING A RIDGE...SO AN EVER SO SLIGHT NUDGE WAS GIVEN
TO THE GFS SOLUTION TO BALANCE OUT THE WILD EUROPEAN
SOLUTION...KEEPING IN MIND THAT THE LAST TIME THE MODELS
DISAGREED...THE ECMWF ENDED UP THE VICTOR. HOWEVER...THAT TIME THERE
WERE SOME OTHER CLUES THAT WOULD LEAD YOU TO THE ECMWF SOLUTION
ANYWAY. THIS TIME...NOT SO MUCH. SO TO SUM IT UP...PEOPLE TRAVELING
FOR THANKSGIVING HOLIDAY WILL NEED TO KEEP AN EYE ON THIS SYSTEM AS
HOPEFULLY THE MODELS COME TOGETHER AS THE TIME DRAWS NEAR.

&&

.AVIATION.../00Z DISCUSSION/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
RELATIVELY BENIGN FORECAST PERIOD FOR AREAS EAST OF THE DIVIDE. VFR
CONDITIONS GENERALLY EXPECTED THROUGH THE EVENING...WITH GUSTY WIND
EXPECTED AT KCPR THROUGH THE PERIOD. SOME PATCHY FOG WILL BE POSSIBLE
AFTER 08Z THIS EVENING...MAINLY IMPACTING THE WIND RIVER BASIN AND
THE BIG HORN BASIN. CONFIDENCE...THOUGH NOT OVERLY HIGH...IS HIGHEST
FOR DEVELOPMENT AROUND KWRL AND KGEY. ANY FOG DEVELOPMENT ACROSS THE
AREA WILL LIFT BY 18Z.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
A WAVE OF LOW PRESSURE MOVING THROUGH THE AREA WILL LEAVE SOME WEAK
SNOWFALL OVER THE WESTERN MOUNTAINS TONIGHT. MOUNTAIN OBSCURATION
WILL BE POSSIBLE WITH ONGOING SNOWFALL AND LOWERED CEILINGS. SOME
PATCHY FOG WILL BE POSSIBLE ACROSS MOST TERMINALS. VCFG HAS BEEN
INCLUDED WITH MOST TERMINALS SOMETIME THROUGH AROUND 18Z. LOWERED
CEILINGS WILL LINGER THROUGH THE AFTERNOON...THOUGH SNOWFALL SHOULD
STILL REMAIN CONFINED TO THE WESTERN MOUNTAINS.

&&

.FIRE WEATHER...

GUSTY WIND WILL REMAIN OVER AREAS OF EASTERN WYOMING OVERNIGHT AND
INTO FRIDAY. LIGHT SNOWFALL MAY OCCUR OVER THE WESTERN
MOUNTAINS...WHICH COULD PERSIST THROUGH FRIDAY AFTERNOON.
ADDITIONALLY...SOME PATCHY MORNING FOG IS POSSIBLE ACROSS THE LOWER
ELEVATIONS DUE TO MORNING INVERSIONS. ANY FOG DEVELOPMENT SHOULD
DISSIPATE BY THE MID TO LATE MORNING HOURS. OVERALL... FIRE WEATHER
CONCERNS ARE GENERALLY EXPECTED TO BE LOW. A BRIEF INCREASE IN SMOKE
DISPERSAL MAY OCCUR FRIDAY AFTERNOON...AND WILL BE GENERALLY
CO-LOCATED WITH ONGOING SNOWFALL. OTHERWISE POOR TO FAIR CONDITIONS
WILL BE WIDESPREAD THROUGH FRIDAY AFTERNOON.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY
NIGHT WYZ001-012-013-023>025.

HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING
WYZ019-020.

&&

$$

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







000
FXUS65 KRIW 201739
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1039 AM MST THU NOV 20 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

WV IMAGERY CONTINUES TO SHOW LONGWAVE TROF ACROSS 70 PERCENT OF THE
CONUS...WITH A TROF/RIDGE COMBO ACROSS THE WRN CONUS. 100+KT JET
CURRENTLY EXTENDS NRN PLAINS...INTO THE MID MS VALLEY. SRN BRANCH
JET ACROSS SRN CALIFORNIA AND THRU THE DESERT SW. VERY LIGHT UPR
FLOW CURRENTLY OVERHEAD OF THE FA. AT THE SFC...GENERALLY WEAK
PRESSURE FIELDS CURRENTLY IN PLACE...WITH WEAK LOW PRESSURE ACROSS
THE FRONT RANGE OF CO AND RELATIVELY WEAK HIGH PRESSURE ACROSS WY
AND POINTS WEST. STATIONARY BACKDOOR FRONT STILL LINGERING FROM
CNTRL MT TO THE SE AND INTO CNTRL OK. MAINLY CLEAR SKIES E OF THE
DIVIDE...WITH PARTLY TO MOSTLY CLOUDY SKIES WEST.

WEAK WARMING CONTINUES TODAY ACROSS THE FA AS HEIGHTS RISE WITH THE
WRN CONUS RIDGE TRANSLATING EWD OVER THE FA. SOME MODEST MID LVL
EPAC MOISTURE CAUGHT UNDER THE RIDGE AND JUST AHEAD OF AN
OPENING/SPLITTING TROF CHASER WILL CONTINUE TO MOVE INTO AND ACROSS
THE WRN ZONES TODAY. INFLUENCES FROM THE TROF BEHIND THE RIDGE WILL
ARRIVE LATER THIS AFTERNOON AND AID IN SOME MINOR INCREASES IN
PRECIP POTENTIAL ALONG WITH LIFT PROVIDED BY THE MOUNTAINS.
HOWEVER...THE STRONGER DYNAMICS WITH THIS WEAK SYSTEM SPLIT WITH ONE
PORTION DIVING WELL S OF THE FA FOLLOWING THE SRN BRANCH OF THE JET
WHILE THE NRN PORTION WEAKENS THRU THE RIDGE AND EXITS STAGE NORTH
INTO SRN CANADA. THIS INITIAL DISTURBANCE (AHEAD OF THE STRONGER
WEEKEND VERSION DUE TO ARRIVE OVERNIGHT FRIDAY) CONTINUES TO LOOK
EMACIATED...WITH LIMITED MOISTURE AND WEAKENED DYNAMICS BARELY ABLE
TO ADD TO THE OROGRAPHIC FORCING. THE MOUNTAINS COULD SEE A COUPLE
OF INCHES THROUGH THE DAY ON FRIDAY...WITH THE VALLEYS RECEIVING A
TRACE TO AN INCH.

A NEW AND BETTER INFLUX OF MOISTURE BEGINS TO INFILTRATE THE WRN
REGION FRIDAY NIGHT...LEADING BACK TO A BETTER WINTER WEATHER
SCENARIO BY SAT MORNING...WITH CONVECTIVE ELEMENTS PLAYING INTO THE
SET-UP BY MID-DAY SATURDAY. A SURVEY OF QPF VALUES THROUGHOUT THE
MDLS REVELS RANGES BETWEEN .4 AND .8 INCH LIQUID BETWEEN 06 SAT AND
12Z SUN BOTH IN THE MOUNTAINS AND VALLEYS WITH HIGHER AMOUNTS ON THE
WINDWARD SIDES. THIS WOULD GIVE GENERALIZED SNOW AMOUNTS RANGING
FROM 4 TO 8 INCHES IN THE VALLEYS AND 8 TO 14 INCHES OR POSSIBLY
HIGHER IN THE MOUNTAINS...ESPECIALLY THE TETONS AND WESTERN WIND
RIVER MOUNTAINS. THIS WILL EQUATE TO A WIDE AREA OF AT A MINIMUM...
ADVISORY CONDITIONS...WITH THE TETONS AND WESTERN WINDS AT WARNING
LEVEL. WINTER WX WARNING CONDITIONS COULD EASILY EXTEND ACROSS A
GREATER AREA IF THE EXIT REGION OF THE INCOMING JET POSITIONS ITSELF
A LITTLE MORE FAVORABLY SLIGHTLY TO THE NORTH OF WHERE IT IS
CURRENTLY FCST. ADDITIONALLY...WINDS FROM THE W TO THE SW WILL ALSO
PICK-UP ACROSS THE REGION...WITH HIGH/STRONG WIND EXPECTED ACROSS
THE ABSAROKAS AND POSSIBLY INTO WESTERN PORTIONS OF THE ADJACENT
FOOTHILLS...AND ALSO OVER THE WIND RIVER MOUNTAINS AND EAST FROM
SOUTH PASS TO THE CASPER AREA INCLUDING CASPER MOUNTAIN BY  MID-DAY
SATURDAY. MOUNTAIN WAVE AND TURBULENCE ACTION IS EXPECTED WITH THIS
SET-UP...ESPECIALLY OVER AND EAST OF THE ABSAROKA MOUNTAINS. IT NOW
APPEARS THAT THIS TOO WILL BE A HIGHLIGHT SITUATION OF SOME SORT.
THE ABSAROKAS FOR EXAMPLE...WHILE NOT SEEING QUITE THE SNOWFALL
AMOUNTS THAT THE FAR WRN MOUNTAINS WILL SEE...WILL HAVE THE
COMBINATION OF MODERATE SNOWFALL TOGETHER WITH VERY STRONG
WINDS...GIVING POSSIBLE BLIZZARD CONDITIONS. HIGH WIND CRITERIA WILL
ALSO POSSIBLY BE MET OVER ZONES 19 20 AND 22 THROUGH THE AFTERNOON
AND EARLY EVENING ON SATURDAY.

.LONG TERM...SUNDAY THROUGH THANKSGIVING

A STRONG...MOIST NORTHWEST FLOW WILL DOMINATE THE PATTERN THROUGH AT
LEAST TUESDAY. THIS WILL RESULT IN PERSISTENT LIGHT SNOWFALL OVER
THE NORTHWEST/NORTHERN MOUNTAINS...AND PERIODS OF LIGHT SNOW IN THE
FAR WESTERN VALLEYS. THE SNOWFALL WILL BE ENHANCED AT TIMES AS
DISTURBANCES IN THE FLOW MOVE ACROSS THE AREA.  CURRENTLY...MODELS
ARE SHOWING A DISTINCT SHORTWAVE IMPACTING THE AREA IN THE SUNDAY
NIGHT/MONDAY TIME FRAME. THIS SYSTEM MIGHT WARRANT MORE WINTER
HIGHLIGHTS OVER THE NORTHWEST ZONES. ALTHOUGH THE LOWER ELEVATIONS
EAST OF THE DIVIDE WILL NOT BE IMPACTED...SOME SNOW SHOWER ACTIVITY
IS EXPECTED AT TIMES...ESPECIALLY IN THE SUNDAY NIGHT/MONDAY TIME
FRAME AS THE ABOVE MENTIONED SHORTWAVE PUSHES ACROSS THE AREA. ALSO
WINDY CONDITIONS WILL OCCUR IN THIS NORTHWEST FLOW
PATTERN...ESPECIALLY BUFFALO...DUBOIS AND ROCK SPRINGS AREAS.

GLOBAL MODELS CONTINUE TO STRUGGLE ON THE EVOLUTION OF SHORTWAVES
EJECTING OUT OF THE CLOSED UPPER LOW OVER THE ALEUTIANS/GULF OF
ALASKA EARLY TO MIDDLE OF NEXT WEEK. THE GFS CONTINUES TO HANG ONTO
A RIDGE OVER THE WEST...ALBEIT NOT AS STRONG AS YESTERDAYS 00Z RUN.
THIS KEEPS A MOIST NORTHWEST FLOW OVER THE AREA...WITH A SIGNIFICANT
WAVE IMPACTING THE AREA TUESDAY NIGHT/WEDNESDAY...WITH A BETTER
CHANCE OF IMPACTS EAST THAN SUN-TUE. THE ECMWF HAS BEEN RELATIVELY
CONSISTENT IN KEEPING THE RIDGE FARTHER WEST INTO THE EASTERN
PACIFIC ALLOWING FOR A DEEPER TROUGH OVER THE WEST. THE ECMWF IS
MUCH COLDER AND HAS MORE SNOWFALL OVER A LARGER SECTION OF THE
FORECAST AREA TUE NIGHT THRU WED NIGHT...THAN THE OPERATIONAL GFS.
HOWEVER THE GFS IS TRENDING TOWARD THE ECMWF SOLUTION...AND THUS
HAVE TRENDED FORECAST COLDER WITH BETTER CHANCES OF SNOWFALL. PEOPLE
TRAVELING FOR THANKSGIVING HOLIDAY WILL NEED TO KEEP AN EYE ON THIS
SYSTEM.

HAVE GONE 10 TO AS MUCH AS 20 DEGREES BELOW MEX MOS GUIDANCE FOR
WEDNESDAY AND THANKSGIVING...ESPECIALLY EAST OF THE DIVIDE.

&&

.AVIATION.../18Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
A GENERALLY QUIET DAY ACROSS THE AREA...THOUGH SOME GUSTY WIND
WILL BE POSSIBLE AT KCPR THROUGH MUCH OF THE FORECAST PERIOD.
OTHERWISE WIDESPREAD VFR CONDITIONS EXPECTED THROUGH 06Z THIS
EVENING. AFTER 06Z...SOME LOW LYING AREAS WILL SEE THE POTENTIAL
FOR PATCHY FOG DEVELOPMENT...BRINGING SOME PERIODS OF IFR
CONDITIONS. THE PRIMARY TERMINALS EXPECTED TO BE IMPACTED ARE KWRL
AND OTHER TERMINALS IN THE BIG HORN BASIN.

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
SNOWFALL WILL OCCUR OVER THE WESTERN MOUNTAINS TODAY...RESULTING
IN MOUNTAIN OBSCURATION FOR THE WESTERN AVIATION PASSES. BRIEF
PERIODS OF SNOW WILL BE POSSIBLE AT KJAC THROUGH THE FORECAST
PERIOD. ADDITIONALLY...ALL TERMINAL SITES WILL SEE THE POTENTIAL
FOR PATCHY FOG DEVELOPMENT TOMORROW AFTER 06Z. THIS FOG
DEVELOPMENT WILL RESULT IN PERIODS OF IFR CONDITIONS THROUGH 16Z
FRIDAY.

&&

.FIRE WEATHER...

FIRE DANGER LOW AND REMAINING LOW THROUGH THE WEEKEND AS SNOW COVER
OR MINIMUM RH VALUES STAY WELL ABOVE CRITICAL LEVELS. INVERSIONS
WILL LIFT SOME AGAIN TODAY...BUT NOT BREAK AT MOST LOCATIONS. THE
INVERSION LEVEL WILL ONCE AGAIN START OUT NEAR SURFACE THIS MORNING
BEFORE REACHING 1000 TO 2500 FEET AT MOST LOCATIONS BY THE MIDDLE OF
THE DAY. THE GREEN RIVER AND WIND RIVER BASINS WILL STAND THE BEST
CHANCE AT MIXING OUT AND BREAKING THE INVERSION FOR A SHORT PERIOD
THIS AFTERNOON...IT IT HAPPENS AT ALL. MOISTURE WILL BEGIN TO
INCREASE ACROSS THE WEST TODAY WITH LIGHT WIDELY SCATTERED AREAS OF
SNOW BECOMING POSSIBLE OVER THE WESTERN FORECAST ZONES. A MUCH
BETTER PRECIP/SNOW PRODUCING SYSTEM WILL ARRIVE OUT WEST THIS
WEEKEND...WITH EVEN LOW CHANCES FOR SNOW BECOMING POSSIBLE LATER ON
SATURDAY. HOWEVER...INCREASING STRONG WEST TO SOUTHWEST WIND WILL
ALSO ACCOMPANY THIS WINTER WEATHER MAKER...WITH HIGH WINDS EXPECTED
ACROSS THE NORTHERN AND CENTRAL MOUNTAINS AND ALSO FROM SOUTH PASS
EASTWARD THROUGH MOST OF NATRONA COUNTY BY SATURDAY
AFTERNOON.

&&

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

$$

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






000
FXUS65 KRIW 201033
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
333 AM MST THU NOV 20 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

WV IMAGERY CONTINUES TO SHOW LONGWAVE TROF ACROSS 70 PERCENT OF THE
CONUS...WITH A TROF/RIDGE COMBO ACROSS THE WRN CONUS. 100+KT JET
CURRENTLY EXTENDS NRN PLAINS...INTO THE MID MS VALLEY. SRN BRANCH
JET ACROSS SRN CALIFORNIA AND THRU THE DESERT SW. VERY LIGHT UPR
FLOW CURRENTLY OVERHEAD OF THE FA. AT THE SFC...GENERALLY WEAK
PRESSURE FIELDS CURRENTLY IN PLACE...WITH WEAK LOW PRESSURE ACROSS
THE FRONT RANGE OF CO AND RELATIVELY WEAK HIGH PRESSURE ACROSS WY
AND POINTS WEST. STATIONARY BACKDOOR FRONT STILL LINGERING FROM
CNTRL MT TO THE SE AND INTO CNTRL OK. MAINLY CLEAR SKIES E OF THE
DIVIDE...WITH PARTLY TO MOSTLY CLOUDY SKIES WEST.

WEAK WARMING CONTINUES TODAY ACROSS THE FA AS HEIGHTS RISE WITH THE
WRN CONUS RIDGE TRANSLATING EWD OVER THE FA. SOME MODEST MID LVL
EPAC MOISTURE CAUGHT UNDER THE RIDGE AND JUST AHEAD OF AN
OPENING/SPLITTING TROF CHASER WILL CONTINUE TO MOVE INTO AND ACROSS
THE WRN ZONES TODAY. INFLUENCES FROM THE TROF BEHIND THE RIDGE WILL
ARRIVE LATER THIS AFTERNOON AND AID IN SOME MINOR INCREASES IN
PRECIP POTENTIAL ALONG WITH LIFT PROVIDED BY THE MOUNTAINS.
HOWEVER...THE STRONGER DYNAMICS WITH THIS WEAK SYSTEM SPLIT WITH ONE
PORTION DIVING WELL S OF THE FA FOLLOWING THE SRN BRANCH OF THE JET
WHILE THE NRN PORTION WEAKENS THRU THE RIDGE AND EXITS STAGE NORTH
INTO SRN CANADA. THIS INITIAL DISTURBANCE (AHEAD OF THE STRONGER
WEEKEND VERSION DUE TO ARRIVE OVERNIGHT FRIDAY) CONTINUES TO LOOK
EMACIATED...WITH LIMITED MOISTURE AND WEAKENED DYNAMICS BARELY ABLE
TO ADD TO THE OROGRAPHIC FORCING. THE MOUNTAINS COULD SEE A COUPLE
OF INCHES THROUGH THE DAY ON FRIDAY...WITH THE VALLEYS RECEIVING A
TRACE TO AN INCH.

A NEW AND BETTER INFLUX OF MOISTURE BEGINS TO INFILTRATE THE WRN
REGION FRIDAY NIGHT...LEADING BACK TO A BETTER WINTER WEATHER
SCENARIO BY SAT MORNING...WITH CONVECTIVE ELEMENTS PLAYING INTO THE
SET-UP BY MID-DAY SATURDAY. A SURVEY OF QPF VALUES THROUGHOUT THE
MDLS REVELS RANGES BETWEEN .4 AND .8 INCH LIQUID BETWEEN 06 SAT AND
12Z SUN BOTH IN THE MOUNTAINS AND VALLEYS WITH HIGHER AMOUNTS ON THE
WINDWARD SIDES. THIS WOULD GIVE GENERALIZED SNOW AMOUNTS RANGING
FROM 4 TO 8 INCHES IN THE VALLEYS AND 8 TO 14 INCHES OR POSSIBLY
HIGHER IN THE MOUNTAINS...ESPECIALLY THE TETONS AND WESTERN WIND
RIVER MOUNTAINS. THIS WILL EQUATE TO A WIDE AREA OF AT A MINIMUM...
ADVISORY CONDITIONS...WITH THE TETONS AND WESTERN WINDS AT WARNING
LEVEL. WINTER WX WARNING CONDITIONS COULD EASILY EXTEND ACROSS A
GREATER AREA IF THE EXIT REGION OF THE INCOMING JET POSITIONS ITSELF
A LITTLE MORE FAVORABLY SLIGHTLY TO THE NORTH OF WHERE IT IS
CURRENTLY FCST. ADDITIONALLY...WINDS FROM THE W TO THE SW WILL ALSO
PICK-UP ACROSS THE REGION...WITH HIGH/STRONG WIND EXPECTED ACROSS
THE ABSAROKAS AND POSSIBLY INTO WESTERN PORTIONS OF THE ADJACENT
FOOTHILLS...AND ALSO OVER THE WIND RIVER MOUNTAINS AND EAST FROM
SOUTH PASS TO THE CASPER AREA INCLUDING CASPER MOUNTAIN BY  MID-DAY
SATURDAY. MOUNTAIN WAVE AND TURBULENCE ACTION IS EXPECTED WITH THIS
SET-UP...ESPECIALLY OVER AND EAST OF THE ABSAROKA MOUNTAINS. IT NOW
APPEARS THAT THIS TOO WILL BE A HIGHLIGHT SITUATION OF SOME SORT.
THE ABSAROKAS FOR EXAMPLE...WHILE NOT SEEING QUITE THE SNOWFALL
AMOUNTS THAT THE FAR WRN MOUNTAINS WILL SEE...WILL HAVE THE
COMBINATION OF MODERATE SNOWFALL TOGETHER WITH VERY STRONG
WINDS...GIVING POSSIBLE BLIZZARD CONDITIONS. HIGH WIND CRITERIA WILL
ALSO POSSIBLY BE MET OVER ZONES 19 20 AND 22 THROUGH THE AFTERNOON
AND EARLY EVENING ON SATURDAY.

.LONG TERM...SUNDAY THROUGH THANKSGIVING

A STRONG...MOIST NORTHWEST FLOW WILL DOMINATE THE PATTERN THROUGH AT
LEAST TUESDAY. THIS WILL RESULT IN PERSISTENT LIGHT SNOWFALL OVER
THE NORTHWEST/NORTHERN MOUNTAINS...AND PERIODS OF LIGHT SNOW IN THE
FAR WESTERN VALLEYS. THE SNOWFALL WILL BE ENHANCED AT TIMES AS
DISTURBANCES IN THE FLOW MOVE ACROSS THE AREA.  CURRENTLY...MODELS
ARE SHOWING A DISTINCT SHORTWAVE IMPACTING THE AREA IN THE SUNDAY
NIGHT/MONDAY TIME FRAME. THIS SYSTEM MIGHT WARRANT MORE WINTER
HIGHLIGHTS OVER THE NORTHWEST ZONES. ALTHOUGH THE LOWER ELEVATIONS
EAST OF THE DIVIDE WILL NOT BE IMPACTED...SOME SNOW SHOWER ACTIVITY
IS EXPECTED AT TIMES...ESPECIALLY IN THE SUNDAY NIGHT/MONDAY TIME
FRAME AS THE ABOVE MENTIONED SHORTWAVE PUSHES ACROSS THE AREA. ALSO
WINDY CONDITIONS WILL OCCUR IN THIS NORTHWEST FLOW
PATTERN...ESPECIALLY BUFFALO...DUBOIS AND ROCK SPRINGS AREAS.

GLOBAL MODELS CONTINUE TO STRUGGLE ON THE EVOLUTION OF SHORTWAVES
EJECTING OUT OF THE CLOSED UPPER LOW OVER THE ALEUTIANS/GULF OF
ALASKA EARLY TO MIDDLE OF NEXT WEEK. THE GFS CONTINUES TO HANG ONTO
A RIDGE OVER THE WEST...ALBEIT NOT AS STRONG AS YESTERDAYS 00Z RUN.
THIS KEEPS A MOIST NORTHWEST FLOW OVER THE AREA...WITH A SIGNIFICANT
WAVE IMPACTING THE AREA TUESDAY NIGHT/WEDNESDAY...WITH A BETTER
CHANCE OF IMPACTS EAST THAN SUN-TUE. THE ECMWF HAS BEEN RELATIVELY
CONSISTENT IN KEEPING THE RIDGE FARTHER WEST INTO THE EASTERN
PACIFIC ALLOWING FOR A DEEPER TROUGH OVER THE WEST. THE ECMWF IS
MUCH COLDER AND HAS MORE SNOWFALL OVER A LARGER SECTION OF THE
FORECAST AREA TUE NIGHT THRU WED NIGHT...THAN THE OPERATIONAL GFS.
HOWEVER THE GFS IS TRENDING TOWARD THE ECMWF SOLUTION...AND THUS
HAVE TRENDED FORECAST COLDER WITH BETTER CHANCES OF SNOWFALL. PEOPLE
TRAVELING FOR THANKSGIVING HOLIDAY WILL NEED TO KEEP AN EYE ON THIS
SYSTEM.

HAVE GONE 10 TO AS MUCH AS 20 DEGREES BELOW MEX MOS GUIDANCE FOR
WEDNESDAY AND THANKSGIVING...ESPECIALLY EAST OF THE DIVIDE.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
PATCHY IFR/LIFR FOG WILL PARTIALLY OBSCURE LOWER RIVER VALLEYS
MAINLY VCNTY AND NORTH OF KRIW-VCNTY KWRL/KGEY THROUGH 16Z.
OTHERWISE EXPECT VFR CONDITIONS WITH INCREASING MID CLOUDS...AREAS
CIGS FL110-140...FROM AROUND 18Z THUR-06Z FRI WITH CLEARING...PATCHY
FOG REDEVELOPING IN THE SAME AREAS EARLY FRIDAY MORNING.


WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
PATCHY IFR/LIFR FOG MAY PARTIALLY OBSCURE TERRAIN VCNTY KJAC THROUGH
16Z. A WEAK UPPER LEVEL DISTURBANCE WILL BRING INCREASING MID-LEVEL
CLOUDS...CIGS PRIMARILY FL110-130...ACROSS THE AREA 14Z THURSDAY
-03Z FRIDAY ALONG WITH PARTIAL MTN OBSCURATIONS IN -SN AND LCL MVFR
CONDITIONS.  A WESTERLY FLOW WILL FOLLOW 03Z-12Z FRIDAY WITH DRYING
IN THE MID-LEVELS.  HOWEVER THE BOUNDARY LAYER WILL REMAIN NEARLY
SATURATED IN UPSLOPE FLOW...SO AREAS OF MVFR/IFR CONDITIONS IN -SN
OR FLURRIES WILL LINGER INTO FRIDAY MORNING...ESPECIALLY VCNTY KJAC
NORTH ACROSS YELLOWSTONE NATIONAL PARK.

&&

.FIRE WEATHER...

FIRE DANGER LOW AND REMAINING LOW THROUGH THE WEEKEND AS SNOW COVER
OR MINIMUM RH VALUES STAY WELL ABOVE CRITICAL LEVELS. INVERSIONS
WILL LIFT SOME AGAIN TODAY...BUT NOT BREAK AT MOST LOCATIONS. THE
INVERSION LEVEL WILL ONCE AGAIN START OUT NEAR SURFACE THIS MORNING
BEFORE REACHING 1000 TO 2500 FEET AT MOST LOCATIONS BY THE MIDDLE OF
THE DAY. THE GREEN RIVER AND WIND RIVER BASINS WILL STAND THE BEST
CHANCE AT MIXING OUT AND BREAKING THE INVERSION FOR A SHORT PERIOD
THIS AFTERNOON...IT IT HAPPENS AT ALL. MOISTURE WILL BEGIN TO
INCREASE ACROSS THE WEST TODAY WITH LIGHT WIDELY SCATTERED AREAS OF
SNOW BECOMING POSSIBLE OVER THE WESTERN FORECAST ZONES. A MUCH
BETTER PRECIP/SNOW PRODUCING SYSTEM WILL ARRIVE OUT WEST THIS
WEEKEND...WITH EVEN LOW CHANCES FOR SNOW BECOMING POSSIBLE LATER ON
SATURDAY. HOWEVER...INCREASING STRONG WEST TO SOUTHWEST WIND WILL
ALSO ACCOMPANY THIS WINTER WEATHER MAKER...WITH HIGH WINDS EXPECTED
ACROSS THE NORTHERN AND CENTRAL MOUNTAINS AND ALSO FROM SOUTH PASS
EASTWARD THROUGH MOST OF NATRONA COUNTY BY SATURDAY
AFTERNOON.

&&

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

&&

$$

SHORT TERM...BRAUN
LONG TERM...WM
AVIATION...AEM
FIRE WEATHER...BRAUN








000
FXUS65 KRIW 201033
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
333 AM MST THU NOV 20 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

WV IMAGERY CONTINUES TO SHOW LONGWAVE TROF ACROSS 70 PERCENT OF THE
CONUS...WITH A TROF/RIDGE COMBO ACROSS THE WRN CONUS. 100+KT JET
CURRENTLY EXTENDS NRN PLAINS...INTO THE MID MS VALLEY. SRN BRANCH
JET ACROSS SRN CALIFORNIA AND THRU THE DESERT SW. VERY LIGHT UPR
FLOW CURRENTLY OVERHEAD OF THE FA. AT THE SFC...GENERALLY WEAK
PRESSURE FIELDS CURRENTLY IN PLACE...WITH WEAK LOW PRESSURE ACROSS
THE FRONT RANGE OF CO AND RELATIVELY WEAK HIGH PRESSURE ACROSS WY
AND POINTS WEST. STATIONARY BACKDOOR FRONT STILL LINGERING FROM
CNTRL MT TO THE SE AND INTO CNTRL OK. MAINLY CLEAR SKIES E OF THE
DIVIDE...WITH PARTLY TO MOSTLY CLOUDY SKIES WEST.

WEAK WARMING CONTINUES TODAY ACROSS THE FA AS HEIGHTS RISE WITH THE
WRN CONUS RIDGE TRANSLATING EWD OVER THE FA. SOME MODEST MID LVL
EPAC MOISTURE CAUGHT UNDER THE RIDGE AND JUST AHEAD OF AN
OPENING/SPLITTING TROF CHASER WILL CONTINUE TO MOVE INTO AND ACROSS
THE WRN ZONES TODAY. INFLUENCES FROM THE TROF BEHIND THE RIDGE WILL
ARRIVE LATER THIS AFTERNOON AND AID IN SOME MINOR INCREASES IN
PRECIP POTENTIAL ALONG WITH LIFT PROVIDED BY THE MOUNTAINS.
HOWEVER...THE STRONGER DYNAMICS WITH THIS WEAK SYSTEM SPLIT WITH ONE
PORTION DIVING WELL S OF THE FA FOLLOWING THE SRN BRANCH OF THE JET
WHILE THE NRN PORTION WEAKENS THRU THE RIDGE AND EXITS STAGE NORTH
INTO SRN CANADA. THIS INITIAL DISTURBANCE (AHEAD OF THE STRONGER
WEEKEND VERSION DUE TO ARRIVE OVERNIGHT FRIDAY) CONTINUES TO LOOK
EMACIATED...WITH LIMITED MOISTURE AND WEAKENED DYNAMICS BARELY ABLE
TO ADD TO THE OROGRAPHIC FORCING. THE MOUNTAINS COULD SEE A COUPLE
OF INCHES THROUGH THE DAY ON FRIDAY...WITH THE VALLEYS RECEIVING A
TRACE TO AN INCH.

A NEW AND BETTER INFLUX OF MOISTURE BEGINS TO INFILTRATE THE WRN
REGION FRIDAY NIGHT...LEADING BACK TO A BETTER WINTER WEATHER
SCENARIO BY SAT MORNING...WITH CONVECTIVE ELEMENTS PLAYING INTO THE
SET-UP BY MID-DAY SATURDAY. A SURVEY OF QPF VALUES THROUGHOUT THE
MDLS REVELS RANGES BETWEEN .4 AND .8 INCH LIQUID BETWEEN 06 SAT AND
12Z SUN BOTH IN THE MOUNTAINS AND VALLEYS WITH HIGHER AMOUNTS ON THE
WINDWARD SIDES. THIS WOULD GIVE GENERALIZED SNOW AMOUNTS RANGING
FROM 4 TO 8 INCHES IN THE VALLEYS AND 8 TO 14 INCHES OR POSSIBLY
HIGHER IN THE MOUNTAINS...ESPECIALLY THE TETONS AND WESTERN WIND
RIVER MOUNTAINS. THIS WILL EQUATE TO A WIDE AREA OF AT A MINIMUM...
ADVISORY CONDITIONS...WITH THE TETONS AND WESTERN WINDS AT WARNING
LEVEL. WINTER WX WARNING CONDITIONS COULD EASILY EXTEND ACROSS A
GREATER AREA IF THE EXIT REGION OF THE INCOMING JET POSITIONS ITSELF
A LITTLE MORE FAVORABLY SLIGHTLY TO THE NORTH OF WHERE IT IS
CURRENTLY FCST. ADDITIONALLY...WINDS FROM THE W TO THE SW WILL ALSO
PICK-UP ACROSS THE REGION...WITH HIGH/STRONG WIND EXPECTED ACROSS
THE ABSAROKAS AND POSSIBLY INTO WESTERN PORTIONS OF THE ADJACENT
FOOTHILLS...AND ALSO OVER THE WIND RIVER MOUNTAINS AND EAST FROM
SOUTH PASS TO THE CASPER AREA INCLUDING CASPER MOUNTAIN BY  MID-DAY
SATURDAY. MOUNTAIN WAVE AND TURBULENCE ACTION IS EXPECTED WITH THIS
SET-UP...ESPECIALLY OVER AND EAST OF THE ABSAROKA MOUNTAINS. IT NOW
APPEARS THAT THIS TOO WILL BE A HIGHLIGHT SITUATION OF SOME SORT.
THE ABSAROKAS FOR EXAMPLE...WHILE NOT SEEING QUITE THE SNOWFALL
AMOUNTS THAT THE FAR WRN MOUNTAINS WILL SEE...WILL HAVE THE
COMBINATION OF MODERATE SNOWFALL TOGETHER WITH VERY STRONG
WINDS...GIVING POSSIBLE BLIZZARD CONDITIONS. HIGH WIND CRITERIA WILL
ALSO POSSIBLY BE MET OVER ZONES 19 20 AND 22 THROUGH THE AFTERNOON
AND EARLY EVENING ON SATURDAY.

.LONG TERM...SUNDAY THROUGH THANKSGIVING

A STRONG...MOIST NORTHWEST FLOW WILL DOMINATE THE PATTERN THROUGH AT
LEAST TUESDAY. THIS WILL RESULT IN PERSISTENT LIGHT SNOWFALL OVER
THE NORTHWEST/NORTHERN MOUNTAINS...AND PERIODS OF LIGHT SNOW IN THE
FAR WESTERN VALLEYS. THE SNOWFALL WILL BE ENHANCED AT TIMES AS
DISTURBANCES IN THE FLOW MOVE ACROSS THE AREA.  CURRENTLY...MODELS
ARE SHOWING A DISTINCT SHORTWAVE IMPACTING THE AREA IN THE SUNDAY
NIGHT/MONDAY TIME FRAME. THIS SYSTEM MIGHT WARRANT MORE WINTER
HIGHLIGHTS OVER THE NORTHWEST ZONES. ALTHOUGH THE LOWER ELEVATIONS
EAST OF THE DIVIDE WILL NOT BE IMPACTED...SOME SNOW SHOWER ACTIVITY
IS EXPECTED AT TIMES...ESPECIALLY IN THE SUNDAY NIGHT/MONDAY TIME
FRAME AS THE ABOVE MENTIONED SHORTWAVE PUSHES ACROSS THE AREA. ALSO
WINDY CONDITIONS WILL OCCUR IN THIS NORTHWEST FLOW
PATTERN...ESPECIALLY BUFFALO...DUBOIS AND ROCK SPRINGS AREAS.

GLOBAL MODELS CONTINUE TO STRUGGLE ON THE EVOLUTION OF SHORTWAVES
EJECTING OUT OF THE CLOSED UPPER LOW OVER THE ALEUTIANS/GULF OF
ALASKA EARLY TO MIDDLE OF NEXT WEEK. THE GFS CONTINUES TO HANG ONTO
A RIDGE OVER THE WEST...ALBEIT NOT AS STRONG AS YESTERDAYS 00Z RUN.
THIS KEEPS A MOIST NORTHWEST FLOW OVER THE AREA...WITH A SIGNIFICANT
WAVE IMPACTING THE AREA TUESDAY NIGHT/WEDNESDAY...WITH A BETTER
CHANCE OF IMPACTS EAST THAN SUN-TUE. THE ECMWF HAS BEEN RELATIVELY
CONSISTENT IN KEEPING THE RIDGE FARTHER WEST INTO THE EASTERN
PACIFIC ALLOWING FOR A DEEPER TROUGH OVER THE WEST. THE ECMWF IS
MUCH COLDER AND HAS MORE SNOWFALL OVER A LARGER SECTION OF THE
FORECAST AREA TUE NIGHT THRU WED NIGHT...THAN THE OPERATIONAL GFS.
HOWEVER THE GFS IS TRENDING TOWARD THE ECMWF SOLUTION...AND THUS
HAVE TRENDED FORECAST COLDER WITH BETTER CHANCES OF SNOWFALL. PEOPLE
TRAVELING FOR THANKSGIVING HOLIDAY WILL NEED TO KEEP AN EYE ON THIS
SYSTEM.

HAVE GONE 10 TO AS MUCH AS 20 DEGREES BELOW MEX MOS GUIDANCE FOR
WEDNESDAY AND THANKSGIVING...ESPECIALLY EAST OF THE DIVIDE.

&&

.AVIATION.../12Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
PATCHY IFR/LIFR FOG WILL PARTIALLY OBSCURE LOWER RIVER VALLEYS
MAINLY VCNTY AND NORTH OF KRIW-VCNTY KWRL/KGEY THROUGH 16Z.
OTHERWISE EXPECT VFR CONDITIONS WITH INCREASING MID CLOUDS...AREAS
CIGS FL110-140...FROM AROUND 18Z THUR-06Z FRI WITH CLEARING...PATCHY
FOG REDEVELOPING IN THE SAME AREAS EARLY FRIDAY MORNING.


WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
PATCHY IFR/LIFR FOG MAY PARTIALLY OBSCURE TERRAIN VCNTY KJAC THROUGH
16Z. A WEAK UPPER LEVEL DISTURBANCE WILL BRING INCREASING MID-LEVEL
CLOUDS...CIGS PRIMARILY FL110-130...ACROSS THE AREA 14Z THURSDAY
-03Z FRIDAY ALONG WITH PARTIAL MTN OBSCURATIONS IN -SN AND LCL MVFR
CONDITIONS.  A WESTERLY FLOW WILL FOLLOW 03Z-12Z FRIDAY WITH DRYING
IN THE MID-LEVELS.  HOWEVER THE BOUNDARY LAYER WILL REMAIN NEARLY
SATURATED IN UPSLOPE FLOW...SO AREAS OF MVFR/IFR CONDITIONS IN -SN
OR FLURRIES WILL LINGER INTO FRIDAY MORNING...ESPECIALLY VCNTY KJAC
NORTH ACROSS YELLOWSTONE NATIONAL PARK.

&&

.FIRE WEATHER...

FIRE DANGER LOW AND REMAINING LOW THROUGH THE WEEKEND AS SNOW COVER
OR MINIMUM RH VALUES STAY WELL ABOVE CRITICAL LEVELS. INVERSIONS
WILL LIFT SOME AGAIN TODAY...BUT NOT BREAK AT MOST LOCATIONS. THE
INVERSION LEVEL WILL ONCE AGAIN START OUT NEAR SURFACE THIS MORNING
BEFORE REACHING 1000 TO 2500 FEET AT MOST LOCATIONS BY THE MIDDLE OF
THE DAY. THE GREEN RIVER AND WIND RIVER BASINS WILL STAND THE BEST
CHANCE AT MIXING OUT AND BREAKING THE INVERSION FOR A SHORT PERIOD
THIS AFTERNOON...IT IT HAPPENS AT ALL. MOISTURE WILL BEGIN TO
INCREASE ACROSS THE WEST TODAY WITH LIGHT WIDELY SCATTERED AREAS OF
SNOW BECOMING POSSIBLE OVER THE WESTERN FORECAST ZONES. A MUCH
BETTER PRECIP/SNOW PRODUCING SYSTEM WILL ARRIVE OUT WEST THIS
WEEKEND...WITH EVEN LOW CHANCES FOR SNOW BECOMING POSSIBLE LATER ON
SATURDAY. HOWEVER...INCREASING STRONG WEST TO SOUTHWEST WIND WILL
ALSO ACCOMPANY THIS WINTER WEATHER MAKER...WITH HIGH WINDS EXPECTED
ACROSS THE NORTHERN AND CENTRAL MOUNTAINS AND ALSO FROM SOUTH PASS
EASTWARD THROUGH MOST OF NATRONA COUNTY BY SATURDAY
AFTERNOON.

&&

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

&&

$$

SHORT TERM...BRAUN
LONG TERM...WM
AVIATION...AEM
FIRE WEATHER...BRAUN









000
FXUS65 KRIW 200553
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1051 PM MST WED NOV 19 2014

UPDATE...UPDATED TO ADD 06Z AVIATION DISCUSSION

.SHORT TERM...TONIGHT THROUGH THURSDAY (ISSUED AT 158 PM MST)

DRY NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG AT NIGHT AND IN THE MORNING WITH GENERALLY LIGHT WINDS.  THE
MIXED AREAS WILL BE 15 TO 20 DEGREES WARMER THAN THE TRAPPED
VALLEYS AND BASINS AT TIMES. DRY CONDITIONS WILL PREVAIL EXCEPT
FOR SOME LIGHT SNOW SHOWERS MOVING INTO THE FAR WEST MOUNTAINS
THURSDAY AFTERNOON. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

A FAIRLY QUIET BEGINNING TO THE PERIOD. A WEAK DISTURBANCE WILL MOVE
INTO THE WESTERN HALF OF THE STATE THURSDAY EVENING...BUT IS
EXPECTED TO BRING LIMITED PRECIPITATION. SHOWERS SHOULD MAINLY
IMPACT THE WESTERN MOUNTAINS. THE PASSAGE OF THE SYSTEM WILL PERMIT
SOME COOLING TEMPERATURES TO BE FOUND ACROSS THE AREA
FRIDAY...THOUGH CENTRAL BASINS MAY SEE A BIT OF WARMING THANKS TO
BREAK THEIR INVERSION.

THE BIGGER STORY REMAINS SATURDAY AND SUNDAY AS A STRONGER SYSTEM
MOVES INTO THE STATE. MOISTURE FROM A NEARBY WAVE OF LOW PRESSURE
WILL IMPACT THE WESTERN MOUNTAINS SATURDAY MORNING AND
AFTERNOON...WITH SHOWER COVERAGE INCREASING THROUGH THE DAY AND
EVENING. SHOWERS WILL MOVE EAST OF THE DIVIDE BY SATURDAY
EVENING...WITH COOLER TEMPERATURES EXPECTED.

SATURDAY NIGHT THROUGH WEDNESDAY EVENING...LINGERING SNOW SHOWERS
WILL CONTINUE ACROSS WESTERN...SOUTHERN...AND A FEW NORTHERN PORTIONS
BEHIND THE PASSAGE OF SATURDAYS COLD FRONT. SNOW WILL DIMINISH EAST
OF THE DIVIDE THROUGH THE DAY SUNDAY...HOWEVER...MOIST NORTHWESTERLY
FLOW CLOUD LINGER SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. A FEW
EMBEDDED DISTURBANCES IN THIS FLOW COULD ALSO LINGER SOME LIGHT SNOW
ACROSS THE WESTERN VAL LIES THROUGH THE DAY. THE STRONG JET...THEN
SHIFTS SLIGHTLY NORTHWARD FOR MONDAY...AS THE CUTOFF LOW ACROSS THE
NORTHERN PLAINS PROGRESSES SLIGHTLY EASTWARD. WEAK DISTURBANCES
CAUGHT UP IN THE RESULTANT NORTHWEST FLOW...COMBINED WITH A WEAK
FRONTAL BOUNDARY...WILL BRING AN INCREASED CHANCE FOR SNOW ACROSS
THE WEST...AND INTO PORTIONS OF NORTHERN WYOMING...WITH PERHAPS ONLY
BRIEF LIGHT SNOW ELSEWHERE. BY TUESDAY THE STRONG JET IS THEN PRETTY
MUCH OVERHEAD. A SHIFT TO MORE WESTERLY FLOW COULD BRING BREEZY
CONDITIONS ACROSS THE USUAL WIND CORRIDORS. MOIST WESTERLY FLOW
COULD ALSO CONTINUE SNOW ACROSS THE WESTERN MOUNTAINS. THE POSITIVE
ABOUT SATURDAYS DISTURBANCE IS IT WILL BRING A SLIGHTLY WARMER AIR
MASS INTO THE REGION...COMPARED TO LAST WEEKS ARCTIC AIR THAT
LINGERED. EXPECT TEMPERATURES TO BE SEASONAL TO SLIGHTLY BELOW
NORMAL INTO NEXT WEEK.

MODELS CONTINUE TO DIVERGE WEDNESDAY INTO THANKSGIVING. BOTH ARE NOW
INDICATING AT LEAST A CHANCE FOR SNOW WEDNESDAY AND THANKSGIVING BUT
FOR DIFFERING REASONS. GFS SOLUTION NOW SWINGS A COLD FRONT DOWN
FROM CANADA WEDNESDAY THROUGH THURSDAY MORNING...THAT COULD BRING
A MORE BRIEF SHOT OF SNOW AND COLD. ECMWF IS STILL SHOWING A
STRONG 700 MB LOW IMPACTING THE AREA...WHICH WOULD BRING MORE OF A
WIDESPREAD SNOW IMPACT THAN THE GFS SOLUTION. COMPROMISED ON POPS
FOR NOW...BUT BOTH OF THESE SOLUTIONS WILL CONTINUED TO BE
MONITORED.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
PATCHY IFR/LIFR FOG WILL PARTIALLY OBSCURE LOWER RIVER VALLEYS
MAINLY VCNTY AND NORTH OF KRIW-VCNTY KWRL/KGEY THROUGH 16Z.
OTHERWISE EXPECT VFR CONDITIONS WITH INCREASING MID CLOUDS...AREAS
CIGS AT FL110-140...FROM AROUND 18Z THUR-06Z FRI WITH
CLEARING...PATCHY FOG REDEVELOPING IN THE SAME AREAS EARLY FRIDAY
MORNING.


WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
PATCHY IFR/LIFR FOG MAY PARTIALLY OBSCURE TERRAIN VCNTY KJAC THROUGH
16Z. A WEAK UPPER LEVEL DISTURBANCE WILL BRING INCREASING MID-LEVEL
CLOUDS...CIGS PRIMARILY FL110-130...ACROSS THE AREA 14Z THURSDAY
-03Z FRIDAY ALONG WITH PARTIAL MTN OBSCURATIONS IN -SN AND LCL MVFR
CONDITIONS.  A WESTERLY FLOW WILL FOLLOW 03Z-12Z FRIDAY WITH DRYING
IN THE MID-LEVELS.  HOWEVER THE BOUNDARY LAYER WILL REMAIN NEARLY
SATURATED IN UPSLOPE FLOW...SO AREAS OF MVFR/IFR CONDITIONS IN -SN
OR FLURRIES WILL LINGER INTO FRIDAY MORNING...ESPECIALLY VCNTY KJAC
NORTH ACROSS YELLOWSTONE NATIONAL PARK.


&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND
POOR SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES
WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY
LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. DRY CONDITIONS
WILL PREVAIL. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

&&

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

$$

SHORT TERM...C.BAKER
LONG TERM...BRANHAM/ANGLIN
AVIATION...AEM
FIRE WEATHER...C.BAKER


















000
FXUS65 KRIW 200553
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1051 PM MST WED NOV 19 2014

UPDATE...UPDATED TO ADD 06Z AVIATION DISCUSSION

.SHORT TERM...TONIGHT THROUGH THURSDAY (ISSUED AT 158 PM MST)

DRY NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG AT NIGHT AND IN THE MORNING WITH GENERALLY LIGHT WINDS.  THE
MIXED AREAS WILL BE 15 TO 20 DEGREES WARMER THAN THE TRAPPED
VALLEYS AND BASINS AT TIMES. DRY CONDITIONS WILL PREVAIL EXCEPT
FOR SOME LIGHT SNOW SHOWERS MOVING INTO THE FAR WEST MOUNTAINS
THURSDAY AFTERNOON. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

A FAIRLY QUIET BEGINNING TO THE PERIOD. A WEAK DISTURBANCE WILL MOVE
INTO THE WESTERN HALF OF THE STATE THURSDAY EVENING...BUT IS
EXPECTED TO BRING LIMITED PRECIPITATION. SHOWERS SHOULD MAINLY
IMPACT THE WESTERN MOUNTAINS. THE PASSAGE OF THE SYSTEM WILL PERMIT
SOME COOLING TEMPERATURES TO BE FOUND ACROSS THE AREA
FRIDAY...THOUGH CENTRAL BASINS MAY SEE A BIT OF WARMING THANKS TO
BREAK THEIR INVERSION.

THE BIGGER STORY REMAINS SATURDAY AND SUNDAY AS A STRONGER SYSTEM
MOVES INTO THE STATE. MOISTURE FROM A NEARBY WAVE OF LOW PRESSURE
WILL IMPACT THE WESTERN MOUNTAINS SATURDAY MORNING AND
AFTERNOON...WITH SHOWER COVERAGE INCREASING THROUGH THE DAY AND
EVENING. SHOWERS WILL MOVE EAST OF THE DIVIDE BY SATURDAY
EVENING...WITH COOLER TEMPERATURES EXPECTED.

SATURDAY NIGHT THROUGH WEDNESDAY EVENING...LINGERING SNOW SHOWERS
WILL CONTINUE ACROSS WESTERN...SOUTHERN...AND A FEW NORTHERN PORTIONS
BEHIND THE PASSAGE OF SATURDAYS COLD FRONT. SNOW WILL DIMINISH EAST
OF THE DIVIDE THROUGH THE DAY SUNDAY...HOWEVER...MOIST NORTHWESTERLY
FLOW CLOUD LINGER SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. A FEW
EMBEDDED DISTURBANCES IN THIS FLOW COULD ALSO LINGER SOME LIGHT SNOW
ACROSS THE WESTERN VAL LIES THROUGH THE DAY. THE STRONG JET...THEN
SHIFTS SLIGHTLY NORTHWARD FOR MONDAY...AS THE CUTOFF LOW ACROSS THE
NORTHERN PLAINS PROGRESSES SLIGHTLY EASTWARD. WEAK DISTURBANCES
CAUGHT UP IN THE RESULTANT NORTHWEST FLOW...COMBINED WITH A WEAK
FRONTAL BOUNDARY...WILL BRING AN INCREASED CHANCE FOR SNOW ACROSS
THE WEST...AND INTO PORTIONS OF NORTHERN WYOMING...WITH PERHAPS ONLY
BRIEF LIGHT SNOW ELSEWHERE. BY TUESDAY THE STRONG JET IS THEN PRETTY
MUCH OVERHEAD. A SHIFT TO MORE WESTERLY FLOW COULD BRING BREEZY
CONDITIONS ACROSS THE USUAL WIND CORRIDORS. MOIST WESTERLY FLOW
COULD ALSO CONTINUE SNOW ACROSS THE WESTERN MOUNTAINS. THE POSITIVE
ABOUT SATURDAYS DISTURBANCE IS IT WILL BRING A SLIGHTLY WARMER AIR
MASS INTO THE REGION...COMPARED TO LAST WEEKS ARCTIC AIR THAT
LINGERED. EXPECT TEMPERATURES TO BE SEASONAL TO SLIGHTLY BELOW
NORMAL INTO NEXT WEEK.

MODELS CONTINUE TO DIVERGE WEDNESDAY INTO THANKSGIVING. BOTH ARE NOW
INDICATING AT LEAST A CHANCE FOR SNOW WEDNESDAY AND THANKSGIVING BUT
FOR DIFFERING REASONS. GFS SOLUTION NOW SWINGS A COLD FRONT DOWN
FROM CANADA WEDNESDAY THROUGH THURSDAY MORNING...THAT COULD BRING
A MORE BRIEF SHOT OF SNOW AND COLD. ECMWF IS STILL SHOWING A
STRONG 700 MB LOW IMPACTING THE AREA...WHICH WOULD BRING MORE OF A
WIDESPREAD SNOW IMPACT THAN THE GFS SOLUTION. COMPROMISED ON POPS
FOR NOW...BUT BOTH OF THESE SOLUTIONS WILL CONTINUED TO BE
MONITORED.

&&

.AVIATION.../06Z ISSUANCE/

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES
PATCHY IFR/LIFR FOG WILL PARTIALLY OBSCURE LOWER RIVER VALLEYS
MAINLY VCNTY AND NORTH OF KRIW-VCNTY KWRL/KGEY THROUGH 16Z.
OTHERWISE EXPECT VFR CONDITIONS WITH INCREASING MID CLOUDS...AREAS
CIGS AT FL110-140...FROM AROUND 18Z THUR-06Z FRI WITH
CLEARING...PATCHY FOG REDEVELOPING IN THE SAME AREAS EARLY FRIDAY
MORNING.


WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES
PATCHY IFR/LIFR FOG MAY PARTIALLY OBSCURE TERRAIN VCNTY KJAC THROUGH
16Z. A WEAK UPPER LEVEL DISTURBANCE WILL BRING INCREASING MID-LEVEL
CLOUDS...CIGS PRIMARILY FL110-130...ACROSS THE AREA 14Z THURSDAY
-03Z FRIDAY ALONG WITH PARTIAL MTN OBSCURATIONS IN -SN AND LCL MVFR
CONDITIONS.  A WESTERLY FLOW WILL FOLLOW 03Z-12Z FRIDAY WITH DRYING
IN THE MID-LEVELS.  HOWEVER THE BOUNDARY LAYER WILL REMAIN NEARLY
SATURATED IN UPSLOPE FLOW...SO AREAS OF MVFR/IFR CONDITIONS IN -SN
OR FLURRIES WILL LINGER INTO FRIDAY MORNING...ESPECIALLY VCNTY KJAC
NORTH ACROSS YELLOWSTONE NATIONAL PARK.


&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND
POOR SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES
WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY
LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. DRY CONDITIONS
WILL PREVAIL. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

&&

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

$$

SHORT TERM...C.BAKER
LONG TERM...BRANHAM/ANGLIN
AVIATION...AEM
FIRE WEATHER...C.BAKER



















000
FXUS65 KRIW 192352 CCA
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
158 PM MST WED NOV 19 2014

.SHORT TERM...TONIGHT THROUGH THURSDAY

DRY NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG AT NIGHT AND IN THE MORNING WITH GENERALLY LIGHT WINDS.  THE
MIXED AREAS WILL BE 15 TO 20 DEGREES WARMER THAN THE TRAPPED
VALLEYS AND BASINS AT TIMES. DRY CONDITIONS WILL PREVAIL EXCEPT
FOR SOME LIGHT SNOW SHOWERS MOVING INTO THE FAR WEST MOUNTAINS
THURSDAY AFTERNOON. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

A FAIRLY QUIET BEGINNING TO THE PERIOD. A WEAK DISTURBANCE WILL MOVE
INTO THE WESTERN HALF OF THE STATE THURSDAY EVENING...BUT IS
EXPECTED TO BRING LIMITED PRECIPITATION. SHOWERS SHOULD MAINLY
IMPACT THE WESTERN MOUNTAINS. THE PASSAGE OF THE SYSTEM WILL PERMIT
SOME COOLING TEMPERATURES TO BE FOUND ACROSS THE AREA
FRIDAY...THOUGH CENTRAL BASINS MAY SEE A BIT OF WARMING THANKS TO
BREAK THEIR INVERSION.

THE BIGGER STORY REMAINS SATURDAY AND SUNDAY AS A STRONGER SYSTEM
MOVES INTO THE STATE. MOISTURE FROM A NEARBY WAVE OF LOW PRESSURE
WILL IMPACT THE WESTERN MOUNTAINS SATURDAY MORNING AND
AFTERNOON...WITH SHOWER COVERAGE INCREASING THROUGH THE DAY AND
EVENING. SHOWERS WILL MOVE EAST OF THE DIVIDE BY SATURDAY
EVENING...WITH COOLER TEMPERATURES EXPECTED.

SATURDAY NIGHT THROUGH WEDNESDAY EVENING...LINGERING SNOW SHOWERS
WILL CONTINUE ACROSS WESTERN...SOUTHERN...AND A FEW NORTHERN PORTIONS
BEHIND THE PASSAGE OF SATURDAYS COLD FRONT. SNOW WILL DIMINISH EAST
OF THE DIVIDE THROUGH THE DAY SUNDAY...HOWEVER...MOIST NORTHWESTERLY
FLOW CLOUD LINGER SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. A FEW
EMBEDDED DISTURBANCES IN THIS FLOW COULD ALSO LINGER SOME LIGHT SNOW
ACROSS THE WESTERN VAL LIES THROUGH THE DAY. THE STRONG JET...THEN
SHIFTS SLIGHTLY NORTHWARD FOR MONDAY...AS THE CUTOFF LOW ACROSS THE
NORTHERN PLAINS PROGRESSES SLIGHTLY EASTWARD. WEAK DISTURBANCES
CAUGHT UP IN THE RESULTANT NORTHWEST FLOW...COMBINED WITH A WEAK
FRONTAL BOUNDARY...WILL BRING AN INCREASED CHANCE FOR SNOW ACROSS
THE WEST...AND INTO PORTIONS OF NORTHERN WYOMING...WITH PERHAPS ONLY
BRIEF LIGHT SNOW ELSEWHERE. BY TUESDAY THE STRONG JET IS THEN PRETTY
MUCH OVERHEAD. A SHIFT TO MORE WESTERLY FLOW COULD BRING BREEZY
CONDITIONS ACROSS THE USUAL WIND CORRIDORS. MOIST WESTERLY FLOW
COULD ALSO CONTINUE SNOW ACROSS THE WESTERN MOUNTAINS. THE POSITIVE
ABOUT SATURDAYS DISTURBANCE IS IT WILL BRING A SLIGHTLY WARMER AIR
MASS INTO THE REGION...COMPARED TO LAST WEEKS ARCTIC AIR THAT
LINGERED. EXPECT TEMPERATURES TO BE SEASONAL TO SLIGHTLY BELOW
NORMAL INTO NEXT WEEK.

MODELS CONTINUE TO DIVERGE WEDNESDAY INTO THANKSGIVING. BOTH ARE NOW
INDICATING AT LEAST A CHANCE FOR SNOW WEDNESDAY AND THANKSGIVING BUT
FOR DIFFERING REASONS. GFS SOLUTION NOW SWINGS A COLD FRONT DOWN
FROM CANADA WEDNESDAY THROUGH THURSDAY MORNING...THAT COULD BRING
A MORE BRIEF SHOT OF SNOW AND COLD. ECMWF IS STILL SHOWING A
STRONG 700 MB LOW IMPACTING THE AREA...WHICH WOULD BRING MORE OF A
WIDESPREAD SNOW IMPACT THAN THE GFS SOLUTION. COMPROMISED ON POPS
FOR NOW...BUT BOTH OF THESE SOLUTIONS WILL CONTINUED TO BE
MONITORED.

&&

.AVIATION.../00Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL AT THE AIRPORTS THROUGH THE PERIOD.
LOCAL AREAS OF FOG OR LOW CLOUDS MAY OCCUR TONIGHT IN THE FAR
WEST VALLEYS AND CENTRAL BASINS.  LOCAL MVFR/IFR CONDITIONS ARE
EXPECTED FROM 06Z TO 18Z THURSDAY IN THE VALLEYS AND BASINS
ALONG RIVERS AND RESERVOIRS.

&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND
POOR SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES
WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY
LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. DRY CONDITIONS
WILL PREVAIL. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

&&

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

$$

SHORT TERM...C.BAKER
LONG TERM...BRANHAM/ANGLIN
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER
















000
FXUS65 KRIW 192352 CCA
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
158 PM MST WED NOV 19 2014

.SHORT TERM...TONIGHT THROUGH THURSDAY

DRY NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG AT NIGHT AND IN THE MORNING WITH GENERALLY LIGHT WINDS.  THE
MIXED AREAS WILL BE 15 TO 20 DEGREES WARMER THAN THE TRAPPED
VALLEYS AND BASINS AT TIMES. DRY CONDITIONS WILL PREVAIL EXCEPT
FOR SOME LIGHT SNOW SHOWERS MOVING INTO THE FAR WEST MOUNTAINS
THURSDAY AFTERNOON. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

A FAIRLY QUIET BEGINNING TO THE PERIOD. A WEAK DISTURBANCE WILL MOVE
INTO THE WESTERN HALF OF THE STATE THURSDAY EVENING...BUT IS
EXPECTED TO BRING LIMITED PRECIPITATION. SHOWERS SHOULD MAINLY
IMPACT THE WESTERN MOUNTAINS. THE PASSAGE OF THE SYSTEM WILL PERMIT
SOME COOLING TEMPERATURES TO BE FOUND ACROSS THE AREA
FRIDAY...THOUGH CENTRAL BASINS MAY SEE A BIT OF WARMING THANKS TO
BREAK THEIR INVERSION.

THE BIGGER STORY REMAINS SATURDAY AND SUNDAY AS A STRONGER SYSTEM
MOVES INTO THE STATE. MOISTURE FROM A NEARBY WAVE OF LOW PRESSURE
WILL IMPACT THE WESTERN MOUNTAINS SATURDAY MORNING AND
AFTERNOON...WITH SHOWER COVERAGE INCREASING THROUGH THE DAY AND
EVENING. SHOWERS WILL MOVE EAST OF THE DIVIDE BY SATURDAY
EVENING...WITH COOLER TEMPERATURES EXPECTED.

SATURDAY NIGHT THROUGH WEDNESDAY EVENING...LINGERING SNOW SHOWERS
WILL CONTINUE ACROSS WESTERN...SOUTHERN...AND A FEW NORTHERN PORTIONS
BEHIND THE PASSAGE OF SATURDAYS COLD FRONT. SNOW WILL DIMINISH EAST
OF THE DIVIDE THROUGH THE DAY SUNDAY...HOWEVER...MOIST NORTHWESTERLY
FLOW CLOUD LINGER SNOW SHOWERS ACROSS THE WESTERN MOUNTAINS. A FEW
EMBEDDED DISTURBANCES IN THIS FLOW COULD ALSO LINGER SOME LIGHT SNOW
ACROSS THE WESTERN VAL LIES THROUGH THE DAY. THE STRONG JET...THEN
SHIFTS SLIGHTLY NORTHWARD FOR MONDAY...AS THE CUTOFF LOW ACROSS THE
NORTHERN PLAINS PROGRESSES SLIGHTLY EASTWARD. WEAK DISTURBANCES
CAUGHT UP IN THE RESULTANT NORTHWEST FLOW...COMBINED WITH A WEAK
FRONTAL BOUNDARY...WILL BRING AN INCREASED CHANCE FOR SNOW ACROSS
THE WEST...AND INTO PORTIONS OF NORTHERN WYOMING...WITH PERHAPS ONLY
BRIEF LIGHT SNOW ELSEWHERE. BY TUESDAY THE STRONG JET IS THEN PRETTY
MUCH OVERHEAD. A SHIFT TO MORE WESTERLY FLOW COULD BRING BREEZY
CONDITIONS ACROSS THE USUAL WIND CORRIDORS. MOIST WESTERLY FLOW
COULD ALSO CONTINUE SNOW ACROSS THE WESTERN MOUNTAINS. THE POSITIVE
ABOUT SATURDAYS DISTURBANCE IS IT WILL BRING A SLIGHTLY WARMER AIR
MASS INTO THE REGION...COMPARED TO LAST WEEKS ARCTIC AIR THAT
LINGERED. EXPECT TEMPERATURES TO BE SEASONAL TO SLIGHTLY BELOW
NORMAL INTO NEXT WEEK.

MODELS CONTINUE TO DIVERGE WEDNESDAY INTO THANKSGIVING. BOTH ARE NOW
INDICATING AT LEAST A CHANCE FOR SNOW WEDNESDAY AND THANKSGIVING BUT
FOR DIFFERING REASONS. GFS SOLUTION NOW SWINGS A COLD FRONT DOWN
FROM CANADA WEDNESDAY THROUGH THURSDAY MORNING...THAT COULD BRING
A MORE BRIEF SHOT OF SNOW AND COLD. ECMWF IS STILL SHOWING A
STRONG 700 MB LOW IMPACTING THE AREA...WHICH WOULD BRING MORE OF A
WIDESPREAD SNOW IMPACT THAN THE GFS SOLUTION. COMPROMISED ON POPS
FOR NOW...BUT BOTH OF THESE SOLUTIONS WILL CONTINUED TO BE
MONITORED.

&&

.AVIATION.../00Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL AT THE AIRPORTS THROUGH THE PERIOD.
LOCAL AREAS OF FOG OR LOW CLOUDS MAY OCCUR TONIGHT IN THE FAR
WEST VALLEYS AND CENTRAL BASINS.  LOCAL MVFR/IFR CONDITIONS ARE
EXPECTED FROM 06Z TO 18Z THURSDAY IN THE VALLEYS AND BASINS
ALONG RIVERS AND RESERVOIRS.

&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND
POOR SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES
WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY
LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. DRY CONDITIONS
WILL PREVAIL. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

&&

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

$$

SHORT TERM...C.BAKER
LONG TERM...BRANHAM/ANGLIN
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER















000
FXUS65 KRIW 192058
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
158 PM MST WED NOV 19 2014

.SHORT TERM...TONIGHT THROUGH THURSDAY

DRY NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG AT NIGHT AND IN THE MORNING WITH GENERALLY LIGHT WINDS.  THE
MIXED AREAS WILL BE 15 TO 20 DEGREES WARMER THAN THE TRAPPED
VALLEYS AND BASINS AT TIMES. DRY CONDITIONS WILL PREVAIL EXCEPT
FOR SOME LIGHT SNOW SHOWERS MOVING INTO THE FAR WEST MOUNTAINS
THURSDAY AFTERNOON. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

A FAIRLY QUIET BEGINNING TO THE PERIOD. A WEAK DISTURBANCE WILL MOVE
INTO THE WESTERN HALF OF THE STATE THURSDAY EVENING...BUT IS
EXPECTED TO BRING LIMITED PRECIPITATION. SHOWERS SHOULD MAINLY
IMPACT THE WESTERN MOUNTAINS. THE PASSAGE OF THE SYSTEM WILL PERMIT
SOME COOLING TEMPERATURES TO BE FOUND ACROSS THE AREA
FRIDAY...THOUGH CENTRAL BASINS MAY SEE A BIT OF WARMING THANKS TO
BREAK THEIR INVERSION.

THE BIGGER STORY REMAINS SATURDAY AND SUNDAY AS A STRONGER SYSTEM
MOVES INTO THE STATE. MOISTURE FROM A NEARBY WAVE OF LOW PRESSURE
WILL IMPACT THE WESTERN MOUNTAINS SATURDAY MORNING AND
AFTERNOON...WITH SHOWER COVERAGE INCREASING THROUGH THE DAY AND
EVENING. SHOWERS WILL MOVE EAST OF THE DIVIDE BY SATURDAY
EVENING...WITH COOLER TEMPERATURES EXPECTED.

SATURDAY NIGHT THROUGH WEDNESDAY EVENING...LINGERING SNOW SHOWERS
WILL CON TINE ACROSS WESTERN...SOUTHERN...AND A FEW NORTHERN
PORTIONS BEHIND THE PASSAGE OF SATURDAYS COLD FRONT. SNOW WILL
DIMINISH EAST OF THE DIVIDE THROUGH THE DAY SUNDAY...HOWEVER...MOIST
NORTHWESTERLY FLOW CLOUD LINGER SNOW SHOWERS ACROSS THE WESTERN
MOUNTAINS. A FEW EMBEDDED DISTURBANCES IN THIS FLOW COULD ALSO
LINGER SOME LIGHT SNOW ACROSS THE WESTERN VAL LIES THROUGH THE DAY.
THE STRONG JET...THEN SHIFTS SLIGHTLY NORTHWARD FOR MONDAY...AS
THE CUTOFF LOW ACROSS THE NORTHERN PLAINS PROGRESSES SLIGHTLY
EASTWARD. WEAK DISTURBANCES CAUGHT UP IN THE RESULTANT NORTHWEST
FLOW...COMBINED WITH A WEAK FRONTAL BOUNDARY...WILL BRING AN
INCREASED CHANCE FOR SNOW ACROSS THE WEST...AND INTO PORTIONS OF
NORTHERN WYOMING...WITH PERHAPS ONLY BRIEF LIGHT SNOW ELSEWHERE.
BY TUESDAY THE STRONG JET IS THEN PRETTY MUCH OVERHEAD. A SHIFT TO
MORE WESTERLY FLOW COULD BRING BREEZY CONDITIONS ACROSS THE USUAL
WIND CORRIDORS. MOIST WESTERLY FLOW COULD ALSO CONTINUE SNOW ACROSS
THE WESTERN MOUNTAINS. THE POSITIVE ABOUT SATURDAYS DISTURBANCE IS
IT WILL BRING A SLIGHTLY WARMER AIR MASS INTO THE REGION...COMPARED
TO LAST WEEKS ARCTIC AIR THAT LINGERED. EXPECT TEMPERATURES TO BE
SEASONAL TO SLIGHTLY BELOW NORMAL INTO NEXT WEEK.

MODELS CONTINUE TO DIVERGE WEDNESDAY INTO THANKSGIVING. BOTH ARE NOW
INDICATING AT LEAST A CHANCE FOR SNOW WEDNESDAY AND THANKSGIVING BUT
FOR DIFFERING REASONS. GFS SOLUTION NOW SWINGS A COLD FRONT DOWN
FROM CANADA WEDNESDAY THROUGH THURSDAY MORNING...THAT COULD BRING
A MORE BRIEF SHOT OF SNOW AND COLD. ECMWRF IS STILL SHOWING A
STRONG 700 MB LOW IMPACTING THE AREA...WHICH WOULD BRING MORE OF A
WIDESPREAD SNOW IMPACT THAN THE GFS SOLUTION. COMPROMISED ON POPS
FOR NOW...BUT BOTH OF THESE SOLUTIONS WILL CONTINUED TO BE
MONITORED.



&&

.AVIATION.../00Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL AT THE AIRPORTS THROUGH THE PERIOD.
LOCAL AREAS OF FOG OR LOW CLOUDS MAY OCCUR TONIGHT IN THE FAR
WEST VALLEYS AND CENTRAL BASINS.  LOCAL MVFR/IFR CONDITIONS ARE
EXPECTED FROM 06Z TO 18Z THURSDAY IN THE VALLEYS AND BASINS
ALONG RIVERS AND RESERVOIRS.

&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE LOCAL LOW STRATUS CLOUDS AND
FOG WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND
POOR SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES
WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY
LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. DRY CONDITIONS
WILL PREVAIL. THE MAIN COLD POOLS ARE IN THE FAR NORTH WIND RIVER
BASIN AND THE EASTERN BIGHORN BASIN.

&&

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

$$

SHORT TERM...C.BAKER
LONG TERM...BRANHAM/ANGLIN
AVIATION...C.BAKER
FIRE WEATHER...C.BAKER












000
FXUS65 KRIW 191738
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1038 AM MST WED NOV 19 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

WV IMAGERY STILL SHOWS LONGWAVE TROF ACROSS 80 PERCENT OF THE
CONUS...WITH A TROF/RIDGE COMBO ACROSS THE FAR WRN CONUS. 100+KT JET
CURRENTLY EXTENDS FROM SOMEWHERE IN WCNTRL CANADA...ACROSS THE ERN
PORTION OF WY AND ON INTO KS. AT THE SFC...TWO AREAS OF WEAK LOW
PRESSURE FROM WRN SD TO NERN CO. COLD NEARLY STATIONARY FRONT FROM
LOW IN WRN SD TO THE NW AND THRU THE NE CORNER OF WY AND ON THRU
CNTRL MT. THIS IS THE CURRENT DEMARCATION/WRN EXTENT OF THE STRATUS
THAT THEN STRETCHES OFF INTO THE NRN PLAINS. GENERAL HIGHER PRESSURE
OFF TO THE WEST ATTM.

SLOW NEARLY FLAT WARMING CONTINUES ACROSS THE FA TODAY AS HEIGHTS
RISE SOME WITH THE APPROACH OF THE RIDGE TO THE WEST. THE STRONG JET
FLOW GETS PUSHES EWD AT THE SAME TIME. MID/UPR LVL MOISTURE TOPPING
THE RIDGE CONTINUES TOP RIDE DOWN THE EAST SIDE OF THE RIDGE ACROSS
MAINLY THE WRN CWA OFFERING UP MAINLY MID CLOUD PRODUCTION THRU MOST
OF THE DAY. TONIGHT/OVERNIGHT...FLOW CHANGES FROM NWRLY TO W AND
INCREASED BUT MODEST MOISTURE FROM THE EPAC BEGIN TO BUILD IN WITH
THE WEAK RIDGING JUST AHEAD OF AN OPENING/SPLITTING TROF CHASER. THE
STRONGER DYNAMICS WITH THIS LEAD SYSTEM WILL DIVE WELL S OF THE FA
FOLLOWING THE SRN BRANCH OF THE JET WHILE THE NRN PORTION WEAKENS
THRU THE RIDGE. PRECIP CHANCES WILL BEGIN TO INCREASE
ACCORDINGLY/SLOWLY  ACROSS THE WRN FA OVERNIGHT WED AS WEAK DYNAMICS
ADD TO THE TERRAIN LIFTING...SQUEEZING OUT LIGHT SNOW MAINLY FROM
THURSDAY MORNING ONWARD. WITH BEST CHCS LATER IN THE AFTERNOON AND
INTO THE THURSDAY EVENING PERIOD. THIS INITIAL DISTURBANCE  (BEFORE
THE STRONGER WEEKEND VERSION) CONTINUES TO LOOK FAIRLY PUNY OVERALL
WITH LIMITED MOISTURE AND DYNAMICS ABLE TO ADD TO THE OROGRAPHIC
FORCING. THAT SAID...THE WRN MOUNTAINS COULD SEE WIDESPREAD 1 TO 4
INCHES OF NEW SNOWFALL BY FRIDAY MORNING...VALLEYS A TRACE TO AN
INCH...BEFORE THE ATMOSPHERE DRIES OUT A BIT AHEAD OF A BETTER
INFLUX OF MOISTURE FRIDAY NIGHT...LEADING TOWARD A BETTER SNOW-MAKER
LATER ON SATURDAY. ADDITIONALLY...WINDS FROM THE W TO THE SW SHOULD
ONCE AGAIN BEGIN TO PICK-UP ACROSS THE USUAL ZONES...ABSAROKAS AND
ADJACENT FOOTHILLS AND FROM SOUTH PASS TO CASPER BY LATER AFTERNOON
FRIDAY AND OVERNIGHT. SOME MODEST MOUNTAIN WAVE ACTION AND
TURBULENCE IS EXPECTED WITH THIS SET-UP ESPECIALLY OVER AND EAST OF
THE ABSAROKA MOUNTAINS...HOWEVER THIS WILL LIKELY NOT BE A HIGHLIGHT
SITUATION.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

A SHORTWAVE TROUGH AND ASSOCIATED PACIFIC COLD FRONT WILL PUSH
QUICKLY EAST ACROSS THE NORTHERN ROCKIES SATURDAY AND SATURDAY
EVENING. THE STRONG 160KT PACIFIC JET IS PROGGED A BIT FARTHER SOUTH
OVER THE WEST...WITH THE FORECAST AREA NOT BEING AS IMPACTED WITH
THE FAVORABLE DYNAMICS ASSOCIATED WITH THE LEFT FRONT QUAD.
DESPITE THAT...SYNOPTIC LIFT FROM THE SHORTWAVE TROUGH...A MOIST
WESTERLY FLOW AND A FRONTAL BOUNDARY SHOULD ALL COMBINE FOR A
SIGNIFICANT SNOW AND WIND EVENT OVER THE WEST...AND POSSIBLY A
HIGH WIND EVENT IN THE ROCK SPRINGS TO CASPER WIND CORRIDOR. SNOW
AMOUNTS FROM LATE FRIDAY NIGHT THROUGH SATURDAY EVENING LOOK TO BE
IN THE LOW END ADVISORY AMOUNTS AT THIS TIME...BUT ADD THE STRONG
WIND AND THIS EVENT WILL PROBABLY WARRANT ADVISORIES OVER MUCH OF
THE WEST...WITH THE TETONS POSSIBLY REACHING WARNING CRITERIA.
ENOUGH WARM AIR COULD BE PULLED NORTHWARD THAT SNOW IN THE LOWER
ELEVATIONS COULD BRIEFLY CHANGE TO RAIN MIDDAY SATURDAY...BEFORE
SWITCHING BACK TO SNOW. THIS WOULD PRIMARILY BE A CONCERN FOR STAR
VALLEY. EAST OF THE DIVIDE...STRONG DOWNSLOPING AHEAD OF THE FRONT
WILL KEEP THINGS DRY. ALONG AND BEHIND THE COLD FRONT...SOME
PRECIPITATION IS EXPECTED TO SPILL EAST OF THE DIVIDE...MAINLY
OVER THE NORTH AND NORTHEAST...BUT AMOUNTS SHOULD REMAIN LIGHT.

IN WAKE OF THIS STORM SYSTEM SATURDAY...MEDIUM RANGE MODELS ARE IN
GOOD AGREEMENT WITH A LONGWAVE TROUGH FORMING AND REMAINING OVER THE
CENTRAL/EASTERN U.S. EARLY NEXT WEEK. ACROSS THE FORECAST
AREA...THIS WILL KEEP A STRONG...MOIST NORTHWEST FLOW THROUGH AT
LEAST TUESDAY...WHICH WILL KEEP GOOD CHANCES OF ACCUMULATING SNOW
OVER THE NORTHWEST AND NORTHERN MOUNTAINS. DISTURBANCES IN THE FLOW
WILL ALLOW FOR FOR THIS ACTIVITY TO OCCASIONAL PUSH INTO THE LOWER
ELEVATIONS. ALSO WINDY TO VERY CONDITIONS WILL CONTINUE AT TIMES.

MODELS THEN DIVERGE SIGNIFICANTLY FOR WEDNESDAY INTO
THANKSGIVING...AS THE ECMWF AND SEVERAL GFS ENSEMBLES SHOW A STORM
SYSTEM...AND ASSOCIATED ARCTIC COLD FRONT DROPPING OUT OF
CANADA...AND IMPACTING THE AREA WEDNESDAY INTO THANKSGIVING. THE
OPERATIONAL 00Z GFS...AND SOME OF ITS ENSEMBLES BUILD UP A RIDGE FOR
A VERY NICE THANKSGIVING.  ON THANKSGIVING MORNING...THE GFS HAS 700
MB TEMPS OVER KRIW AROUND +4C WITH MAINLY DRY CONDITIONS...WHILE THE
ECMWF HAS -17C WITH AN ONGOING SNOW STORM OVER MUCH OF THE AREA.

TEMPERATURES ARE EXPECTED TO BE ABOVE AVERAGE AHEAD OF THE FRONT
SATURDAY...WITH SEASONAL TO SLIGHTLY BELOW AVERAGE TEMPS EARLY
NEXT WEEK. THE PACIFIC NATURE OF THIS COLD FRONT WILL KEEP
TEMPERATURES...MUCH WARMER THAN WHAT OCCURRED IN WAKE OF THE
ARCTIC COLD FRONT ON NOVEMBER 9 AND 10TH. ALSO...BREEZY
WEST/NORTHWEST WINDS SHOULD ALSO KEEP THE BASINS/VALLEYS FROM
GETTING TOO TRAPPED UNDER A STRONG SFC INVERSION.

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. LOCAL AREAS OF FOG
OR LOW CLOUDS MAY OCCUR THIS MORNING IN THE FAR WEST VALLEYS...
INCLUDING THE AFTON AND JACKSON AIRPORTS. LOCAL MVFR/IFR
CONDITIONS ARE EXPECTED UNTIL 18Z ALONG RIVERS AND RESERVOIRS.

.FIRE WEATHER...

FIRE DANGER LOW AND REMAINING LOW THROUGH THE REST OF THE WORK WEEK
AS SNOW COVER OR MINIMUM RH VALUES STAY WELL ABOVE CRITICAL LEVELS.
INVERSIONS WILL LIFT SOME AGAIN TODAY...BUT NOT BREAK...STARTING OUT
NEAR SURFACE THIS MORNING BEFORE REACHING 500 TO 1500 FEET FOR MOST
LOCATIONS BY THE MIDDLE OF THE DAY. THE WESTERN VALLEYS/BASINS WILL
STAND THE BEST CHANCE AT BREAKING THE INVERSION FOR A SHORT PERIOD.
MOISTURE WILL BEGIN TO INCREASE ACROSS THE WEST LATER TONIGHT WITH
LIGHT AREAS OF SNOW BECOMING POSSIBLE OVER THE WESTERN FORECAST
ZONES ON THURSDAY. HIGH PROBABILITY PRECIP/SNOW CHANCES WILL ARRIVE OUT
WEST THIS WEEKEND...WITH LOWER CHANCES FOR SNOW BECOMING POSSIBLE
ACROSS THE EASTERN FORECAST ZONES LATER ON SATURDAY.

&&

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

$$

SHORT TERM...BRAUN
LONG TERM...WM
AVIATION...C.BAKER
FIRE WEATHER...BRAUN







000
FXUS65 KRIW 191025
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
325 AM MST WED NOV 19 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

WV IMAGERY STILL SHOWS LONGWAVE TROF ACROSS 80 PERCENT OF THE
CONUS...WITH A TROF/RIDGE COMBO ACROSS THE FAR WRN CONUS. 100+KT JET
CURRENTLY EXTENDS FROM SOMEWHERE IN WCNTRL CANADA...ACROSS THE ERN
PORTION OF WY AND ON INTO KS. AT THE SFC...TWO AREAS OF WEAK LOW
PRESSURE FROM WRN SD TO NERN CO. COLD NEARLY STATIONARY FRONT FROM
LOW IN WRN SD TO THE NW AND THRU THE NE CORNER OF WY AND ON THRU
CNTRL MT. THIS IS THE CURRENT DEMARCATION/WRN EXTENT OF THE STRATUS
THAT THEN STRETCHES OFF INTO THE NRN PLAINS. GENERAL HIGHER PRESSURE
OFF TO THE WEST ATTM.

SLOW NEARLY FLAT WARMING CONTINUES ACROSS THE FA TODAY AS HEIGHTS
RISE SOME WITH THE APPROACH OF THE RIDGE TO THE WEST. THE STRONG JET
FLOW GETS PUSHES EWD AT THE SAME TIME. MID/UPR LVL MOISTURE TOPPING
THE RIDGE CONTINUES TOP RIDE DOWN THE EAST SIDE OF THE RIDGE ACROSS
MAINLY THE WRN CWA OFFERING UP MAINLY MID CLOUD PRODUCTION THRU MOST
OF THE DAY. TONIGHT/OVERNIGHT...FLOW CHANGES FROM NWRLY TO W AND
INCREASED BUT MODEST MOISTURE FROM THE EPAC BEGIN TO BUILD IN WITH
THE WEAK RIDGING JUST AHEAD OF AN OPENING/SPLITTING TROF CHASER. THE
STRONGER DYNAMICS WITH THIS LEAD SYSTEM WILL DIVE WELL S OF THE FA
FOLLOWING THE SRN BRANCH OF THE JET WHILE THE NRN PORTION WEAKENS
THRU THE RIDGE. PRECIP CHANCES WILL BEGIN TO INCREASE
ACCORDINGLY/SLOWLY  ACROSS THE WRN FA OVERNIGHT WED AS WEAK DYNAMICS
ADD TO THE TERRAIN LIFTING...SQUEEZING OUT LIGHT SNOW MAINLY FROM
THURSDAY MORNING ONWARD. WITH BEST CHCS LATER IN THE AFTERNOON AND
INTO THE THURSDAY EVENING PERIOD. THIS INITIAL DISTURBANCE  (BEFORE
THE STRONGER WEEKEND VERSION) CONTINUES TO LOOK FAIRLY PUNY OVERALL
WITH LIMITED MOISTURE AND DYNAMICS ABLE TO ADD TO THE OROGRAPHIC
FORCING. THAT SAID...THE WRN MOUNTAINS COULD SEE WIDESPREAD 1 TO 4
INCHES OF NEW SNOWFALL BY FRIDAY MORNING...VALLEYS A TRACE TO AN
INCH...BEFORE THE ATMOSPHERE DRIES OUT A BIT AHEAD OF A BETTER
INFLUX OF MOISTURE FRIDAY NIGHT...LEADING TOWARD A BETTER SNOW-MAKER
LATER ON SATURDAY. ADDITIONALLY...WINDS FROM THE W TO THE SW SHOULD
ONCE AGAIN BEGIN TO PICK-UP ACROSS THE USUAL ZONES...ABSAROKAS AND
ADJACENT FOOTHILLS AND FROM SOUTH PASS TO CASPER BY LATER AFTERNOON
FRIDAY AND OVERNIGHT. SOME MODEST MOUNTAIN WAVE ACTION AND
TURBULENCE IS EXPECTED WITH THIS SET-UP ESPECIALLY OVER AND EAST OF
THE ABSAROKA MOUNTAINS...HOWEVER THIS WILL LIKELY NOT BE A HIGHLIGHT
SITUATION.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

A SHORTWAVE TROUGH AND ASSOCIATED PACIFIC COLD FRONT WILL PUSH
QUICKLY EAST ACROSS THE NORTHERN ROCKIES SATURDAY AND SATURDAY
EVENING. THE STRONG 160KT PACIFIC JET IS PROGGED A BIT FARTHER SOUTH
OVER THE WEST...WITH THE FORECAST AREA NOT BEING AS IMPACTED WITH
THE FAVORABLE DYNAMICS ASSOCIATED WITH THE LEFT FRONT QUAD.
DESPITE THAT...SYNOPTIC LIFT FROM THE SHORTWAVE TROUGH...A MOIST
WESTERLY FLOW AND A FRONTAL BOUNDARY SHOULD ALL COMBINE FOR A
SIGNIFICANT SNOW AND WIND EVENT OVER THE WEST...AND POSSIBLY A
HIGH WIND EVENT IN THE ROCK SPRINGS TO CASPER WIND CORRIDOR. SNOW
AMOUNTS FROM LATE FRIDAY NIGHT THROUGH SATURDAY EVENING LOOK TO BE
IN THE LOW END ADVISORY AMOUNTS AT THIS TIME...BUT ADD THE STRONG
WIND AND THIS EVENT WILL PROBABLY WARRANT ADVISORIES OVER MUCH OF
THE WEST...WITH THE TETONS POSSIBLY REACHING WARNING CRITERIA.
ENOUGH WARM AIR COULD BE PULLED NORTHWARD THAT SNOW IN THE LOWER
ELEVATIONS COULD BRIEFLY CHANGE TO RAIN MIDDAY SATURDAY...BEFORE
SWITCHING BACK TO SNOW. THIS WOULD PRIMARILY BE A CONCERN FOR STAR
VALLEY. EAST OF THE DIVIDE...STRONG DOWNSLOPING AHEAD OF THE FRONT
WILL KEEP THINGS DRY. ALONG AND BEHIND THE COLD FRONT...SOME
PRECIPITATION IS EXPECTED TO SPILL EAST OF THE DIVIDE...MAINLY
OVER THE NORTH AND NORTHEAST...BUT AMOUNTS SHOULD REMAIN LIGHT.

IN WAKE OF THIS STORM SYSTEM SATURDAY...MEDIUM RANGE MODELS ARE IN
GOOD AGREEMENT WITH A LONGWAVE TROUGH FORMING AND REMAINING OVER THE
CENTRAL/EASTERN U.S. EARLY NEXT WEEK. ACROSS THE FORECAST
AREA...THIS WILL KEEP A STRONG...MOIST NORTHWEST FLOW THROUGH AT
LEAST TUESDAY...WHICH WILL KEEP GOOD CHANCES OF ACCUMULATING SNOW
OVER THE NORTHWEST AND NORTHERN MOUNTAINS. DISTURBANCES IN THE FLOW
WILL ALLOW FOR FOR THIS ACTIVITY TO OCCASIONAL PUSH INTO THE LOWER
ELEVATIONS. ALSO WINDY TO VERY CONDITIONS WILL CONTINUE AT TIMES.

MODELS THEN DIVERGE SIGNIFICANTLY FOR WEDNESDAY INTO
THANKSGIVING...AS THE ECMWF AND SEVERAL GFS ENSEMBLES SHOW A STORM
SYSTEM...AND ASSOCIATED ARCTIC COLD FRONT DROPPING OUT OF
CANADA...AND IMPACTING THE AREA WEDNESDAY INTO THANKSGIVING. THE
OPERATIONAL 00Z GFS...AND SOME OF ITS ENSEMBLES BUILD UP A RIDGE FOR
A VERY NICE THANKSGIVING.  ON THANKSGIVING MORNING...THE GFS HAS 700
MB TEMPS OVER KRIW AROUND +4C WITH MAINLY DRY CONDITIONS...WHILE THE
ECMWF HAS -17C WITH AN ONGOING SNOW STORM OVER MUCH OF THE AREA.

TEMPERATURES ARE EXPECTED TO BE ABOVE AVERAGE AHEAD OF THE FRONT
SATURDAY...WITH SEASONAL TO SLIGHTLY BELOW AVERAGE TEMPS EARLY
NEXT WEEK. THE PACIFIC NATURE OF THIS COLD FRONT WILL KEEP
TEMPERATURES...MUCH WARMER THAN WHAT OCCURRED IN WAKE OF THE
ARCTIC COLD FRONT ON NOVEMBER 9 AND 10TH. ALSO...BREEZY
WEST/NORTHWEST WINDS SHOULD ALSO KEEP THE BASINS/VALLEYS FROM
GETTING TOO TRAPPED UNDER A STRONG SFC INVERSION.

&&

.AVIATION.../12Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. LOCAL AREAS OF FOG
OR LOW CLOUDS MAY OCCUR THIS MORNING IN THE FAR WEST VALLEYS...
INCLUDING THE AFTON AND JACKSON AIRPORTS. THUS AREAS OF MVFR/IFR
CONDITIONS ARE EXPECTED UNTIL 18Z. THE CURRENT JACKSON TERMINAL
FORECAST HAS VCNTY FOG BUT KEEPS VFR CONDITIONS. WILL MONITOR AND
AMEND FORECAST AS NEEDED AT KJAC AIRPORT.

&&

.FIRE WEATHER...

FIRE DANGER LOW AND REMAINING LOW THROUGH THE REST OF THE WORK WEEK
AS SNOW COVER OR MINIMUM RH VALUES STAY WELL ABOVE CRITICAL LEVELS.
INVERSIONS WILL LIFT SOME AGAIN TODAY...BUT NOT BREAK...STARTING OUT
NEAR SURFACE THIS MORNING BEFORE REACHING 500 TO 1500 FEET FOR MOST
LOCATIONS BY THE MIDDLE OF THE DAY. THE WESTERN VALLEYS/BASINS WILL
STAND THE BEST CHANCE AT BREAKING THE INVERSION FOR A SHORT PERIOD.
MOISTURE WILL BEGIN TO INCREASE ACROSS THE WEST LATER TONIGHT WITH
LIGHT AREAS OF SNOW BECOMING POSSIBLE OVER THE WESTERN FORECAST
ZONES ON THURSDAY. HIGH PROBABILITY PRECIP/SNOW CHANCES WILL ARRIVE OUT
WEST THIS WEEKEND...WITH LOWER CHANCES FOR SNOW BECOMING POSSIBLE
ACROSS THE EASTERN FORECAST ZONES LATER ON SATURDAY.

&&

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

&&

$$

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








000
FXUS65 KRIW 190526
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1026 PM MST TUE NOV 18 2014

.SHORT TERM...TONIGHT THROUGH WEDNESDAY (ISSUED AT 107 PM MST)

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE AREAS OF LOW STRATUS CLOUDS AND FOG
WITH GENERALLY LIGHT WINDS.  THE MIXED AREAS WILL BE 20 TO 30
DEGREES WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES...WITH
SIGNIFICANTLY LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. THE
NORTHERN MOUNTAINS CAN EXPECT SOME VERY LIGHT SNOW THIS EVENING...
OTHERWISE DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

AN AMPLIFYING RIDGE OF HIGH PRESSURE WILL START OFF THE FORECAST
PERIOD. A WAVE OF LOW PRESSURE WILL MOVE EAST OVER THE PACIFIC
COASTLINE WEDNESDAY...AND MODELS CONTINUE TO INDICATE THAT THIS
SYSTEM WILL SPLIT AS IT ADVANCES TOWARDS THE INTERMOUNTAIN WEST.
THE NORTHERN PORTION OF THIS SYSTEM MAY BRING WEAK AMOUNTS OF
MOISTURE FOR AREAS WEST OF THE CONTINENTAL DIVIDE BY LATE WEDNESDAY
NIGHT AND INTO THURSDAY MORNING. THESE SHOWERS ARE NOT EXPECTED TO
BE SIGNIFICANT.

A STRONGER PUSH OF MOISTURE WILL MOVE OVER THE INTERMOUNTAIN WEST ON
SATURDAY...WITH INCREASING SHOWER ACTIVITY EXPECTED OVER THE WESTERN
MOUNTAINS AND VALLEYS. THE WAVE OF LOW PRESSURE ASSOCIATED WITH THIS
SYSTEM WILL CONTINUE ITS EASTWARD PROGRESSION...AND WILL INCREASE
COVERAGE ACROSS WESTERN WYOMING...WITH SHOWERS SPILLING OVER TO THE
EAST SIDE OF THE DIVIDE BY SATURDAY EVENING.

SHOWERS WILL CONTINUE EVEN AS THIS SYSTEM MOVES EAST OF THE FORECAST
AREA ON SUNDAY. A MOIST NORTHWEST FLOW WILL DEVELOP OVER THE AREA
HIGH PRESSURE ATTEMPTS TO BUILD OVER THE WESTERN HALF OF THE UNITED
STATES. A BRIEF REPRIEVE FROM SHOWERS MAY BE FOUND LATE MONDAY...BUT
WILL BE SHORT LIVED AS ANOTHER...POTENTIALLY POTENT SLUG OF MOISTURE
MOVES INTO THE WEST BY LATE MONDAY NIGHT. THIS MOISTURE WILL AGAIN
SPREAD ACROSS THE FORECAST AREA THROUGH TUESDAY.

A GENERAL WARMING TREND IS ANTICIPATED THROUGH SATURDAY...WITH A
RETURN OF COLDER AIR EXPECTED SUNDAY AND INTO THE EARLY PORTION OF
THE WORK WEEK.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. LOCAL AREAS OF FOG
OR LOW CLOUDS MAY OCCUR OVERNIGHT INTO WEDNESDAY MORNING IN THE FAR
WEST VALLEYS...INCLUDING THE AFTON AND JACKSON AIRPORTS. THUS AREAS
OF MVFR/IFR CONDITIONS ARE EXPECTED UNTIL 18Z. THE CURRENT JACKSON
TERMINAL FORECAST HAS VCNTY FOG BUT KEEPS VFR CONDITIONS. WILL
MONITOR AND AMEND FORECAST AS NEEDED AT KJAC AIRPORT.

&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE AREAS OF LOW STRATUS CLOUDS AND FOG
WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND POOR
SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES WARMER THAN
THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY LOWER
RELATIVE HUMIDITY AND STRONG GUSTY WINDS. THE NORTHERN MOUNTAINS
CAN EXPECT SOME VERY LIGHT SNOW... OTHERWISE DRY CONDITIONS WILL
PREVAIL.

&&

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

$$

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













000
FXUS65 KRIW 190526
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1026 PM MST TUE NOV 18 2014

.SHORT TERM...TONIGHT THROUGH WEDNESDAY (ISSUED AT 107 PM MST)

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE AREAS OF LOW STRATUS CLOUDS AND FOG
WITH GENERALLY LIGHT WINDS.  THE MIXED AREAS WILL BE 20 TO 30
DEGREES WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES...WITH
SIGNIFICANTLY LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. THE
NORTHERN MOUNTAINS CAN EXPECT SOME VERY LIGHT SNOW THIS EVENING...
OTHERWISE DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

AN AMPLIFYING RIDGE OF HIGH PRESSURE WILL START OFF THE FORECAST
PERIOD. A WAVE OF LOW PRESSURE WILL MOVE EAST OVER THE PACIFIC
COASTLINE WEDNESDAY...AND MODELS CONTINUE TO INDICATE THAT THIS
SYSTEM WILL SPLIT AS IT ADVANCES TOWARDS THE INTERMOUNTAIN WEST.
THE NORTHERN PORTION OF THIS SYSTEM MAY BRING WEAK AMOUNTS OF
MOISTURE FOR AREAS WEST OF THE CONTINENTAL DIVIDE BY LATE WEDNESDAY
NIGHT AND INTO THURSDAY MORNING. THESE SHOWERS ARE NOT EXPECTED TO
BE SIGNIFICANT.

A STRONGER PUSH OF MOISTURE WILL MOVE OVER THE INTERMOUNTAIN WEST ON
SATURDAY...WITH INCREASING SHOWER ACTIVITY EXPECTED OVER THE WESTERN
MOUNTAINS AND VALLEYS. THE WAVE OF LOW PRESSURE ASSOCIATED WITH THIS
SYSTEM WILL CONTINUE ITS EASTWARD PROGRESSION...AND WILL INCREASE
COVERAGE ACROSS WESTERN WYOMING...WITH SHOWERS SPILLING OVER TO THE
EAST SIDE OF THE DIVIDE BY SATURDAY EVENING.

SHOWERS WILL CONTINUE EVEN AS THIS SYSTEM MOVES EAST OF THE FORECAST
AREA ON SUNDAY. A MOIST NORTHWEST FLOW WILL DEVELOP OVER THE AREA
HIGH PRESSURE ATTEMPTS TO BUILD OVER THE WESTERN HALF OF THE UNITED
STATES. A BRIEF REPRIEVE FROM SHOWERS MAY BE FOUND LATE MONDAY...BUT
WILL BE SHORT LIVED AS ANOTHER...POTENTIALLY POTENT SLUG OF MOISTURE
MOVES INTO THE WEST BY LATE MONDAY NIGHT. THIS MOISTURE WILL AGAIN
SPREAD ACROSS THE FORECAST AREA THROUGH TUESDAY.

A GENERAL WARMING TREND IS ANTICIPATED THROUGH SATURDAY...WITH A
RETURN OF COLDER AIR EXPECTED SUNDAY AND INTO THE EARLY PORTION OF
THE WORK WEEK.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. LOCAL AREAS OF FOG
OR LOW CLOUDS MAY OCCUR OVERNIGHT INTO WEDNESDAY MORNING IN THE FAR
WEST VALLEYS...INCLUDING THE AFTON AND JACKSON AIRPORTS. THUS AREAS
OF MVFR/IFR CONDITIONS ARE EXPECTED UNTIL 18Z. THE CURRENT JACKSON
TERMINAL FORECAST HAS VCNTY FOG BUT KEEPS VFR CONDITIONS. WILL
MONITOR AND AMEND FORECAST AS NEEDED AT KJAC AIRPORT.

&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE AREAS OF LOW STRATUS CLOUDS AND FOG
WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND POOR
SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES WARMER THAN
THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY LOWER
RELATIVE HUMIDITY AND STRONG GUSTY WINDS. THE NORTHERN MOUNTAINS
CAN EXPECT SOME VERY LIGHT SNOW... OTHERWISE DRY CONDITIONS WILL
PREVAIL.

&&

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

$$

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












000
FXUS65 KRIW 182007
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
107 PM MST TUE NOV 18 2014

.SHORT TERM...TONIGHT THROUGH WEDNESDAY

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE AREAS OF LOW STRATUS CLOUDS AND FOG
WITH GENERALLY LIGHT WINDS.  THE MIXED AREAS WILL BE 20 TO 30
DEGREES WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES...WITH
SIGNIFICANTLY LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. THE
NORTHERN MOUNTAINS CAN EXPECT SOME VERY LIGHT SNOW THIS EVENING...
OTHERWISE DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

AN AMPLIFYING RIDGE OF HIGH PRESSURE WILL START OFF THE FORECAST
PERIOD. A WAVE OF LOW PRESSURE WILL MOVE EAST OVER THE PACIFIC
COASTLINE WEDNESDAY...AND MODELS CONTINUE TO INDICATE THAT THIS
SYSTEM WILL SPLIT AS IT ADVANCES TOWARDS THE INTERMOUNTAIN WEST.
THE NORTHERN PORTION OF THIS SYSTEM MAY BRING WEAK AMOUNTS OF
MOISTURE FOR AREAS WEST OF THE CONTINENTAL DIVIDE BY LATE WEDNESDAY
NIGHT AND INTO THURSDAY MORNING. THESE SHOWERS ARE NOT EXPECTED TO
BE SIGNIFICANT.

A STRONGER PUSH OF MOISTURE WILL MOVE OVER THE INTERMOUNTAIN WEST ON
SATURDAY...WITH INCREASING SHOWER ACTIVITY EXPECTED OVER THE WESTERN
MOUNTAINS AND VALLEYS. THE WAVE OF LOW PRESSURE ASSOCIATED WITH THIS
SYSTEM WILL CONTINUE ITS EASTWARD PROGRESSION...AND WILL INCREASE
COVERAGE ACROSS WESTERN WYOMING...WITH SHOWERS SPILLING OVER TO THE
EAST SIDE OF THE DIVIDE BY SATURDAY EVENING.

SHOWERS WILL CONTINUE EVEN AS THIS SYSTEM MOVES EAST OF THE FORECAST
AREA ON SUNDAY. A MOIST NORTHWEST FLOW WILL DEVELOP OVER THE AREA
HIGH PRESSURE ATTEMPTS TO BUILD OVER THE WESTERN HALF OF THE UNITED
STATES. A BRIEF REPRIEVE FROM SHOWERS MAY BE FOUND LATE MONDAY...BUT
WILL BE SHORT LIVED AS ANOTHER...POTENTIALLY POTENT SLUG OF MOISTURE
MOVES INTO THE WEST BY LATE MONDAY NIGHT. THIS MOISTURE WILL AGAIN
SPREAD ACROSS THE FORECAST AREA THROUGH TUESDAY.

A GENERAL WARMING TREND IS ANTICIPATED THROUGH SATURDAY...WITH A
RETURN OF COLDER AIR EXPECTED SUNDAY AND INTO THE EARLY PORTION OF
THE WORK WEEK.

&&

.AVIATION.../00Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH 00Z THURSDAY AT THE AIRPORTS WITH
THE EXCEPTION OF KJAC AND KAFO WHERE LOW STRATUS AND AREAS OF FOG
WILL PERSIST IN THE VICINITY WITH PERIODS OF MVFR TO IFR CEILINGS
AND VISIBILITIES.

LOW LYING AREAS IN THE VALLEYS AND BASINS OF WESTERN AND CENTRAL
WYOMING WILL ALSO SEE AREAS OF LOW STRATUS AND PATCHY FOG...
ESPECIALLY ALONG RIVERS AND RESERVOIRS. BREEZY TO WINDY CONDITIONS
WILL OCCUR TODAY INTO THIS EVENING IN THE FAVORED WIND LOCATIONS...
INCLUDING VICINITY OF KCOD...AND FROM VICINITY OF KCPR TO KRKS.

&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE AREAS OF LOW STRATUS CLOUDS AND FOG
WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND POOR
SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES WARMER THAN
THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY LOWER
RELATIVE HUMIDITY AND STRONG GUSTY WINDS. THE NORTHERN MOUNTAINS
CAN EXPECT SOME VERY LIGHT SNOW... OTHERWISE DRY CONDITIONS WILL
PREVAIL.

&&

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

$$

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









000
FXUS65 KRIW 182007
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
107 PM MST TUE NOV 18 2014

.SHORT TERM...TONIGHT THROUGH WEDNESDAY

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE AREAS OF LOW STRATUS CLOUDS AND FOG
WITH GENERALLY LIGHT WINDS.  THE MIXED AREAS WILL BE 20 TO 30
DEGREES WARMER THAN THE TRAPPED VALLEYS AND BASINS AT TIMES...WITH
SIGNIFICANTLY LOWER RELATIVE HUMIDITY AND STRONG GUSTY WINDS. THE
NORTHERN MOUNTAINS CAN EXPECT SOME VERY LIGHT SNOW THIS EVENING...
OTHERWISE DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

AN AMPLIFYING RIDGE OF HIGH PRESSURE WILL START OFF THE FORECAST
PERIOD. A WAVE OF LOW PRESSURE WILL MOVE EAST OVER THE PACIFIC
COASTLINE WEDNESDAY...AND MODELS CONTINUE TO INDICATE THAT THIS
SYSTEM WILL SPLIT AS IT ADVANCES TOWARDS THE INTERMOUNTAIN WEST.
THE NORTHERN PORTION OF THIS SYSTEM MAY BRING WEAK AMOUNTS OF
MOISTURE FOR AREAS WEST OF THE CONTINENTAL DIVIDE BY LATE WEDNESDAY
NIGHT AND INTO THURSDAY MORNING. THESE SHOWERS ARE NOT EXPECTED TO
BE SIGNIFICANT.

A STRONGER PUSH OF MOISTURE WILL MOVE OVER THE INTERMOUNTAIN WEST ON
SATURDAY...WITH INCREASING SHOWER ACTIVITY EXPECTED OVER THE WESTERN
MOUNTAINS AND VALLEYS. THE WAVE OF LOW PRESSURE ASSOCIATED WITH THIS
SYSTEM WILL CONTINUE ITS EASTWARD PROGRESSION...AND WILL INCREASE
COVERAGE ACROSS WESTERN WYOMING...WITH SHOWERS SPILLING OVER TO THE
EAST SIDE OF THE DIVIDE BY SATURDAY EVENING.

SHOWERS WILL CONTINUE EVEN AS THIS SYSTEM MOVES EAST OF THE FORECAST
AREA ON SUNDAY. A MOIST NORTHWEST FLOW WILL DEVELOP OVER THE AREA
HIGH PRESSURE ATTEMPTS TO BUILD OVER THE WESTERN HALF OF THE UNITED
STATES. A BRIEF REPRIEVE FROM SHOWERS MAY BE FOUND LATE MONDAY...BUT
WILL BE SHORT LIVED AS ANOTHER...POTENTIALLY POTENT SLUG OF MOISTURE
MOVES INTO THE WEST BY LATE MONDAY NIGHT. THIS MOISTURE WILL AGAIN
SPREAD ACROSS THE FORECAST AREA THROUGH TUESDAY.

A GENERAL WARMING TREND IS ANTICIPATED THROUGH SATURDAY...WITH A
RETURN OF COLDER AIR EXPECTED SUNDAY AND INTO THE EARLY PORTION OF
THE WORK WEEK.

&&

.AVIATION.../00Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH 00Z THURSDAY AT THE AIRPORTS WITH
THE EXCEPTION OF KJAC AND KAFO WHERE LOW STRATUS AND AREAS OF FOG
WILL PERSIST IN THE VICINITY WITH PERIODS OF MVFR TO IFR CEILINGS
AND VISIBILITIES.

LOW LYING AREAS IN THE VALLEYS AND BASINS OF WESTERN AND CENTRAL
WYOMING WILL ALSO SEE AREAS OF LOW STRATUS AND PATCHY FOG...
ESPECIALLY ALONG RIVERS AND RESERVOIRS. BREEZY TO WINDY CONDITIONS
WILL OCCUR TODAY INTO THIS EVENING IN THE FAVORED WIND LOCATIONS...
INCLUDING VICINITY OF KCOD...AND FROM VICINITY OF KCPR TO KRKS.

&&

.FIRE WEATHER...

NORTH NORTHWEST FLOW ALOFT WILL CONTINUE TO BRING AREAS OF MID AND
UPPER LEVEL CLOUD COVER TO WESTERN AND CENTRAL WYOMING.  AREAS IMPACTED
BY STRONG INVERSIONS ARE GRADUALLY DECREASING WITH STRONG TEMPERATURE
AND WIND GRADIENTS EXISTING BOTH HORIZONTALLY AND VERTICALLY. THE COLDER
TRAPPED AREAS WILL CONTINUE TO SEE AREAS OF LOW STRATUS CLOUDS AND FOG
WITH GENERALLY LIGHT WINDS AND VERY LOW MIXING HEIGHTS AND POOR
SMOKE DISPERSAL. THE MIXED AREAS WILL BE 20 TO 30 DEGREES WARMER THAN
THE TRAPPED VALLEYS AND BASINS AT TIMES WITH SIGNIFICANTLY LOWER
RELATIVE HUMIDITY AND STRONG GUSTY WINDS. THE NORTHERN MOUNTAINS
CAN EXPECT SOME VERY LIGHT SNOW... OTHERWISE DRY CONDITIONS WILL
PREVAIL.

&&

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

$$

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










000
FXUS65 KRIW 181731
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1031 AM MST TUE NOV 18 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

WV IMAGERY SHOWS LONGWAVE TROF ACROSS MOST OF THE CONUS...SAVE THE
WEST COAST UNDER AN AMPLIFIED RIDGE...WITH CENTER OF CLOSED LOW
ROTATING AROUND THE NRN GREAT LAKES AND ANOTHER SWIFT MOVING SW/JET
STREAK OVR SWRN CANADA MOVING S INTO NRN INTERMOUNTAIN REGION. AT
THE SFC...LEFT OVER STATIONARY FRONT STILL EXTENDS ACROSS NERN WY...
UP THRU CNTRL MT. SFC COLD POOL CONTINUES OVR THE FA TO THE WEST OF
THE STATIONARY FRONT UNDER MOSTLY CLEAR SKIES AND CONTINUING HIGH
PRESSURE...WITH A BULLSEYE ONCE AGAIN OVR THE BIGHORN BASIN.

MODEST WARM ADVECTION CONTINUES ACROSS MOST OF THE CWA WITH SLOW
WARMING THRU THE FCST PERIOD. OTHERWISE...THE FCST WILL BE MOSTLY
DRY THRU THE DAY WED WITH THE EXCEPTION OF LIGHT SNOW ACROSS THE
HIGHER PEAKS OF THE BIGHORN MOUNTAINS ACCOMPANYING A FLY-BY ANOTHER
CLIPPER FRONT LATER TODAY. BRISK NW WINDS WILL ONCE AGAIN PUSH INTO
NRN JOHNSON COUNTY TODAY...WITH INCREASED WEST WIND AHEAD OF THE
FRONT BETWEEN SWEETWATER AND NATRONA COUNTIES.
ADDITIONALLY...INCREASING NWRLY MID/UPR LVL WIND ASSOCIATED WITH THE
APPROACHING JET STREAK MOVING OUT OF CANADA TODAY WILL REACT WITH AN
INCREASING THERMO/OMEGA GRAD BETWEEN THE FOOTHILLS AND MOUNTAINS OF
NRN AND CNTRL WY TO GIVE QUITE GUSTY SFC WIND CONDITIONS THIS
AFTERNOON FROM AROUND NOON TO THE EARLY EVENING PERIOD OVR THE WRN
WIND RIVER MOUNTAINS TO THE NORTH OVR THE ABSAROKA CHAIN. MOUNTAIN
WAVE PRODUCTION LOOKS TO REMAIN RELATIVELY LOW AS WIND DIRECTION IS
NOT IDEAL. HOWEVER...SOME AREAS COULD APPROACH MIN WARNING
CONDITIONS FOR AN HR OR TWO OVR/NEAR THE USUAL SUSPECTS INCLUDING
CHIEF JOSEPH AND CLARK AT THE LOWER ELEVATIONS. WINDS WILL BE CONDUCIVE IN
THIS CASE IN GETTING INTO CODY...BLOWING 20 TO 30 MPH WITH GUSTS TO
40 MPH POSSIBLE. SAME THING FOR THE DUBOIS/CROWHEART AREA IN
WESTERN FREMONT COUNTY. THE SNOWPACK TODAY SHOULD BE MORE MORE
STABLE AND ICE CRUSTED AND NOT NEARLY AS DRY AND LOOSE AS THE
PREVIOUS FEW DAYS...FOREGOING THE NEED FOR ANOTHER WSW/BLOWING
SNOW SITUATION. HOWEVER...AS ALLUDED TO WITH THE WIND FCST
ABOVE...THE HIGHER MOUNTAIN PEAKS MAY EXPERIENCE BLOWING SNOW
CONDITIONS THIS AFTERNOON.

WED...THE STRONGER JET FLOW SUBSIDES ALONG WITH THE GUSTIER SFC
WINDS OF TODAY AS WEST COAST RIDGE APPROACHES THE STATE FROM THE
WEST. ALSO...A MODEST INFLUX OF MID LVL MOISTURE WILL TOP THE RIDGE
AND BEGIN TO INFILTRATE THE REGION...OFFERING UP A LOW END CHC
FOR SOME ISOLATED MAINLY TERRAIN FORCED LIGHT SNOW ACROSS THE
WRN/NWRN MOUNTAINS WED NIGHT.

THU...MODEST UPR RIDGING CONTINUES ACROSS WY...CHASED CLOSELY BY THE
NEXT SW TROF COMING FROM THE EPAC...BRINGING SOME INCREASED BUT
MODEST MOISTURE ALONG WITH IT. PRECIP CHANCES WILL INCREASE SOME
ACCORDINGLY ACROSS THE WRN FA AS MARGINAL DYNAMICS ADD TO THE
TERRAIN LIFTING...SQUEEZING OUT SOME LIGHT SNOW...ESPECIALLY LATER
IN THE AFTERNOON AND LASTING THRU THE EVENING PERIOD. ATTM...THIS
INITIAL DISTURBANCE (BEFORE THE WEEKEND VERSION) IS NOT ALL THAT
IMPRESSIVE LOOKING INASMUCH AS QPF OR SNOWFALL POTENTIAL THROUGH THE
END OF THIS FCST PERIOD AS DEEP MOISTURE AND COLD TEMPS ALONG WITH
IMPRESSIVE DYNAMICS APPEAR TO BE SOMEWHAT LACKING. THAT SAID...THE
WRN MOUNTAINS STILL COULD SEE WIDESPREAD 2 TO 4 INCHES OF NEW
SNOWFALL BY FRIDAY MORNING WITH THE HIGHER PEAKS RECEIVING 3 TO 6
INCHES. THE VALLEYS GENERALLY LOOK TO STAY IN THE HALF INCH TO 2
INCH CATEGORY.

.LONG TERM...FRIDAY THROUGH TUESDAY

A STRONG STORM SYSTEM POSSIBLE SATURDAY WITH SIGNIFICANT SNOW AND
WIND WEST...AND STRONG/HIGH WIND EAST.

FRIDAY LOOKS TO BE THE PROVERBIAL CALM BEFORE THE STORM...WITH SOME
LIGHT SNOW/FLURRIES OVER THE FAR WEST...WITH TEMPERATURES SEASONAL
TO SLIGHTLY BELOW AVERAGE. THE EXCEPTION COULD BE THE EASTERN
BIGHORN BASIN WHERE THE ARCTIC AIR MASS OVER THE PAST WEEK COULD
HANG TOUGH...WHERE TEMPS COULD REMAIN AROUND 10 DEGREES BELOW
AVERAGE. HOWEVER THIS IS THE FAR CRY FROM THE 30 TO 50 DEGREES
BELOW AVERAGE OVER THE PAST SEVERAL DAYS.

AHEAD OF THE STORM SYSTEM SATURDAY...MODELS ARE SHOWING A MOIST
ISENTROPIC UPGLIDE PATTERN DEVELOPING BETWEEN 06Z AND 12Z. THIS
SHOULD RESULT IN WIDESPREAD SNOWFALL DEVELOPING OVER THE FAR WEST
AFTER MIDNIGHT FRIDAY NIGHT. THE QUICK MOVING SHORTWAVE TROUGH AND
THE ASSOCIATED PACIFIC COLD FRONT IN THE FAST WESTERLY FLOW IS
EXPECTED TO PUSH ACROSS THE FORECAST AREA SATURDAY AFTERNOON AND
EVENING. THE SYNOPTIC LIFT ASSOCIATED WITH THE SHORTWAVE AND
BAROCLINIC ZONE/FRONT COULD BE ENHANCED BY THE LEFT FRONT QUAD OF A
150+ KT UPPER JET SATURDAY. WINTER HIGHLIGHTS APPEAR MORE LIKELY
OVER PORTIONS OF THE WEST FROM LATE FRIDAY NIGHT THROUGH SUNDAY TIME
FRAME...WITH THE MAIN IMPACT PROBABLY SATURDAY. TO COMPLICATE
MATTERS A BIT...MODELS ARE HINTING ENOUGH WARM AIR COULD BE PULLED
NORTHWARD TO HAVE THE SNOW CHANGE TO RAIN MIDDAY SATURDAY ACROSS THE
WESTERN VALLEYS ESPECIALLY STAR VALLEY. HOWEVER THIS WOULD BE SHORT
LIVED...WITH A CHANGE BACK TO SNOW IN WAKE OF THE COLD FRONT
SATURDAY AFTERNOON. WHILE SIGNIFICANT SNOWFALL/WIND COULD BE
OCCURRING OVER THE WEST SATURDAY...A STRONG SURFACE PRESSURE
GRADIENT AND 700MB WEST WINDS AROUND 50 KTS WILL PROBABLY RESULT
IN VERY STRONG TO HIGH WIND ESPECIALLY IN RKS TO CPR WIND CORRIDOR
SATURDAY. COULD ALSO SEE SOME STRONG WIND IN THE CODY FOOTHILLS
LATE FRIDAY NIGHT INTO SATURDAY WITH SOME MOUNTAIN WAVE POTENTIAL
AND STRONG GAP FLOW FROM A STRONG TEMP GRADIENT BETWEEN
YELLOWSTONE AND THE CODY FOOTHILLS. STRONG DOWNSLOPING SATURDAY
EAST OF THE DIVIDE WILL KEEP THOSE AREAS MAINLY DRY...BUT COULD
SEE SOME PRECIPITATION ALONG AND IN WAKE OF THE FRONT.

ALTHOUGH THE MAIN SYSTEM WILL BE EAST OF THE AREA SUNDAY...THE
FORECAST AREA WILL REMAIN ON THE CYCLONIC SIDE OF THE JET WITH A
RELATIVELY UNSTABLE ATMOSPHERE FOR NOVEMBER. THIS SHOULD RESULT IN
ISOLATED TO SCATTERED SNOW SHOWERS...WITH MORE SNOW SHOWER ACTIVITY
OVER THE NORTHWEST AND NORTHERN MOUNTAINS WHICH FAVOR A MOIST
NORTHWEST FLOW. THIS PATTERN CONTINUES INTO MONDAY...BUT WITH A
MORE STABLE ENVIRONMENT FOR MONDAY. THUS WILL DECREASE POPS A
BIT...BUT STILL KEEP CHANCE POPS FOR THE NORTHWEST/NORTHERN
MOUNTAINS.

A RELATIVELY MOIST NORTHWEST FLOW CONTINUES TUESDAY...BUT THE AREA
WILL BE ON THE ANTICYCLONIC SIDE OF THE UPPER JET WHICH SHOULD
RESULT IN EVEN LESS SNOW SHOWER ACTIVITY.

DUE TO THE PACIFIC NATURE OF THIS SYSTEM...THE AIR MASS IN WAKE OF
THIS COLD FRONT SATURDAY/SATURDAY NIGHT WILL NOT BE NEARLY AS COLD
AS THE ARCTIC AIR MASS THAT HAS IMPACTED THE REGION FOR THE PAST
WEEK.

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH 18Z WEDNESDAY AT THE AIRPORTS
WITH THE EXCEPTION OF KJAC AND KAFO WHERE LOW STRATUS AND AREAS
OF FOG WILL PERSIST IN THE VICINITY WITH PERIODS OF MVFR TO IFR
CEILINGS AND VISIBILITIES.

LOW LYING AREAS IN THE VALLEYS AND BASINS OF WESTERN AND CENTRAL
 WYOMING WILL ALSO SEE AREAS OF LOW STRATUS AND PATCHY
FOG...ESPECIALLY ALONG RIVERS AND RESERVOIRS.  BREEZY TO WINDY
CONDITIONS WILL OCCUR TODAY INTO THIS EVENING IN THE FAVORED WIND
LOCATIONS...INCLUDING VICINITY OF KCOD...AND FROM VICINITY OF KCPR
TO KRKS.

.FIRE WEATHER...

FIRE DANGER LOW AND REMAINING LOW THROUGH THE REST OF THE WORK WEEK
AS SNOW COVER OR MINIMUM RH VALUES STAY WELL ABOVE CRITICAL LEVELS.
HOWEVER...BRISK WEST TO NORTHWEST WINDS WILL BE PREVALENT TODAY
ACROSS THE EASTERN ZONES AND OVER THE NORTHERN AND CENTRAL MOUNTAINS AS
ANOTHER CLIPPER FRONT APPROACHES NORTHEASTERN WYOMING THIS
AFTERNOON. INVERSIONS WILL LIFT SOME TODAY...BUT NOT BREAK FOR MOST
LOCATIONS...REMAINING AT OR BELOW 1500 FEET FOR MOST LOCATIONS IN
THE MIDDLE OF THE DAY...AND A FEW LOCATIONS NOT RISING MORE THAN A
FEW HUNDRED FEET. WINDS WILL DECREASE TONIGHT WITH A NICE DAY ON
TAP FOR WEDNESDAY. CLOUDS AND MOISTURE BEGIN TO INCREASE ACROSS
THE WEST WEDNESDAY NIGHT WITH LIGHT AREAS OF SNOW INCREASING OVER
THE WESTERN FORECAST ZONES ON THURSDAY...LASTING ON AND OFF AGAIN
THROUGH THE WEEKEND.

&&

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

$$

SHORT TERM...BRAUN
LONG TERM...WM
AVIATION...C.BAKER
FIRE WEATHER...BRAUN










000
FXUS65 KRIW 181048
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
348 AM MST TUE NOV 18 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

WV IMAGERY SHOWS LONGWAVE TROF ACROSS MOST OF THE CONUS...SAVE THE
WEST COAST UNDER AN AMPLIFIED RIDGE...WITH CENTER OF CLOSED LOW
ROTATING AROUND THE NRN GREAT LAKES AND ANOTHER SWIFT MOVING SW/JET
STREAK OVR SWRN CANADA MOVING S INTO NRN INTERMOUNTAIN REGION. AT
THE SFC...LEFT OVER STATIONARY FRONT STILL EXTENDS ACROSS NERN WY...
UP THRU CNTRL MT. SFC COLD POOL CONTINUES OVR THE FA TO THE WEST OF
THE STATIONARY FRONT UNDER MOSTLY CLEAR SKIES AND CONTINUING HIGH
PRESSURE...WITH A BULLSEYE ONCE AGAIN OVR THE BIGHORN BASIN.

MODEST WARM ADVECTION CONTINUES ACROSS MOST OF THE CWA WITH SLOW
WARMING THRU THE FCST PERIOD. OTHERWISE...THE FCST WILL BE MOSTLY
DRY THRU THE DAY WED WITH THE EXCEPTION OF LIGHT SNOW ACROSS THE
HIGHER PEAKS OF THE BIGHORN MOUNTAINS ACCOMPANYING A FLY-BY ANOTHER
CLIPPER FRONT LATER TODAY. BRISK NW WINDS WILL ONCE AGAIN PUSH INTO
NRN JOHNSON COUNTY TODAY...WITH INCREASED WEST WIND AHEAD OF THE
FRONT BETWEEN SWEETWATER AND NATRONA COUNTIES.
ADDITIONALLY...INCREASING NWRLY MID/UPR LVL WIND ASSOCIATED WITH THE
APPROACHING JET STREAK MOVING OUT OF CANADA TODAY WILL REACT WITH AN
INCREASING THERMO/OMEGA GRAD BETWEEN THE FOOTHILLS AND MOUNTAINS OF
NRN AND CNTRL WY TO GIVE QUITE GUSTY SFC WIND CONDITIONS THIS
AFTERNOON FROM AROUND NOON TO THE EARLY EVENING PERIOD OVR THE WRN
WIND RIVER MOUNTAINS TO THE NORTH OVR THE ABSAROKA CHAIN. MOUNTAIN
WAVE PRODUCTION LOOKS TO REMAIN RELATIVELY LOW AS WIND DIRECTION IS
NOT IDEAL. HOWEVER...SOME AREAS COULD APPROACH MIN WARNING
CONDITIONS FOR AN HR OR TWO OVR/NEAR THE USUAL SUSPECTS INCLUDING
CHIEF JOSEPH AND CLARK AT THE LOWER ELEVATIONS. WINDS WILL BE CONDUCIVE IN
THIS CASE IN GETTING INTO CODY...BLOWING 20 TO 30 MPH WITH GUSTS TO
40 MPH POSSIBLE. SAME THING FOR THE DUBOIS/CROWHEART AREA IN
WESTERN FREMONT COUNTY. THE SNOWPACK TODAY SHOULD BE MORE MORE
STABLE AND ICE CRUSTED AND NOT NEARLY AS DRY AND LOOSE AS THE
PREVIOUS FEW DAYS...FOREGOING THE NEED FOR ANOTHER WSW/BLOWING
SNOW SITUATION. HOWEVER...AS ALLUDED TO WITH THE WIND FCST
ABOVE...THE HIGHER MOUNTAIN PEAKS MAY EXPERIENCE BLOWING SNOW
CONDITIONS THIS AFTERNOON.

WED...THE STRONGER JET FLOW SUBSIDES ALONG WITH THE GUSTIER SFC
WINDS OF TODAY AS WEST COAST RIDGE APPROACHES THE STATE FROM THE
WEST. ALSO...A MODEST INFLUX OF MID LVL MOISTURE WILL TOP THE RIDGE
AND BEGIN TO INFILTRATE THE REGION...OFFERING UP A LOW END CHC
FOR SOME ISOLATED MAINLY TERRAIN FORCED LIGHT SNOW ACROSS THE
WRN/NWRN MOUNTAINS WED NIGHT.

THU...MODEST UPR RIDGING CONTINUES ACROSS WY...CHASED CLOSELY BY THE
NEXT SW TROF COMING FROM THE EPAC...BRINGING SOME INCREASED BUT
MODEST MOISTURE ALONG WITH IT. PRECIP CHANCES WILL INCREASE SOME
ACCORDINGLY ACROSS THE WRN FA AS MARGINAL DYNAMICS ADD TO THE
TERRAIN LIFTING...SQUEEZING OUT SOME LIGHT SNOW...ESPECIALLY LATER
IN THE AFTERNOON AND LASTING THRU THE EVENING PERIOD. ATTM...THIS
INITIAL DISTURBANCE (BEFORE THE WEEKEND VERSION) IS NOT ALL THAT
IMPRESSIVE LOOKING INASMUCH AS QPF OR SNOWFALL POTENTIAL THROUGH THE
END OF THIS FCST PERIOD AS DEEP MOISTURE AND COLD TEMPS ALONG WITH
IMPRESSIVE DYNAMICS APPEAR TO BE SOMEWHAT LACKING. THAT SAID...THE
WRN MOUNTAINS STILL COULD SEE WIDESPREAD 2 TO 4 INCHES OF NEW
SNOWFALL BY FRIDAY MORNING WITH THE HIGHER PEAKS RECEIVING 3 TO 6
INCHES. THE VALLEYS GENERALLY LOOK TO STAY IN THE HALF INCH TO 2
INCH CATEGORY.

.LONG TERM...FRIDAY THROUGH TUESDAY

A STRONG STORM SYSTEM POSSIBLE SATURDAY WITH SIGNIFICANT SNOW AND
WIND WEST...AND STRONG/HIGH WIND EAST.

FRIDAY LOOKS TO BE THE PROVERBIAL CALM BEFORE THE STORM...WITH SOME
LIGHT SNOW/FLURRIES OVER THE FAR WEST...WITH TEMPERATURES SEASONAL
TO SLIGHTLY BELOW AVERAGE. THE EXCEPTION COULD BE THE EASTERN
BIGHORN BASIN WHERE THE ARCTIC AIR MASS OVER THE PAST WEEK COULD
HANG TOUGH...WHERE TEMPS COULD REMAIN AROUND 10 DEGREES BELOW
AVERAGE. HOWEVER THIS IS THE FAR CRY FROM THE 30 TO 50 DEGREES
BELOW AVERAGE OVER THE PAST SEVERAL DAYS.

AHEAD OF THE STORM SYSTEM SATURDAY...MODELS ARE SHOWING A MOIST
ISENTROPIC UPGLIDE PATTERN DEVELOPING BETWEEN 06Z AND 12Z. THIS
SHOULD RESULT IN WIDESPREAD SNOWFALL DEVELOPING OVER THE FAR WEST
AFTER MIDNIGHT FRIDAY NIGHT. THE QUICK MOVING SHORTWAVE TROUGH AND
THE ASSOCIATED PACIFIC COLD FRONT IN THE FAST WESTERLY FLOW IS
EXPECTED TO PUSH ACROSS THE FORECAST AREA SATURDAY AFTERNOON AND
EVENING. THE SYNOPTIC LIFT ASSOCIATED WITH THE SHORTWAVE AND
BAROCLINIC ZONE/FRONT COULD BE ENHANCED BY THE LEFT FRONT QUAD OF A
150+ KT UPPER JET SATURDAY. WINTER HIGHLIGHTS APPEAR MORE LIKELY
OVER PORTIONS OF THE WEST FROM LATE FRIDAY NIGHT THROUGH SUNDAY TIME
FRAME...WITH THE MAIN IMPACT PROBABLY SATURDAY. TO COMPLICATE
MATTERS A BIT...MODELS ARE HINTING ENOUGH WARM AIR COULD BE PULLED
NORTHWARD TO HAVE THE SNOW CHANGE TO RAIN MIDDAY SATURDAY ACROSS THE
WESTERN VALLEYS ESPECIALLY STAR VALLEY. HOWEVER THIS WOULD BE SHORT
LIVED...WITH A CHANGE BACK TO SNOW IN WAKE OF THE COLD FRONT
SATURDAY AFTERNOON. WHILE SIGNIFICANT SNOWFALL/WIND COULD BE
OCCURRING OVER THE WEST SATURDAY...A STRONG SURFACE PRESSURE
GRADIENT AND 700MB WEST WINDS AROUND 50 KTS WILL PROBABLY RESULT
IN VERY STRONG TO HIGH WIND ESPECIALLY IN RKS TO CPR WIND CORRIDOR
SATURDAY. COULD ALSO SEE SOME STRONG WIND IN THE CODY FOOTHILLS
LATE FRIDAY NIGHT INTO SATURDAY WITH SOME MOUNTAIN WAVE POTENTIAL
AND STRONG GAP FLOW FROM A STRONG TEMP GRADIENT BETWEEN
YELLOWSTONE AND THE CODY FOOTHILLS. STRONG DOWNSLOPING SATURDAY
EAST OF THE DIVIDE WILL KEEP THOSE AREAS MAINLY DRY...BUT COULD
SEE SOME PRECIPITATION ALONG AND IN WAKE OF THE FRONT.

ALTHOUGH THE MAIN SYSTEM WILL BE EAST OF THE AREA SUNDAY...THE
FORECAST AREA WILL REMAIN ON THE CYCLONIC SIDE OF THE JET WITH A
RELATIVELY UNSTABLE ATMOSPHERE FOR NOVEMBER. THIS SHOULD RESULT IN
ISOLATED TO SCATTERED SNOW SHOWERS...WITH MORE SNOW SHOWER ACTIVITY
OVER THE NORTHWEST AND NORTHERN MOUNTAINS WHICH FAVOR A MOIST
NORTHWEST FLOW. THIS PATTERN CONTINUES INTO MONDAY...BUT WITH A
MORE STABLE ENVIRONMENT FOR MONDAY. THUS WILL DECREASE POPS A
BIT...BUT STILL KEEP CHANCE POPS FOR THE NORTHWEST/NORTHERN
MOUNTAINS.

A RELATIVELY MOIST NORTHWEST FLOW CONTINUES TUESDAY...BUT THE AREA
WILL BE ON THE ANTICYCLONIC SIDE OF THE UPPER JET WHICH SHOULD
RESULT IN EVEN LESS SNOW SHOWER ACTIVITY.

DUE TO THE PACIFIC NATURE OF THIS SYSTEM...THE AIR MASS IN WAKE OF
THIS COLD FRONT SATURDAY/SATURDAY NIGHT WILL NOT BE NEARLY AS COLD
AS THE ARCTIC AIR MASS THAT HAS IMPACTED THE REGION FOR THE PAST
WEEK.

&&

.AVIATION.../12Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT IN MOST AREAS. IN THE
FAR WEST VALLEYS AND BASINS LOW CLOUDS AND PATCHY FOG WILL PERSIST
THIS MORNING WITH MVFR TO IFR CONDITIONS EXPECTED. THE FOG WILL LIFT
BY 19Z WITH THE LOW CLOUDS DISSIPATING BY 21Z IN THE WEST.

LOW LYING AREAS IN CENTRAL WYOMING WILL ALSO SEE AREAS OF LOW CLOUDS
AND PATCHY FOG...ESPECIALLY IN LOW LYING AREAS IN THE BIGHORN BASIN
AND AROUND BOYSEN RESERVOIR NORTH OF RIVERTON. EXPECT LOCAL MVFR TO
IFR CONDITIONS WITH CONDITIONS IMPROVING BY 19Z.

BREEZY TO WINDY CONDITIONS WILL OCCUR TODAY INTO THIS EVENING IN THE
FAVORED WIND LOCATIONS...INCLUDING KCOD...KCPR AND KRKS.

&&

.FIRE WEATHER...

FIRE DANGER LOW AND REMAINING LOW THROUGH THE REST OF THE WORK WEEK
AS SNOW COVER OR MINIMUM RH VALUES STAY WELL ABOVE CRITICAL LEVELS.
HOWEVER...BRISK WEST TO NORTHWEST WINDS WILL BE PREVALENT TODAY
ACROSS THE EASTERN ZONES AND OVER THE NORTHERN AND CENTRAL MOUNTAINS AS
ANOTHER CLIPPER FRONT APPROACHES NORTHEASTERN WYOMING THIS
AFTERNOON. INVERSIONS WILL LIFT SOME TODAY...BUT NOT BREAK FOR MOST
LOCATIONS...REMAINING AT OR BELOW 1500 FEET FOR MOST LOCATIONS IN
THE MIDDLE OF THE DAY...AND A FEW LOCATIONS NOT RISING MORE THAN A
FEW HUNDRED FEET. WINDS WILL DECREASE TONIGHT WITH A NICE DAY ON
TAP FOR WEDNESDAY. CLOUDS AND MOISTURE BEGIN TO INCREASE ACROSS
THE WEST WEDNESDAY NIGHT WITH LIGHT AREAS OF SNOW INCREASING OVER
THE WESTERN FORECAST ZONES ON THURSDAY...LASTING ON AND OFF AGAIN
THROUGH THE WEEKEND.


&&

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

&&

$$

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









000
FXUS65 KRIW 180524
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1024 PM MST MON NOV 17 2014

.SHORT TERM...TONIGHT THROUGH TUESDAY (ISSUED AT 140 PM MST)

WARMING IN THE MID LEVELS WILL LEAD TO STEEPENING INVERSIONS FOR
THE WESTERN AND CENTRAL BASINS AND VALLEYS TONIGHT AND TUESDAY
MORNING. SEE NO REASON WHILE LOW CLOUDS AND FOG WILL NOT RETURN TO
THE FAR WEST VALLEYS AND LIKELY DEVELOP OR EXPAND IN THE LOW LYING
SPOTS ALONG THE BIGHORN BASIN...NORTH OF RIVERTON AND EVEN IN THE
NORMAL AREA OVER NWRN SWEETWATER COUNTY AND FAR SRN SUBLETTE
COUNTY. LOWERED LOWS AND HIGHS IN THESE AREAS AND WILL DO SOME
LAST MINUTE TWEAKING BASED ON HOW WE LOOK LATER THIS AFTERNOON.
WIND CORRIDOR SHOULD SEE INCREASING WINDS LATER TONIGHT THROUGH
TUESDAY. THE CODY FOOTHILLS WILL ALSO SEE DEVELOPING GAP FLOW
WHICH WILL PLAY HAVOC WITH OVERNIGHT LOWS. SOME AREAS LIKE CODY
WILL LIKELY SEE AN EVENING LOW WITH RISING TEMPERATURES AFTER THE
WIND KICKS IN. THE CLOSER TO THE FOOTHILLS THE WARMER IT WILL BE
WITH ANY LULLS IN THE WIND AWAY FROM THE FOOTHILLS RESULTING IN
RAPID TEMPERATURE DROPS. WEAK SYSTEM OVER NRN B.C. WILL MOVE
QUICKLY SWD AND CLIP OUR NERN ZONES LATE TUESDAY WITH SOME MID AND
HIGH CLOUDS AND MAYBE A FEW MTN FLURRIES IN THE NRN BIGHORN MTNS.
WEAK SURFACE REFLECTION WILL LIKELY KICK UP THE WINDS IN NRN
JOHNSON COUNTY TOMORROW AFTERNOON. OTHERWISE...WARMER IN THE WINDY
AND MTN AREAS AND LITTLE CHANGE TO A TAD WARMER ELSEWHERE.

.LONG TERM...TUESDAY NIGHT THROUGH MONDAY

HIGH PRESSURE AND GENERALLY DRY CONDITIONS START OFF THE FORECAST
PERIOD. SOME INVERSIONS WILL KEEP TEMPERATURES A BIT COOLER THAN
GUIDANCE HAS...BUT A WARMING TREND IS STILL ANTICIPATED. THE DRY
TREND WILL CONTINUE INTO THURSDAY MORNING.

A WEAK DISTURBANCE MAY THEN IMPACT NORTHWESTERN WYOMING...SPREADING
SOME LIGHT SHOWER ACTIVITY ACROSS THE AREA THURSDAY AFTERNOON AND
EVENING. THE AREA OF LOW PRESSURE ASSOCIATED WITH THIS SYSTEM IS
EXPECTED TO SPLIT AS IT APPROACHES THE INTERMOUNTAIN WEST. LIGHT
ACTIVITY WILL REMAIN POSSIBLE ACROSS THE EXTREME NORTHWEST...WITH
THE GREATER BULK OF ACTIVITY EXPECTED TO MOVE SOUTH OF THE FORECAST
AREA. A BRIEF TRANSITORY RIDGE IS THEN EXPECTED BY FRIDAY NIGHT
ACROSS THE AREA.

THE NEXT APPROACHING WINTRY SYSTEM WILL MOVE OFF THE PACIFIC COAST
LATE FRIDAY...WITH SHOWER ACTIVITY REACHING INTO EXTREME WESTERN
WYOMING BY SATURDAY MORNING. A WAVE OF LOW PRESSURE WILL DEEPEN AS
IT APPROACHES THE STATE SATURDAY AFTERNOON...WITH PRECIPITATION
SPREADING TO INCLUDE MUCH OF THE AREA WEST OF THE DIVIDE. ACTIVITY
WILL SPREAD EAST OF THE CONTINENTAL DIVIDE SATURDAY NIGHT. MOISTURE
WILL REMAIN ACROSS THE AREA FOR THE NEXT FEW DAYS...WITH PERIODS OF
SHOWERS ANTICIPATED INTO THE EARLY PORTION OF NEXT WEEK.

A GENERAL WARMING TREND IS ANTICIPATED THROUGH SATURDAY...WITH A
COOLING TEMPERATURES THEN LASTING INTO THE BEGINNING OF NEXT WEEK.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY IN MOST AREAS. THE
EXCEPTION WILL BE IN THE FAR WEST VALLEYS AND BASINS WHERE
CONSIDERABLE LOW CLOUDS AND PATCHY FOG WILL DEVELOP OVERNIGHT AND
LAST THROUGH MUCH OF TUESDAY MORNING. LOW LYING AREAS IN CENTRAL
WYOMING WILL ALSO SEE AREAS OF LOW CLOUDS AND PATCHY FOG...
ESPECIALLY IN LOW LYING AREAS IN THE BIGHORN BASIN AND AROUND BOYSEN
RESERVOIR NORTH OF RIVERTON. BREEZY TO WINDY CONDITIONS WILL OCCUR
OVERNIGHT THROUGH SUNSET TUESDAY IN THE FAVORED WIND LOCATIONS...
INCLUDING KCOD...KCPR AND KRKS.

&&

.FIRE WEATHER...

INVERSIONS WILL HOLD ACROSS THE FAR WEST VALLEYS AND IN THE LOW
LYING BASIN AREAS IN CENTRAL WYOMING THE NEXT SEVERAL DAYS. BETTER
MIXING WILL OCCUR IN THE NORMALLY WINDY AREAS AT TIMES FROM KRKS
TO KCPR...ALONG THE CODY FOOTHILLS AND EAST SLOPE OF THE MOUNTAINS.
IT WILL REMAIN DRY THROUGH MIDWEEK EXCEPT FOR A FEW MOUNTAIN
FLURRIES AROUND THE BIGHORN MOUNTAINS LATE TUESDAY OR TUESDAY NIGHT.

&&

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

&&

$$

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







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