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000
FXUS65 KCYS 021147
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 AM MDT THU OCT 2 2014

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

RADAR HAS CLEARED OUT OVERNIGHT BUT A FEW AREAS OF MID AND HIGH
LEVEL CLOUDS REMAIN IN PLACE AS THE UPPER LEVEL TROUGH MOVES
OVERHEAD. COULD SEE SOME PATCHY FOG OVER THE FAR WESTERN ZONES IN
WEAK BUT MOIST WESTERLY UPSLOPE FLOW...INCLUDING THE HIGHER
TERRAIN SUCH AS THE SUMMIT. TODAY WILL BE COOL SIMILAR TO
YESTERDAY WITH H7 TEMPS PROGGED TO RANGE FROM -2C TO 2C FROM NORTH
TO SOUTH BY THIS AFTERNOON. WESTERLY WINDS WILL BE QUITE BLUSTERY
ALONG AND WEST OF THE LARAMIE RANGE TODAY IN ADVANCE OF THE NEXT
FAIRLY POTENT CLIPPER SYSTEM THAT WILL BLAST SOUTHEAST INTO THE
HIGH PLAINS FROM CANADA ON THE LEADING EDGE OF A 150KT JET THROUGH
THE AFTERNOON AND EVENING. A STRONG COLD FRONT ASSOCIATED WITH THIS
SYSTEM WILL RACE SOUTH ACROSS THE FORECAST AREA BETWEEN 23 AND 05Z
WITH 10-15MB/6HR PRESSURE RISES IN ITS WAKE. EXPECT NNW WINDS OF
20 TO 30 MPH GUSTING 35 TO 45 MPH FOR A BRIEF PERIOD BEHIND THE
FRONT DUE TO THE STRONG PRESSURE GRADIENT IN PLACE. FORECAST
SOUNDINGS SUGGEST A WELL MIXED LAYER TO ROUGHLY 50MB ABOVE THE
SURFACE IN THE POST FRONTAL ENVIRONMENT WILL ALSO CONTRIBUTE TO
THE GUSTY WINDS. THE HIGHEST WINDS SHOULD OCCUR ACROSS THE EASTERN
PLAINS WHERE THE HIGHER PRESSURE RISES COMBINE WITH STRONGEST
UPPER LEVEL WINDS...ESPECIALLY ALONG RIDGETOPS SUCH AS THE PINE
RIDGE...WILDCAT HILLS...AND CHEYENNE RIDGE. IN ADDITION TO THE
WINDS...GOOD QG AND FRONTAL FORCING WILL PRODUCE SHOWERS IN THE
EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. TEMPS WILL BE
WARM ENOUGH INITIALLY TO KEEP PRECIP LIQUID...BUT STRONG CAA WILL
BRING SNOW LEVELS DOWN TO NEAR 5KFT THRU THE EVENING SO EXPECT TO
SEE A TRANSITION FROM RAIN TO SNOW DURING THIS TIME. STILL LOOKS
LIKE THE BEST JUXTAPOSITION OF COLD AIR AND PRECIP CHANCES WILL
OCCUR FROM THE NORTHERN LARAMIE RANGE/DOUGLAS TO THE PINE RIDGE
AROUND SUNSET...SO WILL MAINTAIN THE FOCUS FOR LIGHT SNOW IN
THIS REGION. EXPECTING ACCUMS OF JUST A DUSTING TO ONE INCH.
CANNOT RULE OUT SNOW MIXING WITH RAIN FURTHER SOUTH IN THE EARLY
OVERNIGHT PERIOD AS WELL...BUT PRECIP AND THUS OVERALL CHANCE FOR
SNOW WILL DIMINISH AS THE FRONT RACES SOUTHEASTWARD AND UPPER
LEVEL FORCING DECOUPLES AND SHIFTS TO THE EAST. TEMPS WILL DROP TO
NEAR OR BELOW FREEZING VALUES OVERNIGHT...BUT WINDS SHOULD REMAIN
ELEVATED ENOUGH TO PREVENT WIDESPREAD FROST FORMATION SO WILL
REFRAIN FROM ISSUING HIGHLIGHTS.

FRIDAY WILL BE MUCH COOLER IN THE POST FRONTAL ENVIRONMENT WITH
BRISK NORTHWEST WINDS PERSISTING AS THE JET REMAINS OVER THE HIGH
PLAINS THRU THE AFTERNOON. DRY CONDITIONS WILL PREVAIL WITH MUCH
DRIER AIR AND SUBSIDENCE MOVING IN FROM THE WEST. THE UPPER JET
WILL STEADILY SHIFT EAST THRU THE EVENING AND OVERNIGHT WITH SKIES
PARTIALLY CLEARING AND SFC WINDS EXPECTED TO BE LIGHT. THIS WILL
INCREASE THE CHANCE FOR A MORE SUBSTANTIAL FROST/FREEZE FRIDAY
NIGHT...SO MAY HAVE TO CONSIDER FROST HIGHLIGHTS FOR THE EASTERN
PANHANDLE DURING THIS TIME.

DRY NORTHWEST FLOW WILL REMAIN OVERHEAD FOR SATURDAY WITH H7 TEMPS
INCREASING TO BETWEEN 2C AND 6C. THE LEESIDE PRESSURE TROUGH WILL
DEEPEN AS A WEAK PIECE OF ENERGY MOVES OVERHEAD IN THIS FLOW
PATTERN...SO WESTERLY WINDS WILL INCREASE ONCE AGAIN ALONG AND WEST
OF THE LARAMIE RANGE. MAX TEMPS LOOK TO RETURN TO THE 60S AND 70S
FOR MUCH OF THE AREA.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

DRY AND MILD CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE EXTENDED
FCST PERIOD. MEDIUM RANGE MODELS REMAIN IN EXCELLENT AGREEMENT WITH
THE OVERALL WEATHER PATTERN. THE CWA SHOULD REMAIN IN THE TRANSITION
ZONE BETWEEN DEEP TROUGHING OVER THE GREAT LAKES REGION AND AN UPPER
RIDGE BUILDING OVER THE WESTERN CONUS. THE UPPER-LEVEL FLOW PATTERN
LOOKS TO BE QUITE ACTIVE...BUT THE MAJORITY OF IMPULSES EMBEDDED IN
THE FLOW ARE EXPECTED TO REMAIN TO THE EAST OF THE CWA. HOWEVER THE
ECMWF STILL SUGGESTS LIGHT QPF OVER EAST CENTRAL WY AND THE NORTHERN
PANHANDLE ON SUN AFTN. THIS IS QUITE POSSIBLE WITH A BACKDOOR COOL
FRONT ENCROACHING ON THOSE ZONES ALONG WITH INCREASING DIFFLUENCE IN
THE EXIT REGION OF AN INTENSE 120+ KT H25 JET...BUT NAM/GFS HAVE
BEEN CONSISTENT WITH A DRY FCST AS BETTER FORCING IS OVER THE
PLAINS. REFRAINED FROM MENTION OF SHOWERS OR TSTMS ATTM. OTHERWISE
CONVECTIVE ACTIVITY WILL BE LACKING AS UPPER RIDGING BECOMES THE
DOMINANT FEATURE ALOFT. MAIN CHANGE TO TEMPERATURE GRIDS WAS TO
INCREASE HIGHS A FEW DEGREES FOR TUE AFTN. THE GFS SHOWS H7 TEMPS
APPROACHING 10C OVER THE PLAINS BY 18Z...AND ANY MIXING WOULD BRING
WESTERLY DOWNSLOPE WINDS DOWN TO THE SFC BY AFTN. TRENDED WARMER
THAN CONSENSUS GUIDANCE AS PATTERN SHOULD FAVOR TEMPS NEAR 80F IN
THE PANHANDLE...ESPECIALLY ALONG THE PLATTE RIVER VALLEY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 535 AM MDT THU OCT 2 2014

PATCHY FOG AND LOCALLY REDUCED VSBYS AS LOW AS 1/4 SM HAVE BEEN
OBSERVED AT KLAR EARLY THIS AM. THIS SHOULD ERODE BY 14Z WITH VFR
CONDITIONS EXPECTED FOR MUCH OF THE DAY. WINDS WILL INCREASE OVER
ALL TERMINALS WIGH GUSTS AROUND 30 KTS COMMON...ESPECIALLY ALONG
AND WEST OF THE LARAMIE RANGE. A STRONG COLD FRONT WILL MOVE SOUTH
ACROSS THE AREA TONIGHT. WINDS WILL SHIFT TO THE NORTH AND REMAIN
GUSTY OVERNIGHT. SHOWERS...POSSIBLY MIXED WITH SNOW...WILL DEVELOP
FROM NORTH TO SOUTH AFTER 00Z. MVFR TO LOCALLY IFR CIGS ARE LIKELY
OVERNIGHT BEHIND THE FRONT. KCDR AND KAIA COULD SEE REDUCED VSBYS
IN SNOW SHOWERS.

&&

.FIRE WEATHER...
ISSUED AT 407 AM MDT THU OCT 2 2014

COOL AND BREEZY CONDITIONS WILL PERSIST OVER THE REGION TODAY AND
FRIDAY. A FAST MOVING CLIPPER SYSTEM WILL BRING A CHANCE FOR LIGHT
PRECIP THIS EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. RAIN
LOOKS TO MIX WITH SNOW POSSIBLY DOWN TO 5000 FEET OR SO...WITH THE
BEST CHANCE FOR SNOW ALONG A LINE FROM THE NORTHERN LARAMIE RANGE TO
THE PINE RIDGE. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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







000
FXUS65 KCYS 021147
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 AM MDT THU OCT 2 2014

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

RADAR HAS CLEARED OUT OVERNIGHT BUT A FEW AREAS OF MID AND HIGH
LEVEL CLOUDS REMAIN IN PLACE AS THE UPPER LEVEL TROUGH MOVES
OVERHEAD. COULD SEE SOME PATCHY FOG OVER THE FAR WESTERN ZONES IN
WEAK BUT MOIST WESTERLY UPSLOPE FLOW...INCLUDING THE HIGHER
TERRAIN SUCH AS THE SUMMIT. TODAY WILL BE COOL SIMILAR TO
YESTERDAY WITH H7 TEMPS PROGGED TO RANGE FROM -2C TO 2C FROM NORTH
TO SOUTH BY THIS AFTERNOON. WESTERLY WINDS WILL BE QUITE BLUSTERY
ALONG AND WEST OF THE LARAMIE RANGE TODAY IN ADVANCE OF THE NEXT
FAIRLY POTENT CLIPPER SYSTEM THAT WILL BLAST SOUTHEAST INTO THE
HIGH PLAINS FROM CANADA ON THE LEADING EDGE OF A 150KT JET THROUGH
THE AFTERNOON AND EVENING. A STRONG COLD FRONT ASSOCIATED WITH THIS
SYSTEM WILL RACE SOUTH ACROSS THE FORECAST AREA BETWEEN 23 AND 05Z
WITH 10-15MB/6HR PRESSURE RISES IN ITS WAKE. EXPECT NNW WINDS OF
20 TO 30 MPH GUSTING 35 TO 45 MPH FOR A BRIEF PERIOD BEHIND THE
FRONT DUE TO THE STRONG PRESSURE GRADIENT IN PLACE. FORECAST
SOUNDINGS SUGGEST A WELL MIXED LAYER TO ROUGHLY 50MB ABOVE THE
SURFACE IN THE POST FRONTAL ENVIRONMENT WILL ALSO CONTRIBUTE TO
THE GUSTY WINDS. THE HIGHEST WINDS SHOULD OCCUR ACROSS THE EASTERN
PLAINS WHERE THE HIGHER PRESSURE RISES COMBINE WITH STRONGEST
UPPER LEVEL WINDS...ESPECIALLY ALONG RIDGETOPS SUCH AS THE PINE
RIDGE...WILDCAT HILLS...AND CHEYENNE RIDGE. IN ADDITION TO THE
WINDS...GOOD QG AND FRONTAL FORCING WILL PRODUCE SHOWERS IN THE
EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. TEMPS WILL BE
WARM ENOUGH INITIALLY TO KEEP PRECIP LIQUID...BUT STRONG CAA WILL
BRING SNOW LEVELS DOWN TO NEAR 5KFT THRU THE EVENING SO EXPECT TO
SEE A TRANSITION FROM RAIN TO SNOW DURING THIS TIME. STILL LOOKS
LIKE THE BEST JUXTAPOSITION OF COLD AIR AND PRECIP CHANCES WILL
OCCUR FROM THE NORTHERN LARAMIE RANGE/DOUGLAS TO THE PINE RIDGE
AROUND SUNSET...SO WILL MAINTAIN THE FOCUS FOR LIGHT SNOW IN
THIS REGION. EXPECTING ACCUMS OF JUST A DUSTING TO ONE INCH.
CANNOT RULE OUT SNOW MIXING WITH RAIN FURTHER SOUTH IN THE EARLY
OVERNIGHT PERIOD AS WELL...BUT PRECIP AND THUS OVERALL CHANCE FOR
SNOW WILL DIMINISH AS THE FRONT RACES SOUTHEASTWARD AND UPPER
LEVEL FORCING DECOUPLES AND SHIFTS TO THE EAST. TEMPS WILL DROP TO
NEAR OR BELOW FREEZING VALUES OVERNIGHT...BUT WINDS SHOULD REMAIN
ELEVATED ENOUGH TO PREVENT WIDESPREAD FROST FORMATION SO WILL
REFRAIN FROM ISSUING HIGHLIGHTS.

FRIDAY WILL BE MUCH COOLER IN THE POST FRONTAL ENVIRONMENT WITH
BRISK NORTHWEST WINDS PERSISTING AS THE JET REMAINS OVER THE HIGH
PLAINS THRU THE AFTERNOON. DRY CONDITIONS WILL PREVAIL WITH MUCH
DRIER AIR AND SUBSIDENCE MOVING IN FROM THE WEST. THE UPPER JET
WILL STEADILY SHIFT EAST THRU THE EVENING AND OVERNIGHT WITH SKIES
PARTIALLY CLEARING AND SFC WINDS EXPECTED TO BE LIGHT. THIS WILL
INCREASE THE CHANCE FOR A MORE SUBSTANTIAL FROST/FREEZE FRIDAY
NIGHT...SO MAY HAVE TO CONSIDER FROST HIGHLIGHTS FOR THE EASTERN
PANHANDLE DURING THIS TIME.

DRY NORTHWEST FLOW WILL REMAIN OVERHEAD FOR SATURDAY WITH H7 TEMPS
INCREASING TO BETWEEN 2C AND 6C. THE LEESIDE PRESSURE TROUGH WILL
DEEPEN AS A WEAK PIECE OF ENERGY MOVES OVERHEAD IN THIS FLOW
PATTERN...SO WESTERLY WINDS WILL INCREASE ONCE AGAIN ALONG AND WEST
OF THE LARAMIE RANGE. MAX TEMPS LOOK TO RETURN TO THE 60S AND 70S
FOR MUCH OF THE AREA.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

DRY AND MILD CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE EXTENDED
FCST PERIOD. MEDIUM RANGE MODELS REMAIN IN EXCELLENT AGREEMENT WITH
THE OVERALL WEATHER PATTERN. THE CWA SHOULD REMAIN IN THE TRANSITION
ZONE BETWEEN DEEP TROUGHING OVER THE GREAT LAKES REGION AND AN UPPER
RIDGE BUILDING OVER THE WESTERN CONUS. THE UPPER-LEVEL FLOW PATTERN
LOOKS TO BE QUITE ACTIVE...BUT THE MAJORITY OF IMPULSES EMBEDDED IN
THE FLOW ARE EXPECTED TO REMAIN TO THE EAST OF THE CWA. HOWEVER THE
ECMWF STILL SUGGESTS LIGHT QPF OVER EAST CENTRAL WY AND THE NORTHERN
PANHANDLE ON SUN AFTN. THIS IS QUITE POSSIBLE WITH A BACKDOOR COOL
FRONT ENCROACHING ON THOSE ZONES ALONG WITH INCREASING DIFFLUENCE IN
THE EXIT REGION OF AN INTENSE 120+ KT H25 JET...BUT NAM/GFS HAVE
BEEN CONSISTENT WITH A DRY FCST AS BETTER FORCING IS OVER THE
PLAINS. REFRAINED FROM MENTION OF SHOWERS OR TSTMS ATTM. OTHERWISE
CONVECTIVE ACTIVITY WILL BE LACKING AS UPPER RIDGING BECOMES THE
DOMINANT FEATURE ALOFT. MAIN CHANGE TO TEMPERATURE GRIDS WAS TO
INCREASE HIGHS A FEW DEGREES FOR TUE AFTN. THE GFS SHOWS H7 TEMPS
APPROACHING 10C OVER THE PLAINS BY 18Z...AND ANY MIXING WOULD BRING
WESTERLY DOWNSLOPE WINDS DOWN TO THE SFC BY AFTN. TRENDED WARMER
THAN CONSENSUS GUIDANCE AS PATTERN SHOULD FAVOR TEMPS NEAR 80F IN
THE PANHANDLE...ESPECIALLY ALONG THE PLATTE RIVER VALLEY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 535 AM MDT THU OCT 2 2014

PATCHY FOG AND LOCALLY REDUCED VSBYS AS LOW AS 1/4 SM HAVE BEEN
OBSERVED AT KLAR EARLY THIS AM. THIS SHOULD ERODE BY 14Z WITH VFR
CONDITIONS EXPECTED FOR MUCH OF THE DAY. WINDS WILL INCREASE OVER
ALL TERMINALS WIGH GUSTS AROUND 30 KTS COMMON...ESPECIALLY ALONG
AND WEST OF THE LARAMIE RANGE. A STRONG COLD FRONT WILL MOVE SOUTH
ACROSS THE AREA TONIGHT. WINDS WILL SHIFT TO THE NORTH AND REMAIN
GUSTY OVERNIGHT. SHOWERS...POSSIBLY MIXED WITH SNOW...WILL DEVELOP
FROM NORTH TO SOUTH AFTER 00Z. MVFR TO LOCALLY IFR CIGS ARE LIKELY
OVERNIGHT BEHIND THE FRONT. KCDR AND KAIA COULD SEE REDUCED VSBYS
IN SNOW SHOWERS.

&&

.FIRE WEATHER...
ISSUED AT 407 AM MDT THU OCT 2 2014

COOL AND BREEZY CONDITIONS WILL PERSIST OVER THE REGION TODAY AND
FRIDAY. A FAST MOVING CLIPPER SYSTEM WILL BRING A CHANCE FOR LIGHT
PRECIP THIS EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. RAIN
LOOKS TO MIX WITH SNOW POSSIBLY DOWN TO 5000 FEET OR SO...WITH THE
BEST CHANCE FOR SNOW ALONG A LINE FROM THE NORTHERN LARAMIE RANGE TO
THE PINE RIDGE. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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







000
FXUS65 KCYS 021147
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 AM MDT THU OCT 2 2014

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

RADAR HAS CLEARED OUT OVERNIGHT BUT A FEW AREAS OF MID AND HIGH
LEVEL CLOUDS REMAIN IN PLACE AS THE UPPER LEVEL TROUGH MOVES
OVERHEAD. COULD SEE SOME PATCHY FOG OVER THE FAR WESTERN ZONES IN
WEAK BUT MOIST WESTERLY UPSLOPE FLOW...INCLUDING THE HIGHER
TERRAIN SUCH AS THE SUMMIT. TODAY WILL BE COOL SIMILAR TO
YESTERDAY WITH H7 TEMPS PROGGED TO RANGE FROM -2C TO 2C FROM NORTH
TO SOUTH BY THIS AFTERNOON. WESTERLY WINDS WILL BE QUITE BLUSTERY
ALONG AND WEST OF THE LARAMIE RANGE TODAY IN ADVANCE OF THE NEXT
FAIRLY POTENT CLIPPER SYSTEM THAT WILL BLAST SOUTHEAST INTO THE
HIGH PLAINS FROM CANADA ON THE LEADING EDGE OF A 150KT JET THROUGH
THE AFTERNOON AND EVENING. A STRONG COLD FRONT ASSOCIATED WITH THIS
SYSTEM WILL RACE SOUTH ACROSS THE FORECAST AREA BETWEEN 23 AND 05Z
WITH 10-15MB/6HR PRESSURE RISES IN ITS WAKE. EXPECT NNW WINDS OF
20 TO 30 MPH GUSTING 35 TO 45 MPH FOR A BRIEF PERIOD BEHIND THE
FRONT DUE TO THE STRONG PRESSURE GRADIENT IN PLACE. FORECAST
SOUNDINGS SUGGEST A WELL MIXED LAYER TO ROUGHLY 50MB ABOVE THE
SURFACE IN THE POST FRONTAL ENVIRONMENT WILL ALSO CONTRIBUTE TO
THE GUSTY WINDS. THE HIGHEST WINDS SHOULD OCCUR ACROSS THE EASTERN
PLAINS WHERE THE HIGHER PRESSURE RISES COMBINE WITH STRONGEST
UPPER LEVEL WINDS...ESPECIALLY ALONG RIDGETOPS SUCH AS THE PINE
RIDGE...WILDCAT HILLS...AND CHEYENNE RIDGE. IN ADDITION TO THE
WINDS...GOOD QG AND FRONTAL FORCING WILL PRODUCE SHOWERS IN THE
EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. TEMPS WILL BE
WARM ENOUGH INITIALLY TO KEEP PRECIP LIQUID...BUT STRONG CAA WILL
BRING SNOW LEVELS DOWN TO NEAR 5KFT THRU THE EVENING SO EXPECT TO
SEE A TRANSITION FROM RAIN TO SNOW DURING THIS TIME. STILL LOOKS
LIKE THE BEST JUXTAPOSITION OF COLD AIR AND PRECIP CHANCES WILL
OCCUR FROM THE NORTHERN LARAMIE RANGE/DOUGLAS TO THE PINE RIDGE
AROUND SUNSET...SO WILL MAINTAIN THE FOCUS FOR LIGHT SNOW IN
THIS REGION. EXPECTING ACCUMS OF JUST A DUSTING TO ONE INCH.
CANNOT RULE OUT SNOW MIXING WITH RAIN FURTHER SOUTH IN THE EARLY
OVERNIGHT PERIOD AS WELL...BUT PRECIP AND THUS OVERALL CHANCE FOR
SNOW WILL DIMINISH AS THE FRONT RACES SOUTHEASTWARD AND UPPER
LEVEL FORCING DECOUPLES AND SHIFTS TO THE EAST. TEMPS WILL DROP TO
NEAR OR BELOW FREEZING VALUES OVERNIGHT...BUT WINDS SHOULD REMAIN
ELEVATED ENOUGH TO PREVENT WIDESPREAD FROST FORMATION SO WILL
REFRAIN FROM ISSUING HIGHLIGHTS.

FRIDAY WILL BE MUCH COOLER IN THE POST FRONTAL ENVIRONMENT WITH
BRISK NORTHWEST WINDS PERSISTING AS THE JET REMAINS OVER THE HIGH
PLAINS THRU THE AFTERNOON. DRY CONDITIONS WILL PREVAIL WITH MUCH
DRIER AIR AND SUBSIDENCE MOVING IN FROM THE WEST. THE UPPER JET
WILL STEADILY SHIFT EAST THRU THE EVENING AND OVERNIGHT WITH SKIES
PARTIALLY CLEARING AND SFC WINDS EXPECTED TO BE LIGHT. THIS WILL
INCREASE THE CHANCE FOR A MORE SUBSTANTIAL FROST/FREEZE FRIDAY
NIGHT...SO MAY HAVE TO CONSIDER FROST HIGHLIGHTS FOR THE EASTERN
PANHANDLE DURING THIS TIME.

DRY NORTHWEST FLOW WILL REMAIN OVERHEAD FOR SATURDAY WITH H7 TEMPS
INCREASING TO BETWEEN 2C AND 6C. THE LEESIDE PRESSURE TROUGH WILL
DEEPEN AS A WEAK PIECE OF ENERGY MOVES OVERHEAD IN THIS FLOW
PATTERN...SO WESTERLY WINDS WILL INCREASE ONCE AGAIN ALONG AND WEST
OF THE LARAMIE RANGE. MAX TEMPS LOOK TO RETURN TO THE 60S AND 70S
FOR MUCH OF THE AREA.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

DRY AND MILD CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE EXTENDED
FCST PERIOD. MEDIUM RANGE MODELS REMAIN IN EXCELLENT AGREEMENT WITH
THE OVERALL WEATHER PATTERN. THE CWA SHOULD REMAIN IN THE TRANSITION
ZONE BETWEEN DEEP TROUGHING OVER THE GREAT LAKES REGION AND AN UPPER
RIDGE BUILDING OVER THE WESTERN CONUS. THE UPPER-LEVEL FLOW PATTERN
LOOKS TO BE QUITE ACTIVE...BUT THE MAJORITY OF IMPULSES EMBEDDED IN
THE FLOW ARE EXPECTED TO REMAIN TO THE EAST OF THE CWA. HOWEVER THE
ECMWF STILL SUGGESTS LIGHT QPF OVER EAST CENTRAL WY AND THE NORTHERN
PANHANDLE ON SUN AFTN. THIS IS QUITE POSSIBLE WITH A BACKDOOR COOL
FRONT ENCROACHING ON THOSE ZONES ALONG WITH INCREASING DIFFLUENCE IN
THE EXIT REGION OF AN INTENSE 120+ KT H25 JET...BUT NAM/GFS HAVE
BEEN CONSISTENT WITH A DRY FCST AS BETTER FORCING IS OVER THE
PLAINS. REFRAINED FROM MENTION OF SHOWERS OR TSTMS ATTM. OTHERWISE
CONVECTIVE ACTIVITY WILL BE LACKING AS UPPER RIDGING BECOMES THE
DOMINANT FEATURE ALOFT. MAIN CHANGE TO TEMPERATURE GRIDS WAS TO
INCREASE HIGHS A FEW DEGREES FOR TUE AFTN. THE GFS SHOWS H7 TEMPS
APPROACHING 10C OVER THE PLAINS BY 18Z...AND ANY MIXING WOULD BRING
WESTERLY DOWNSLOPE WINDS DOWN TO THE SFC BY AFTN. TRENDED WARMER
THAN CONSENSUS GUIDANCE AS PATTERN SHOULD FAVOR TEMPS NEAR 80F IN
THE PANHANDLE...ESPECIALLY ALONG THE PLATTE RIVER VALLEY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 535 AM MDT THU OCT 2 2014

PATCHY FOG AND LOCALLY REDUCED VSBYS AS LOW AS 1/4 SM HAVE BEEN
OBSERVED AT KLAR EARLY THIS AM. THIS SHOULD ERODE BY 14Z WITH VFR
CONDITIONS EXPECTED FOR MUCH OF THE DAY. WINDS WILL INCREASE OVER
ALL TERMINALS WIGH GUSTS AROUND 30 KTS COMMON...ESPECIALLY ALONG
AND WEST OF THE LARAMIE RANGE. A STRONG COLD FRONT WILL MOVE SOUTH
ACROSS THE AREA TONIGHT. WINDS WILL SHIFT TO THE NORTH AND REMAIN
GUSTY OVERNIGHT. SHOWERS...POSSIBLY MIXED WITH SNOW...WILL DEVELOP
FROM NORTH TO SOUTH AFTER 00Z. MVFR TO LOCALLY IFR CIGS ARE LIKELY
OVERNIGHT BEHIND THE FRONT. KCDR AND KAIA COULD SEE REDUCED VSBYS
IN SNOW SHOWERS.

&&

.FIRE WEATHER...
ISSUED AT 407 AM MDT THU OCT 2 2014

COOL AND BREEZY CONDITIONS WILL PERSIST OVER THE REGION TODAY AND
FRIDAY. A FAST MOVING CLIPPER SYSTEM WILL BRING A CHANCE FOR LIGHT
PRECIP THIS EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. RAIN
LOOKS TO MIX WITH SNOW POSSIBLY DOWN TO 5000 FEET OR SO...WITH THE
BEST CHANCE FOR SNOW ALONG A LINE FROM THE NORTHERN LARAMIE RANGE TO
THE PINE RIDGE. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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







000
FXUS65 KCYS 021147
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 AM MDT THU OCT 2 2014

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

RADAR HAS CLEARED OUT OVERNIGHT BUT A FEW AREAS OF MID AND HIGH
LEVEL CLOUDS REMAIN IN PLACE AS THE UPPER LEVEL TROUGH MOVES
OVERHEAD. COULD SEE SOME PATCHY FOG OVER THE FAR WESTERN ZONES IN
WEAK BUT MOIST WESTERLY UPSLOPE FLOW...INCLUDING THE HIGHER
TERRAIN SUCH AS THE SUMMIT. TODAY WILL BE COOL SIMILAR TO
YESTERDAY WITH H7 TEMPS PROGGED TO RANGE FROM -2C TO 2C FROM NORTH
TO SOUTH BY THIS AFTERNOON. WESTERLY WINDS WILL BE QUITE BLUSTERY
ALONG AND WEST OF THE LARAMIE RANGE TODAY IN ADVANCE OF THE NEXT
FAIRLY POTENT CLIPPER SYSTEM THAT WILL BLAST SOUTHEAST INTO THE
HIGH PLAINS FROM CANADA ON THE LEADING EDGE OF A 150KT JET THROUGH
THE AFTERNOON AND EVENING. A STRONG COLD FRONT ASSOCIATED WITH THIS
SYSTEM WILL RACE SOUTH ACROSS THE FORECAST AREA BETWEEN 23 AND 05Z
WITH 10-15MB/6HR PRESSURE RISES IN ITS WAKE. EXPECT NNW WINDS OF
20 TO 30 MPH GUSTING 35 TO 45 MPH FOR A BRIEF PERIOD BEHIND THE
FRONT DUE TO THE STRONG PRESSURE GRADIENT IN PLACE. FORECAST
SOUNDINGS SUGGEST A WELL MIXED LAYER TO ROUGHLY 50MB ABOVE THE
SURFACE IN THE POST FRONTAL ENVIRONMENT WILL ALSO CONTRIBUTE TO
THE GUSTY WINDS. THE HIGHEST WINDS SHOULD OCCUR ACROSS THE EASTERN
PLAINS WHERE THE HIGHER PRESSURE RISES COMBINE WITH STRONGEST
UPPER LEVEL WINDS...ESPECIALLY ALONG RIDGETOPS SUCH AS THE PINE
RIDGE...WILDCAT HILLS...AND CHEYENNE RIDGE. IN ADDITION TO THE
WINDS...GOOD QG AND FRONTAL FORCING WILL PRODUCE SHOWERS IN THE
EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. TEMPS WILL BE
WARM ENOUGH INITIALLY TO KEEP PRECIP LIQUID...BUT STRONG CAA WILL
BRING SNOW LEVELS DOWN TO NEAR 5KFT THRU THE EVENING SO EXPECT TO
SEE A TRANSITION FROM RAIN TO SNOW DURING THIS TIME. STILL LOOKS
LIKE THE BEST JUXTAPOSITION OF COLD AIR AND PRECIP CHANCES WILL
OCCUR FROM THE NORTHERN LARAMIE RANGE/DOUGLAS TO THE PINE RIDGE
AROUND SUNSET...SO WILL MAINTAIN THE FOCUS FOR LIGHT SNOW IN
THIS REGION. EXPECTING ACCUMS OF JUST A DUSTING TO ONE INCH.
CANNOT RULE OUT SNOW MIXING WITH RAIN FURTHER SOUTH IN THE EARLY
OVERNIGHT PERIOD AS WELL...BUT PRECIP AND THUS OVERALL CHANCE FOR
SNOW WILL DIMINISH AS THE FRONT RACES SOUTHEASTWARD AND UPPER
LEVEL FORCING DECOUPLES AND SHIFTS TO THE EAST. TEMPS WILL DROP TO
NEAR OR BELOW FREEZING VALUES OVERNIGHT...BUT WINDS SHOULD REMAIN
ELEVATED ENOUGH TO PREVENT WIDESPREAD FROST FORMATION SO WILL
REFRAIN FROM ISSUING HIGHLIGHTS.

FRIDAY WILL BE MUCH COOLER IN THE POST FRONTAL ENVIRONMENT WITH
BRISK NORTHWEST WINDS PERSISTING AS THE JET REMAINS OVER THE HIGH
PLAINS THRU THE AFTERNOON. DRY CONDITIONS WILL PREVAIL WITH MUCH
DRIER AIR AND SUBSIDENCE MOVING IN FROM THE WEST. THE UPPER JET
WILL STEADILY SHIFT EAST THRU THE EVENING AND OVERNIGHT WITH SKIES
PARTIALLY CLEARING AND SFC WINDS EXPECTED TO BE LIGHT. THIS WILL
INCREASE THE CHANCE FOR A MORE SUBSTANTIAL FROST/FREEZE FRIDAY
NIGHT...SO MAY HAVE TO CONSIDER FROST HIGHLIGHTS FOR THE EASTERN
PANHANDLE DURING THIS TIME.

DRY NORTHWEST FLOW WILL REMAIN OVERHEAD FOR SATURDAY WITH H7 TEMPS
INCREASING TO BETWEEN 2C AND 6C. THE LEESIDE PRESSURE TROUGH WILL
DEEPEN AS A WEAK PIECE OF ENERGY MOVES OVERHEAD IN THIS FLOW
PATTERN...SO WESTERLY WINDS WILL INCREASE ONCE AGAIN ALONG AND WEST
OF THE LARAMIE RANGE. MAX TEMPS LOOK TO RETURN TO THE 60S AND 70S
FOR MUCH OF THE AREA.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

DRY AND MILD CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE EXTENDED
FCST PERIOD. MEDIUM RANGE MODELS REMAIN IN EXCELLENT AGREEMENT WITH
THE OVERALL WEATHER PATTERN. THE CWA SHOULD REMAIN IN THE TRANSITION
ZONE BETWEEN DEEP TROUGHING OVER THE GREAT LAKES REGION AND AN UPPER
RIDGE BUILDING OVER THE WESTERN CONUS. THE UPPER-LEVEL FLOW PATTERN
LOOKS TO BE QUITE ACTIVE...BUT THE MAJORITY OF IMPULSES EMBEDDED IN
THE FLOW ARE EXPECTED TO REMAIN TO THE EAST OF THE CWA. HOWEVER THE
ECMWF STILL SUGGESTS LIGHT QPF OVER EAST CENTRAL WY AND THE NORTHERN
PANHANDLE ON SUN AFTN. THIS IS QUITE POSSIBLE WITH A BACKDOOR COOL
FRONT ENCROACHING ON THOSE ZONES ALONG WITH INCREASING DIFFLUENCE IN
THE EXIT REGION OF AN INTENSE 120+ KT H25 JET...BUT NAM/GFS HAVE
BEEN CONSISTENT WITH A DRY FCST AS BETTER FORCING IS OVER THE
PLAINS. REFRAINED FROM MENTION OF SHOWERS OR TSTMS ATTM. OTHERWISE
CONVECTIVE ACTIVITY WILL BE LACKING AS UPPER RIDGING BECOMES THE
DOMINANT FEATURE ALOFT. MAIN CHANGE TO TEMPERATURE GRIDS WAS TO
INCREASE HIGHS A FEW DEGREES FOR TUE AFTN. THE GFS SHOWS H7 TEMPS
APPROACHING 10C OVER THE PLAINS BY 18Z...AND ANY MIXING WOULD BRING
WESTERLY DOWNSLOPE WINDS DOWN TO THE SFC BY AFTN. TRENDED WARMER
THAN CONSENSUS GUIDANCE AS PATTERN SHOULD FAVOR TEMPS NEAR 80F IN
THE PANHANDLE...ESPECIALLY ALONG THE PLATTE RIVER VALLEY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 535 AM MDT THU OCT 2 2014

PATCHY FOG AND LOCALLY REDUCED VSBYS AS LOW AS 1/4 SM HAVE BEEN
OBSERVED AT KLAR EARLY THIS AM. THIS SHOULD ERODE BY 14Z WITH VFR
CONDITIONS EXPECTED FOR MUCH OF THE DAY. WINDS WILL INCREASE OVER
ALL TERMINALS WIGH GUSTS AROUND 30 KTS COMMON...ESPECIALLY ALONG
AND WEST OF THE LARAMIE RANGE. A STRONG COLD FRONT WILL MOVE SOUTH
ACROSS THE AREA TONIGHT. WINDS WILL SHIFT TO THE NORTH AND REMAIN
GUSTY OVERNIGHT. SHOWERS...POSSIBLY MIXED WITH SNOW...WILL DEVELOP
FROM NORTH TO SOUTH AFTER 00Z. MVFR TO LOCALLY IFR CIGS ARE LIKELY
OVERNIGHT BEHIND THE FRONT. KCDR AND KAIA COULD SEE REDUCED VSBYS
IN SNOW SHOWERS.

&&

.FIRE WEATHER...
ISSUED AT 407 AM MDT THU OCT 2 2014

COOL AND BREEZY CONDITIONS WILL PERSIST OVER THE REGION TODAY AND
FRIDAY. A FAST MOVING CLIPPER SYSTEM WILL BRING A CHANCE FOR LIGHT
PRECIP THIS EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. RAIN
LOOKS TO MIX WITH SNOW POSSIBLY DOWN TO 5000 FEET OR SO...WITH THE
BEST CHANCE FOR SNOW ALONG A LINE FROM THE NORTHERN LARAMIE RANGE TO
THE PINE RIDGE. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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







000
FXUS65 KCYS 021007
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
407 AM MDT THU OCT 2 2014

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

RADAR HAS CLEARED OUT OVERNIGHT BUT A FEW AREAS OF MID AND HIGH
LEVEL CLOUDS REMAIN IN PLACE AS THE UPPER LEVEL TROUGH MOVES
OVERHEAD. COULD SEE SOME PATCHY FOG OVER THE FAR WESTERN ZONES IN
WEAK BUT MOIST WESTERLY UPSLOPE FLOW...INCLUDING THE HIGHER
TERRAIN SUCH AS THE SUMMIT. TODAY WILL BE COOL SIMILAR TO
YESTERDAY WITH H7 TEMPS PROGGED TO RANGE FROM -2C TO 2C FROM NORTH
TO SOUTH BY THIS AFTERNOON. WESTERLY WINDS WILL BE QUITE BLUSTERY
ALONG AND WEST OF THE LARAMIE RANGE TODAY IN ADVANCE OF THE NEXT
FAIRLY POTENT CLIPPER SYSTEM THAT WILL BLAST SOUTHEAST INTO THE
HIGH PLAINS FROM CANADA ON THE LEADING EDGE OF A 150KT JET THROUGH
THE AFTERNOON AND EVENING. A STRONG COLD FRONT ASSOCIATED WITH THIS
SYSTEM WILL RACE SOUTH ACROSS THE FORECAST AREA BETWEEN 23 AND 05Z
WITH 10-15MB/6HR PRESSURE RISES IN ITS WAKE. EXPECT NNW WINDS OF
20 TO 30 MPH GUSTING 35 TO 45 MPH FOR A BRIEF PERIOD BEHIND THE
FRONT DUE TO THE STRONG PRESSURE GRADIENT IN PLACE. FORECAST
SOUNDINGS SUGGEST A WELL MIXED LAYER TO ROUGHLY 50MB ABOVE THE
SURFACE IN THE POST FRONTAL ENVIRONMENT WILL ALSO CONTRIBUTE TO
THE GUSTY WINDS. THE HIGHEST WINDS SHOULD OCCUR ACROSS THE EASTERN
PLAINS WHERE THE HIGHER PRESSURE RISES COMBINE WITH STRONGEST
UPPER LEVEL WINDS...ESPECIALLY ALONG RIDGETOPS SUCH AS THE PINE
RIDGE...WILDCAT HILLS...AND CHEYENNE RIDGE. IN ADDITION TO THE
WINDS...GOOD QG AND FRONTAL FORCING WILL PRODUCE SHOWERS IN THE
EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. TEMPS WILL BE
WARM ENOUGH INITIALLY TO KEEP PRECIP LIQUID...BUT STRONG CAA WILL
BRING SNOW LEVELS DOWN TO NEAR 5KFT THRU THE EVENING SO EXPECT TO
SEE A TRANSITION FROM RAIN TO SNOW DURING THIS TIME. STILL LOOKS
LIKE THE BEST JUXTAPOSITION OF COLD AIR AND PRECIP CHANCES WILL
OCCUR FROM THE NORTHERN LARAMIE RANGE/DOUGLAS TO THE PINE RIDGE
AROUND SUNSET...SO WILL MAINTAIN THE FOCUS FOR LIGHT SNOW IN
THIS REGION. EXPECTING ACCUMS OF JUST A DUSTING TO ONE INCH.
CANNOT RULE OUT SNOW MIXING WITH RAIN FURTHER SOUTH IN THE EARLY
OVERNIGHT PERIOD AS WELL...BUT PRECIP AND THUS OVERALL CHANCE FOR
SNOW WILL DIMINISH AS THE FRONT RACES SOUTHEASTWARD AND UPPER
LEVEL FORCING DECOUPLES AND SHIFTS TO THE EAST. TEMPS WILL DROP TO
NEAR OR BELOW FREEZING VALUES OVERNIGHT...BUT WINDS SHOULD REMAIN
ELEVATED ENOUGH TO PREVENT WIDESPREAD FROST FORMATION SO WILL
REFRAIN FROM ISSUING HIGHLIGHTS.

FRIDAY WILL BE MUCH COOLER IN THE POST FRONTAL ENVIRONMENT WITH
BRISK NORTHWEST WINDS PERSISTING AS THE JET REMAINS OVER THE HIGH
PLAINS THRU THE AFTERNOON. DRY CONDITIONS WILL PREVAIL WITH MUCH
DRIER AIR AND SUBSIDENCE MOVING IN FROM THE WEST. THE UPPER JET
WILL STEADILY SHIFT EAST THRU THE EVENING AND OVERNIGHT WITH SKIES
PARTIALLY CLEARING AND SFC WINDS EXPECTED TO BE LIGHT. THIS WILL
INCREASE THE CHANCE FOR A MORE SUBSTANTIAL FROST/FREEZE FRIDAY
NIGHT...SO MAY HAVE TO CONSIDER FROST HIGHLIGHTS FOR THE EASTERN
PANHANDLE DURING THIS TIME.

DRY NORTHWEST FLOW WILL REMAIN OVERHEAD FOR SATURDAY WITH H7 TEMPS
INCREASING TO BETWEEN 2C AND 6C. THE LEESIDE PRESSURE TROUGH WILL
DEEPEN AS A WEAK PIECE OF ENERGY MOVES OVERHEAD IN THIS FLOW
PATTERN...SO WESTERLY WINDS WILL INCREASE ONCE AGAIN ALONG AND WEST
OF THE LARAMIE RANGE. MAX TEMPS LOOK TO RETURN TO THE 60S AND 70S
FOR MUCH OF THE AREA.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

DRY AND MILD CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE EXTENDED
FCST PERIOD. MEDIUM RANGE MODELS REMAIN IN EXCELLENT AGREEMENT WITH
THE OVERALL WEATHER PATTERN. THE CWA SHOULD REMAIN IN THE TRANSITION
ZONE BETWEEN DEEP TROUGHING OVER THE GREAT LAKES REGION AND AN UPPER
RIDGE BUILDING OVER THE WESTERN CONUS. THE UPPER-LEVEL FLOW PATTERN
LOOKS TO BE QUITE ACTIVE...BUT THE MAJORITY OF IMPULSES EMBEDDED IN
THE FLOW ARE EXPECTED TO REMAIN TO THE EAST OF THE CWA. HOWEVER THE
ECMWF STILL SUGGESTS LIGHT QPF OVER EAST CENTRAL WY AND THE NORTHERN
PANHANDLE ON SUN AFTN. THIS IS QUITE POSSIBLE WITH A BACKDOOR COOL
FRONT ENCROACHING ON THOSE ZONES ALONG WITH INCREASING DIFFLUENCE IN
THE EXIT REGION OF AN INTENSE 120+ KT H25 JET...BUT NAM/GFS HAVE
BEEN CONSISTENT WITH A DRY FCST AS BETTER FORCING IS OVER THE
PLAINS. REFRAINED FROM MENTION OF SHOWERS OR TSTMS ATTM. OTHERWISE
CONVECTIVE ACTIVITY WILL BE LACKING AS UPPER RIDGING BECOMES THE
DOMINANT FEATURE ALOFT. MAIN CHANGE TO TEMPERATURE GRIDS WAS TO
INCREASE HIGHS A FEW DEGREES FOR TUE AFTN. THE GFS SHOWS H7 TEMPS
APPROACHING 10C OVER THE PLAINS BY 18Z...AND ANY MIXING WOULD BRING
WESTERLY DOWNSLOPE WINDS DOWN TO THE SFC BY AFTN. TRENDED WARMER
THAN CONSENSUS GUIDANCE AS PATTERN SHOULD FAVOR TEMPS NEAR 80F IN
THE PANHANDLE...ESPECIALLY ALONG THE PLATTE RIVER VALLEY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 1135 PM MDT WED OCT 1 2014

BRIEF MVFR TO IFR CIGS WILL BE POSSIBLE OVER THE PANHANDLE SITES
AND KCYS THROUGH 09Z THU. CONDITIONS WILL IMPROVE ACROSS THE AREA
BEYOND THAT TIME WITH VFR PREVAILING THROUGH THE REMAINDER OF THE
TAF PERIOD. GUSTY WINDS EXPECTED FOR THU AFTN AS A COLD FRONT
MOVES ACROSS THE REGION.

&&

.FIRE WEATHER...
ISSUED AT 407 AM MDT THU OCT 2 2014

COOL AND BREEZY CONDITIONS WILL PERSIST OVER THE REGION TODAY AND
FRIDAY. A FAST MOVING CLIPPER SYSTEM WILL BRING A CHANCE FOR LIGHT
PRECIP THIS EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. RAIN
LOOKS TO MIX WITH SNOW POSSIBLY DOWN TO 5000 FEET OR SO...WITH THE
BEST CHANCE FOR SNOW ALONG A LINE FROM THE NORTHERN LARAMIE RANGE TO
THE PINE RIDGE. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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







000
FXUS65 KCYS 021007
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
407 AM MDT THU OCT 2 2014

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

RADAR HAS CLEARED OUT OVERNIGHT BUT A FEW AREAS OF MID AND HIGH
LEVEL CLOUDS REMAIN IN PLACE AS THE UPPER LEVEL TROUGH MOVES
OVERHEAD. COULD SEE SOME PATCHY FOG OVER THE FAR WESTERN ZONES IN
WEAK BUT MOIST WESTERLY UPSLOPE FLOW...INCLUDING THE HIGHER
TERRAIN SUCH AS THE SUMMIT. TODAY WILL BE COOL SIMILAR TO
YESTERDAY WITH H7 TEMPS PROGGED TO RANGE FROM -2C TO 2C FROM NORTH
TO SOUTH BY THIS AFTERNOON. WESTERLY WINDS WILL BE QUITE BLUSTERY
ALONG AND WEST OF THE LARAMIE RANGE TODAY IN ADVANCE OF THE NEXT
FAIRLY POTENT CLIPPER SYSTEM THAT WILL BLAST SOUTHEAST INTO THE
HIGH PLAINS FROM CANADA ON THE LEADING EDGE OF A 150KT JET THROUGH
THE AFTERNOON AND EVENING. A STRONG COLD FRONT ASSOCIATED WITH THIS
SYSTEM WILL RACE SOUTH ACROSS THE FORECAST AREA BETWEEN 23 AND 05Z
WITH 10-15MB/6HR PRESSURE RISES IN ITS WAKE. EXPECT NNW WINDS OF
20 TO 30 MPH GUSTING 35 TO 45 MPH FOR A BRIEF PERIOD BEHIND THE
FRONT DUE TO THE STRONG PRESSURE GRADIENT IN PLACE. FORECAST
SOUNDINGS SUGGEST A WELL MIXED LAYER TO ROUGHLY 50MB ABOVE THE
SURFACE IN THE POST FRONTAL ENVIRONMENT WILL ALSO CONTRIBUTE TO
THE GUSTY WINDS. THE HIGHEST WINDS SHOULD OCCUR ACROSS THE EASTERN
PLAINS WHERE THE HIGHER PRESSURE RISES COMBINE WITH STRONGEST
UPPER LEVEL WINDS...ESPECIALLY ALONG RIDGETOPS SUCH AS THE PINE
RIDGE...WILDCAT HILLS...AND CHEYENNE RIDGE. IN ADDITION TO THE
WINDS...GOOD QG AND FRONTAL FORCING WILL PRODUCE SHOWERS IN THE
EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. TEMPS WILL BE
WARM ENOUGH INITIALLY TO KEEP PRECIP LIQUID...BUT STRONG CAA WILL
BRING SNOW LEVELS DOWN TO NEAR 5KFT THRU THE EVENING SO EXPECT TO
SEE A TRANSITION FROM RAIN TO SNOW DURING THIS TIME. STILL LOOKS
LIKE THE BEST JUXTAPOSITION OF COLD AIR AND PRECIP CHANCES WILL
OCCUR FROM THE NORTHERN LARAMIE RANGE/DOUGLAS TO THE PINE RIDGE
AROUND SUNSET...SO WILL MAINTAIN THE FOCUS FOR LIGHT SNOW IN
THIS REGION. EXPECTING ACCUMS OF JUST A DUSTING TO ONE INCH.
CANNOT RULE OUT SNOW MIXING WITH RAIN FURTHER SOUTH IN THE EARLY
OVERNIGHT PERIOD AS WELL...BUT PRECIP AND THUS OVERALL CHANCE FOR
SNOW WILL DIMINISH AS THE FRONT RACES SOUTHEASTWARD AND UPPER
LEVEL FORCING DECOUPLES AND SHIFTS TO THE EAST. TEMPS WILL DROP TO
NEAR OR BELOW FREEZING VALUES OVERNIGHT...BUT WINDS SHOULD REMAIN
ELEVATED ENOUGH TO PREVENT WIDESPREAD FROST FORMATION SO WILL
REFRAIN FROM ISSUING HIGHLIGHTS.

FRIDAY WILL BE MUCH COOLER IN THE POST FRONTAL ENVIRONMENT WITH
BRISK NORTHWEST WINDS PERSISTING AS THE JET REMAINS OVER THE HIGH
PLAINS THRU THE AFTERNOON. DRY CONDITIONS WILL PREVAIL WITH MUCH
DRIER AIR AND SUBSIDENCE MOVING IN FROM THE WEST. THE UPPER JET
WILL STEADILY SHIFT EAST THRU THE EVENING AND OVERNIGHT WITH SKIES
PARTIALLY CLEARING AND SFC WINDS EXPECTED TO BE LIGHT. THIS WILL
INCREASE THE CHANCE FOR A MORE SUBSTANTIAL FROST/FREEZE FRIDAY
NIGHT...SO MAY HAVE TO CONSIDER FROST HIGHLIGHTS FOR THE EASTERN
PANHANDLE DURING THIS TIME.

DRY NORTHWEST FLOW WILL REMAIN OVERHEAD FOR SATURDAY WITH H7 TEMPS
INCREASING TO BETWEEN 2C AND 6C. THE LEESIDE PRESSURE TROUGH WILL
DEEPEN AS A WEAK PIECE OF ENERGY MOVES OVERHEAD IN THIS FLOW
PATTERN...SO WESTERLY WINDS WILL INCREASE ONCE AGAIN ALONG AND WEST
OF THE LARAMIE RANGE. MAX TEMPS LOOK TO RETURN TO THE 60S AND 70S
FOR MUCH OF THE AREA.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 407 AM MDT THU OCT 2 2014

DRY AND MILD CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE EXTENDED
FCST PERIOD. MEDIUM RANGE MODELS REMAIN IN EXCELLENT AGREEMENT WITH
THE OVERALL WEATHER PATTERN. THE CWA SHOULD REMAIN IN THE TRANSITION
ZONE BETWEEN DEEP TROUGHING OVER THE GREAT LAKES REGION AND AN UPPER
RIDGE BUILDING OVER THE WESTERN CONUS. THE UPPER-LEVEL FLOW PATTERN
LOOKS TO BE QUITE ACTIVE...BUT THE MAJORITY OF IMPULSES EMBEDDED IN
THE FLOW ARE EXPECTED TO REMAIN TO THE EAST OF THE CWA. HOWEVER THE
ECMWF STILL SUGGESTS LIGHT QPF OVER EAST CENTRAL WY AND THE NORTHERN
PANHANDLE ON SUN AFTN. THIS IS QUITE POSSIBLE WITH A BACKDOOR COOL
FRONT ENCROACHING ON THOSE ZONES ALONG WITH INCREASING DIFFLUENCE IN
THE EXIT REGION OF AN INTENSE 120+ KT H25 JET...BUT NAM/GFS HAVE
BEEN CONSISTENT WITH A DRY FCST AS BETTER FORCING IS OVER THE
PLAINS. REFRAINED FROM MENTION OF SHOWERS OR TSTMS ATTM. OTHERWISE
CONVECTIVE ACTIVITY WILL BE LACKING AS UPPER RIDGING BECOMES THE
DOMINANT FEATURE ALOFT. MAIN CHANGE TO TEMPERATURE GRIDS WAS TO
INCREASE HIGHS A FEW DEGREES FOR TUE AFTN. THE GFS SHOWS H7 TEMPS
APPROACHING 10C OVER THE PLAINS BY 18Z...AND ANY MIXING WOULD BRING
WESTERLY DOWNSLOPE WINDS DOWN TO THE SFC BY AFTN. TRENDED WARMER
THAN CONSENSUS GUIDANCE AS PATTERN SHOULD FAVOR TEMPS NEAR 80F IN
THE PANHANDLE...ESPECIALLY ALONG THE PLATTE RIVER VALLEY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 1135 PM MDT WED OCT 1 2014

BRIEF MVFR TO IFR CIGS WILL BE POSSIBLE OVER THE PANHANDLE SITES
AND KCYS THROUGH 09Z THU. CONDITIONS WILL IMPROVE ACROSS THE AREA
BEYOND THAT TIME WITH VFR PREVAILING THROUGH THE REMAINDER OF THE
TAF PERIOD. GUSTY WINDS EXPECTED FOR THU AFTN AS A COLD FRONT
MOVES ACROSS THE REGION.

&&

.FIRE WEATHER...
ISSUED AT 407 AM MDT THU OCT 2 2014

COOL AND BREEZY CONDITIONS WILL PERSIST OVER THE REGION TODAY AND
FRIDAY. A FAST MOVING CLIPPER SYSTEM WILL BRING A CHANCE FOR LIGHT
PRECIP THIS EVENING MAINLY ALONG AND EAST OF THE LARAMIE RANGE. RAIN
LOOKS TO MIX WITH SNOW POSSIBLY DOWN TO 5000 FEET OR SO...WITH THE
BEST CHANCE FOR SNOW ALONG A LINE FROM THE NORTHERN LARAMIE RANGE TO
THE PINE RIDGE. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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







  [top]

000
FXUS63 KUNR 020924
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
324 AM MDT THU OCT 2 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 323 AM MDT THU OCT 2 2014

OVERALL CYCLONIC FLOW CONTINUING ACROSS ACROSS THE CENTRAL THIRD
OF THE CONUS...WITH A STRONG UPPER WAVE NOW CROSSING THE CENTRAL
DAKOTAS DOWN TO THE ERN CO PLAINS. A SECONDARY WAVE IS CROSSING
ALBERTA INTO MT...WITH WEAK RIDGING NOW ACROSS WRN HALF OF THE
DAKOTAS INTO WYOMING. THE UPPER WAVE WILL APPROACH ALONG WITH A
STRONG COLD FRONT THIS AFTERNOON AND EVENING. MODELS ARE SHOWING
AGREEMENT WITH THE FRONTAL PASSAGE ENTERING NW SD LATER THIS
AFTERNOON AND QUICKLY PUSHING ACROSS THE CWA...EXITING TO NEB BY
AROUND 02Z. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE
FRONT...WHICH AT THIS TIME IS LOOKING LIKE IT WILL BE MARGINALLY
AT WIND ADVISORY CRITERIA. POSSIBLY THE INITIAL PUSH WILL HAVE
STRONGER GUSTS...BEFORE SETTLING AN HOUR OR TWO LATER. HAVE
DECIDED AGAINST ANY HEADLINES AT THIS TIME...BUT THE DAYSHIFT WILL
NEED TO TAKE A SECOND LOOK WITH 12Z MODEL DATA. SHOWERS ARE
EXPECTED TO DEVELOP AHEAD OF THE FRONTAL PUSH...BUT LITTLE QPF IS
EXPECTED AS THE SHOWERS PUSH THROUGH QUICKLY.

STRONG PRESSURE GRADIENT WILL REMAIN THROUGH FRIDAY WITH LL MIXING
INCREASING WINDS THROUGH THE DAY. WINDIEST CONDITIONS WILL BE ACROSS
THE ERN TWO THIRDS OF SD...BUT A GOOD PORTION OF THE WRN SD PLAINS
MAY NEED WIND HEADLINES. OTHERWISE FRIDAY WILL BE A QUIET DAY AND
SUNNY SKIES. MODELS SLOWED DOWN THE EXIT OF THE COLD AIRMASS...SO
HAVE DROPPED TEMPS 5-10 DEGREES. LOOKS LIKE HIGHS FRIDAY WILL BE IN
THE 40S TO LOWER 50S. STRONG SURFACE HIGH WILL SLIDE INTO THE REGION
FRIDAY NIGHT WITH WINDS QUICKLY DECREASING TO LIGHT AND VARIABLE.
WITH CLEAR SKIES AND LIGHT WINDS...TEMPS ARE EXPECTED TO DROP INTO
THE UPPER 20S TO MID 30S ACROSS MOST LOCATIONS. A FREEZE LOOKS
MARGINAL FOR SCNTRL SD FRI NIGHT...BUT ITS POSSIBLE...AND HEADLINES
MAY BE NEEDED.

&&

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 323 AM MDT THU OCT 2 2014

DEEP UPPER TROF WILL PERSIST OVER THE GREAT LAKES THROUGH EARLY
NEXT WEEK BEFORE WEAKENING AND LIFTING NORTH. CYCLONIC NW FLOW
ACRS THE NRN PLAINS ON SUNDAY WILL LEAD TO BREEZY
CONDITIONS...ALONG WITH A FEW SHOWERS IN THE BLKHLS GIVEN STEEP LO
LVL LAPSE RATES. ZONAL FLOW TO WEAK RIDGING WILL THEN BUILD INTO
THE NRN PLAINS AND PERSIST THROUGH THE WEEK. THIS WILL LEAD TO
MAINLY DRY CONDITIONS ALONG WITH NEAR OR SLIGHTLY ABOVE AVERAGE.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING
ISSUED AT 323 AM MDT THU OCT 2 2014

SCATTERED SHOWERS WILL LINGER THROUGH THE NIGHT ACROSS SOUTH
CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH THE SHOWERS. VFR
CONDITIONS ELSEWHERE. A STRONG COLD FRONT WILL MOVE THROUGH
NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THIS AFTERNOON AND
EVENING...PRODUCING GUSTY NORTHWEST WINDS TO AROUND 35 KNOTS.
BRIEF MVFR CIGS MAY ALSO ACCOMPANY THE FRONT...MOSTLY OVER
NORTHEAST WYOMING AND THE BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...13
LONG TERM...JOHNSON
AVIATION...JOHNSON






000
FXUS63 KUNR 020924
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
324 AM MDT THU OCT 2 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 323 AM MDT THU OCT 2 2014

OVERALL CYCLONIC FLOW CONTINUING ACROSS ACROSS THE CENTRAL THIRD
OF THE CONUS...WITH A STRONG UPPER WAVE NOW CROSSING THE CENTRAL
DAKOTAS DOWN TO THE ERN CO PLAINS. A SECONDARY WAVE IS CROSSING
ALBERTA INTO MT...WITH WEAK RIDGING NOW ACROSS WRN HALF OF THE
DAKOTAS INTO WYOMING. THE UPPER WAVE WILL APPROACH ALONG WITH A
STRONG COLD FRONT THIS AFTERNOON AND EVENING. MODELS ARE SHOWING
AGREEMENT WITH THE FRONTAL PASSAGE ENTERING NW SD LATER THIS
AFTERNOON AND QUICKLY PUSHING ACROSS THE CWA...EXITING TO NEB BY
AROUND 02Z. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE
FRONT...WHICH AT THIS TIME IS LOOKING LIKE IT WILL BE MARGINALLY
AT WIND ADVISORY CRITERIA. POSSIBLY THE INITIAL PUSH WILL HAVE
STRONGER GUSTS...BEFORE SETTLING AN HOUR OR TWO LATER. HAVE
DECIDED AGAINST ANY HEADLINES AT THIS TIME...BUT THE DAYSHIFT WILL
NEED TO TAKE A SECOND LOOK WITH 12Z MODEL DATA. SHOWERS ARE
EXPECTED TO DEVELOP AHEAD OF THE FRONTAL PUSH...BUT LITTLE QPF IS
EXPECTED AS THE SHOWERS PUSH THROUGH QUICKLY.

STRONG PRESSURE GRADIENT WILL REMAIN THROUGH FRIDAY WITH LL MIXING
INCREASING WINDS THROUGH THE DAY. WINDIEST CONDITIONS WILL BE ACROSS
THE ERN TWO THIRDS OF SD...BUT A GOOD PORTION OF THE WRN SD PLAINS
MAY NEED WIND HEADLINES. OTHERWISE FRIDAY WILL BE A QUIET DAY AND
SUNNY SKIES. MODELS SLOWED DOWN THE EXIT OF THE COLD AIRMASS...SO
HAVE DROPPED TEMPS 5-10 DEGREES. LOOKS LIKE HIGHS FRIDAY WILL BE IN
THE 40S TO LOWER 50S. STRONG SURFACE HIGH WILL SLIDE INTO THE REGION
FRIDAY NIGHT WITH WINDS QUICKLY DECREASING TO LIGHT AND VARIABLE.
WITH CLEAR SKIES AND LIGHT WINDS...TEMPS ARE EXPECTED TO DROP INTO
THE UPPER 20S TO MID 30S ACROSS MOST LOCATIONS. A FREEZE LOOKS
MARGINAL FOR SCNTRL SD FRI NIGHT...BUT ITS POSSIBLE...AND HEADLINES
MAY BE NEEDED.

&&

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 323 AM MDT THU OCT 2 2014

DEEP UPPER TROF WILL PERSIST OVER THE GREAT LAKES THROUGH EARLY
NEXT WEEK BEFORE WEAKENING AND LIFTING NORTH. CYCLONIC NW FLOW
ACRS THE NRN PLAINS ON SUNDAY WILL LEAD TO BREEZY
CONDITIONS...ALONG WITH A FEW SHOWERS IN THE BLKHLS GIVEN STEEP LO
LVL LAPSE RATES. ZONAL FLOW TO WEAK RIDGING WILL THEN BUILD INTO
THE NRN PLAINS AND PERSIST THROUGH THE WEEK. THIS WILL LEAD TO
MAINLY DRY CONDITIONS ALONG WITH NEAR OR SLIGHTLY ABOVE AVERAGE.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING
ISSUED AT 323 AM MDT THU OCT 2 2014

SCATTERED SHOWERS WILL LINGER THROUGH THE NIGHT ACROSS SOUTH
CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH THE SHOWERS. VFR
CONDITIONS ELSEWHERE. A STRONG COLD FRONT WILL MOVE THROUGH
NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THIS AFTERNOON AND
EVENING...PRODUCING GUSTY NORTHWEST WINDS TO AROUND 35 KNOTS.
BRIEF MVFR CIGS MAY ALSO ACCOMPANY THE FRONT...MOSTLY OVER
NORTHEAST WYOMING AND THE BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...13
LONG TERM...JOHNSON
AVIATION...JOHNSON






000
FXUS63 KUNR 020924
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
324 AM MDT THU OCT 2 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 323 AM MDT THU OCT 2 2014

OVERALL CYCLONIC FLOW CONTINUING ACROSS ACROSS THE CENTRAL THIRD
OF THE CONUS...WITH A STRONG UPPER WAVE NOW CROSSING THE CENTRAL
DAKOTAS DOWN TO THE ERN CO PLAINS. A SECONDARY WAVE IS CROSSING
ALBERTA INTO MT...WITH WEAK RIDGING NOW ACROSS WRN HALF OF THE
DAKOTAS INTO WYOMING. THE UPPER WAVE WILL APPROACH ALONG WITH A
STRONG COLD FRONT THIS AFTERNOON AND EVENING. MODELS ARE SHOWING
AGREEMENT WITH THE FRONTAL PASSAGE ENTERING NW SD LATER THIS
AFTERNOON AND QUICKLY PUSHING ACROSS THE CWA...EXITING TO NEB BY
AROUND 02Z. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE
FRONT...WHICH AT THIS TIME IS LOOKING LIKE IT WILL BE MARGINALLY
AT WIND ADVISORY CRITERIA. POSSIBLY THE INITIAL PUSH WILL HAVE
STRONGER GUSTS...BEFORE SETTLING AN HOUR OR TWO LATER. HAVE
DECIDED AGAINST ANY HEADLINES AT THIS TIME...BUT THE DAYSHIFT WILL
NEED TO TAKE A SECOND LOOK WITH 12Z MODEL DATA. SHOWERS ARE
EXPECTED TO DEVELOP AHEAD OF THE FRONTAL PUSH...BUT LITTLE QPF IS
EXPECTED AS THE SHOWERS PUSH THROUGH QUICKLY.

STRONG PRESSURE GRADIENT WILL REMAIN THROUGH FRIDAY WITH LL MIXING
INCREASING WINDS THROUGH THE DAY. WINDIEST CONDITIONS WILL BE ACROSS
THE ERN TWO THIRDS OF SD...BUT A GOOD PORTION OF THE WRN SD PLAINS
MAY NEED WIND HEADLINES. OTHERWISE FRIDAY WILL BE A QUIET DAY AND
SUNNY SKIES. MODELS SLOWED DOWN THE EXIT OF THE COLD AIRMASS...SO
HAVE DROPPED TEMPS 5-10 DEGREES. LOOKS LIKE HIGHS FRIDAY WILL BE IN
THE 40S TO LOWER 50S. STRONG SURFACE HIGH WILL SLIDE INTO THE REGION
FRIDAY NIGHT WITH WINDS QUICKLY DECREASING TO LIGHT AND VARIABLE.
WITH CLEAR SKIES AND LIGHT WINDS...TEMPS ARE EXPECTED TO DROP INTO
THE UPPER 20S TO MID 30S ACROSS MOST LOCATIONS. A FREEZE LOOKS
MARGINAL FOR SCNTRL SD FRI NIGHT...BUT ITS POSSIBLE...AND HEADLINES
MAY BE NEEDED.

&&

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 323 AM MDT THU OCT 2 2014

DEEP UPPER TROF WILL PERSIST OVER THE GREAT LAKES THROUGH EARLY
NEXT WEEK BEFORE WEAKENING AND LIFTING NORTH. CYCLONIC NW FLOW
ACRS THE NRN PLAINS ON SUNDAY WILL LEAD TO BREEZY
CONDITIONS...ALONG WITH A FEW SHOWERS IN THE BLKHLS GIVEN STEEP LO
LVL LAPSE RATES. ZONAL FLOW TO WEAK RIDGING WILL THEN BUILD INTO
THE NRN PLAINS AND PERSIST THROUGH THE WEEK. THIS WILL LEAD TO
MAINLY DRY CONDITIONS ALONG WITH NEAR OR SLIGHTLY ABOVE AVERAGE.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING
ISSUED AT 323 AM MDT THU OCT 2 2014

SCATTERED SHOWERS WILL LINGER THROUGH THE NIGHT ACROSS SOUTH
CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH THE SHOWERS. VFR
CONDITIONS ELSEWHERE. A STRONG COLD FRONT WILL MOVE THROUGH
NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THIS AFTERNOON AND
EVENING...PRODUCING GUSTY NORTHWEST WINDS TO AROUND 35 KNOTS.
BRIEF MVFR CIGS MAY ALSO ACCOMPANY THE FRONT...MOSTLY OVER
NORTHEAST WYOMING AND THE BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...13
LONG TERM...JOHNSON
AVIATION...JOHNSON






000
FXUS63 KUNR 020924
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
324 AM MDT THU OCT 2 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 323 AM MDT THU OCT 2 2014

OVERALL CYCLONIC FLOW CONTINUING ACROSS ACROSS THE CENTRAL THIRD
OF THE CONUS...WITH A STRONG UPPER WAVE NOW CROSSING THE CENTRAL
DAKOTAS DOWN TO THE ERN CO PLAINS. A SECONDARY WAVE IS CROSSING
ALBERTA INTO MT...WITH WEAK RIDGING NOW ACROSS WRN HALF OF THE
DAKOTAS INTO WYOMING. THE UPPER WAVE WILL APPROACH ALONG WITH A
STRONG COLD FRONT THIS AFTERNOON AND EVENING. MODELS ARE SHOWING
AGREEMENT WITH THE FRONTAL PASSAGE ENTERING NW SD LATER THIS
AFTERNOON AND QUICKLY PUSHING ACROSS THE CWA...EXITING TO NEB BY
AROUND 02Z. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE
FRONT...WHICH AT THIS TIME IS LOOKING LIKE IT WILL BE MARGINALLY
AT WIND ADVISORY CRITERIA. POSSIBLY THE INITIAL PUSH WILL HAVE
STRONGER GUSTS...BEFORE SETTLING AN HOUR OR TWO LATER. HAVE
DECIDED AGAINST ANY HEADLINES AT THIS TIME...BUT THE DAYSHIFT WILL
NEED TO TAKE A SECOND LOOK WITH 12Z MODEL DATA. SHOWERS ARE
EXPECTED TO DEVELOP AHEAD OF THE FRONTAL PUSH...BUT LITTLE QPF IS
EXPECTED AS THE SHOWERS PUSH THROUGH QUICKLY.

STRONG PRESSURE GRADIENT WILL REMAIN THROUGH FRIDAY WITH LL MIXING
INCREASING WINDS THROUGH THE DAY. WINDIEST CONDITIONS WILL BE ACROSS
THE ERN TWO THIRDS OF SD...BUT A GOOD PORTION OF THE WRN SD PLAINS
MAY NEED WIND HEADLINES. OTHERWISE FRIDAY WILL BE A QUIET DAY AND
SUNNY SKIES. MODELS SLOWED DOWN THE EXIT OF THE COLD AIRMASS...SO
HAVE DROPPED TEMPS 5-10 DEGREES. LOOKS LIKE HIGHS FRIDAY WILL BE IN
THE 40S TO LOWER 50S. STRONG SURFACE HIGH WILL SLIDE INTO THE REGION
FRIDAY NIGHT WITH WINDS QUICKLY DECREASING TO LIGHT AND VARIABLE.
WITH CLEAR SKIES AND LIGHT WINDS...TEMPS ARE EXPECTED TO DROP INTO
THE UPPER 20S TO MID 30S ACROSS MOST LOCATIONS. A FREEZE LOOKS
MARGINAL FOR SCNTRL SD FRI NIGHT...BUT ITS POSSIBLE...AND HEADLINES
MAY BE NEEDED.

&&

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 323 AM MDT THU OCT 2 2014

DEEP UPPER TROF WILL PERSIST OVER THE GREAT LAKES THROUGH EARLY
NEXT WEEK BEFORE WEAKENING AND LIFTING NORTH. CYCLONIC NW FLOW
ACRS THE NRN PLAINS ON SUNDAY WILL LEAD TO BREEZY
CONDITIONS...ALONG WITH A FEW SHOWERS IN THE BLKHLS GIVEN STEEP LO
LVL LAPSE RATES. ZONAL FLOW TO WEAK RIDGING WILL THEN BUILD INTO
THE NRN PLAINS AND PERSIST THROUGH THE WEEK. THIS WILL LEAD TO
MAINLY DRY CONDITIONS ALONG WITH NEAR OR SLIGHTLY ABOVE AVERAGE.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING
ISSUED AT 323 AM MDT THU OCT 2 2014

SCATTERED SHOWERS WILL LINGER THROUGH THE NIGHT ACROSS SOUTH
CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH THE SHOWERS. VFR
CONDITIONS ELSEWHERE. A STRONG COLD FRONT WILL MOVE THROUGH
NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THIS AFTERNOON AND
EVENING...PRODUCING GUSTY NORTHWEST WINDS TO AROUND 35 KNOTS.
BRIEF MVFR CIGS MAY ALSO ACCOMPANY THE FRONT...MOSTLY OVER
NORTHEAST WYOMING AND THE BLKHLS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...13
LONG TERM...JOHNSON
AVIATION...JOHNSON





  [top]

000
FXUS65 KRIW 020906
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
306 AM MDT THU OCT 2 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

LW TROF ACROSS THE CONUS...BOOKENDED BY RIDGES OVR EACH OCEAN.
TROF AXIS HAS NOW PASSED THRU THE FA AND IS CURRENTLY ALIGNED NEAR
ALONG THE ERN WY BORDER...PUTTING THE CWA UNDER NW FLOW. UPSTREAM
IN THE UPR LVLS...NEXT SW/JET STREAK MOVING THRU THE MAIN FLOW IS
CURRENTLY LOCATED OVR SWRN CANADA...AND WILL ARRIVE LATER TODAY.
AT THE SFC...HIGH PRESSURE INCREASING ACROSS THE STATE WITH A
DEVELOPING FRONT WELL TO THE NORTH OVR SRN CA. THIS FEATURE WILL
BE PUSHED SWD BY THE ADVANCE OF THE UPR LVL SW.

TODAY/TONIGHT...LIGHT MIXING WINDS NEAR SFC ALONG WITH INCREASING
DRY DENSE AIR ALOFT OVERRUNNING A MODESTLY MOIST BOUNDARY LAYER WILL
POSSIBLY MAKE FOR AREAS OF PATCHY FOG TO BEGIN THE DAY.
OTHERWISE...FLAT TO MODEST RIDGING WILL QUICKLY GIVE WAY TO THE UPR
SW MENTIONED ABOVE AS IT SWINGS THRU THE BACKSIDE OF THE MAIN
TROF...DRIVING THE AFOREMENTIONED DEVELOPING COLD FRONT DOWN THRU
THE FA EAST OF THE DIVIDE IN A CLIPPER-LIKE FASHION IN THE AFTERNOON
AND EVENING. SPEED AND MODEST MOISTURE WILL BE THE LIMITING FACTORS
WITH THIS FEATURE. WHILE PRECIP CHANCES WILL DEFINITELY INCREASE E
OF THE DIVIDE...MAINLY ACROSS THE NRN MOUNTAINS...BIGHORN
BASIN...AND JOHNSON AND NATRONA COUNTIES...QPF LL REMAIN ON THE LOW
SIDE OF THINGS. CHANCES FOR LIGHT SNOW WILL BE POSSIBLE ACROSS THE
MOUNTAINS ONCE AGAIN ABOVE STARTING OUT JUST ABOVE 7000 FEET...BUT
LOWERING RATHER QUICKLY BEHIND THE FRONT TO BASIN LEVEL DURING THE
EVENING PERIOD. MEASURABLE AMOUNTS OF SNOW ATTM LOOK TO REMAIN
MOSTLY IN THE MOUNTAINS WITH AN INCH OR TWO AT MOST FROM THIS QUICK
MOVING SYSTEM. THE LOWER LEVELS OF JOHNSON...NATRONA...BIG HORN AND
PERHAPS EVEN FREMONT COUNTIES WILL PERHAPS BE PRIVY TO TRACE TO A
FEW TENTHS OF AN INCH OF SNOW. THIS SYSTEM WILL QUICKLY MOVE OUT OF
THE AREA OVERNIGHT...LEAVING MAINLY CLEAR COLD AND DRY SKIES BY FRI
MORNING. HAVE LOWERED MIN TEMPS TO FIT THIS PROFILE UNDER H7 TEMPS
RANGING FROM -7 TO -9 DEG C. OTHERWISE/ELSEWHERE...BREEZY TO LOW END
WINDY CONDITIONS WILL BE THE STORY OF THE DAY ACROSS THE FA...AS A
MODESTLY STRENGTHENING SFC P GRAD COMBINES WILL GREATLY INCREASING
UPR LVL FLOW UNDER MODEST INSTABILITY THROUGH THE DAY TO GIVE WEST
WINDS CAPABLE OF GUSTS OF 30 TO 40 MPH BY AFTERNOON.
ADDITIONALLY...WINDS WILL ALSO INCREASE AND BECOME GUSTY NORTHERLY
BEHIND THE FRONT LATE IN THE AFTERNOON AND INTO THE EVENING AS A
STRONG E/W ORIENTED P GRAD IS INTRODUCED TO THE FA...TRAVELING FROM
N TO S.

FRI/SAT...STRONG SFC HIGH P IN PLACE STILL UNDER RELATIVELY STRONG
NW FLOW TO BEGIN THE DAY FRIDAY...WITH MOSTLY SUNNY/DRY AND WARMING
CONDITIONS CWA WIDE. WINDS WILL ACCORDINGLY DROP FROM WHAT THEY WERE
THE PREVIOUS DAY AS THE SFC P GRAD WEAKENS UNDER THE HIGH PRESSURE
IN ADDITION TO WEAKENING WINDS ALOFT. SAT...HIGH PRESSURE BEGINS TO
WEAKEN AS LL WARMING CONTINUES AND LOWER PRESSURE IS INTRODUCED.
SFC TO 700 MB LAPSE RATES WILL BECOME UNSTABLE ENOUGH TO BRING DOWN
WINDS FROM ALOFT THIS DAY...RESULTING IN MODERATELY GUSTY W WINDS
MAINLY W OF THE DIVIDE AND OVR THE HIGHER MOUNTAINS...ALTHOUGH NOT
NEARLY AS STRONG AS THOSE OF TODAY. EARLY IN THE DAY ON SAT...A
SLIGHT INCREASE IN MAINLY MID LVL MOISTURE MAY INTRODUCE AN ISOLATED
SHOWER OR TWO OVR THE NRN HIGH MOUNTAINS...BUT NOTHING WORTH
MEASURING AT THIS POINT.

.LONG TERM...SUNDAY THROUGH THURSDAY

SYNOPSIS...NORTHWEST FLOW ALOFT WILL PREVAIL SUNDAY AND MONDAY
BETWEEN AN UPPER RIDGE ALONG THE WEST COAST AND UPPER TROUGH ACROSS
THE EASTERN U.S.   THIS FLOW WILL BECOME MORE ZONAL OR WESTERLY
TUESDAY THROUGH THURSDAY WITH POSSIBLY SOME RAIN AND SNOW SHOWERS
PUSHING INTO THE NORTHERN MOUNTAINS WEDNESDAY AND THURSDAY.

DISCUSSION...A CLIPPER IN NW FLOW WILL DIVE SOUTHEAST ACROSS THE
NORTHERN HIGH PLAINS SUNDAY AROUND BACKSIDE OF UPPER LOW OVER
ONTARIO THAT IS EXPECTED TO WOBBLE SLIGHTLY WESTWARD.  ECMWF
GENERATES SOME PRECIPITATION ACROSS EASTERN WYOMING...IN THE VCNTY
OF THE BIGHORNS AND ALONG AND EAST OF I-25...WHILE THE GFS KEEPS
THINGS DRY.   BOTH MODELS SHOW SOME CONTINUITY WITH THEIR RESPECTIVE
QPF FIELDS.  WE CONTINUED THE IDEA OF A DRY FORECAST ON SUNDAY WITH
OUR NEIGHBORS TO THE NORTH AND EAST ALSO KEEPING ANY CHANCES OF
PRECIPITATION WELL AWAY FROM OUR BORDERS FOR NOW.  TEMPERATURES WERE
COOLED A FEW DEGREES ACROSS EASTERN ZONES ON THE EDGE OF A DEEPER
COLDER AIRMASS SPILLING INTO THE NORTHERN PLAINS.

FLOW BACKS MONDAY WITH WEAK WARM ADVECTION RESULTING IN TEMPERATURES
A FEW DEGREES WARMER.

TRANSITION TO A MORE ZONAL FLOW BEGINS ON TUESDAY AS UPPER TROUGH
LIFTS OUT OF THE EASTERN U.S. AND OMEGA BLOCK BREAKS DOWN OVER
ALASKA/BERING SEA.  ECMWF AND GFS IN BETTER AGREEMENT KEEPING MEAN
RIDGE JUST OF THE WEST COAST WEDNESDAY AND THURSDAY WITH ELONGATED
W-E TROUGH DOWNSTREAM ACROSS CANADA.  THUS...ANY FRONTAL INTRUSIONS
FROM THE NORTH LATE IN THE WEEK WILL LIKELY BE SHALLOW AND MAINLY
DRY...COOLING TEMPERATURES BY ONLY A FEW DEGREES.  SLIGHT CHANCE
POPS WERE KEPT IN THE NORTHERN MOUNTAINS WEDNESDAY AND THURSDAY AS
WESTERLY FLOW MOISTENS UP A BIT.


&&

.AVIATION.../12Z ISSUANCE/

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

PATCHY LOW LYING FOG IS POSSIBLE IN THE CENTRAL BASINS UNTIL 15Z.
A NEW COLD FRONT WILL MOVE INTO NORTHERN WY AROUND 21Z AND MOVE
QUICKLY SOUTH INTO CENTRAL WY AFTER 01Z. RAIN SHOWERS WILL TURN TO
SNOW SHOWERS OVER NORTHERN WY BY 00Z WITH MVFR TO IFR CONDITIONS
AND MOUNTAIN OBSCURATION. THE RAIN AND SNOW SHOWERS WILL MOVE INTO
CENTRAL WY BY 03Z AND CONTINUE UNTIL 09Z WITH MVFR TO IFR CONDITIONS
AND MOUNTAIN OBSCURATION. CONDITIONS OVER THE NORTH WILL IMPROVE
AFTER 06Z FRIDAY. PLEASE SEE INDIVIDUAL TAF SITES FOR MORE DETAILS.

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

PATCHY LOW FOG AND LOW CLOUDS WILL OCCUR UNTIL 16Z WITH LOCAL MVFR
TO IFR CONDITIONS. VFR CONDITIONS WILL OCCUR OVER THE REGION THROUGH
TONIGHT. ISOLATED RAIN OR SNOW SHOWERS WILL OCCUR IN THE NW WY
MOUNTAINS LATE IN THE AFTERNOON INTO THE EVENING...ENDING BY 06Z
FRIDAY. EXPECT GUSTY WIND AT THE TAF SITES BY 18Z UNTIL 01Z. KRKS
WILL SEE A WIND SHIFT AFTER 06Z AS THE COLD FRONT BRUSHES BY THAT
AREA.

&&

.FIRE WEATHER...

FIRE DANGER WILL REMAIN LOW ACROSS THE FORECAST AREA THROUGH THE
REST OF THE WEEK. HOWEVER...BREEZY TO WINDY CONDITIONS WILL DEVELOP
TODAY AS SURFACE LOW PRESSURE IS REPLACED BY HIGH PRESSURE AND UPPER
LEVEL WINDS BEGIN TO INCREASE IN RESPONSE TO A STRENGTHENING UPPER
LEVEL JET STREAK. ADDITIONALLY...ANOTHER CHANCE FOR LIGHT
PRECIPITATION...BOTH LIQUID AND FROZEN...WILL PRESENT ITSELF LATER
THIS AFTERNOON AND INTO EVENING...MAINLY EAST OF THE DIVIDE AS
ANOTHER COLD FRONT PUSHES SOUTH ACROSS THE FORECAST AREA.

&&

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

$$

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









000
FXUS65 KRIW 020906
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
306 AM MDT THU OCT 2 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

LW TROF ACROSS THE CONUS...BOOKENDED BY RIDGES OVR EACH OCEAN.
TROF AXIS HAS NOW PASSED THRU THE FA AND IS CURRENTLY ALIGNED NEAR
ALONG THE ERN WY BORDER...PUTTING THE CWA UNDER NW FLOW. UPSTREAM
IN THE UPR LVLS...NEXT SW/JET STREAK MOVING THRU THE MAIN FLOW IS
CURRENTLY LOCATED OVR SWRN CANADA...AND WILL ARRIVE LATER TODAY.
AT THE SFC...HIGH PRESSURE INCREASING ACROSS THE STATE WITH A
DEVELOPING FRONT WELL TO THE NORTH OVR SRN CA. THIS FEATURE WILL
BE PUSHED SWD BY THE ADVANCE OF THE UPR LVL SW.

TODAY/TONIGHT...LIGHT MIXING WINDS NEAR SFC ALONG WITH INCREASING
DRY DENSE AIR ALOFT OVERRUNNING A MODESTLY MOIST BOUNDARY LAYER WILL
POSSIBLY MAKE FOR AREAS OF PATCHY FOG TO BEGIN THE DAY.
OTHERWISE...FLAT TO MODEST RIDGING WILL QUICKLY GIVE WAY TO THE UPR
SW MENTIONED ABOVE AS IT SWINGS THRU THE BACKSIDE OF THE MAIN
TROF...DRIVING THE AFOREMENTIONED DEVELOPING COLD FRONT DOWN THRU
THE FA EAST OF THE DIVIDE IN A CLIPPER-LIKE FASHION IN THE AFTERNOON
AND EVENING. SPEED AND MODEST MOISTURE WILL BE THE LIMITING FACTORS
WITH THIS FEATURE. WHILE PRECIP CHANCES WILL DEFINITELY INCREASE E
OF THE DIVIDE...MAINLY ACROSS THE NRN MOUNTAINS...BIGHORN
BASIN...AND JOHNSON AND NATRONA COUNTIES...QPF LL REMAIN ON THE LOW
SIDE OF THINGS. CHANCES FOR LIGHT SNOW WILL BE POSSIBLE ACROSS THE
MOUNTAINS ONCE AGAIN ABOVE STARTING OUT JUST ABOVE 7000 FEET...BUT
LOWERING RATHER QUICKLY BEHIND THE FRONT TO BASIN LEVEL DURING THE
EVENING PERIOD. MEASURABLE AMOUNTS OF SNOW ATTM LOOK TO REMAIN
MOSTLY IN THE MOUNTAINS WITH AN INCH OR TWO AT MOST FROM THIS QUICK
MOVING SYSTEM. THE LOWER LEVELS OF JOHNSON...NATRONA...BIG HORN AND
PERHAPS EVEN FREMONT COUNTIES WILL PERHAPS BE PRIVY TO TRACE TO A
FEW TENTHS OF AN INCH OF SNOW. THIS SYSTEM WILL QUICKLY MOVE OUT OF
THE AREA OVERNIGHT...LEAVING MAINLY CLEAR COLD AND DRY SKIES BY FRI
MORNING. HAVE LOWERED MIN TEMPS TO FIT THIS PROFILE UNDER H7 TEMPS
RANGING FROM -7 TO -9 DEG C. OTHERWISE/ELSEWHERE...BREEZY TO LOW END
WINDY CONDITIONS WILL BE THE STORY OF THE DAY ACROSS THE FA...AS A
MODESTLY STRENGTHENING SFC P GRAD COMBINES WILL GREATLY INCREASING
UPR LVL FLOW UNDER MODEST INSTABILITY THROUGH THE DAY TO GIVE WEST
WINDS CAPABLE OF GUSTS OF 30 TO 40 MPH BY AFTERNOON.
ADDITIONALLY...WINDS WILL ALSO INCREASE AND BECOME GUSTY NORTHERLY
BEHIND THE FRONT LATE IN THE AFTERNOON AND INTO THE EVENING AS A
STRONG E/W ORIENTED P GRAD IS INTRODUCED TO THE FA...TRAVELING FROM
N TO S.

FRI/SAT...STRONG SFC HIGH P IN PLACE STILL UNDER RELATIVELY STRONG
NW FLOW TO BEGIN THE DAY FRIDAY...WITH MOSTLY SUNNY/DRY AND WARMING
CONDITIONS CWA WIDE. WINDS WILL ACCORDINGLY DROP FROM WHAT THEY WERE
THE PREVIOUS DAY AS THE SFC P GRAD WEAKENS UNDER THE HIGH PRESSURE
IN ADDITION TO WEAKENING WINDS ALOFT. SAT...HIGH PRESSURE BEGINS TO
WEAKEN AS LL WARMING CONTINUES AND LOWER PRESSURE IS INTRODUCED.
SFC TO 700 MB LAPSE RATES WILL BECOME UNSTABLE ENOUGH TO BRING DOWN
WINDS FROM ALOFT THIS DAY...RESULTING IN MODERATELY GUSTY W WINDS
MAINLY W OF THE DIVIDE AND OVR THE HIGHER MOUNTAINS...ALTHOUGH NOT
NEARLY AS STRONG AS THOSE OF TODAY. EARLY IN THE DAY ON SAT...A
SLIGHT INCREASE IN MAINLY MID LVL MOISTURE MAY INTRODUCE AN ISOLATED
SHOWER OR TWO OVR THE NRN HIGH MOUNTAINS...BUT NOTHING WORTH
MEASURING AT THIS POINT.

.LONG TERM...SUNDAY THROUGH THURSDAY

SYNOPSIS...NORTHWEST FLOW ALOFT WILL PREVAIL SUNDAY AND MONDAY
BETWEEN AN UPPER RIDGE ALONG THE WEST COAST AND UPPER TROUGH ACROSS
THE EASTERN U.S.   THIS FLOW WILL BECOME MORE ZONAL OR WESTERLY
TUESDAY THROUGH THURSDAY WITH POSSIBLY SOME RAIN AND SNOW SHOWERS
PUSHING INTO THE NORTHERN MOUNTAINS WEDNESDAY AND THURSDAY.

DISCUSSION...A CLIPPER IN NW FLOW WILL DIVE SOUTHEAST ACROSS THE
NORTHERN HIGH PLAINS SUNDAY AROUND BACKSIDE OF UPPER LOW OVER
ONTARIO THAT IS EXPECTED TO WOBBLE SLIGHTLY WESTWARD.  ECMWF
GENERATES SOME PRECIPITATION ACROSS EASTERN WYOMING...IN THE VCNTY
OF THE BIGHORNS AND ALONG AND EAST OF I-25...WHILE THE GFS KEEPS
THINGS DRY.   BOTH MODELS SHOW SOME CONTINUITY WITH THEIR RESPECTIVE
QPF FIELDS.  WE CONTINUED THE IDEA OF A DRY FORECAST ON SUNDAY WITH
OUR NEIGHBORS TO THE NORTH AND EAST ALSO KEEPING ANY CHANCES OF
PRECIPITATION WELL AWAY FROM OUR BORDERS FOR NOW.  TEMPERATURES WERE
COOLED A FEW DEGREES ACROSS EASTERN ZONES ON THE EDGE OF A DEEPER
COLDER AIRMASS SPILLING INTO THE NORTHERN PLAINS.

FLOW BACKS MONDAY WITH WEAK WARM ADVECTION RESULTING IN TEMPERATURES
A FEW DEGREES WARMER.

TRANSITION TO A MORE ZONAL FLOW BEGINS ON TUESDAY AS UPPER TROUGH
LIFTS OUT OF THE EASTERN U.S. AND OMEGA BLOCK BREAKS DOWN OVER
ALASKA/BERING SEA.  ECMWF AND GFS IN BETTER AGREEMENT KEEPING MEAN
RIDGE JUST OF THE WEST COAST WEDNESDAY AND THURSDAY WITH ELONGATED
W-E TROUGH DOWNSTREAM ACROSS CANADA.  THUS...ANY FRONTAL INTRUSIONS
FROM THE NORTH LATE IN THE WEEK WILL LIKELY BE SHALLOW AND MAINLY
DRY...COOLING TEMPERATURES BY ONLY A FEW DEGREES.  SLIGHT CHANCE
POPS WERE KEPT IN THE NORTHERN MOUNTAINS WEDNESDAY AND THURSDAY AS
WESTERLY FLOW MOISTENS UP A BIT.


&&

.AVIATION.../12Z ISSUANCE/

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

PATCHY LOW LYING FOG IS POSSIBLE IN THE CENTRAL BASINS UNTIL 15Z.
A NEW COLD FRONT WILL MOVE INTO NORTHERN WY AROUND 21Z AND MOVE
QUICKLY SOUTH INTO CENTRAL WY AFTER 01Z. RAIN SHOWERS WILL TURN TO
SNOW SHOWERS OVER NORTHERN WY BY 00Z WITH MVFR TO IFR CONDITIONS
AND MOUNTAIN OBSCURATION. THE RAIN AND SNOW SHOWERS WILL MOVE INTO
CENTRAL WY BY 03Z AND CONTINUE UNTIL 09Z WITH MVFR TO IFR CONDITIONS
AND MOUNTAIN OBSCURATION. CONDITIONS OVER THE NORTH WILL IMPROVE
AFTER 06Z FRIDAY. PLEASE SEE INDIVIDUAL TAF SITES FOR MORE DETAILS.

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

PATCHY LOW FOG AND LOW CLOUDS WILL OCCUR UNTIL 16Z WITH LOCAL MVFR
TO IFR CONDITIONS. VFR CONDITIONS WILL OCCUR OVER THE REGION THROUGH
TONIGHT. ISOLATED RAIN OR SNOW SHOWERS WILL OCCUR IN THE NW WY
MOUNTAINS LATE IN THE AFTERNOON INTO THE EVENING...ENDING BY 06Z
FRIDAY. EXPECT GUSTY WIND AT THE TAF SITES BY 18Z UNTIL 01Z. KRKS
WILL SEE A WIND SHIFT AFTER 06Z AS THE COLD FRONT BRUSHES BY THAT
AREA.

&&

.FIRE WEATHER...

FIRE DANGER WILL REMAIN LOW ACROSS THE FORECAST AREA THROUGH THE
REST OF THE WEEK. HOWEVER...BREEZY TO WINDY CONDITIONS WILL DEVELOP
TODAY AS SURFACE LOW PRESSURE IS REPLACED BY HIGH PRESSURE AND UPPER
LEVEL WINDS BEGIN TO INCREASE IN RESPONSE TO A STRENGTHENING UPPER
LEVEL JET STREAK. ADDITIONALLY...ANOTHER CHANCE FOR LIGHT
PRECIPITATION...BOTH LIQUID AND FROZEN...WILL PRESENT ITSELF LATER
THIS AFTERNOON AND INTO EVENING...MAINLY EAST OF THE DIVIDE AS
ANOTHER COLD FRONT PUSHES SOUTH ACROSS THE FORECAST AREA.

&&

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

$$

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









000
FXUS65 KRIW 020906
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
306 AM MDT THU OCT 2 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

LW TROF ACROSS THE CONUS...BOOKENDED BY RIDGES OVR EACH OCEAN.
TROF AXIS HAS NOW PASSED THRU THE FA AND IS CURRENTLY ALIGNED NEAR
ALONG THE ERN WY BORDER...PUTTING THE CWA UNDER NW FLOW. UPSTREAM
IN THE UPR LVLS...NEXT SW/JET STREAK MOVING THRU THE MAIN FLOW IS
CURRENTLY LOCATED OVR SWRN CANADA...AND WILL ARRIVE LATER TODAY.
AT THE SFC...HIGH PRESSURE INCREASING ACROSS THE STATE WITH A
DEVELOPING FRONT WELL TO THE NORTH OVR SRN CA. THIS FEATURE WILL
BE PUSHED SWD BY THE ADVANCE OF THE UPR LVL SW.

TODAY/TONIGHT...LIGHT MIXING WINDS NEAR SFC ALONG WITH INCREASING
DRY DENSE AIR ALOFT OVERRUNNING A MODESTLY MOIST BOUNDARY LAYER WILL
POSSIBLY MAKE FOR AREAS OF PATCHY FOG TO BEGIN THE DAY.
OTHERWISE...FLAT TO MODEST RIDGING WILL QUICKLY GIVE WAY TO THE UPR
SW MENTIONED ABOVE AS IT SWINGS THRU THE BACKSIDE OF THE MAIN
TROF...DRIVING THE AFOREMENTIONED DEVELOPING COLD FRONT DOWN THRU
THE FA EAST OF THE DIVIDE IN A CLIPPER-LIKE FASHION IN THE AFTERNOON
AND EVENING. SPEED AND MODEST MOISTURE WILL BE THE LIMITING FACTORS
WITH THIS FEATURE. WHILE PRECIP CHANCES WILL DEFINITELY INCREASE E
OF THE DIVIDE...MAINLY ACROSS THE NRN MOUNTAINS...BIGHORN
BASIN...AND JOHNSON AND NATRONA COUNTIES...QPF LL REMAIN ON THE LOW
SIDE OF THINGS. CHANCES FOR LIGHT SNOW WILL BE POSSIBLE ACROSS THE
MOUNTAINS ONCE AGAIN ABOVE STARTING OUT JUST ABOVE 7000 FEET...BUT
LOWERING RATHER QUICKLY BEHIND THE FRONT TO BASIN LEVEL DURING THE
EVENING PERIOD. MEASURABLE AMOUNTS OF SNOW ATTM LOOK TO REMAIN
MOSTLY IN THE MOUNTAINS WITH AN INCH OR TWO AT MOST FROM THIS QUICK
MOVING SYSTEM. THE LOWER LEVELS OF JOHNSON...NATRONA...BIG HORN AND
PERHAPS EVEN FREMONT COUNTIES WILL PERHAPS BE PRIVY TO TRACE TO A
FEW TENTHS OF AN INCH OF SNOW. THIS SYSTEM WILL QUICKLY MOVE OUT OF
THE AREA OVERNIGHT...LEAVING MAINLY CLEAR COLD AND DRY SKIES BY FRI
MORNING. HAVE LOWERED MIN TEMPS TO FIT THIS PROFILE UNDER H7 TEMPS
RANGING FROM -7 TO -9 DEG C. OTHERWISE/ELSEWHERE...BREEZY TO LOW END
WINDY CONDITIONS WILL BE THE STORY OF THE DAY ACROSS THE FA...AS A
MODESTLY STRENGTHENING SFC P GRAD COMBINES WILL GREATLY INCREASING
UPR LVL FLOW UNDER MODEST INSTABILITY THROUGH THE DAY TO GIVE WEST
WINDS CAPABLE OF GUSTS OF 30 TO 40 MPH BY AFTERNOON.
ADDITIONALLY...WINDS WILL ALSO INCREASE AND BECOME GUSTY NORTHERLY
BEHIND THE FRONT LATE IN THE AFTERNOON AND INTO THE EVENING AS A
STRONG E/W ORIENTED P GRAD IS INTRODUCED TO THE FA...TRAVELING FROM
N TO S.

FRI/SAT...STRONG SFC HIGH P IN PLACE STILL UNDER RELATIVELY STRONG
NW FLOW TO BEGIN THE DAY FRIDAY...WITH MOSTLY SUNNY/DRY AND WARMING
CONDITIONS CWA WIDE. WINDS WILL ACCORDINGLY DROP FROM WHAT THEY WERE
THE PREVIOUS DAY AS THE SFC P GRAD WEAKENS UNDER THE HIGH PRESSURE
IN ADDITION TO WEAKENING WINDS ALOFT. SAT...HIGH PRESSURE BEGINS TO
WEAKEN AS LL WARMING CONTINUES AND LOWER PRESSURE IS INTRODUCED.
SFC TO 700 MB LAPSE RATES WILL BECOME UNSTABLE ENOUGH TO BRING DOWN
WINDS FROM ALOFT THIS DAY...RESULTING IN MODERATELY GUSTY W WINDS
MAINLY W OF THE DIVIDE AND OVR THE HIGHER MOUNTAINS...ALTHOUGH NOT
NEARLY AS STRONG AS THOSE OF TODAY. EARLY IN THE DAY ON SAT...A
SLIGHT INCREASE IN MAINLY MID LVL MOISTURE MAY INTRODUCE AN ISOLATED
SHOWER OR TWO OVR THE NRN HIGH MOUNTAINS...BUT NOTHING WORTH
MEASURING AT THIS POINT.

.LONG TERM...SUNDAY THROUGH THURSDAY

SYNOPSIS...NORTHWEST FLOW ALOFT WILL PREVAIL SUNDAY AND MONDAY
BETWEEN AN UPPER RIDGE ALONG THE WEST COAST AND UPPER TROUGH ACROSS
THE EASTERN U.S.   THIS FLOW WILL BECOME MORE ZONAL OR WESTERLY
TUESDAY THROUGH THURSDAY WITH POSSIBLY SOME RAIN AND SNOW SHOWERS
PUSHING INTO THE NORTHERN MOUNTAINS WEDNESDAY AND THURSDAY.

DISCUSSION...A CLIPPER IN NW FLOW WILL DIVE SOUTHEAST ACROSS THE
NORTHERN HIGH PLAINS SUNDAY AROUND BACKSIDE OF UPPER LOW OVER
ONTARIO THAT IS EXPECTED TO WOBBLE SLIGHTLY WESTWARD.  ECMWF
GENERATES SOME PRECIPITATION ACROSS EASTERN WYOMING...IN THE VCNTY
OF THE BIGHORNS AND ALONG AND EAST OF I-25...WHILE THE GFS KEEPS
THINGS DRY.   BOTH MODELS SHOW SOME CONTINUITY WITH THEIR RESPECTIVE
QPF FIELDS.  WE CONTINUED THE IDEA OF A DRY FORECAST ON SUNDAY WITH
OUR NEIGHBORS TO THE NORTH AND EAST ALSO KEEPING ANY CHANCES OF
PRECIPITATION WELL AWAY FROM OUR BORDERS FOR NOW.  TEMPERATURES WERE
COOLED A FEW DEGREES ACROSS EASTERN ZONES ON THE EDGE OF A DEEPER
COLDER AIRMASS SPILLING INTO THE NORTHERN PLAINS.

FLOW BACKS MONDAY WITH WEAK WARM ADVECTION RESULTING IN TEMPERATURES
A FEW DEGREES WARMER.

TRANSITION TO A MORE ZONAL FLOW BEGINS ON TUESDAY AS UPPER TROUGH
LIFTS OUT OF THE EASTERN U.S. AND OMEGA BLOCK BREAKS DOWN OVER
ALASKA/BERING SEA.  ECMWF AND GFS IN BETTER AGREEMENT KEEPING MEAN
RIDGE JUST OF THE WEST COAST WEDNESDAY AND THURSDAY WITH ELONGATED
W-E TROUGH DOWNSTREAM ACROSS CANADA.  THUS...ANY FRONTAL INTRUSIONS
FROM THE NORTH LATE IN THE WEEK WILL LIKELY BE SHALLOW AND MAINLY
DRY...COOLING TEMPERATURES BY ONLY A FEW DEGREES.  SLIGHT CHANCE
POPS WERE KEPT IN THE NORTHERN MOUNTAINS WEDNESDAY AND THURSDAY AS
WESTERLY FLOW MOISTENS UP A BIT.


&&

.AVIATION.../12Z ISSUANCE/

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

PATCHY LOW LYING FOG IS POSSIBLE IN THE CENTRAL BASINS UNTIL 15Z.
A NEW COLD FRONT WILL MOVE INTO NORTHERN WY AROUND 21Z AND MOVE
QUICKLY SOUTH INTO CENTRAL WY AFTER 01Z. RAIN SHOWERS WILL TURN TO
SNOW SHOWERS OVER NORTHERN WY BY 00Z WITH MVFR TO IFR CONDITIONS
AND MOUNTAIN OBSCURATION. THE RAIN AND SNOW SHOWERS WILL MOVE INTO
CENTRAL WY BY 03Z AND CONTINUE UNTIL 09Z WITH MVFR TO IFR CONDITIONS
AND MOUNTAIN OBSCURATION. CONDITIONS OVER THE NORTH WILL IMPROVE
AFTER 06Z FRIDAY. PLEASE SEE INDIVIDUAL TAF SITES FOR MORE DETAILS.

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

PATCHY LOW FOG AND LOW CLOUDS WILL OCCUR UNTIL 16Z WITH LOCAL MVFR
TO IFR CONDITIONS. VFR CONDITIONS WILL OCCUR OVER THE REGION THROUGH
TONIGHT. ISOLATED RAIN OR SNOW SHOWERS WILL OCCUR IN THE NW WY
MOUNTAINS LATE IN THE AFTERNOON INTO THE EVENING...ENDING BY 06Z
FRIDAY. EXPECT GUSTY WIND AT THE TAF SITES BY 18Z UNTIL 01Z. KRKS
WILL SEE A WIND SHIFT AFTER 06Z AS THE COLD FRONT BRUSHES BY THAT
AREA.

&&

.FIRE WEATHER...

FIRE DANGER WILL REMAIN LOW ACROSS THE FORECAST AREA THROUGH THE
REST OF THE WEEK. HOWEVER...BREEZY TO WINDY CONDITIONS WILL DEVELOP
TODAY AS SURFACE LOW PRESSURE IS REPLACED BY HIGH PRESSURE AND UPPER
LEVEL WINDS BEGIN TO INCREASE IN RESPONSE TO A STRENGTHENING UPPER
LEVEL JET STREAK. ADDITIONALLY...ANOTHER CHANCE FOR LIGHT
PRECIPITATION...BOTH LIQUID AND FROZEN...WILL PRESENT ITSELF LATER
THIS AFTERNOON AND INTO EVENING...MAINLY EAST OF THE DIVIDE AS
ANOTHER COLD FRONT PUSHES SOUTH ACROSS THE FORECAST AREA.

&&

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

$$

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









000
FXUS65 KRIW 020906
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
306 AM MDT THU OCT 2 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

LW TROF ACROSS THE CONUS...BOOKENDED BY RIDGES OVR EACH OCEAN.
TROF AXIS HAS NOW PASSED THRU THE FA AND IS CURRENTLY ALIGNED NEAR
ALONG THE ERN WY BORDER...PUTTING THE CWA UNDER NW FLOW. UPSTREAM
IN THE UPR LVLS...NEXT SW/JET STREAK MOVING THRU THE MAIN FLOW IS
CURRENTLY LOCATED OVR SWRN CANADA...AND WILL ARRIVE LATER TODAY.
AT THE SFC...HIGH PRESSURE INCREASING ACROSS THE STATE WITH A
DEVELOPING FRONT WELL TO THE NORTH OVR SRN CA. THIS FEATURE WILL
BE PUSHED SWD BY THE ADVANCE OF THE UPR LVL SW.

TODAY/TONIGHT...LIGHT MIXING WINDS NEAR SFC ALONG WITH INCREASING
DRY DENSE AIR ALOFT OVERRUNNING A MODESTLY MOIST BOUNDARY LAYER WILL
POSSIBLY MAKE FOR AREAS OF PATCHY FOG TO BEGIN THE DAY.
OTHERWISE...FLAT TO MODEST RIDGING WILL QUICKLY GIVE WAY TO THE UPR
SW MENTIONED ABOVE AS IT SWINGS THRU THE BACKSIDE OF THE MAIN
TROF...DRIVING THE AFOREMENTIONED DEVELOPING COLD FRONT DOWN THRU
THE FA EAST OF THE DIVIDE IN A CLIPPER-LIKE FASHION IN THE AFTERNOON
AND EVENING. SPEED AND MODEST MOISTURE WILL BE THE LIMITING FACTORS
WITH THIS FEATURE. WHILE PRECIP CHANCES WILL DEFINITELY INCREASE E
OF THE DIVIDE...MAINLY ACROSS THE NRN MOUNTAINS...BIGHORN
BASIN...AND JOHNSON AND NATRONA COUNTIES...QPF LL REMAIN ON THE LOW
SIDE OF THINGS. CHANCES FOR LIGHT SNOW WILL BE POSSIBLE ACROSS THE
MOUNTAINS ONCE AGAIN ABOVE STARTING OUT JUST ABOVE 7000 FEET...BUT
LOWERING RATHER QUICKLY BEHIND THE FRONT TO BASIN LEVEL DURING THE
EVENING PERIOD. MEASURABLE AMOUNTS OF SNOW ATTM LOOK TO REMAIN
MOSTLY IN THE MOUNTAINS WITH AN INCH OR TWO AT MOST FROM THIS QUICK
MOVING SYSTEM. THE LOWER LEVELS OF JOHNSON...NATRONA...BIG HORN AND
PERHAPS EVEN FREMONT COUNTIES WILL PERHAPS BE PRIVY TO TRACE TO A
FEW TENTHS OF AN INCH OF SNOW. THIS SYSTEM WILL QUICKLY MOVE OUT OF
THE AREA OVERNIGHT...LEAVING MAINLY CLEAR COLD AND DRY SKIES BY FRI
MORNING. HAVE LOWERED MIN TEMPS TO FIT THIS PROFILE UNDER H7 TEMPS
RANGING FROM -7 TO -9 DEG C. OTHERWISE/ELSEWHERE...BREEZY TO LOW END
WINDY CONDITIONS WILL BE THE STORY OF THE DAY ACROSS THE FA...AS A
MODESTLY STRENGTHENING SFC P GRAD COMBINES WILL GREATLY INCREASING
UPR LVL FLOW UNDER MODEST INSTABILITY THROUGH THE DAY TO GIVE WEST
WINDS CAPABLE OF GUSTS OF 30 TO 40 MPH BY AFTERNOON.
ADDITIONALLY...WINDS WILL ALSO INCREASE AND BECOME GUSTY NORTHERLY
BEHIND THE FRONT LATE IN THE AFTERNOON AND INTO THE EVENING AS A
STRONG E/W ORIENTED P GRAD IS INTRODUCED TO THE FA...TRAVELING FROM
N TO S.

FRI/SAT...STRONG SFC HIGH P IN PLACE STILL UNDER RELATIVELY STRONG
NW FLOW TO BEGIN THE DAY FRIDAY...WITH MOSTLY SUNNY/DRY AND WARMING
CONDITIONS CWA WIDE. WINDS WILL ACCORDINGLY DROP FROM WHAT THEY WERE
THE PREVIOUS DAY AS THE SFC P GRAD WEAKENS UNDER THE HIGH PRESSURE
IN ADDITION TO WEAKENING WINDS ALOFT. SAT...HIGH PRESSURE BEGINS TO
WEAKEN AS LL WARMING CONTINUES AND LOWER PRESSURE IS INTRODUCED.
SFC TO 700 MB LAPSE RATES WILL BECOME UNSTABLE ENOUGH TO BRING DOWN
WINDS FROM ALOFT THIS DAY...RESULTING IN MODERATELY GUSTY W WINDS
MAINLY W OF THE DIVIDE AND OVR THE HIGHER MOUNTAINS...ALTHOUGH NOT
NEARLY AS STRONG AS THOSE OF TODAY. EARLY IN THE DAY ON SAT...A
SLIGHT INCREASE IN MAINLY MID LVL MOISTURE MAY INTRODUCE AN ISOLATED
SHOWER OR TWO OVR THE NRN HIGH MOUNTAINS...BUT NOTHING WORTH
MEASURING AT THIS POINT.

.LONG TERM...SUNDAY THROUGH THURSDAY

SYNOPSIS...NORTHWEST FLOW ALOFT WILL PREVAIL SUNDAY AND MONDAY
BETWEEN AN UPPER RIDGE ALONG THE WEST COAST AND UPPER TROUGH ACROSS
THE EASTERN U.S.   THIS FLOW WILL BECOME MORE ZONAL OR WESTERLY
TUESDAY THROUGH THURSDAY WITH POSSIBLY SOME RAIN AND SNOW SHOWERS
PUSHING INTO THE NORTHERN MOUNTAINS WEDNESDAY AND THURSDAY.

DISCUSSION...A CLIPPER IN NW FLOW WILL DIVE SOUTHEAST ACROSS THE
NORTHERN HIGH PLAINS SUNDAY AROUND BACKSIDE OF UPPER LOW OVER
ONTARIO THAT IS EXPECTED TO WOBBLE SLIGHTLY WESTWARD.  ECMWF
GENERATES SOME PRECIPITATION ACROSS EASTERN WYOMING...IN THE VCNTY
OF THE BIGHORNS AND ALONG AND EAST OF I-25...WHILE THE GFS KEEPS
THINGS DRY.   BOTH MODELS SHOW SOME CONTINUITY WITH THEIR RESPECTIVE
QPF FIELDS.  WE CONTINUED THE IDEA OF A DRY FORECAST ON SUNDAY WITH
OUR NEIGHBORS TO THE NORTH AND EAST ALSO KEEPING ANY CHANCES OF
PRECIPITATION WELL AWAY FROM OUR BORDERS FOR NOW.  TEMPERATURES WERE
COOLED A FEW DEGREES ACROSS EASTERN ZONES ON THE EDGE OF A DEEPER
COLDER AIRMASS SPILLING INTO THE NORTHERN PLAINS.

FLOW BACKS MONDAY WITH WEAK WARM ADVECTION RESULTING IN TEMPERATURES
A FEW DEGREES WARMER.

TRANSITION TO A MORE ZONAL FLOW BEGINS ON TUESDAY AS UPPER TROUGH
LIFTS OUT OF THE EASTERN U.S. AND OMEGA BLOCK BREAKS DOWN OVER
ALASKA/BERING SEA.  ECMWF AND GFS IN BETTER AGREEMENT KEEPING MEAN
RIDGE JUST OF THE WEST COAST WEDNESDAY AND THURSDAY WITH ELONGATED
W-E TROUGH DOWNSTREAM ACROSS CANADA.  THUS...ANY FRONTAL INTRUSIONS
FROM THE NORTH LATE IN THE WEEK WILL LIKELY BE SHALLOW AND MAINLY
DRY...COOLING TEMPERATURES BY ONLY A FEW DEGREES.  SLIGHT CHANCE
POPS WERE KEPT IN THE NORTHERN MOUNTAINS WEDNESDAY AND THURSDAY AS
WESTERLY FLOW MOISTENS UP A BIT.


&&

.AVIATION.../12Z ISSUANCE/

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

PATCHY LOW LYING FOG IS POSSIBLE IN THE CENTRAL BASINS UNTIL 15Z.
A NEW COLD FRONT WILL MOVE INTO NORTHERN WY AROUND 21Z AND MOVE
QUICKLY SOUTH INTO CENTRAL WY AFTER 01Z. RAIN SHOWERS WILL TURN TO
SNOW SHOWERS OVER NORTHERN WY BY 00Z WITH MVFR TO IFR CONDITIONS
AND MOUNTAIN OBSCURATION. THE RAIN AND SNOW SHOWERS WILL MOVE INTO
CENTRAL WY BY 03Z AND CONTINUE UNTIL 09Z WITH MVFR TO IFR CONDITIONS
AND MOUNTAIN OBSCURATION. CONDITIONS OVER THE NORTH WILL IMPROVE
AFTER 06Z FRIDAY. PLEASE SEE INDIVIDUAL TAF SITES FOR MORE DETAILS.

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

PATCHY LOW FOG AND LOW CLOUDS WILL OCCUR UNTIL 16Z WITH LOCAL MVFR
TO IFR CONDITIONS. VFR CONDITIONS WILL OCCUR OVER THE REGION THROUGH
TONIGHT. ISOLATED RAIN OR SNOW SHOWERS WILL OCCUR IN THE NW WY
MOUNTAINS LATE IN THE AFTERNOON INTO THE EVENING...ENDING BY 06Z
FRIDAY. EXPECT GUSTY WIND AT THE TAF SITES BY 18Z UNTIL 01Z. KRKS
WILL SEE A WIND SHIFT AFTER 06Z AS THE COLD FRONT BRUSHES BY THAT
AREA.

&&

.FIRE WEATHER...

FIRE DANGER WILL REMAIN LOW ACROSS THE FORECAST AREA THROUGH THE
REST OF THE WEEK. HOWEVER...BREEZY TO WINDY CONDITIONS WILL DEVELOP
TODAY AS SURFACE LOW PRESSURE IS REPLACED BY HIGH PRESSURE AND UPPER
LEVEL WINDS BEGIN TO INCREASE IN RESPONSE TO A STRENGTHENING UPPER
LEVEL JET STREAK. ADDITIONALLY...ANOTHER CHANCE FOR LIGHT
PRECIPITATION...BOTH LIQUID AND FROZEN...WILL PRESENT ITSELF LATER
THIS AFTERNOON AND INTO EVENING...MAINLY EAST OF THE DIVIDE AS
ANOTHER COLD FRONT PUSHES SOUTH ACROSS THE FORECAST AREA.

&&

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

$$

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









000
FXUS65 KCYS 020540
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1140 PM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 834 PM MDT WED OCT 1 2014

IR IMAGERY SHOWS THE COLDEST CLOUD TOPS ASSOCIATED WITH THE
SHORTWAVE MOVING QUICKLY OFF TO THE EAST ACROSS WESTERN NEBRASKA.
WILL KEEP SCATTERED SHOWERS IN THE FCST FOR THE NEXT FEW HOURS
ACROSS THE FAR EASTERN ZONES AS THE RADAR STILL INDICATES LIGHT
RAIN OVER CHEYENNE AND MORRILL COUNTIES. OUTSIDE OF THE EASTERN
CWA BOUNDARY AND THE MTNS...PRECIP CHANCES WILL BE SMALL THROUGH
THE REMAINDER OF THE NIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 1135 PM MDT WED OCT 1 2014

BRIEF MVFR TO IFR CIGS WILL BE POSSIBLE OVER THE PANHANDLE SITES
AND KCYS THROUGH 09Z THU. CONDITIONS WILL IMPROVE ACROSS THE AREA
BEYOND THAT TIME WITH VFR PREVAILING THROUGH THE REMAINDER OF THE
TAF PERIOD. GUSTY WINDS EXPECTED FOR THU AFTN AS A COLD FRONT
MOVES ACROSS THE REGION.

&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...JAMSKI
AVIATION...HAMMER
FIRE WEATHER...HAHN







000
FXUS65 KCYS 020540
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1140 PM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 834 PM MDT WED OCT 1 2014

IR IMAGERY SHOWS THE COLDEST CLOUD TOPS ASSOCIATED WITH THE
SHORTWAVE MOVING QUICKLY OFF TO THE EAST ACROSS WESTERN NEBRASKA.
WILL KEEP SCATTERED SHOWERS IN THE FCST FOR THE NEXT FEW HOURS
ACROSS THE FAR EASTERN ZONES AS THE RADAR STILL INDICATES LIGHT
RAIN OVER CHEYENNE AND MORRILL COUNTIES. OUTSIDE OF THE EASTERN
CWA BOUNDARY AND THE MTNS...PRECIP CHANCES WILL BE SMALL THROUGH
THE REMAINDER OF THE NIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 1135 PM MDT WED OCT 1 2014

BRIEF MVFR TO IFR CIGS WILL BE POSSIBLE OVER THE PANHANDLE SITES
AND KCYS THROUGH 09Z THU. CONDITIONS WILL IMPROVE ACROSS THE AREA
BEYOND THAT TIME WITH VFR PREVAILING THROUGH THE REMAINDER OF THE
TAF PERIOD. GUSTY WINDS EXPECTED FOR THU AFTN AS A COLD FRONT
MOVES ACROSS THE REGION.

&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...JAMSKI
AVIATION...HAMMER
FIRE WEATHER...HAHN






000
FXUS63 KUNR 020523
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1123 PM MDT WED OCT 1 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER LEVEL WAVE IS MOVING THROUGH WYOMING...CONTINUING TO
PRODUCE SHOWERS ACROSS NORTHEAST WY AND FAR WESTERN SD. FAIRLY
TIGHT PRESSURE GRADIENT IS CAUSING SOME BREEZY NORTHWEST WINDS
ACROSS THE CWA...ESPECIALLY IN NW SOUTH DAKOTA.

LIGHT SHOWERS WILL TRANSITION EASTWARD ACROSS SOUTHERN SD
TONIGHT...AND CLOUDS WILL DISSIPATE. WINDS WILL BECOME LIGHT...AND
LOWS WILL BE IN THE MID 30S TO MID 40S.

A FAST-MOVING CANADIAN LOW PRESSURE SYSTEM WILL SWEEP A COLD FRONT
THROUGH THE NORTHERN PLAINS ON THURSDAY. WINDS WILL BECOME GUSTY
FROM THE NORTHWEST THURSDAY AFTERNOON INTO THE EVENING. THE MAV
REACHES WIND ADVISORY CRITERIA ACROSS NORTHWEST SD...BUT AS USUAL IT
IS STRONGER THAN THE OTHER MODELS. HIGHEST PRESSURE RISES OF 7-8
MB/3HR SLIDE WEST OF THE USUAL WINDY AREAS AND INCREASE AFTER
SUNSET...SO AT THIS POINT A WIND ADVISORY SEEMS MARGINAL. HOWEVER
WITH THE COLD ADVECTION FOLLOWING THE FRONT...30-40KT 850MB
WINDS...AND IF MODELS COME INTO BETTER AGREEMENT...LATER SHIFTS MAY
DECIDE TO ISSUE ONE.

ALSO FOLLOWING THIS COLD FRONT WILL BE A CHANCE FOR SHOWERS...MAINLY
ACROSS NORTHEAST WY AND FAR WESTERN SD. THESE WILL BE AIDED BY UPPER
LEVEL DIVERGENCE ASSOCIATED WITH THE LEFT EXIT REGION OF THE JET. AS
TEMPS COOL THURSDAY NIGHT...SOME OF THE LINGERING SHOWERS MAY BE IN
THE FORM OF SNOW. MINIMAL ACCUMULATIONS ARE EXPECTED.

TEMPERATURES ON THURSDAY WILL BE TRICKY WITH THE TIMING OF THE COLD
FRONT. MID 50S ARE IN THE FORECAST FOR NORTHEAST WY AND NORTHWEST
SD...WITH MID 60S ACROSS SOUTH CENTRAL SD. ON THURSDAY NIGHT...LOWS
WILL RANGE FROM THE 20S ACROSS THE BLACK HILLS...NORTHEAST WY...AND
NORTHWEST SD...TO THE MID 30S OVER SOUTH CENTRAL SD. FROST/FREEZE
HEADLINES MAY BE NECESSARY ACROSS CENTRAL SD WHERE TEMPS HAVE NOT
DIPPED THAT LOW YET THIS SEASON.

&&

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS
THE LARGE UPPER TROUGH SHIFTS INTO THE MIDWEST. LITTLE CHANGE TO THE
PATTERN IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE
LONGWAVE PATTERN BECOMES A BIT PERSISTENT. NORTHWEST FLOW OVER THE
AREA WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS THROUGH EARLY
NEXT WEEK. OCCASIONAL SHORTWAVES WILL SLIDE OVER THE RIDGE...WHICH
WILL BRING BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE FRIDAY
WILL BE THE WINDIEST DAY IN THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM MDT WED OCT 1 2014

SCATTERED SHOWERS WILL LINGER THROUGH THE NIGHT ACROSS SOUTHWEST
SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH THE SHOWERS.
VFR CONDITIONS ELSEWHERE. STRONG COLD FRONT WILL MOVE THROUGH
NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THURSDAY AFTERNOON AND
EVENING. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE COLD FRONT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...POJORLIE
LONG TERM...15
AVIATION...7






000
FXUS63 KUNR 020523
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1123 PM MDT WED OCT 1 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER LEVEL WAVE IS MOVING THROUGH WYOMING...CONTINUING TO
PRODUCE SHOWERS ACROSS NORTHEAST WY AND FAR WESTERN SD. FAIRLY
TIGHT PRESSURE GRADIENT IS CAUSING SOME BREEZY NORTHWEST WINDS
ACROSS THE CWA...ESPECIALLY IN NW SOUTH DAKOTA.

LIGHT SHOWERS WILL TRANSITION EASTWARD ACROSS SOUTHERN SD
TONIGHT...AND CLOUDS WILL DISSIPATE. WINDS WILL BECOME LIGHT...AND
LOWS WILL BE IN THE MID 30S TO MID 40S.

A FAST-MOVING CANADIAN LOW PRESSURE SYSTEM WILL SWEEP A COLD FRONT
THROUGH THE NORTHERN PLAINS ON THURSDAY. WINDS WILL BECOME GUSTY
FROM THE NORTHWEST THURSDAY AFTERNOON INTO THE EVENING. THE MAV
REACHES WIND ADVISORY CRITERIA ACROSS NORTHWEST SD...BUT AS USUAL IT
IS STRONGER THAN THE OTHER MODELS. HIGHEST PRESSURE RISES OF 7-8
MB/3HR SLIDE WEST OF THE USUAL WINDY AREAS AND INCREASE AFTER
SUNSET...SO AT THIS POINT A WIND ADVISORY SEEMS MARGINAL. HOWEVER
WITH THE COLD ADVECTION FOLLOWING THE FRONT...30-40KT 850MB
WINDS...AND IF MODELS COME INTO BETTER AGREEMENT...LATER SHIFTS MAY
DECIDE TO ISSUE ONE.

ALSO FOLLOWING THIS COLD FRONT WILL BE A CHANCE FOR SHOWERS...MAINLY
ACROSS NORTHEAST WY AND FAR WESTERN SD. THESE WILL BE AIDED BY UPPER
LEVEL DIVERGENCE ASSOCIATED WITH THE LEFT EXIT REGION OF THE JET. AS
TEMPS COOL THURSDAY NIGHT...SOME OF THE LINGERING SHOWERS MAY BE IN
THE FORM OF SNOW. MINIMAL ACCUMULATIONS ARE EXPECTED.

TEMPERATURES ON THURSDAY WILL BE TRICKY WITH THE TIMING OF THE COLD
FRONT. MID 50S ARE IN THE FORECAST FOR NORTHEAST WY AND NORTHWEST
SD...WITH MID 60S ACROSS SOUTH CENTRAL SD. ON THURSDAY NIGHT...LOWS
WILL RANGE FROM THE 20S ACROSS THE BLACK HILLS...NORTHEAST WY...AND
NORTHWEST SD...TO THE MID 30S OVER SOUTH CENTRAL SD. FROST/FREEZE
HEADLINES MAY BE NECESSARY ACROSS CENTRAL SD WHERE TEMPS HAVE NOT
DIPPED THAT LOW YET THIS SEASON.

&&

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS
THE LARGE UPPER TROUGH SHIFTS INTO THE MIDWEST. LITTLE CHANGE TO THE
PATTERN IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE
LONGWAVE PATTERN BECOMES A BIT PERSISTENT. NORTHWEST FLOW OVER THE
AREA WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS THROUGH EARLY
NEXT WEEK. OCCASIONAL SHORTWAVES WILL SLIDE OVER THE RIDGE...WHICH
WILL BRING BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE FRIDAY
WILL BE THE WINDIEST DAY IN THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM MDT WED OCT 1 2014

SCATTERED SHOWERS WILL LINGER THROUGH THE NIGHT ACROSS SOUTHWEST
SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH THE SHOWERS.
VFR CONDITIONS ELSEWHERE. STRONG COLD FRONT WILL MOVE THROUGH
NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THURSDAY AFTERNOON AND
EVENING. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE COLD FRONT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...POJORLIE
LONG TERM...15
AVIATION...7






000
FXUS63 KUNR 020523
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1123 PM MDT WED OCT 1 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER LEVEL WAVE IS MOVING THROUGH WYOMING...CONTINUING TO
PRODUCE SHOWERS ACROSS NORTHEAST WY AND FAR WESTERN SD. FAIRLY
TIGHT PRESSURE GRADIENT IS CAUSING SOME BREEZY NORTHWEST WINDS
ACROSS THE CWA...ESPECIALLY IN NW SOUTH DAKOTA.

LIGHT SHOWERS WILL TRANSITION EASTWARD ACROSS SOUTHERN SD
TONIGHT...AND CLOUDS WILL DISSIPATE. WINDS WILL BECOME LIGHT...AND
LOWS WILL BE IN THE MID 30S TO MID 40S.

A FAST-MOVING CANADIAN LOW PRESSURE SYSTEM WILL SWEEP A COLD FRONT
THROUGH THE NORTHERN PLAINS ON THURSDAY. WINDS WILL BECOME GUSTY
FROM THE NORTHWEST THURSDAY AFTERNOON INTO THE EVENING. THE MAV
REACHES WIND ADVISORY CRITERIA ACROSS NORTHWEST SD...BUT AS USUAL IT
IS STRONGER THAN THE OTHER MODELS. HIGHEST PRESSURE RISES OF 7-8
MB/3HR SLIDE WEST OF THE USUAL WINDY AREAS AND INCREASE AFTER
SUNSET...SO AT THIS POINT A WIND ADVISORY SEEMS MARGINAL. HOWEVER
WITH THE COLD ADVECTION FOLLOWING THE FRONT...30-40KT 850MB
WINDS...AND IF MODELS COME INTO BETTER AGREEMENT...LATER SHIFTS MAY
DECIDE TO ISSUE ONE.

ALSO FOLLOWING THIS COLD FRONT WILL BE A CHANCE FOR SHOWERS...MAINLY
ACROSS NORTHEAST WY AND FAR WESTERN SD. THESE WILL BE AIDED BY UPPER
LEVEL DIVERGENCE ASSOCIATED WITH THE LEFT EXIT REGION OF THE JET. AS
TEMPS COOL THURSDAY NIGHT...SOME OF THE LINGERING SHOWERS MAY BE IN
THE FORM OF SNOW. MINIMAL ACCUMULATIONS ARE EXPECTED.

TEMPERATURES ON THURSDAY WILL BE TRICKY WITH THE TIMING OF THE COLD
FRONT. MID 50S ARE IN THE FORECAST FOR NORTHEAST WY AND NORTHWEST
SD...WITH MID 60S ACROSS SOUTH CENTRAL SD. ON THURSDAY NIGHT...LOWS
WILL RANGE FROM THE 20S ACROSS THE BLACK HILLS...NORTHEAST WY...AND
NORTHWEST SD...TO THE MID 30S OVER SOUTH CENTRAL SD. FROST/FREEZE
HEADLINES MAY BE NECESSARY ACROSS CENTRAL SD WHERE TEMPS HAVE NOT
DIPPED THAT LOW YET THIS SEASON.

&&

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS
THE LARGE UPPER TROUGH SHIFTS INTO THE MIDWEST. LITTLE CHANGE TO THE
PATTERN IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE
LONGWAVE PATTERN BECOMES A BIT PERSISTENT. NORTHWEST FLOW OVER THE
AREA WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS THROUGH EARLY
NEXT WEEK. OCCASIONAL SHORTWAVES WILL SLIDE OVER THE RIDGE...WHICH
WILL BRING BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE FRIDAY
WILL BE THE WINDIEST DAY IN THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM MDT WED OCT 1 2014

SCATTERED SHOWERS WILL LINGER THROUGH THE NIGHT ACROSS SOUTHWEST
SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH THE SHOWERS.
VFR CONDITIONS ELSEWHERE. STRONG COLD FRONT WILL MOVE THROUGH
NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THURSDAY AFTERNOON AND
EVENING. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE COLD FRONT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...POJORLIE
LONG TERM...15
AVIATION...7






000
FXUS63 KUNR 020523
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1123 PM MDT WED OCT 1 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER LEVEL WAVE IS MOVING THROUGH WYOMING...CONTINUING TO
PRODUCE SHOWERS ACROSS NORTHEAST WY AND FAR WESTERN SD. FAIRLY
TIGHT PRESSURE GRADIENT IS CAUSING SOME BREEZY NORTHWEST WINDS
ACROSS THE CWA...ESPECIALLY IN NW SOUTH DAKOTA.

LIGHT SHOWERS WILL TRANSITION EASTWARD ACROSS SOUTHERN SD
TONIGHT...AND CLOUDS WILL DISSIPATE. WINDS WILL BECOME LIGHT...AND
LOWS WILL BE IN THE MID 30S TO MID 40S.

A FAST-MOVING CANADIAN LOW PRESSURE SYSTEM WILL SWEEP A COLD FRONT
THROUGH THE NORTHERN PLAINS ON THURSDAY. WINDS WILL BECOME GUSTY
FROM THE NORTHWEST THURSDAY AFTERNOON INTO THE EVENING. THE MAV
REACHES WIND ADVISORY CRITERIA ACROSS NORTHWEST SD...BUT AS USUAL IT
IS STRONGER THAN THE OTHER MODELS. HIGHEST PRESSURE RISES OF 7-8
MB/3HR SLIDE WEST OF THE USUAL WINDY AREAS AND INCREASE AFTER
SUNSET...SO AT THIS POINT A WIND ADVISORY SEEMS MARGINAL. HOWEVER
WITH THE COLD ADVECTION FOLLOWING THE FRONT...30-40KT 850MB
WINDS...AND IF MODELS COME INTO BETTER AGREEMENT...LATER SHIFTS MAY
DECIDE TO ISSUE ONE.

ALSO FOLLOWING THIS COLD FRONT WILL BE A CHANCE FOR SHOWERS...MAINLY
ACROSS NORTHEAST WY AND FAR WESTERN SD. THESE WILL BE AIDED BY UPPER
LEVEL DIVERGENCE ASSOCIATED WITH THE LEFT EXIT REGION OF THE JET. AS
TEMPS COOL THURSDAY NIGHT...SOME OF THE LINGERING SHOWERS MAY BE IN
THE FORM OF SNOW. MINIMAL ACCUMULATIONS ARE EXPECTED.

TEMPERATURES ON THURSDAY WILL BE TRICKY WITH THE TIMING OF THE COLD
FRONT. MID 50S ARE IN THE FORECAST FOR NORTHEAST WY AND NORTHWEST
SD...WITH MID 60S ACROSS SOUTH CENTRAL SD. ON THURSDAY NIGHT...LOWS
WILL RANGE FROM THE 20S ACROSS THE BLACK HILLS...NORTHEAST WY...AND
NORTHWEST SD...TO THE MID 30S OVER SOUTH CENTRAL SD. FROST/FREEZE
HEADLINES MAY BE NECESSARY ACROSS CENTRAL SD WHERE TEMPS HAVE NOT
DIPPED THAT LOW YET THIS SEASON.

&&

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS
THE LARGE UPPER TROUGH SHIFTS INTO THE MIDWEST. LITTLE CHANGE TO THE
PATTERN IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE
LONGWAVE PATTERN BECOMES A BIT PERSISTENT. NORTHWEST FLOW OVER THE
AREA WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS THROUGH EARLY
NEXT WEEK. OCCASIONAL SHORTWAVES WILL SLIDE OVER THE RIDGE...WHICH
WILL BRING BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE FRIDAY
WILL BE THE WINDIEST DAY IN THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM MDT WED OCT 1 2014

SCATTERED SHOWERS WILL LINGER THROUGH THE NIGHT ACROSS SOUTHWEST
SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH THE SHOWERS.
VFR CONDITIONS ELSEWHERE. STRONG COLD FRONT WILL MOVE THROUGH
NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA THURSDAY AFTERNOON AND
EVENING. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE COLD FRONT.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...POJORLIE
LONG TERM...15
AVIATION...7






000
FXUS65 KRIW 020513
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1113 PM MDT WED OCT 1 2014

.SHORT TERM...TONIGHT AND THURSDAY (ISSUED AT 215 PM MDT)

UPPER CIRCULATION APPEARS TO BE MOVING RIGHT THROUGH CENTRAL WYO
ATTM WITH SEVERAL WEAK CIRCULATIONS BETWEEN THE SRN ABSAROKAS AND
SERN FREMONT COUNTY. CONSIDERABLE SHOWER ACTIVITY AROUND AND AHEAD
OF THE TROUGH WITH SNOW DOWN AS LOW AS 6500-7K. TEMPS HOVERING IN
THE UPPER 30S TO MID 40S WHERE THE THICK CLOUDS AND SHOWERS CONTINUE
IN THE LOWER ELEVATIONS WITH 30S IN THE NEARBY MOUNTAINS. VORT ON
THE SOUTH END OF THE TROUGH IS IGNITING A FEW TSTMS BUT SOUTH OF OUR
AREA ATTM. SHOWERS WILL CONTINUE AROUND THE CIRCULATION AND AHEAD OF
THE TROUGH FOR A FEW MORE HOURS INTO THE EARLY EVENING BEFORE ALL
BUT EXITING THE AREA. SOME LOW CLOUDS AND PATCHY FOG WILL BE
POSSIBLE OVERNIGHT AHEAD OF OUR NEXT SYSTEM. THIS SYSTEM OVER FAR
NRN B.C. AND ALBERTA HAS -30C AIR AT H5 AND UP TO -18C AIR AT H7 SO
IT WILL BE COLDER. MODELS ARE SHOWING QUITE THE FRONTAL PASSAGE UP
NORTH WITH NAM12 SHOWING ALMOST 8MB 3HR PRESSURE RISES LATE THURSDAY
AFTERNOON. BUMPED UP THE WINDS ACROSS THE NORTH...ESPECIALLY NRN
JOHNSON COUNTY WHERE 50 MPH+ GUSTS QUITE POSSIBLE. IN
ADDITION...SHOWERS WILL BECOME LIKELY IN THE FAR NRN
MOUNTAINS...ESPECIALLY THE BIGHORNS BY LATE AFTERNOON WITH A GOOD
CHANCE OF SHOWERS ACROSS THE LOWER ELEVATIONS OF OUR FAR NRN ZONES.
TEMPERATURES DROP QUICKLY AND IF THE PRECIP LINGERS LONG ENOUGH
COULD SEE IT BEGIN TO CHANGE TO SNOW IN THE LOWER ELEVATIONS BY THE
END OF THIS PERIOD (6 PM THURSDAY). AHEAD OF THIS SYSTEM...WE GET
SOME MOUNTAIN WAVE ACTION IN THE LEE OF THE ABSAROKAS AND BIGHORNS.
SIGNATURE IS NOT IMPRESSIVE BUT ENOUGH TO INCREASE THE WIND ALONG
THE EAST SLOPE...ESPECIALLY THE FAVORED CODY FOOTHILL/EAST SLOPE OF
THE ABSAROKAS. GENERALLY WENT 25G40MPH IN THE FAVORED AREAS. FROUDE
CALCULATION IS RATHER LOW AS MOUNTAIN TOP FLOW IS NOT STRONG ENOUGH
TO CAUSE WAVE BREAKING OVER THE BIGGER MOUNTAINS. SOME MARGINALLY
STABLE AIR IS POSSIBLE BUT DOESN`T LOOK OPTIMAL. SO WINDY BUT NOT
EXPECTING HIGH WINDS.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

THURSDAY NIGHT CANADIAN COLD FRONT WILL CONTINUE PASSING SOUTH
IN THE EVENING WITH AREAS OF RAIN...AND MOUNTAIN SNOW SHOWERS IN THE
NORTH AND EAST...ESPECIALLY IN THE NORTHERN MOUNTAINS.  SOME SHOWERS
WILL LINGER ALONG THE FRONT OVER NATRONA COUNTY WHILE CLEARING
OCCURS TO THE NORTH AND WEST.  TEMPERATURES CONTINUE TO COOL AND
HAVE GONE COLDER THAN PREVIOUS FORECAST WITH MOST AREAS BELOW
FREEZING AND SOME TEEN POSSIBLE IN THE NORTHWEST MOUNTAINS.

FRIDAY AND FRIDAY NIGHT  FLOW ALOFT REMAINS NORTH NORTHWEST WITH COLD
AIR ADVECTION AND HAVE CONTINUED COOLER TREND WITH HIGHS ON FRIDAY
AND LOWS LATE FRIDAY NIGHT.  UPPER LEVEL HIGH PRESSURE RIDGE BUILDS
TO THE WEST STARTING A LONG DRY SPELL.

SATURDAY AND SATURDAY NIGHT  TEMPERATURES WILL BEGIN TO WARM AS THE
WESTERN HIGH PRESSURE RIDGE ALOFT BUILDS INTO THE WEST WITH MOSTLY
CLEAR CONDITIONS.

SUNDAY AND SUNDAY NIGHT  DRY AND WARMER CONDITIONS CONTINUE AS HIGH
PRESSURE RIDGE CONTINUES TO DOMINATE THE WEATHER ACROSS THE REGION.

MONDAY AND MONDAY NIGHT LITTLE ADDITIONAL WARMING IS EXPECTED WITH
DRY CONDITIONS CONTINUING.  SOME SHORT WAVE LOW PRESSURE TROUGHS
MOVING ACROSS SOUTHWEST CANADA WILL KEEP THE WESTERN HIGH PRESSURE
RIDGE FROM BUILDING.

TUESDAY AND TUESDAY NIGHT  FLOW ALOFT BECOMES MORE WESTERLY RETAINING
SOME NORTHERLY COMPONENT AS  SHORT WAVE LOW PRESSURE TROUGHS CONTINUE
MOVING ACROSS SOUTHWEST CANADA AND NORTHERN MONTANA SUPPRESSING THE
RIDGE.  NORTH MAY SEE SOME INCREASED CLOUD COVER BUT EXPECT THE COLD
FRONT ASSOCIATED WITH THE SERIES OF SHORT WAVE LOW PRESSURE TROUGHS
TO REMAIN NORTH AND EAST OF THE FORECAST AREA.

WEDNESDAY  FLOW BECOMES ZONAL AS RIDGE CONTINUES TO FLATTEN.
EXTENDED MODELS SHOW THE CANADIAN/MONTANA COLD FRONT REMAINS JUST TO
THE NORTH KEEPING WYOMING DRY.  WILL SEE INCREASING WEST SURFACE
WINDS AND CONTINUED DRYING.  WILL HAVE TO KEEP AN EYE ON THE COLD
FRONT TO THE NORTH OVER TIME AS A MOVEMENT FARTHER TO THE SOUTH WILL
BRING CLOUDS...SHOWERS COLDER TEMPERATURES TO THE NORTH AND POSSIBLY
THE EAST.

.AVIATION.../06Z ISSUANCE/

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

PATCHY LOW LYING FOG IS POSSIBLE IN THE CENTRAL BASINS. A NEW COLD
FRONT WILL ARRIVE ACROSS THE NORTH THURSDAY AFTERNOON WITH AN
INCREASING CHANCE OF SHOWERS AND LOWERING CIGS. VFR CONDITIONS WILL
PREVAIL THROUGH IN MOST AREAS THROUGH THE AFTERNOON EXCEPT FROM NEAR
A KCOD TO KBYG LINE WHERE MVFR/IFR CIGS WILL DEVELOP BEFORE 00Z
FRIDAY AND THEN MOVE SOUTH TO A KLND TO KCPR LINE BY 03Z. EXPECT
RAIN TO CHANGE TO SNOW BEHIND THE COLD FRONT WITH MOUNTAIN
OBSCURATION. MVFR TO IFR VISIBILITY WILL OCCUR DUE TO SNOW.

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

PATCHY LOW FOG AND LOW CLOUDS MAY REDEVELOP LATER TONIGHT WITH MTN
OBSCURATION AND BRIEF VSBYS UNDER 3 MILES. OTHERWISE...MOST AREAS
WILL BE VFR OVERNIGHT BUT WITH SOME MTN OBSCURATION IN LOW CLOUDS.
ONCE ANY LOW CLOUDS OR FOG BURNS OFF...ALL AREAS SHOULD SEE VFR
CONDITIONS ON THURSDAY WITH THE POSSIBLE EXCEPTION OF YELLOWSTONE
NATIONAL PARK WHERE SOME LATE DAY SHOWERS DEVELOP AND CONTINUE
THROUGH ABOUT 04Z.

.FIRE WEATHER...

CONSIDERABLE SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM OR TWO IN
CENTRAL WYOMING INTO THE EARLY EVENING BEFORE MOVING SOUTHEAST AND
DECREASING. MORE WIDELY SCATTERED TO SCATTERED SHOWERS ELSEWHERE
UNTIL AROUND SUNSET. GUSTY WEST TO NORTHWEST WINDS ACROSS THE WEST
AND SOUTH WILL DECREASE THIS EVENING BUT PICK BACK UP AGAIN
THURSDAY. A NEW WEATHER SYSTEM WILL PUSH A STRONG COLD FRONT INTO
THE FAR NORTHERN ZONES DURING THE AFTERNOON WITH STRONG NORTH WIND
GUSTS OF 40 TO 50 MPH AND AN INCREASING CHANCE OF SHOWERS. SOUTH OF
THE FRONT IN CENTRAL AND SOUTHERN WYOMING...IT WILL BE DRY BUT WITH
SOME GUSTY WEST TO NORTHWEST WIND. THE COLD FRONT WILL PUSH SOUTH
INTO CENTRAL WYOMING BY EARLY EVENING.

&&

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

&&

$$

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










000
FXUS65 KCYS 020243
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
843 PM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 834 PM MDT WED OCT 1 2014

IR IMAGERY SHOWS THE COLDEST CLOUD TOPS ASSOCIATED WITH THE
SHORTWAVE MOVING QUICKLY OFF TO THE EAST ACROSS WESTERN NEBRASKA.
WILL KEEP SCATTERED SHOWERS IN THE FCST FOR THE NEXT FEW HOURS
ACROSS THE FAR EASTERN ZONES AS THE RADAR STILL INDICATES LIGHT
RAIN OVER CHEYENNE AND MORRILL COUNTIES. OUTSIDE OF THE EASTERN
CWA BOUNDARY AND THE MTNS...PRECIP CHANCES WILL BE SMALL THROUGH
THE REMAINDER OF THE NIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 541 PM MDT WED OCT 1 2014

THE AREA OF RAIN THAT WAS AFFECTING SOUTHEAST WY THIS AFTERNOON
HAS SHIFTED EASTWARD INTO THE NEBRASKA PANHANDLE. THE BEST CHANCE
OF MODERATE RAIN AND BRIEF MVFR VIS THROUGH AROUND 03Z WILL BE AT
SNY. OTHERWISE...THE NEBRASKA SITES WILL SEE VFR CONDITIONS WITH
RAIN SHOWERS THROUGH THE EVENING. A COLD FRONT IS MOVING OVER THE
PANHANDLE AND WILL PRODUCE OCCASIONAL NORTHWEST GUSTS TO 25 KTS
AT SNY. SKIES WILL CLEAR OUT OVERNIGHT WITH JUST A SCT LAYER OF
MIDLEVEL CLOUDS.


&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...JAMSKI
AVIATION...FINCH
FIRE WEATHER...HAHN




000
FXUS65 KCYS 020243
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
843 PM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 834 PM MDT WED OCT 1 2014

IR IMAGERY SHOWS THE COLDEST CLOUD TOPS ASSOCIATED WITH THE
SHORTWAVE MOVING QUICKLY OFF TO THE EAST ACROSS WESTERN NEBRASKA.
WILL KEEP SCATTERED SHOWERS IN THE FCST FOR THE NEXT FEW HOURS
ACROSS THE FAR EASTERN ZONES AS THE RADAR STILL INDICATES LIGHT
RAIN OVER CHEYENNE AND MORRILL COUNTIES. OUTSIDE OF THE EASTERN
CWA BOUNDARY AND THE MTNS...PRECIP CHANCES WILL BE SMALL THROUGH
THE REMAINDER OF THE NIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 541 PM MDT WED OCT 1 2014

THE AREA OF RAIN THAT WAS AFFECTING SOUTHEAST WY THIS AFTERNOON
HAS SHIFTED EASTWARD INTO THE NEBRASKA PANHANDLE. THE BEST CHANCE
OF MODERATE RAIN AND BRIEF MVFR VIS THROUGH AROUND 03Z WILL BE AT
SNY. OTHERWISE...THE NEBRASKA SITES WILL SEE VFR CONDITIONS WITH
RAIN SHOWERS THROUGH THE EVENING. A COLD FRONT IS MOVING OVER THE
PANHANDLE AND WILL PRODUCE OCCASIONAL NORTHWEST GUSTS TO 25 KTS
AT SNY. SKIES WILL CLEAR OUT OVERNIGHT WITH JUST A SCT LAYER OF
MIDLEVEL CLOUDS.


&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...JAMSKI
AVIATION...FINCH
FIRE WEATHER...HAHN





000
FXUS63 KUNR 020026
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
626 PM MDT WED OCT 1 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER LEVEL WAVE IS MOVING THROUGH WYOMING...CONTINUING TO
PRODUCE SHOWERS ACROSS NORTHEAST WY AND FAR WESTERN SD. FAIRLY
TIGHT PRESSURE GRADIENT IS CAUSING SOME BREEZY NORTHWEST WINDS
ACROSS THE CWA...ESPECIALLY IN NW SOUTH DAKOTA.

LIGHT SHOWERS WILL TRANSITION EASTWARD ACROSS SOUTHERN SD
TONIGHT...AND CLOUDS WILL DISSIPATE. WINDS WILL BECOME LIGHT...AND
LOWS WILL BE IN THE MID 30S TO MID 40S.

A FAST-MOVING CANADIAN LOW PRESSURE SYSTEM WILL SWEEP A COLD FRONT
THROUGH THE NORTHERN PLAINS ON THURSDAY. WINDS WILL BECOME GUSTY
FROM THE NORTHWEST THURSDAY AFTERNOON INTO THE EVENING. THE MAV
REACHES WIND ADVISORY CRITERIA ACROSS NORTHWEST SD...BUT AS USUAL IT
IS STRONGER THAN THE OTHER MODELS. HIGHEST PRESSURE RISES OF 7-8
MB/3HR SLIDE WEST OF THE USUAL WINDY AREAS AND INCREASE AFTER
SUNSET...SO AT THIS POINT A WIND ADVISORY SEEMS MARGINAL. HOWEVER
WITH THE COLD ADVECTION FOLLOWING THE FRONT...30-40KT 850MB
WINDS...AND IF MODELS COME INTO BETTER AGREEMENT...LATER SHIFTS MAY
DECIDE TO ISSUE ONE.

ALSO FOLLOWING THIS COLD FRONT WILL BE A CHANCE FOR SHOWERS...MAINLY
ACROSS NORTHEAST WY AND FAR WESTERN SD. THESE WILL BE AIDED BY UPPER
LEVEL DIVERGENCE ASSOCIATED WITH THE LEFT EXIT REGION OF THE JET. AS
TEMPS COOL THURSDAY NIGHT...SOME OF THE LINGERING SHOWERS MAY BE IN
THE FORM OF SNOW. MINIMAL ACCUMULATIONS ARE EXPECTED.

TEMPERATURES ON THURSDAY WILL BE TRICKY WITH THE TIMING OF THE COLD
FRONT. MID 50S ARE IN THE FORECAST FOR NORTHEAST WY AND NORTHWEST
SD...WITH MID 60S ACROSS SOUTH CENTRAL SD. ON THURSDAY NIGHT...LOWS
WILL RANGE FROM THE 20S ACROSS THE BLACK HILLS...NORTHEAST WY...AND
NORTHWEST SD...TO THE MID 30S OVER SOUTH CENTRAL SD. FROST/FREEZE
HEADLINES MAY BE NECESSARY ACROSS CENTRAL SD WHERE TEMPS HAVE NOT
DIPPED THAT LOW YET THIS SEASON.

&&

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS
THE LARGE UPPER TROUGH SHIFTS INTO THE MIDWEST. LITTLE CHANGE TO THE
PATTERN IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE
LONGWAVE PATTERN BECOMES A BIT PERSISTENT. NORTHWEST FLOW OVER THE
AREA WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS THROUGH EARLY
NEXT WEEK. OCCASIONAL SHORTWAVES WILL SLIDE OVER THE RIDGE...WHICH
WILL BRING BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE FRIDAY
WILL BE THE WINDIEST DAY IN THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 625 PM MDT WED OCT 1 2014

SCATTERED SHOWERS WILL LINGER THROUGH THIS EVENING ACROSS
SOUTHWEST AND SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH
THE SHOWERS. VFR CONDITIONS ELSEWHERE.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...POJORLIE
LONG TERM...15
AVIATION...7







000
FXUS63 KUNR 020026
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
626 PM MDT WED OCT 1 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER LEVEL WAVE IS MOVING THROUGH WYOMING...CONTINUING TO
PRODUCE SHOWERS ACROSS NORTHEAST WY AND FAR WESTERN SD. FAIRLY
TIGHT PRESSURE GRADIENT IS CAUSING SOME BREEZY NORTHWEST WINDS
ACROSS THE CWA...ESPECIALLY IN NW SOUTH DAKOTA.

LIGHT SHOWERS WILL TRANSITION EASTWARD ACROSS SOUTHERN SD
TONIGHT...AND CLOUDS WILL DISSIPATE. WINDS WILL BECOME LIGHT...AND
LOWS WILL BE IN THE MID 30S TO MID 40S.

A FAST-MOVING CANADIAN LOW PRESSURE SYSTEM WILL SWEEP A COLD FRONT
THROUGH THE NORTHERN PLAINS ON THURSDAY. WINDS WILL BECOME GUSTY
FROM THE NORTHWEST THURSDAY AFTERNOON INTO THE EVENING. THE MAV
REACHES WIND ADVISORY CRITERIA ACROSS NORTHWEST SD...BUT AS USUAL IT
IS STRONGER THAN THE OTHER MODELS. HIGHEST PRESSURE RISES OF 7-8
MB/3HR SLIDE WEST OF THE USUAL WINDY AREAS AND INCREASE AFTER
SUNSET...SO AT THIS POINT A WIND ADVISORY SEEMS MARGINAL. HOWEVER
WITH THE COLD ADVECTION FOLLOWING THE FRONT...30-40KT 850MB
WINDS...AND IF MODELS COME INTO BETTER AGREEMENT...LATER SHIFTS MAY
DECIDE TO ISSUE ONE.

ALSO FOLLOWING THIS COLD FRONT WILL BE A CHANCE FOR SHOWERS...MAINLY
ACROSS NORTHEAST WY AND FAR WESTERN SD. THESE WILL BE AIDED BY UPPER
LEVEL DIVERGENCE ASSOCIATED WITH THE LEFT EXIT REGION OF THE JET. AS
TEMPS COOL THURSDAY NIGHT...SOME OF THE LINGERING SHOWERS MAY BE IN
THE FORM OF SNOW. MINIMAL ACCUMULATIONS ARE EXPECTED.

TEMPERATURES ON THURSDAY WILL BE TRICKY WITH THE TIMING OF THE COLD
FRONT. MID 50S ARE IN THE FORECAST FOR NORTHEAST WY AND NORTHWEST
SD...WITH MID 60S ACROSS SOUTH CENTRAL SD. ON THURSDAY NIGHT...LOWS
WILL RANGE FROM THE 20S ACROSS THE BLACK HILLS...NORTHEAST WY...AND
NORTHWEST SD...TO THE MID 30S OVER SOUTH CENTRAL SD. FROST/FREEZE
HEADLINES MAY BE NECESSARY ACROSS CENTRAL SD WHERE TEMPS HAVE NOT
DIPPED THAT LOW YET THIS SEASON.

&&

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS
THE LARGE UPPER TROUGH SHIFTS INTO THE MIDWEST. LITTLE CHANGE TO THE
PATTERN IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE
LONGWAVE PATTERN BECOMES A BIT PERSISTENT. NORTHWEST FLOW OVER THE
AREA WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS THROUGH EARLY
NEXT WEEK. OCCASIONAL SHORTWAVES WILL SLIDE OVER THE RIDGE...WHICH
WILL BRING BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE FRIDAY
WILL BE THE WINDIEST DAY IN THE EXTENDED PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 625 PM MDT WED OCT 1 2014

SCATTERED SHOWERS WILL LINGER THROUGH THIS EVENING ACROSS
SOUTHWEST AND SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR CIGS/VSBY WITH
THE SHOWERS. VFR CONDITIONS ELSEWHERE.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...POJORLIE
LONG TERM...15
AVIATION...7






000
FXUS65 KCYS 012347
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 PM MDT WED OCT 1 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 541 PM MDT WED OCT 1 2014

THE AREA OF RAIN THAT WAS AFFECTING SOUTHEAST WY THIS AFTERNOON
HAS SHIFTED EASTWARD INTO THE NEBRASKA PANHANDLE. THE BEST CHANCE
OF MODERATE RAIN AND BRIEF MVFR VIS THROUGH AROUND 03Z WILL BE AT
SNY. OTHERWISE...THE NEBRASKA SITES WILL SEE VFR CONDITIONS WITH
RAIN SHOWERS THROUGH THE EVENING. A COLD FRONT IS MOVING OVER THE
PANHANDLE AND WILL PRODUCE OCCASIONAL NORTHWEST GUSTS TO 25 KTS
AT SNY. SKIES WILL CLEAR OUT OVERNIGHT WITH JUST A SCT LAYER OF
MIDLEVEL CLOUDS.

&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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




000
FXUS65 KCYS 012347
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 PM MDT WED OCT 1 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 541 PM MDT WED OCT 1 2014

THE AREA OF RAIN THAT WAS AFFECTING SOUTHEAST WY THIS AFTERNOON
HAS SHIFTED EASTWARD INTO THE NEBRASKA PANHANDLE. THE BEST CHANCE
OF MODERATE RAIN AND BRIEF MVFR VIS THROUGH AROUND 03Z WILL BE AT
SNY. OTHERWISE...THE NEBRASKA SITES WILL SEE VFR CONDITIONS WITH
RAIN SHOWERS THROUGH THE EVENING. A COLD FRONT IS MOVING OVER THE
PANHANDLE AND WILL PRODUCE OCCASIONAL NORTHWEST GUSTS TO 25 KTS
AT SNY. SKIES WILL CLEAR OUT OVERNIGHT WITH JUST A SCT LAYER OF
MIDLEVEL CLOUDS.

&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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




000
FXUS65 KCYS 012347
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 PM MDT WED OCT 1 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 541 PM MDT WED OCT 1 2014

THE AREA OF RAIN THAT WAS AFFECTING SOUTHEAST WY THIS AFTERNOON
HAS SHIFTED EASTWARD INTO THE NEBRASKA PANHANDLE. THE BEST CHANCE
OF MODERATE RAIN AND BRIEF MVFR VIS THROUGH AROUND 03Z WILL BE AT
SNY. OTHERWISE...THE NEBRASKA SITES WILL SEE VFR CONDITIONS WITH
RAIN SHOWERS THROUGH THE EVENING. A COLD FRONT IS MOVING OVER THE
PANHANDLE AND WILL PRODUCE OCCASIONAL NORTHWEST GUSTS TO 25 KTS
AT SNY. SKIES WILL CLEAR OUT OVERNIGHT WITH JUST A SCT LAYER OF
MIDLEVEL CLOUDS.

&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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




000
FXUS65 KCYS 012347
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
547 PM MDT WED OCT 1 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 541 PM MDT WED OCT 1 2014

THE AREA OF RAIN THAT WAS AFFECTING SOUTHEAST WY THIS AFTERNOON
HAS SHIFTED EASTWARD INTO THE NEBRASKA PANHANDLE. THE BEST CHANCE
OF MODERATE RAIN AND BRIEF MVFR VIS THROUGH AROUND 03Z WILL BE AT
SNY. OTHERWISE...THE NEBRASKA SITES WILL SEE VFR CONDITIONS WITH
RAIN SHOWERS THROUGH THE EVENING. A COLD FRONT IS MOVING OVER THE
PANHANDLE AND WILL PRODUCE OCCASIONAL NORTHWEST GUSTS TO 25 KTS
AT SNY. SKIES WILL CLEAR OUT OVERNIGHT WITH JUST A SCT LAYER OF
MIDLEVEL CLOUDS.

&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

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




000
FXUS65 KCYS 012142
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
342 PM MDT WED OCT 1 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1125 AM MDT WED OCT 1 2014

THE NEXT PACIFIC COLD FRONT AND UPPER LOW PRESSURE TROUGH WILL
IMPACT THE FORECAST AREA THROUGH TONIGHT. CEILINGS WILL LOWER TO
MVFR WITH MORE WIDESPREAD PRECIPITATION DEVELOPING FROM WEST TO
EAST. SHOWERS WILL BE THE PRIMARY PRECIP TYPE...WITH ISOLATED
THUNDER POSSIBLE SOUTH OF A DOUGLAS TO ALLIANCE LINE THIS
AFTERNOON. WINDS WILL BECOME NORTHERLY WITH THE PASSAGE OF THE
FRONT AND MAY BE BREEZY AT TIMES ACROSS SOUTHEAST WYOMING. LOW
CEILINGS WILL LINGER BEHIND THE FRONT THROUGH TONIGHT ALONG AND
SOUTH OF A RAWLINS TO ALLIANCE LINE.


&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

SHORT TERM...HAHN
LONG TERM...JAMSKI
AVIATION...JAMSKI
FIRE WEATHER...HAHN







000
FXUS65 KCYS 012142
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
342 PM MDT WED OCT 1 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM MDT WED OCT 1 2014

REGIONAL RADARS HAVE BEEN FILLING IN OVER THE PAST SEVERAL
HOURS...WITH RAIN BEGINNING TO FALL ACROSS LARAMIE COUNTY. SNOW
LEVELS THUS FAR HAVE FALLEN TO AROUND 7 KFT...WITH PUMPKIN VINE
TURNING OVER AT AROUND NOON AND AREAS OVR THE I-80 SUMMIT SHORTLY
THEREAFTER. THIS ALL HAS BEEN A RESULT OF A FAST-MOVING YET SHARP
SHORTWAVE...ITS AXIS OF WHICH WILL PASS OVERHEAD THIS EVENING AND
BE EAST OF THE CWFA BY THURSDAY MORNING. AT THE SFC...THE FRONT
HAS PUSHED SOUTH OF THE WY/CO STATE LINE AS EVIDENT BY WIND SHIFT
TO THE NORTH...11 DEGREES OF COOLING AND ONSET OF RAIN BETWEEN
17-18Z. MODELS ARE CONSISTENT IN TRACKING THE AREA OF BEST H7
OMEGA AND QG ASCENT LARAMIE COUNTY...SOUTHERN GOSHEN COUNTY AND
THE SOUTHERN NEBRASKA PANHANDLE THROUGH THE EVENING HOURS. SNOW-
LEVELS WILL FALL TO AROUND 6500 FEET THIS EVENING BEFORE
PRECIPITATION FINALLY ENDS. MAY EVEN MIX BELOW BRIEFLY. HRRR
PUSHES THIS AREA OF PRECIP OUT OF WYOMING BY AROUND 02-03Z AND OUT
OF THE WESTERN NEBRASKA PANHANDLE BY AROUND 06Z...SO HAVE TRENDED
PRECIP CHANCES DOWN ACCORDINGLY. SHOULD SEE 3-5 INCHES OVER THE
SNOWY/SIERRA MADRES WITH MAYBE 1-3 INCHES OVER THE SRN LARAMIE
RANGE BY THE TIME THE SYSTEM DEPARTS. WILL BE A BRIEF BREAK IN
PRECIP BEHIND THE DEPARTING SHORTWAVE AND AHEAD OF THE NEXT FAST
MOVING CLIPPER POISED TO PUSH THROUGH LATE THURSDAY. IN THE
MEANTIME...WILL SEE A DRY...BUT BREEZY/RAW DAY TOMORROW AS
SUBSIDENCE ALLOWS FOR 25-30 KNOT 650-700MB BELOW THE INVERSION TO
SFC. SUBSIDENT INVERSION ERODES QUICKLY THOUGH...WITH THE NEXT
CLIPPER QUICKLY APPROACHING THE CWFA. LATEST MODELS HAVE BEEN
TRENDING A BIT STRONGER AND DEEPER WITH THIS SYSTEM COMPARED TO
THOSE A FEW DAYS AGO. WILL SEE PRECIP BEGIN ACROSS EAST CENTRAL
WYOMING AND THE NRN NEBRASKA PANHANDLE THURSDAY EVENING SPREADING
SOUTH INTO SOUTHEAST WYOMING AND THE REST OF THE PANHANDLE THRU
MIDNIGHT. TEMPERATURES WILL AGAIN BE TRICKY WITH THIS
SYSTEM...WITH SOME INDICATION THAT SNOW LEVELS WILL AGAIN FALL TO
AROUND 5 KFT...WHICH WOULD SUGGEST A TRANSITION TO SNOW FROM
DOUGLAS TO LUSK AND PERHAPS EVEN EAST ALONG THE PINE RIDGE. ANY
PRECIPITATION THAT FALLS THURSDAY EVENING SHOULD END BY
MIDNIGHT...WITH CLEARING CONDITIONS THEREAFTER. OVERNIGHT LOWS
WILL DROP BELOW FREEZING...WITH ROADWAYS AT LEAST HAVING THE
POTENTIAL OF BECOMING SLICK WHERE PRECIPITATION FALLS EARLIER.
WILL NEED TO CONSIDER HIGHLIGHTS IN TIME FOR THOSE AREAS THAT HAVE
NOT ALREADY RECEIVED A KILLING FREEZE...WHICH IS FROM CHADRON
SOUTH TO SIDNEY AS WELL AS IN SCOTTS BLUFF AND BANNER COUNTIES.
WILL LET FOLLOWING SHIFTS EVALUATE THAT NEED. FRIDAY WILL BE A DRY
BUT COOLER DAY AS THE POST-FRONTAL AIR MASS ERODES...WITH HIGHS
REACHING THE 50S IN WY AND 60S OVR THE PANHANDLE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM MDT WED OCT 1 2014

THE MEDIUM RANGE MODELS REMAIN CONSISTENT WITH THE DRY AND MILD
WEATHER PATTERN UNDER PERSISTENT NORTHWEST FLOW ALOFT. THE UPPER
JET AXIS WILL BE POSITIONED FROM SOUTHWEST CANADA THROUGH THE
CENTRAL GREAT PLAINS AND OHIO VALLEY...WITH A RATHER DEEP LONG
WAVE TROUGH OVER THE EASTERN CONUS AND A HIGH AMPLITUDE RIDGE OVER
THE WESTERN CONUS. POTENTIAL ALBERTA CLIPPER SYSTEMS WILL REMAIN
TO THE EAST OF THE CWA. THE ECMWF PROGS A STRONG SHORT WAVE MOVING
THROUGH THE NORTHWEST FLOW ALOFT SUNDAY AFTERNOON WHICH COULD
BRING SOME MOISTURE AND LIFT FOR SHOWER ACTIVITY OVER THE HIGH
PLAINS. THE GFS KEEPS SHORT WAVE ENERGY FURTHER EAST WITH NO
PRECIPITATION. FOR CONSISTENCY SAKE...KEPT SUNDAY DRY WITH
INCREASING CLOUDINESS DURING THE AFTERNOON. TEMPERATURES DURING
THE LONG TERM WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL NORMALS...
WITH HIGHS IN THE MID 60S TO MID 70S AND MID 50S TO MID 60S FOR
THE HIGH VALLEYS AND MOUNTAINS. BREEZY WEST TO NORTHWEST WINDS
WILL DEVELOP EACH AFTERNOON AND EVENING...MAINLY FOR SOUTHEAST
WYOMING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1125 AM MDT WED OCT 1 2014

THE NEXT PACIFIC COLD FRONT AND UPPER LOW PRESSURE TROUGH WILL
IMPACT THE FORECAST AREA THROUGH TONIGHT. CEILINGS WILL LOWER TO
MVFR WITH MORE WIDESPREAD PRECIPITATION DEVELOPING FROM WEST TO
EAST. SHOWERS WILL BE THE PRIMARY PRECIP TYPE...WITH ISOLATED
THUNDER POSSIBLE SOUTH OF A DOUGLAS TO ALLIANCE LINE THIS
AFTERNOON. WINDS WILL BECOME NORTHERLY WITH THE PASSAGE OF THE
FRONT AND MAY BE BREEZY AT TIMES ACROSS SOUTHEAST WYOMING. LOW
CEILINGS WILL LINGER BEHIND THE FRONT THROUGH TONIGHT ALONG AND
SOUTH OF A RAWLINS TO ALLIANCE LINE.


&&

.FIRE WEATHER...
ISSUED AT 325 PM MDT WED OCT 1 2014

A FAST MOVING WEATHER DISTURBANCE TO BRING ANOTHER ROUND OF
PRECIPITATION TO A PORTION OF THE DISTRICTS THROUGH THE REST OF THE
EVENING. SNOW LEVELS HAVE RECENTLY FELL TO AROUND 8 KFT WITH AREAS
ALONG HWY 287 SOUTH OF LARAMIE TURNING OVER. BEST CHANCES FOR
PRECIPITATION WILL BE BETWEEN LARAMIE AND SIDNEY ALONG THE SOUTHERN
TIER OF COUNTIES. THE SYSTEM WILL DEPART TONIGHT AS QUICKLY AS IT
MOVED IN...LEAVING IMPROVING BUT BREEZY AND COOL CONDITIONS FOR
THURSDAY. ANOTHER FAST MOVING CLIPPER SYSTEM WILL "CLIP" THE REGION
THURSDAY NIGHT. ANOTHER ROUND OF LIGHT PRECIP WILL BE POSSIBLE
THURSDAY EVENING WITH RAIN MIXING WITH SNOW POSSIBLY DOWN TO 6000
FEET OR SO. DRY AND WARMING CONDITIONS ARE ANTICIPATED INTO THE
WEEKEND.

&&

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

$$

SHORT TERM...HAHN
LONG TERM...JAMSKI
AVIATION...JAMSKI
FIRE WEATHER...HAHN








000
FXUS65 KRIW 012015
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
215 PM MDT WED OCT 1 2014

.SHORT TERM...TONIGHT AND THURSDAY

UPPER CIRCULATION APPEARS TO BE MOVING RIGHT THROUGH CENTRAL WYO
ATTM WITH SEVERAL WEAK CIRCULATIONS BETWEEN THE SRN ABSAROKAS AND
SERN FREMONT COUNTY. CONSIDERABLE SHOWER ACTIVITY AROUND AND AHEAD
OF THE TROUGH WITH SNOW DOWN AS LOW AS 6500-7K. TEMPS HOVERING IN
THE UPPER 30S TO MID 40S WHERE THE THICK CLOUDS AND SHOWERS CONTINUE
IN THE LOWER ELEVATIONS WITH 30S IN THE NEARBY MOUNTAINS. VORT ON
THE SOUTH END OF THE TROUGH IS IGNITING A FEW TSTMS BUT SOUTH OF OUR
AREA ATTM. SHOWERS WILL CONTINUE AROUND THE CIRCULATION AND AHEAD OF
THE TROUGH FOR A FEW MORE HOURS INTO THE EARLY EVENING BEFORE ALL
BUT EXITING THE AREA. SOME LOW CLOUDS AND PATCHY FOG WILL BE
POSSIBLE OVERNIGHT AHEAD OF OUR NEXT SYSTEM. THIS SYSTEM OVER FAR
NRN B.C. AND ALBERTA HAS -30C AIR AT H5 AND UP TO -18C AIR AT H7 SO
IT WILL BE COLDER. MODELS ARE SHOWING QUITE THE FRONTAL PASSAGE UP
NORTH WITH NAM12 SHOWING ALMOST 8MB 3HR PRESSURE RISES LATE THURSDAY
AFTERNOON. BUMPED UP THE WINDS ACROSS THE NORTH...ESPECIALLY NRN
JOHNSON COUNTY WHERE 50 MPH+ GUSTS QUITE POSSIBLE. IN
ADDITION...SHOWERS WILL BECOME LIKELY IN THE FAR NRN
MOUNTAINS...ESPECIALLY THE BIGHORNS BY LATE AFTERNOON WITH A GOOD
CHANCE OF SHOWERS ACROSS THE LOWER ELEVATIONS OF OUR FAR NRN ZONES.
TEMPERATURES DROP QUICKLY AND IF THE PRECIP LINGERS LONG ENOUGH
COULD SEE IT BEGIN TO CHANGE TO SNOW IN THE LOWER ELEVATIONS BY THE
END OF THIS PERIOD (6 PM THURSDAY). AHEAD OF THIS SYSTEM...WE GET
SOME MOUNTAIN WAVE ACTION IN THE LEE OF THE ABSAROKAS AND BIGHORNS.
SIGNATURE IS NOT IMPRESSIVE BUT ENOUGH TO INCREASE THE WIND ALONG
THE EAST SLOPE...ESPECIALLY THE FAVORED CODY FOOTHILL/EAST SLOPE OF
THE ABSAROKAS. GENERALLY WENT 25G40MPH IN THE FAVORED AREAS. FROUDE
CALCULATION IS RATHER LOW AS MOUNTAIN TOP FLOW IS NOT STRONG ENOUGH
TO CAUSE WAVE BREAKING OVER THE BIGGER MOUNTAINS. SOME MARGINALLY
STABLE AIR IS POSSIBLE BUT DOESN`T LOOK OPTIMAL. SO WINDY BUT NOT
EXPECTING HIGH WINDS.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

THURSDAY NIGHT CANADIAN COLD FRONT WILL CONTINUE PASSING SOUTH
IN THE EVENING WITH AREAS OF RAIN...AND MOUNTAIN SNOW SHOWERS IN THE
NORTH AND EAST...ESPECIALLY IN THE NORTHERN MOUNTAINS.  SOME SHOWERS
WILL LINGER ALONG THE FRONT OVER NATRONA COUNTY WHILE CLEARING
OCCURS TO THE NORTH AND WEST.  TEMPERATURES CONTINUE TO COOL AND
HAVE GONE COLDER THAN PREVIOUS FORECAST WITH MOST AREAS BELOW
FREEZING AND SOME TEEN POSSIBLE IN THE NORTHWEST MOUNTAINS.

FRIDAY AND FRIDAY NIGHT  FLOW ALOFT REMAINS NORTH NORTHWEST WITH COLD
AIR ADVECTION AND HAVE CONTINUED COOLER TREND WITH HIGHS ON FRIDAY
AND LOWS LATE FRIDAY NIGHT.  UPPER LEVEL HIGH PRESSURE RIDGE BUILDS
TO THE WEST STARTING A LONG DRY SPELL.

SATURDAY AND SATURDAY NIGHT  TEMPERATURES WILL BEGIN TO WARM AS THE
WESTERN HIGH PRESSURE RIDGE ALOFT BUILDS INTO THE WEST WITH MOSTLY
CLEAR CONDITIONS.

SUNDAY AND SUNDAY NIGHT  DRY AND WARMER CONDITIONS CONTINUE AS HIGH
PRESSURE RIDGE CONTINUES TO DOMINATE THE WEATHER ACROSS THE REGION.

MONDAY AND MONDAY NIGHT LITTLE ADDITIONAL WARMING IS EXPECTED WITH
DRY CONDITIONS CONTINUING.  SOME SHORT WAVE LOW PRESSURE TROUGHS
MOVING ACROSS SOUTHWEST CANADA WILL KEEP THE WESTERN HIGH PRESSURE
RIDGE FROM BUILDING.

TUESDAY AND TUESDAY NIGHT  FLOW ALOFT BECOMES MORE WESTERLY RETAINING
SOME NORTHERLY COMPONENT AS  SHORT WAVE LOW PRESSURE TROUGHS CONTINUE
MOVING ACROSS SOUTHWEST CANADA AND NORTHERN MONTANA SUPPRESSING THE
RIDGE.  NORTH MAY SEE SOME INCREASED CLOUD COVER BUT EXPECT THE COLD
FRONT ASSOCIATED WITH THE SERIES OF SHORT WAVE LOW PRESSURE TROUGHS
TO REMAIN NORTH AND EAST OF THE FORECAST AREA.

WEDNESDAY  FLOW BECOMES ZONAL AS RIDGE CONTINUES TO FLATTEN.
EXTENDED MODELS SHOW THE CANADIAN/MONTANA COLD FRONT REMAINS JUST TO
THE NORTH KEEPING WYOMING DRY.  WILL SEE INCREASING WEST SURFACE
WINDS AND CONTINUED DRYING.  WILL HAVE TO KEEP AN EYE ON THE COLD
FRONT TO THE NORTH OVER TIME AS A MOVEMENT FARTHER TO THE SOUTH WILL
BRING CLOUDS...SHOWERS COLDER TEMPERATURES TO THE NORTH AND POSSIBLY
THE EAST.

.AVIATION.../00Z ISSUANCE/

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

LOW PRESSURE SYSTEM MOVING SOUTHEAST ACROSS THE AREA WILL KEEP IT
UNSETTLED WITH MTN OBSCURATION INTO THE EARLY EVENING WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITH OCNL MVFR DURING
SHOWERS. MOST CIGS WILL BE IN THE 025-045 RANGE WITH BRIEF CIGS
DOWN TO 010-015 DURING PASSING SHOWERS. CIGS WILL LIFT OR
DISSIPATE TONIGHT BUT PATCHY LOW LYING FOG IS POSSIBLE IN THE
CENTRAL BASINS. A NEW COLD FRONT WILL ARRIVE ACROSS THE NORTH IN
THE AFTERNOON WITH AN INCREASING CHANCE OF SHOWERS AND LOWERING
CIGS. VFR CONDS WILL PREVAIL THROUGH IN MOST AREAS THROUGH THE
AFTERNOON EXCEPT FROM NEAR A KCOD TO KBYG LINE WHERE MVFR CIGS
COULD DEVELOP BEFORE 00Z FRIDAY ALONG WITH MTN OBSCURATION WHERE
SNOW WILL DEVELOP.

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

WIDELY SCATTERED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
PREVAIL THROUGH EARLY THIS EVENING BEFORE ENDING. BRIEF MVFR CONDS
WILL OCCUR DURING SOME SHOWERS AND MAY AFFECT THE WESTERN TAF SITES.
PATCHY LOW FOG AND LOW CLOUDS MAY REDEVELOP LATER TONIGHT WITH MTN
OBSCURATION AND BRIEF VSBYS UNDER 3 MILES. OTHERWISE...MOST AREAS
WILL BE VFR OVERNIGHT BUT WITH SOME MTN OBSCURATION IN LOW CLOUDS.
ONCE ANY LOW CLOUDS OR FOG BURNS OFF...ALL AREAS SHOULD SEE VFR
CONDITIONS ON THURSDAY WITH THE POSSIBLE EXCEPTION OF YELLOWSTONE
NATIONAL PARK WHERE SOME LATE DAY SHOWERS DEVELOP.

.FIRE WEATHER...

CONSIDERABLE SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM OR TWO IN
CENTRAL WYOMING INTO THE EARLY EVENING BEFORE MOVING SOUTHEAST AND
DECREASING. MORE WIDELY SCATTERED TO SCATTERED SHOWERS ELSEWHERE
UNTIL AROUND SUNSET. GUSTY WEST TO NORTHWEST WINDS ACROSS THE WEST
AND SOUTH WILL DECREASE THIS EVENING BUT PICK BACK UP AGAIN
THURSDAY. A NEW WEATHER SYSTEM WILL PUSH A STRONG COLD FRONT INTO
THE FAR NORTHERN ZONES DURING THE AFTERNOON WITH STRONG NORTH WIND
GUSTS OF 40 TO 50 MPH AND AN INCREASING CHANCE OF SHOWERS. SOUTH OF
THE FRONT IN CENTRAL AND SOUTHERN WYOMING...IT WILL BE DRY BUT WITH
SOME GUSTY WEST TO NORTHWEST WIND. THE COLD FRONT WILL PUSH SOUTH
INTO CENTRAL WYOMING BY EARLY EVENING.

&&

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

&&

$$

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






000
FXUS65 KRIW 012015
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
215 PM MDT WED OCT 1 2014

.SHORT TERM...TONIGHT AND THURSDAY

UPPER CIRCULATION APPEARS TO BE MOVING RIGHT THROUGH CENTRAL WYO
ATTM WITH SEVERAL WEAK CIRCULATIONS BETWEEN THE SRN ABSAROKAS AND
SERN FREMONT COUNTY. CONSIDERABLE SHOWER ACTIVITY AROUND AND AHEAD
OF THE TROUGH WITH SNOW DOWN AS LOW AS 6500-7K. TEMPS HOVERING IN
THE UPPER 30S TO MID 40S WHERE THE THICK CLOUDS AND SHOWERS CONTINUE
IN THE LOWER ELEVATIONS WITH 30S IN THE NEARBY MOUNTAINS. VORT ON
THE SOUTH END OF THE TROUGH IS IGNITING A FEW TSTMS BUT SOUTH OF OUR
AREA ATTM. SHOWERS WILL CONTINUE AROUND THE CIRCULATION AND AHEAD OF
THE TROUGH FOR A FEW MORE HOURS INTO THE EARLY EVENING BEFORE ALL
BUT EXITING THE AREA. SOME LOW CLOUDS AND PATCHY FOG WILL BE
POSSIBLE OVERNIGHT AHEAD OF OUR NEXT SYSTEM. THIS SYSTEM OVER FAR
NRN B.C. AND ALBERTA HAS -30C AIR AT H5 AND UP TO -18C AIR AT H7 SO
IT WILL BE COLDER. MODELS ARE SHOWING QUITE THE FRONTAL PASSAGE UP
NORTH WITH NAM12 SHOWING ALMOST 8MB 3HR PRESSURE RISES LATE THURSDAY
AFTERNOON. BUMPED UP THE WINDS ACROSS THE NORTH...ESPECIALLY NRN
JOHNSON COUNTY WHERE 50 MPH+ GUSTS QUITE POSSIBLE. IN
ADDITION...SHOWERS WILL BECOME LIKELY IN THE FAR NRN
MOUNTAINS...ESPECIALLY THE BIGHORNS BY LATE AFTERNOON WITH A GOOD
CHANCE OF SHOWERS ACROSS THE LOWER ELEVATIONS OF OUR FAR NRN ZONES.
TEMPERATURES DROP QUICKLY AND IF THE PRECIP LINGERS LONG ENOUGH
COULD SEE IT BEGIN TO CHANGE TO SNOW IN THE LOWER ELEVATIONS BY THE
END OF THIS PERIOD (6 PM THURSDAY). AHEAD OF THIS SYSTEM...WE GET
SOME MOUNTAIN WAVE ACTION IN THE LEE OF THE ABSAROKAS AND BIGHORNS.
SIGNATURE IS NOT IMPRESSIVE BUT ENOUGH TO INCREASE THE WIND ALONG
THE EAST SLOPE...ESPECIALLY THE FAVORED CODY FOOTHILL/EAST SLOPE OF
THE ABSAROKAS. GENERALLY WENT 25G40MPH IN THE FAVORED AREAS. FROUDE
CALCULATION IS RATHER LOW AS MOUNTAIN TOP FLOW IS NOT STRONG ENOUGH
TO CAUSE WAVE BREAKING OVER THE BIGGER MOUNTAINS. SOME MARGINALLY
STABLE AIR IS POSSIBLE BUT DOESN`T LOOK OPTIMAL. SO WINDY BUT NOT
EXPECTING HIGH WINDS.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

THURSDAY NIGHT CANADIAN COLD FRONT WILL CONTINUE PASSING SOUTH
IN THE EVENING WITH AREAS OF RAIN...AND MOUNTAIN SNOW SHOWERS IN THE
NORTH AND EAST...ESPECIALLY IN THE NORTHERN MOUNTAINS.  SOME SHOWERS
WILL LINGER ALONG THE FRONT OVER NATRONA COUNTY WHILE CLEARING
OCCURS TO THE NORTH AND WEST.  TEMPERATURES CONTINUE TO COOL AND
HAVE GONE COLDER THAN PREVIOUS FORECAST WITH MOST AREAS BELOW
FREEZING AND SOME TEEN POSSIBLE IN THE NORTHWEST MOUNTAINS.

FRIDAY AND FRIDAY NIGHT  FLOW ALOFT REMAINS NORTH NORTHWEST WITH COLD
AIR ADVECTION AND HAVE CONTINUED COOLER TREND WITH HIGHS ON FRIDAY
AND LOWS LATE FRIDAY NIGHT.  UPPER LEVEL HIGH PRESSURE RIDGE BUILDS
TO THE WEST STARTING A LONG DRY SPELL.

SATURDAY AND SATURDAY NIGHT  TEMPERATURES WILL BEGIN TO WARM AS THE
WESTERN HIGH PRESSURE RIDGE ALOFT BUILDS INTO THE WEST WITH MOSTLY
CLEAR CONDITIONS.

SUNDAY AND SUNDAY NIGHT  DRY AND WARMER CONDITIONS CONTINUE AS HIGH
PRESSURE RIDGE CONTINUES TO DOMINATE THE WEATHER ACROSS THE REGION.

MONDAY AND MONDAY NIGHT LITTLE ADDITIONAL WARMING IS EXPECTED WITH
DRY CONDITIONS CONTINUING.  SOME SHORT WAVE LOW PRESSURE TROUGHS
MOVING ACROSS SOUTHWEST CANADA WILL KEEP THE WESTERN HIGH PRESSURE
RIDGE FROM BUILDING.

TUESDAY AND TUESDAY NIGHT  FLOW ALOFT BECOMES MORE WESTERLY RETAINING
SOME NORTHERLY COMPONENT AS  SHORT WAVE LOW PRESSURE TROUGHS CONTINUE
MOVING ACROSS SOUTHWEST CANADA AND NORTHERN MONTANA SUPPRESSING THE
RIDGE.  NORTH MAY SEE SOME INCREASED CLOUD COVER BUT EXPECT THE COLD
FRONT ASSOCIATED WITH THE SERIES OF SHORT WAVE LOW PRESSURE TROUGHS
TO REMAIN NORTH AND EAST OF THE FORECAST AREA.

WEDNESDAY  FLOW BECOMES ZONAL AS RIDGE CONTINUES TO FLATTEN.
EXTENDED MODELS SHOW THE CANADIAN/MONTANA COLD FRONT REMAINS JUST TO
THE NORTH KEEPING WYOMING DRY.  WILL SEE INCREASING WEST SURFACE
WINDS AND CONTINUED DRYING.  WILL HAVE TO KEEP AN EYE ON THE COLD
FRONT TO THE NORTH OVER TIME AS A MOVEMENT FARTHER TO THE SOUTH WILL
BRING CLOUDS...SHOWERS COLDER TEMPERATURES TO THE NORTH AND POSSIBLY
THE EAST.

.AVIATION.../00Z ISSUANCE/

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

LOW PRESSURE SYSTEM MOVING SOUTHEAST ACROSS THE AREA WILL KEEP IT
UNSETTLED WITH MTN OBSCURATION INTO THE EARLY EVENING WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITH OCNL MVFR DURING
SHOWERS. MOST CIGS WILL BE IN THE 025-045 RANGE WITH BRIEF CIGS
DOWN TO 010-015 DURING PASSING SHOWERS. CIGS WILL LIFT OR
DISSIPATE TONIGHT BUT PATCHY LOW LYING FOG IS POSSIBLE IN THE
CENTRAL BASINS. A NEW COLD FRONT WILL ARRIVE ACROSS THE NORTH IN
THE AFTERNOON WITH AN INCREASING CHANCE OF SHOWERS AND LOWERING
CIGS. VFR CONDS WILL PREVAIL THROUGH IN MOST AREAS THROUGH THE
AFTERNOON EXCEPT FROM NEAR A KCOD TO KBYG LINE WHERE MVFR CIGS
COULD DEVELOP BEFORE 00Z FRIDAY ALONG WITH MTN OBSCURATION WHERE
SNOW WILL DEVELOP.

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

WIDELY SCATTERED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
PREVAIL THROUGH EARLY THIS EVENING BEFORE ENDING. BRIEF MVFR CONDS
WILL OCCUR DURING SOME SHOWERS AND MAY AFFECT THE WESTERN TAF SITES.
PATCHY LOW FOG AND LOW CLOUDS MAY REDEVELOP LATER TONIGHT WITH MTN
OBSCURATION AND BRIEF VSBYS UNDER 3 MILES. OTHERWISE...MOST AREAS
WILL BE VFR OVERNIGHT BUT WITH SOME MTN OBSCURATION IN LOW CLOUDS.
ONCE ANY LOW CLOUDS OR FOG BURNS OFF...ALL AREAS SHOULD SEE VFR
CONDITIONS ON THURSDAY WITH THE POSSIBLE EXCEPTION OF YELLOWSTONE
NATIONAL PARK WHERE SOME LATE DAY SHOWERS DEVELOP.

.FIRE WEATHER...

CONSIDERABLE SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM OR TWO IN
CENTRAL WYOMING INTO THE EARLY EVENING BEFORE MOVING SOUTHEAST AND
DECREASING. MORE WIDELY SCATTERED TO SCATTERED SHOWERS ELSEWHERE
UNTIL AROUND SUNSET. GUSTY WEST TO NORTHWEST WINDS ACROSS THE WEST
AND SOUTH WILL DECREASE THIS EVENING BUT PICK BACK UP AGAIN
THURSDAY. A NEW WEATHER SYSTEM WILL PUSH A STRONG COLD FRONT INTO
THE FAR NORTHERN ZONES DURING THE AFTERNOON WITH STRONG NORTH WIND
GUSTS OF 40 TO 50 MPH AND AN INCREASING CHANCE OF SHOWERS. SOUTH OF
THE FRONT IN CENTRAL AND SOUTHERN WYOMING...IT WILL BE DRY BUT WITH
SOME GUSTY WEST TO NORTHWEST WIND. THE COLD FRONT WILL PUSH SOUTH
INTO CENTRAL WYOMING BY EARLY EVENING.

&&

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

&&

$$

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







000
FXUS63 KUNR 011952
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
152 PM MDT WED OCT 1 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER LEVEL WAVE IS MOVING THROUGH WYOMING...CONTINUING TO
PRODUCE SHOWERS ACROSS NORTHEAST WY AND FAR WESTERN SD. FAIRLY
TIGHT PRESSURE GRADIENT IS CAUSING SOME BREEZY NORTHWEST WINDS
ACROSS THE CWA...ESPECIALLY IN NW SOUTH DAKOTA.

LIGHT SHOWERS WILL TRANSITION EASTWARD ACROSS SOUTHERN SD
TONIGHT...AND CLOUDS WILL DISSIPATE. WINDS WILL BECOME LIGHT...AND
LOWS WILL BE IN THE MID 30S TO MID 40S.

A FAST-MOVING CANADIAN LOW PRESSURE SYSTEM WILL SWEEP A COLD FRONT
THROUGH THE NORTHERN PLAINS ON THURSDAY. WINDS WILL BECOME GUSTY
FROM THE NORTHWEST THURSDAY AFTERNOON INTO THE EVENING. THE MAV
REACHES WIND ADVISORY CRITERIA ACROSS NORTHWEST SD...BUT AS USUAL IT
IS STRONGER THAN THE OTHER MODELS. HIGHEST PRESSURE RISES OF 7-8
MB/3HR SLIDE WEST OF THE USUAL WINDY AREAS AND INCREASE AFTER
SUNSET...SO AT THIS POINT A WIND ADVISORY SEEMS MARGINAL. HOWEVER
WITH THE COLD ADVECTION FOLLOWING THE FRONT...30-40KT 850MB
WINDS...AND IF MODELS COME INTO BETTER AGREEMENT...LATER SHIFTS MAY
DECIDE TO ISSUE ONE.

ALSO FOLLOWING THIS COLD FRONT WILL BE A CHANCE FOR SHOWERS...MAINLY
ACROSS NORTHEAST WY AND FAR WESTERN SD. THESE WILL BE AIDED BY UPPER
LEVEL DIVERGENCE ASSOCIATED WITH THE LEFT EXIT REGION OF THE JET. AS
TEMPS COOL THURSDAY NIGHT...SOME OF THE LINGERING SHOWERS MAY BE IN
THE FORM OF SNOW. MINIMAL ACCUMULATIONS ARE EXPECTED.

TEMPERATURES ON THURSDAY WILL BE TRICKY WITH THE TIMING OF THE COLD
FRONT. MID 50S ARE IN THE FORECAST FOR NORTHEAST WY AND NORTHWEST
SD...WITH MID 60S ACROSS SOUTH CENTRAL SD. ON THURSDAY NIGHT...LOWS
WILL RANGE FROM THE 20S ACROSS THE BLACK HILLS...NORTHEAST WY...AND
NORTHWEST SD...TO THE MID 30S OVER SOUTH CENTRAL SD. FROST/FREEZE
HEADLINES MAY BE NECESSARY ACROSS CENTRAL SD WHERE TEMPS HAVE NOT
DIPPED THAT LOW YET THIS SEASON.

&&

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 150 PM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS
THE LARGE UPPER TROUGH SHIFTS INTO THE MIDWEST. LITTLE CHANGE TO THE
PATTERN IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE
LONGWAVE PATTERN BECOMES A BIT PERSISTENT. NORTHWEST FLOW OVER THE
AREA WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS THROUGH EARLY
NEXT WEEK. OCCASIONAL SHORTWAVES WILL SLIDE OVER THE RIDGE...WHICH
WILL BRING BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE FRIDAY
WILL BE THE WINDIEST DAY IN THE EXTENDED PERIOD.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 150 PM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS
NORTHEAST WYOMING AND FAR WESTERN SOUTH DAKOTA THIS AFTERNOON...THEN
SPREADING INTO SOUTH CENTRAL SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY
ARE EXPECTED WITH ANY SHOWERS THAT DEVELOP. IFR CIGS ARE POSSIBLE
WITH ANY SHOWER DEVELOPMENT NEAR THE BLACK HILLS. BREEZY NORTHWEST
WINDS WILL PERSIST THROUGH EARLY EVENING ACROSS THE
PLAINS...ESPECIALLY ACROSS THE SOUTH DAKOTA PLAINS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...POJORLIE
LONG TERM...15
AVIATION...15







000
FXUS65 KRIW 011810
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1209 PM MDT WED OCT 1 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

LARGE LW TROF ACROSS THE CONUS W OF THE MISSISSIPPI...WITH TWO
EMBEDDED SW TROFS ROTATING THRU THE FLOW...ONE TO THE E AND OVR THE
NRN PLAINS...THE OTHER JUST NOW KNOCKING ON THE DOORSTEP OF THE WRN
FA. FURTHER UPSTREAM...SW RIDGING COMING INTO THE PAC NW WITH SW
TROF ON ITS HEALS COMING OUT OF SRN AK. SFC SHOWS
DEVELOPED/ASSOCIATED CYCLONE OVR THE NRN PLAINS W/ TRAILING FRONT
FROM ERN MT SWD AND THRU CNTRL WY...THEN OFF TO THE SW AND INTO THE
GREAT BASIN...WHILE ANOTHER SFC TROF/DEVELOPING FRONT JUST
APPROACHING THE NW CORNER OF THE STATE.

THIS MORNING/TODAY THRU TONIGHT...SOME MID/UPR LIFT INCREASES AS SW
NEAR WRN CORRIDOR CONTINUES TO TRANSLATE THRU THE LARGE-SCALE FLOW
AND OVR THE WRN HALF OF THE CWA BY MORNING...WITH COLDER AND
MODESTLY DIFLUENT UPR LVLS. ATTM...WV IMAGERY SHOWS TWO PLUMES OF
MOISTURE ASSOCIATED WITH APPROACHING SW TROF...ONE RIDING INTO THE
NW CORNER OF WY WITH THE TROF/FRONT...THE OTHER TO THE S AND RIDING
THRU RATHER FLAT FLOW OUT OF THE SERN ID/NRN UT...WITH DRIER AIR IN
BETWEEN THE TWO. PRECIPITATION...BOTH LIQUID AND FROZEN WILL
CONTINUE ACROSS THE NRN CWA THROUGH THE DAY BEHIND A FRONT...WHILE
THE CNTRL CWA INCLUDING THE WIND RIVER BASIN AND WIND RIVER
MOUNTAINS WILL HAVE TO WAIT A BIT LONGER FOR THE MAIN UPR TROF TO
PUSH FURTHER ACROSS AND FORCE THE FRONT FURTHER SOUTH THROUGH THE
LATE MORNING BEFORE PRECIP THERE GETS GOING. H7 TEMPS WILL CONTINUE
TO FALL FROM AROUND -1 DEG C TO NEAR -4 THRU THE MORNING HRS. WHILE
COLD AIR WILL BE ADVECTING INTO THE FA FROM THE N...CLOUD COVER WILL
KEEP SOME WARMER AIR TRAPPED AT LOWER ELEVATIONS AND WILL HAVE TO
MIX OUT THOROUGHLY...WHICH MAY TAKE A WHILE.
ADDITIONALLY...EVAPORATIVE COOLING FROM ALOFT MAY BE LIMITED AS
CEILINGS CONTINUE TO FALL THIS MORNING...CLOSING THE DRY/MOIST AIR GAP
QUICKLY. SNOW TOTALS FROM EARLY THIS MORNING THROUGH THE EVENING
PERIOD WILL VARY FROM AS MUCH AS 6 INCHES OVER PORTIONS OF THE
ABSAROKAS AND BIGHORN MOUNTAINS...5 INCHES IN THE TETONS...AND UP TO
4 INCHES IN THE WIND RIVERS. RAIN SHOWERS MAY MIX WITH SNOW OR
BECOME ALL SNOW FOR A BRIEF PERIOD AT SOME LOWER ELEVATIONS IN THE
WESTERN BIGHORN BASIN THIS MORNING...WITH MOSTLY AN INCH OR LESS
POSSIBLE AT SOME LOCATIONS...BUT WITH ISOLATED AREAS...SUCH AS
AROUND MEETEETSE RECEIVING 1 TO 2 INCHES OF SNOWFALL...IF THE
CHANGEOVER OCCURS.  TONIGHT...UPR TROF AXIS PUSHES ACROSS THE
FA...QUICKLY CLEARING SKIES AND COOLING THINGS OFF FROM W TO E BY
MIDNIGHT OR SHORTLY THEREAFTER. PATCHY FOG MAY BECOME AN ISSUE
OVERNIGHT AND INTO THURSDAY MORNING WEST OF THE DIVIDE AND OVER
PARTS OF THE BIGHORN BASIN.

THU...QUICK MODEST RIDGING GIVES WAY TO YET ANOTHER AND FINAL UPR SW
TROF THAT WILL SWING THRU THE BACKSIDE OF THE MAIN TROF...DRIVING
ANOTHER COLD FRONT DOWN THRU THE FA EAST OF THE DIVIDE.
HOWEVER...MOISTURE WILL BE AT A PREMIUM WITH THIS FEATURE. WHILE
PRECIP CHANCES WILL INCREASE E OF THE DIVIDE...MAINLY ACROSS THE NRN
MOUNTAINS AND BIGHORN BASIN...QPF WILL REMAIN QUITE LOW. CHANCES FOR
LIGHT SNOW WILL BE POSSIBLE ACROSS THE MOUNTAINS ONCE AGAIN ABOVE
7000 FEET...BUT MEASURABLE AMOUNTS ATTM LOOK TO REMAIN MOSTLY BE AN
INCH. THIS SW TROF WILL QUICKLY MOVE OUT OF THE AREA THROUGH THE
EVENING...WITH ONLY CLEAR COLD AND DRY SKIES LEFT BY FRI
MORNING.

FRI...LARGE MAIN UPR TROF PROGRESSES EWD INTO THE CNTRL CONUS...WITH
RIDGING W SLOWLY INCHES ITS WAY TOWARDS WY...LEAVING THE FA UNDER NW
FLOW ALOFT AND STRONG HIGH PRESSURE AT THE SFC. FRI WILL BE
CHARACTERIZED BY MOSTLY CLEAR AND SUNNY SKIES...AND WARMER AFTER A
RATHER COLD START.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

SYNOPSIS...UPPER RIDGE OF HIGH PRESSURE ALONG THE WEST COAST WILL
BRING A DRY AND MILD NORTHWEST FLOW ACROSS THE AREA THROUGH TUESDAY.

DISCUSSION...THIS PERIOD BEGINS WITH AN UPPER RIDGE ALONG THE WEST
COAST AND DOWNSTREAM LONGWAVE TROUGH ACROSS THE EASTERN U.S.  THIS
PATTERN IS EXPECTED TO SLOWLY DEAMPLIFY EARLY NEXT WEEK AS UPSTREAM
OMEGA BLOCK BUILDS ALONG THE ALEUTIAN CHAIN WITH UPPER LOW OVER THE
CENTRAL PACIFIC (NEAR 43N/165W EARLY THIS MORNING) BECOMING THE
EASTERN ANCHOR OF THIS BLOCK NEAR JUNEAU AK.  GFS AND ECMWF
DETERMINISTIC RUNS BOTH SHOW INCREASING SPREAD FROM THEIR RESPECTIVE
ENSEMBLE MEANS ON HOW THIS BLOCK WILL EVOLVE.  FORECAST PREFERS THE
LEAST AMOUNT OF TRANSITION OFFERED BY THE GEFS MEAN THIS
MORNING...HOLDING ON TO FLATTER WESTERN RIDGE...EASTERN TROUGH
PATTERN THROUGH MIDWEEK AND KEEPING POLAR FRONT NORTH OF THE AREA.
EXPECT TEMPERATURES TO BE 5-8F DEGREES ABOVE NORMAL THROUGH THE
PERIOD WITH A SLIGHT WARMING TREND MONDAY AND TUESDAY.  SLIGHT
CHANCE POPS WERE INTRODUCED TO THE NORTHERN MOUNTAINS ON WEDNESDAY
AS FLOW BECOMES MORE WESTERLY.

&&

.AVIATION.../18Z ISSUANCE/

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

LOW PRESSURE SYSTEM MOVING SOUTHEAST ACROSS THE AREA WILL KEEP IT
UNSETTLED WITH MTN OBSCURATION INTO THE EARLY EVENING WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITH OCNL MVFR DURING
SHOWERS. MOST CIGS WILL BE IN THE 025-045 RANGE WITH BRIEF CIGS
DOWN TO 010-015 DURING PASSING SHOWERS. CIGS WILL LIFT OR
DISSIPATE TONIGHT BUT PATCHY LOW LYING FOG IS POSSIBLE IN THE
CENTRAL BASINS. A NEW COLD FRONT WILL ARRIVE ACROSS THE NORTH IN
THE AFTERNOON WITH AN INCREASING CHANCE OF SHOWERS AND LOWERING
CIGS. VFR CONDS WILL PREVAIL THROUGH IN MOST AREAS THROUGH THE
AFTERNOON EXCEPT FROM NEAR A KCOD TO KBYG LINE WHERE MVFR CIGS
COULD DEVELOP BEFORE 00Z FRIDAY ALONG WITH MTN OBSCURATION WHERE
SNOW WILL DEVELOP.

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

WIDELY SCATTERED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
PREVAIL THROUGH EARLY THIS EVENING BEFORE ENDING. BRIEF MVFR CONDS
WILL OCCUR DURING SOME SHOWERS AND MAY AFFECT THE WESTERN TAF SITES.
PATCHY LOW FOG AND LOW CLOUDS MAY REDEVELOP LATER TONIGHT WITH MTN
OBSCURATION AND BRIEF VSBYS UNDER 3 MILES. OTHERWISE...MOST AREAS
WILL BE VFR OVERNIGHT BUT WITH SOME MTN OBSCURATION IN LOW CLOUDS.
ONCE ANY LOW CLOUDS OR FOG BURNS OFF...ALL AREAS SHOULD SEE VFR
CONDITIONS ON THURSDAY WITH THE POSSIBLE EXCEPTION OF YELLOWSTONE
NATIONAL PARK WHERE SOME LATE DAY SHOWERS DEVELOP.

&&

.FIRE WEATHER...

FIRE DANGER WILL REMAIN LOW ACROSS THE FORECAST AREA THROUGH THE
REST OF THE WEEK. SHOWERS WILL CONTINUE ACROSS WEST AND NORTH
THROUGH THE DAY...ENDING FROM WEST TO EAST LATER THIS AFTERNOON AND
THROUGH THIS EVENING. THE BEST CHANCE FOR WETTING RAINS (OR SNOW)
WILL OCCUR IN THE TETONS EARLY...THEN THE ABSAROKA AND BIGHORN
MOUNTAINS THROUGH THE REST OF THE DAY...WITH BEST CHANCES ACROSS THE
LOWER ELEVATIONS COMING IN THE CODY FOOTHILLS AND SOUTHERN BIGHORN
BASIN. ANOTHER CHANCE FOR LIGHT PRECIPITATION WILL PRESENT ITSELF BY
THURSDAY AFTERNOON OVER THE NORTHEASTERN DISPATCH ZONES...EXITING
QUICKLY BY EVENING.

&&

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

&&

$$

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










000
FXUS63 KUNR 011738
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1138 AM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 852 AM MDT WED OCT 1 2014

SHORTWAVE CONTINUES TO APPROACH THE REGION...PUSHING SOME LIGHT
SHOWERS INTO NORTHEASTERN WYOMING. INCREASED POPS OVER THAT AREA
TODAY. UPDATED SKY GRIDS TO MATCH SATELLITE. STILL LOOKS LIKE IT
WILL BE BREEZY THROUGH THE AFTERNOON...ESPECIALLY ACROSS NORTHWEST
SOUTH DAKOTA.

&&

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

08Z SURFACE ANALYSIS HAD LOW OVER NORTH CENTRAL ND WITH UPPER LOW
SPINNING ON TOP...WITH SYSTEM MOVING NORTH/NORTHEAST PER SATELLITE
LOOPS. NEXT SHORTWAVE TROUGH OF INTEREST OVER WESTERN MT/ID PER
WATER VAPOR. THIS WAVE WILL MOVE SOUTHEAST TODAY ROUNDING BASE OF
MEAN TROUGH OVER CENTRAL NORTH AMERICA. COMBINATION OF CYCLONIC
FLOW AND WEAK FORCING WITH SHORTWAVE TROUGH WILL RESULT IN A FEW
-SHRA OVER THE CWA TODAY...SHIFTING EAST/SOUTH OF THE AREA
TONIGHT. TEMPERATURES WILL BE NEAR GUIDANCE TODAY/TONIGHT.

THURSDAY...FAST MOVING UPPER TROUGH/SHORTWAVE WILL RACE INTO THE
NORTHERN PLAINS BY 00Z FRIDAY DRIVING A SHARP COLD FRONT INTO THE
CWA. A FEW -SHRA MAY OCCUR WITH THE SYSTEM...BUT THE MAIN EFFECT
WILL BE RATHER STRONG COLD AIR ADVECTION AND 30-40KT 850-700MB
WINDS. HAVE BUMPED UP WINDS ON THE SD PLAINS TO ACCOUNT...AND MAY
NEED SOME SORT OF WIND HEADLINES WHEN ALL IS SAID AND DONE. IT/LL BE
COLD ENOUGH EARLY THURSDAY EVENING OVER THE HIGHER ELEVATIONS FOR A
FEW -SHRASN. TEMPERATURES WILL BE NEAR GUIDANCE...AND PROBABLY COLD
ENOUGH FOR FROST/FREEZE OVER PARTS OF THE CWA THURSDAY NIGHT.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 237 AM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS THE LARGE
UPPER TROUGH EXITS INTO THE MIDWEST. LITTLE CHANGE TO THE PATTERN
IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE OVERALL
PROGRESS SLOWS TO A CRAWL. PERSISTENT NORTHWEST FLOW OVER THE AREA
WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS. OCCASIONAL
UPPER WAVES WILL PUSH ACROSS THE NORTHWEST FLOW...WHICH WILL BRING
BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE WINDS FRIDAY AND
PERHAPS SATURDAY WILL BE GUSTIER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1133 AM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA THIS AFTERNOON...THEN SOUTH
CENTRAL SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY ARE EXPECTED WITH ANY
SHOWERS THAT DEVELOP. IFR CIGS ARE POSSIBLE WITH ANY SHOWER
DEVELOPMENT NEAR THE BLACK HILLS. BREEZY NORTHWEST WINDS WILL
PERSIST THROUGH EARLY EVENING ACROSS THE PLAINS...ESPECIALLY OVER
NORTHWEST SOUTH DAKOTA.


&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...POJORLIE
SHORT TERM...HELGESON
LONG TERM...13
AVIATION...15






000
FXUS65 KCYS 011732
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1132 AM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 1132 AM MDT WED OCT 1 2014

GOING FORECAST IN GOOD SHAPE FOR THIS AFTERNOON. SATELLITE PIX
SHOW NEXT SHORTWAVE OVR WRN WYOMING WITH A BAROCLINIC LEAF
DEVELOPING IN ADVANCE OF IT ACROSS WRN COLORADO/CENTRAL WY.
SHOWERS HAVE ALREADY BEEN DEVELOPING ACROSS WESTERN AND CENTRAL
WYOMING...AS WELL AS ACROSS COLORADO. LATEST DATA FROM KCYS 88D
SHOW SHOWERS DEVELOPING FROM AROUND WOODS LANDING EAST TOWARDS
PUMPKIN VINE OVER THE PAST HOUR OR TWO. THIS AREA WILL EXPAND
EAST/NORTHEAST ACROSS THE LARAMIE VALLEY...SRN LARAMIE RANGE...
LARAMIE COUNTY AND ADJACENT LOCALES THIS AFTERNOON. HAVE BOOSTED
PRECIP CHANCES ACROSS THESE AREAS TO REFLECT THE GROWING
CONFIDENCE OF THIS OCCURRING. OTHERWISE...HAVE INCREASED
TEMPERATURES 2-5 DEGREES EAST OF THE LARAMIE RANGE AS SUNSHINE HAS
BEEN A BIT MORE PLENTIFUL THAN EARLIER THOUGHT. STILL LOOKS TO BE
A QUICK HITTING SYSTEM...WITH DEPARTURE EXPECTED TONIGHT.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 206 AM MDT WED OCT 1 2014

CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR TO PARTLY CLOUDY
SKIES ACROSS MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA EARLY
THIS MORNING AS THE LOW PRESSURE SYSTEM WHICH BROUGHT HEAVY RAIN
TO THE AREA YESTERDAY IS NOW ENTERING SOUTHERN SASKATCHEWAN AND
MANITOBA. HOWEVER...THE NEXT UPPER LEVEL TROUGH IS CURRENTLY DIGGING
SOUTH ACROSS THE EASTERN GREAT BASIN REGION...WITH SHOWERS AND
TSTORMS DEVELOPING OVER UTAH AND ENTERING WESTERN COLORADO AT THIS
HOUR. THIS WILL BE OUR NEXT PRECIPITATION PRODUCER TODAY AS THE
UPPER LEVEL SYSTEM CONTINUES TO DIG SOUTHEAST THIS MORNING AND
EVENTUALLY PUSHES EASTWARD THIS AFTERNOON. NOT MUCH DYNAMIC LIFT
AT THE SURFACE WITH THIS SYSTEM...BUT MODELS INDICATE STRONG UPPER
LEVEL DIVERGENCE AS A 100 KT JET LIFT NORTHEAST INTO THE HIGH
PLAINS TODAY. THE GFS AND ECMWF DO INDICATE STRONG 700MB
CONVERGENCE ACROSS NORTHEAST COLORADO AND EXTREME SE WYOMING AS A
700MB LOW TRIES TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING.
THIS MID TO UPPER LEVEL COUPLET WILL ALLOW FOR SOME SUBSTANTIAL
LIFT IN ADDITION TO ANY LLVL INSTABILITY. CONTINUED TO INCREASE
POP BETWEEN 70 TO 90 PERCENT THIS AFTERNOON THROUGH LATE THIS
EVENING. THIS SYSTEM WILL MOVE RATHER QUICK ACROSS THE AREA...SO
ONLY EXPECT PERHAPS 3 TO 6 HOURS OF PRECIPITATION. IN THE
MOUNTAINS AND LOCATIONS ABOVE 7500 FEET...RAIN WILL MIX WITH AND
CHANGE TO SNOW. THIS INCLUDES THE SOUTHERN LARAMIE RANGE AND THE
I80 SUMMIT WHICH MAY RECEIVE 1 TO 3 INCHES OF SNOW BY LATE THIS
AFTERNOON. THE SNOWY AND SIERRA MADRE RANGES MAY SEE A LITTLE
MORE...BUT NO MORE THAN 3 TO 5 INCHES IS EXPECTED INTO THIS
EVENING. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES DUE TO THE
PROGRESSIVE NATURE OF THE TROUGH. FOR THE LOWER ELEVATIONS...THE
HEAVIEST RAINFALL AMOUNTS WILL GENERALLY BE ALONG THE I80 CORRIDOR
FROM LARAMIE...EASTWARD TO CHEYENNE AND SIDNEY NEBRASKA. CAN NOT
RULE OUT SOME RAIN/SNOW MIX AS THE PRECIPITATION COMES TO AN END
ACROSS THE LARAMIE VALLEY THIS AFTERNOON WITH SNOW LEVELS
LOWERING BETWEEN 7000 TO 7500 FEET. TONIGHT WILL BE MUCH COOLER
WITH LOWS IN THE 20S TO LOW 30S ACROSS SOUTHEAST WYOMING DUE TO
CLEARING SKIES AND GOOD RADIATIONAL COOLING.

MODELS ARE STRUGGLING WITH AN ALBERTA CLIPPER POTENTIALLY
IMPACTING THE AREA FOR LATE THURSDAY. CURRENT WATER VAPOR LOOP SHOWS
THIS BROAD TROUGH DIGGING SOUTH INTO WESTERN CANADA EARLY THIS
MORNING...WITH AN INTENSIFYING SHORTWAVE AND ASSOCIATED COLD FRONT
AS IT MOVES SOUTHWARD INTO MONTANA. MODELS WERE NOT SHOWING THIS
FEATURE 24 TO 48 HOURS AGO...AND ARE GENERALLY TRENDING COLDER
WITH MORE PRECIPITATION. THE MAIN CONCERN IS FREEZING TEMPERATURES
THURSDAY NIGHT AFTER RAIN/SNOW MIX OR EVEN A QUICK BURST OF SNOW
AS THE FRONT MOVES ACROSS THE AREA. THIS MAY CREATE PROBLEMS ON
THE ROADWAYS DUE TO BLACK ICE AND SLICK CONDITIONS. INCREASED POP
TO 20 PERCENT...AND STARTED ADDING A MIX OF RAIN/SNOW FOR AREAS
BETWEEN 6000 TO 7000 FEET. WILL HAVE TO CLOSELY MONITOR THIS
CLIPPER...DUE TO POTENTIAL IMPACTS TO TRAVEL ACROSS THE AREA.
OTHERWISE...A DRYING TREND AND SLOW WARMING TREND WILL BEGIN ON
FRIDAY AS AN UPPER LEVEL RIDGE ALONG THE WEST COAST STRENGTHENS
AND DRIFTS EASTWARD.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 301 AM MDT WED OCT 1 2014

THE EXTENDED PERIOD WILL BE DRY AND MILD UNDER PERSISTENT NORTHWEST
FLOW ALOFT. THE MAIN JET CORE WILL REMAIN OVER THE CENTRAL
PLAINS...SEPARATING A DEEP LONG WAVE TROUGH OVER THE EASTERN CONUS
AND A BROAD RIDGE OVER THE WESTERN STATES/EASTERN PACIFIC. THE
POSITION OF THE JET WILL KEEP THE FORECAST AREA ON THE DRY SIDE OF
THE FLOW PATTERN AND ON THE SOUTHWESTERN EDGE OF ANY CLIPPER
SYSTEMS. THUS...NOT EXPECTING ANY PRECIP THRU THE PERIOD. A SOMEWHAT
STRONGER SHORTWAVE MOVING WITHIN THE NORTHWEST FLOW ON SUNDAY COULD
DEEPEN THE LONGWAVE TROUGH ENOUGH TO BRING SOME MOISTURE AND ENERGY
OVER EASTERN PORTIONS OF THE CWA...BUT WILL JUST MAINTAIN
INCREASING CLOUDS THROUGH THE AFTERNOON AS THIS SEEMS A MORE
LIKELY SCENARIO RIGHT NOW. TEMPS THRU THE PERIOD WILL REMAIN AT OR
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR...WITH MAX TEMPS OF
60S/70S EXPECTED FOR THE EASTERN PLAINS AND 50S/60S OUT WEST IN
THE HIGH VALLEYS AND MOUNTAINS. WINDS WILL BE QUITE SIMILAR EACH
DAY AS WELL WITH BREEZY WEST-NORTHWEST WINDS DEVELOPING EACH
AFTERNOON AND EVENING FOR THE MAJORITY OF THE CWA. THESE BREEZY
CONDITIONS WILL PERSIST THRU THE OVERNIGHT HOURS IN THE WIND PRONE
AREAS ALONG AND WEST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1125 AM MDT WED OCT 1 2014

THE NEXT PACIFIC COLD FRONT AND UPPER LOW PRESSURE TROUGH WILL
IMPACT THE FORECAST AREA THROUGH TONIGHT. CEILINGS WILL LOWER TO
MVFR WITH MORE WIDESPREAD PRECIPITATION DEVELOPING FROM WEST TO
EAST. SHOWERS WILL BE THE PRIMARY PRECIP TYPE...WITH ISOLATED
THUNDER POSSIBLE SOUTH OF A DOUGLAS TO ALLIANCE LINE THIS
AFTERNOON. WINDS WILL BECOME NORTHERLY WITH THE PASSAGE OF THE
FRONT AND MAY BE BREEZY AT TIMES ACROSS SOUTHEAST WYOMING. LOW
CEILINGS WILL LINGER BEHIND THE FRONT THROUGH TONIGHT ALONG AND
SOUTH OF A RAWLINS TO ALLIANCE LINE.

&&

.FIRE WEATHER...
ISSUED AT 206 AM MDT WED OCT 1 2014

NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND DUE TO RECENT HEAVY
RAINFALL AND COOL TEMPERATURES. AN UPPER LEVEL DISTURBANCE WILL
QUICKLY MOVE ACROSS WYOMING AND COLORADO TODAY RESULTING IN MORE
RAIN AND ISOLATED THUNDERSTORMS...MAINLY ALONG THE INTERSTATE 80
CORRIDOR NEAR THE COLORADO BORDER. WETTING RAINS APPEAR LIKELY IN
THIS AREA AS THE SYSTEM WILL QUICKLY MOVE INTO THE GREAT PLAINS
TONIGHT. A DRYING TREND IS EXPECTED FOR LATE THIS WEEK AND INTO
THIS WEEKEND WITH SLIGHTLY WARMER TEMPERATURES AND DAYTIME
HUMIDITIES TRENDING LOWER EACH DAY...BUT REMAINING ABOVE 20
PERCENT THROUGH THE WEEKEND.

&&

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

$$

UPDATE...HAHN
SHORT TERM...TJT
LONG TERM...RJM
AVIATION...JAMSKI
FIRE WEATHER...TJT









000
FXUS65 KCYS 011732
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1132 AM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 1132 AM MDT WED OCT 1 2014

GOING FORECAST IN GOOD SHAPE FOR THIS AFTERNOON. SATELLITE PIX
SHOW NEXT SHORTWAVE OVR WRN WYOMING WITH A BAROCLINIC LEAF
DEVELOPING IN ADVANCE OF IT ACROSS WRN COLORADO/CENTRAL WY.
SHOWERS HAVE ALREADY BEEN DEVELOPING ACROSS WESTERN AND CENTRAL
WYOMING...AS WELL AS ACROSS COLORADO. LATEST DATA FROM KCYS 88D
SHOW SHOWERS DEVELOPING FROM AROUND WOODS LANDING EAST TOWARDS
PUMPKIN VINE OVER THE PAST HOUR OR TWO. THIS AREA WILL EXPAND
EAST/NORTHEAST ACROSS THE LARAMIE VALLEY...SRN LARAMIE RANGE...
LARAMIE COUNTY AND ADJACENT LOCALES THIS AFTERNOON. HAVE BOOSTED
PRECIP CHANCES ACROSS THESE AREAS TO REFLECT THE GROWING
CONFIDENCE OF THIS OCCURRING. OTHERWISE...HAVE INCREASED
TEMPERATURES 2-5 DEGREES EAST OF THE LARAMIE RANGE AS SUNSHINE HAS
BEEN A BIT MORE PLENTIFUL THAN EARLIER THOUGHT. STILL LOOKS TO BE
A QUICK HITTING SYSTEM...WITH DEPARTURE EXPECTED TONIGHT.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 206 AM MDT WED OCT 1 2014

CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR TO PARTLY CLOUDY
SKIES ACROSS MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA EARLY
THIS MORNING AS THE LOW PRESSURE SYSTEM WHICH BROUGHT HEAVY RAIN
TO THE AREA YESTERDAY IS NOW ENTERING SOUTHERN SASKATCHEWAN AND
MANITOBA. HOWEVER...THE NEXT UPPER LEVEL TROUGH IS CURRENTLY DIGGING
SOUTH ACROSS THE EASTERN GREAT BASIN REGION...WITH SHOWERS AND
TSTORMS DEVELOPING OVER UTAH AND ENTERING WESTERN COLORADO AT THIS
HOUR. THIS WILL BE OUR NEXT PRECIPITATION PRODUCER TODAY AS THE
UPPER LEVEL SYSTEM CONTINUES TO DIG SOUTHEAST THIS MORNING AND
EVENTUALLY PUSHES EASTWARD THIS AFTERNOON. NOT MUCH DYNAMIC LIFT
AT THE SURFACE WITH THIS SYSTEM...BUT MODELS INDICATE STRONG UPPER
LEVEL DIVERGENCE AS A 100 KT JET LIFT NORTHEAST INTO THE HIGH
PLAINS TODAY. THE GFS AND ECMWF DO INDICATE STRONG 700MB
CONVERGENCE ACROSS NORTHEAST COLORADO AND EXTREME SE WYOMING AS A
700MB LOW TRIES TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING.
THIS MID TO UPPER LEVEL COUPLET WILL ALLOW FOR SOME SUBSTANTIAL
LIFT IN ADDITION TO ANY LLVL INSTABILITY. CONTINUED TO INCREASE
POP BETWEEN 70 TO 90 PERCENT THIS AFTERNOON THROUGH LATE THIS
EVENING. THIS SYSTEM WILL MOVE RATHER QUICK ACROSS THE AREA...SO
ONLY EXPECT PERHAPS 3 TO 6 HOURS OF PRECIPITATION. IN THE
MOUNTAINS AND LOCATIONS ABOVE 7500 FEET...RAIN WILL MIX WITH AND
CHANGE TO SNOW. THIS INCLUDES THE SOUTHERN LARAMIE RANGE AND THE
I80 SUMMIT WHICH MAY RECEIVE 1 TO 3 INCHES OF SNOW BY LATE THIS
AFTERNOON. THE SNOWY AND SIERRA MADRE RANGES MAY SEE A LITTLE
MORE...BUT NO MORE THAN 3 TO 5 INCHES IS EXPECTED INTO THIS
EVENING. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES DUE TO THE
PROGRESSIVE NATURE OF THE TROUGH. FOR THE LOWER ELEVATIONS...THE
HEAVIEST RAINFALL AMOUNTS WILL GENERALLY BE ALONG THE I80 CORRIDOR
FROM LARAMIE...EASTWARD TO CHEYENNE AND SIDNEY NEBRASKA. CAN NOT
RULE OUT SOME RAIN/SNOW MIX AS THE PRECIPITATION COMES TO AN END
ACROSS THE LARAMIE VALLEY THIS AFTERNOON WITH SNOW LEVELS
LOWERING BETWEEN 7000 TO 7500 FEET. TONIGHT WILL BE MUCH COOLER
WITH LOWS IN THE 20S TO LOW 30S ACROSS SOUTHEAST WYOMING DUE TO
CLEARING SKIES AND GOOD RADIATIONAL COOLING.

MODELS ARE STRUGGLING WITH AN ALBERTA CLIPPER POTENTIALLY
IMPACTING THE AREA FOR LATE THURSDAY. CURRENT WATER VAPOR LOOP SHOWS
THIS BROAD TROUGH DIGGING SOUTH INTO WESTERN CANADA EARLY THIS
MORNING...WITH AN INTENSIFYING SHORTWAVE AND ASSOCIATED COLD FRONT
AS IT MOVES SOUTHWARD INTO MONTANA. MODELS WERE NOT SHOWING THIS
FEATURE 24 TO 48 HOURS AGO...AND ARE GENERALLY TRENDING COLDER
WITH MORE PRECIPITATION. THE MAIN CONCERN IS FREEZING TEMPERATURES
THURSDAY NIGHT AFTER RAIN/SNOW MIX OR EVEN A QUICK BURST OF SNOW
AS THE FRONT MOVES ACROSS THE AREA. THIS MAY CREATE PROBLEMS ON
THE ROADWAYS DUE TO BLACK ICE AND SLICK CONDITIONS. INCREASED POP
TO 20 PERCENT...AND STARTED ADDING A MIX OF RAIN/SNOW FOR AREAS
BETWEEN 6000 TO 7000 FEET. WILL HAVE TO CLOSELY MONITOR THIS
CLIPPER...DUE TO POTENTIAL IMPACTS TO TRAVEL ACROSS THE AREA.
OTHERWISE...A DRYING TREND AND SLOW WARMING TREND WILL BEGIN ON
FRIDAY AS AN UPPER LEVEL RIDGE ALONG THE WEST COAST STRENGTHENS
AND DRIFTS EASTWARD.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 301 AM MDT WED OCT 1 2014

THE EXTENDED PERIOD WILL BE DRY AND MILD UNDER PERSISTENT NORTHWEST
FLOW ALOFT. THE MAIN JET CORE WILL REMAIN OVER THE CENTRAL
PLAINS...SEPARATING A DEEP LONG WAVE TROUGH OVER THE EASTERN CONUS
AND A BROAD RIDGE OVER THE WESTERN STATES/EASTERN PACIFIC. THE
POSITION OF THE JET WILL KEEP THE FORECAST AREA ON THE DRY SIDE OF
THE FLOW PATTERN AND ON THE SOUTHWESTERN EDGE OF ANY CLIPPER
SYSTEMS. THUS...NOT EXPECTING ANY PRECIP THRU THE PERIOD. A SOMEWHAT
STRONGER SHORTWAVE MOVING WITHIN THE NORTHWEST FLOW ON SUNDAY COULD
DEEPEN THE LONGWAVE TROUGH ENOUGH TO BRING SOME MOISTURE AND ENERGY
OVER EASTERN PORTIONS OF THE CWA...BUT WILL JUST MAINTAIN
INCREASING CLOUDS THROUGH THE AFTERNOON AS THIS SEEMS A MORE
LIKELY SCENARIO RIGHT NOW. TEMPS THRU THE PERIOD WILL REMAIN AT OR
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR...WITH MAX TEMPS OF
60S/70S EXPECTED FOR THE EASTERN PLAINS AND 50S/60S OUT WEST IN
THE HIGH VALLEYS AND MOUNTAINS. WINDS WILL BE QUITE SIMILAR EACH
DAY AS WELL WITH BREEZY WEST-NORTHWEST WINDS DEVELOPING EACH
AFTERNOON AND EVENING FOR THE MAJORITY OF THE CWA. THESE BREEZY
CONDITIONS WILL PERSIST THRU THE OVERNIGHT HOURS IN THE WIND PRONE
AREAS ALONG AND WEST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1125 AM MDT WED OCT 1 2014

THE NEXT PACIFIC COLD FRONT AND UPPER LOW PRESSURE TROUGH WILL
IMPACT THE FORECAST AREA THROUGH TONIGHT. CEILINGS WILL LOWER TO
MVFR WITH MORE WIDESPREAD PRECIPITATION DEVELOPING FROM WEST TO
EAST. SHOWERS WILL BE THE PRIMARY PRECIP TYPE...WITH ISOLATED
THUNDER POSSIBLE SOUTH OF A DOUGLAS TO ALLIANCE LINE THIS
AFTERNOON. WINDS WILL BECOME NORTHERLY WITH THE PASSAGE OF THE
FRONT AND MAY BE BREEZY AT TIMES ACROSS SOUTHEAST WYOMING. LOW
CEILINGS WILL LINGER BEHIND THE FRONT THROUGH TONIGHT ALONG AND
SOUTH OF A RAWLINS TO ALLIANCE LINE.

&&

.FIRE WEATHER...
ISSUED AT 206 AM MDT WED OCT 1 2014

NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND DUE TO RECENT HEAVY
RAINFALL AND COOL TEMPERATURES. AN UPPER LEVEL DISTURBANCE WILL
QUICKLY MOVE ACROSS WYOMING AND COLORADO TODAY RESULTING IN MORE
RAIN AND ISOLATED THUNDERSTORMS...MAINLY ALONG THE INTERSTATE 80
CORRIDOR NEAR THE COLORADO BORDER. WETTING RAINS APPEAR LIKELY IN
THIS AREA AS THE SYSTEM WILL QUICKLY MOVE INTO THE GREAT PLAINS
TONIGHT. A DRYING TREND IS EXPECTED FOR LATE THIS WEEK AND INTO
THIS WEEKEND WITH SLIGHTLY WARMER TEMPERATURES AND DAYTIME
HUMIDITIES TRENDING LOWER EACH DAY...BUT REMAINING ABOVE 20
PERCENT THROUGH THE WEEKEND.

&&

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

$$

UPDATE...HAHN
SHORT TERM...TJT
LONG TERM...RJM
AVIATION...JAMSKI
FIRE WEATHER...TJT








000
FXUS63 KUNR 011500
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
900 AM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 852 AM MDT WED OCT 1 2014

SHORTWAVE CONTINUES TO APPROACH THE REGION...PUSHING SOME LIGHT
SHOWERS INTO NORTHEASTERN WYOMING. INCREASED POPS OVER THAT AREA
TODAY. UPDATED SKY GRIDS TO MATCH SATELLITE. STILL LOOKS LIKE IT
WILL BE BREEZY THROUGH THE AFTERNOON...ESPECIALLY ACROSS NORTHWEST
SOUTH DAKOTA.

&&

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

08Z SURFACE ANALYSIS HAD LOW OVER NORTH CENTRAL ND WITH UPPER LOW
SPINNING ON TOP...WITH SYSTEM MOVING NORTH/NORTHEAST PER SATELLITE
LOOPS. NEXT SHORTWAVE TROUGH OF INTEREST OVER WESTERN MT/ID PER
WATER VAPOR. THIS WAVE WILL MOVE SOUTHEAST TODAY ROUNDING BASE OF
MEAN TROUGH OVER CENTRAL NORTH AMERICA. COMBINATION OF CYCLONIC
FLOW AND WEAK FORCING WITH SHORTWAVE TROUGH WILL RESULT IN A FEW
-SHRA OVER THE CWA TODAY...SHIFTING EAST/SOUTH OF THE AREA
TONIGHT. TEMPERATURES WILL BE NEAR GUIDANCE TODAY/TONIGHT.

THURSDAY...FAST MOVING UPPER TROUGH/SHORTWAVE WILL RACE INTO THE
NORTHERN PLAINS BY 00Z FRIDAY DRIVING A SHARP COLD FRONT INTO THE
CWA. A FEW -SHRA MAY OCCUR WITH THE SYSTEM...BUT THE MAIN EFFECT
WILL BE RATHER STRONG COLD AIR ADVECTION AND 30-40KT 850-700MB
WINDS. HAVE BUMPED UP WINDS ON THE SD PLAINS TO ACCOUNT...AND MAY
NEED SOME SORT OF WIND HEADLINES WHEN ALL IS SAID AND DONE. IT/LL BE
COLD ENOUGH EARLY THURSDAY EVENING OVER THE HIGHER ELEVATIONS FOR A
FEW -SHRASN. TEMPERATURES WILL BE NEAR GUIDANCE...AND PROBABLY COLD
ENOUGH FOR FROST/FREEZE OVER PARTS OF THE CWA THURSDAY NIGHT.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 237 AM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS THE LARGE
UPPER TROUGH EXITS INTO THE MIDWEST. LITTLE CHANGE TO THE PATTERN
IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE OVERALL
PROGRESS SLOWS TO A CRAWL. PERSISTENT NORTHWEST FLOW OVER THE AREA
WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS. OCCASIONAL
UPPER WAVES WILL PUSH ACROSS THE NORTHWEST FLOW...WHICH WILL BRING
BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE WINDS FRIDAY AND
PERHAPS SATURDAY WILL BE GUSTIER.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 446 AM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA TODAY...THEN SOUTH CENTRAL
SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY ARE EXPECTED WITH ANY SHOWERS
THAT DEVELOP. IFR CIGS ARE POSSIBLE WITH ANY SHOWER DEVELOPMENT
NEAR THE BLACK HILLS. NORTHWEST WINDS WILL BECOME BREEZY ACROSS
THE PLAINS...ESPECIALLY OVER NORTHWEST SOUTH DAKOTA.


&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...POJORLIE
SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 011500
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
900 AM MDT WED OCT 1 2014

.UPDATE...
ISSUED AT 852 AM MDT WED OCT 1 2014

SHORTWAVE CONTINUES TO APPROACH THE REGION...PUSHING SOME LIGHT
SHOWERS INTO NORTHEASTERN WYOMING. INCREASED POPS OVER THAT AREA
TODAY. UPDATED SKY GRIDS TO MATCH SATELLITE. STILL LOOKS LIKE IT
WILL BE BREEZY THROUGH THE AFTERNOON...ESPECIALLY ACROSS NORTHWEST
SOUTH DAKOTA.

&&

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

08Z SURFACE ANALYSIS HAD LOW OVER NORTH CENTRAL ND WITH UPPER LOW
SPINNING ON TOP...WITH SYSTEM MOVING NORTH/NORTHEAST PER SATELLITE
LOOPS. NEXT SHORTWAVE TROUGH OF INTEREST OVER WESTERN MT/ID PER
WATER VAPOR. THIS WAVE WILL MOVE SOUTHEAST TODAY ROUNDING BASE OF
MEAN TROUGH OVER CENTRAL NORTH AMERICA. COMBINATION OF CYCLONIC
FLOW AND WEAK FORCING WITH SHORTWAVE TROUGH WILL RESULT IN A FEW
-SHRA OVER THE CWA TODAY...SHIFTING EAST/SOUTH OF THE AREA
TONIGHT. TEMPERATURES WILL BE NEAR GUIDANCE TODAY/TONIGHT.

THURSDAY...FAST MOVING UPPER TROUGH/SHORTWAVE WILL RACE INTO THE
NORTHERN PLAINS BY 00Z FRIDAY DRIVING A SHARP COLD FRONT INTO THE
CWA. A FEW -SHRA MAY OCCUR WITH THE SYSTEM...BUT THE MAIN EFFECT
WILL BE RATHER STRONG COLD AIR ADVECTION AND 30-40KT 850-700MB
WINDS. HAVE BUMPED UP WINDS ON THE SD PLAINS TO ACCOUNT...AND MAY
NEED SOME SORT OF WIND HEADLINES WHEN ALL IS SAID AND DONE. IT/LL BE
COLD ENOUGH EARLY THURSDAY EVENING OVER THE HIGHER ELEVATIONS FOR A
FEW -SHRASN. TEMPERATURES WILL BE NEAR GUIDANCE...AND PROBABLY COLD
ENOUGH FOR FROST/FREEZE OVER PARTS OF THE CWA THURSDAY NIGHT.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 237 AM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS THE LARGE
UPPER TROUGH EXITS INTO THE MIDWEST. LITTLE CHANGE TO THE PATTERN
IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE OVERALL
PROGRESS SLOWS TO A CRAWL. PERSISTENT NORTHWEST FLOW OVER THE AREA
WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS. OCCASIONAL
UPPER WAVES WILL PUSH ACROSS THE NORTHWEST FLOW...WHICH WILL BRING
BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE WINDS FRIDAY AND
PERHAPS SATURDAY WILL BE GUSTIER.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 446 AM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA TODAY...THEN SOUTH CENTRAL
SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY ARE EXPECTED WITH ANY SHOWERS
THAT DEVELOP. IFR CIGS ARE POSSIBLE WITH ANY SHOWER DEVELOPMENT
NEAR THE BLACK HILLS. NORTHWEST WINDS WILL BECOME BREEZY ACROSS
THE PLAINS...ESPECIALLY OVER NORTHWEST SOUTH DAKOTA.


&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...POJORLIE
SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13







000
FXUS65 KCYS 011213
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
613 AM MDT WED OCT 1 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 206 AM MDT WED OCT 1 2014

CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR TO PARTLY CLOUDY
SKIES ACROSS MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA EARLY
THIS MORNING AS THE LOW PRESSURE SYSTEM WHICH BROUGHT HEAVY RAIN
TO THE AREA YESTERDAY IS NOW ENTERING SOUTHERN SASKATCHEWAN AND
MANITOBA. HOWEVER...THE NEXT UPPER LEVEL TROUGH IS CURRENTLY DIGGING
SOUTH ACROSS THE EASTERN GREAT BASIN REGION...WITH SHOWERS AND
TSTORMS DEVELOPING OVER UTAH AND ENTERING WESTERN COLORADO AT THIS
HOUR. THIS WILL BE OUR NEXT PRECIPITATION PRODUCER TODAY AS THE
UPPER LEVEL SYSTEM CONTINUES TO DIG SOUTHEAST THIS MORNING AND
EVENTUALLY PUSHES EASTWARD THIS AFTERNOON. NOT MUCH DYNAMIC LIFT
AT THE SURFACE WITH THIS SYSTEM...BUT MODELS INDICATE STRONG UPPER
LEVEL DIVERGENCE AS A 100 KT JET LIFT NORTHEAST INTO THE HIGH
PLAINS TODAY. THE GFS AND ECMWF DO INDICATE STRONG 700MB
CONVERGENCE ACROSS NORTHEAST COLORADO AND EXTREME SE WYOMING AS A
700MB LOW TRIES TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING.
THIS MID TO UPPER LEVEL COUPLET WILL ALLOW FOR SOME SUBSTANTIAL
LIFT IN ADDITION TO ANY LLVL INSTABILITY. CONTINUED TO INCREASE
POP BETWEEN 70 TO 90 PERCENT THIS AFTERNOON THROUGH LATE THIS
EVENING. THIS SYSTEM WILL MOVE RATHER QUICK ACROSS THE AREA...SO
ONLY EXPECT PERHAPS 3 TO 6 HOURS OF PRECIPITATION. IN THE
MOUNTAINS AND LOCATIONS ABOVE 7500 FEET...RAIN WILL MIX WITH AND
CHANGE TO SNOW. THIS INCLUDES THE SOUTHERN LARAMIE RANGE AND THE
I80 SUMMIT WHICH MAY RECEIVE 1 TO 3 INCHES OF SNOW BY LATE THIS
AFTERNOON. THE SNOWY AND SIERRA MADRE RANGES MAY SEE A LITTLE
MORE...BUT NO MORE THAN 3 TO 5 INCHES IS EXPECTED INTO THIS
EVENING. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES DUE TO THE
PROGRESSIVE NATURE OF THE TROUGH. FOR THE LOWER ELEVATIONS...THE
HEAVIEST RAINFALL AMOUNTS WILL GENERALLY BE ALONG THE I80 CORRIDOR
FROM LARAMIE...EASTWARD TO CHEYENNE AND SIDNEY NEBRASKA. CAN NOT
RULE OUT SOME RAIN/SNOW MIX AS THE PRECIPITATION COMES TO AN END ACROSS
THE LARAMIE VALLEY THIS AFTERNOON WITH SNOW LEVELS LOWERING
BETWEEN 7000 TO 7500 FEET. TONIGHT WILL BE MUCH COOLER WITH LOWS
IN THE 20S TO LOW 30S ACROSS SOUTHEAST WYOMING DUE TO CLEARING
SKIES AND GOOD RADIATIONAL COOLING.

MODELS ARE STRUGGLING WITH AN ALBERTA CLIPPER POTENTIALLY
IMPACTING THE AREA FOR LATE THURSDAY. CURRENT WATERVAPOR LOOP SHOWS
THIS BROAD TROUGH DIGGING SOUTH INTO WESTERN CANADA EARLY THIS
MORNING...WITH AN INTENSIFYING SHORTWAVE AND ASSOCIATED COLD FRONT
AS IT MOVES SOUTHWARD INTO MONTANA. MODELS WERE NOT SHOWING THIS
FEATURE 24 TO 48 HOURS AGO...AND ARE GENERALLY TRENDING COLDER
WITH MORE PRECIPITATION. THE MAIN CONCERN IS FREEZING TEMPERATURES
THURSDAY NIGHT AFTER RAIN/SNOW MIX OR EVEN A QUICK BURST OF SNOW
AS THE FRONT MOVES ACROSS THE AREA. THIS MAY CREATE PROBLEMS ON
THE ROADWAYS DUE TO BLACK ICE AND SLICK CONDITIONS. INCREASED POP
TO 20 PERCENT...AND STARTED ADDING A MIX OF RAIN/SNOW FOR AREAS
BETWEEN 6000 TO 7000 FEET. WILL HAVE TO CLOSELY MONITOR THIS
CLIPPER...DUE TO POTENTIAL IMPACTS TO TRAVEL ACROSS THE AREA.
OTHERWISE...A DRYING TREND AND SLOW WARMING TREND WILL BEGIN ON
FRIDAY AS AN UPPER LEVEL RIDGE ALONG THE WEST COAST STRENGTHENS
AND DRIFTS EASTWARD.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 301 AM MDT WED OCT 1 2014

THE EXTENDED PERIOD WILL BE DRY AND MILD UNDER PERSISTENT NORTHWEST
FLOW ALOFT. THE MAIN JET CORE WILL REMAIN OVER THE CENTRAL
PLAINS...SEPARATING A DEEP LONG WAVE TROUGH OVER THE EASTERN CONUS
AND A BROAD RIDGE OVER THE WESTERN STATES/EASTERN PACIFIC. THE
POSITION OF THE JET WILL KEEP THE FORECAST AREA ON THE DRY SIDE OF
THE FLOW PATTERN AND ON THE SOUTHWESTERN EDGE OF ANY CLIPPER
SYSTEMS. THUS...NOT EXPECTING ANY PRECIP THRU THE PERIOD. A SOMEWHAT
STRONGER SHORTWAVE MOVING WITHIN THE NORTHWEST FLOW ON SUNDAY COULD
DEEPEN THE LONGWAVE TROUGH ENOUGH TO BRING SOME MOISTURE AND ENERGY
OVER EASTERN PORTIONS OF THE CWA...BUT WILL JUST MAINTAIN
INCREASING CLOUDS THROUGH THE AFTERNOON AS THIS SEEMS A MORE
LIKELY SCENARIO RIGHT NOW. TEMPS THRU THE PERIOD WILL REMAIN AT OR
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR...WITH MAX TEMPS OF
60S/70S EXPECTED FOR THE EASTERN PLAINS AND 50S/60S OUT WEST IN
THE HIGH VALLEYS AND MOUNTAINS. WINDS WILL BE QUITE SIMILAR EACH
DAY AS WELL WITH BREEZY WEST-NORTHWEST WINDS DEVELOPING EACH
AFTERNOON AND EVENING FOR THE MAJORITY OF THE CWA. THESE BREEZY
CONDITIONS WILL PERSIST THRU THE OVERNIGHT HOURS IN THE WIND PRONE
AREAS ALONG AND WEST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 613 AM MDT WED OCT 1 2014

A WEAK SFC FRONT WILL CONTINUE TO SLOWLY MOVE SOUTH ACROSS THE
FORECAST AREA THIS MORNING...WITH WINDS SHIFTING TO THE NORTH TO
NORTHWEST AND BECOMING BREEZY AT TIMES THIS AFTERNOON. SHOWERS
WILL MOVE FROM WEST TO EAST THIS MORNING WITH T-STORMS DEVELOPING
IN THE AFTERNOON AND EVENING AS AN UPPER LEVEL DISTURBANCE MOVES
OVER THE ROCKIES. THE BEST COVERAGE FOR STORMS STILL LOOKS TO BE
FOCUSED TOWARDS AREAS NEAR THE COLORADO BORDER WHERE THE STRONGEST
UPSLOPE FLOW WILL BE IN PLACE. LOOKING AT MAINLY MVFR CONDITIONS
WITH THIS ACTIVITY...WITH SCT-BKN MVFR CIGS LINGERING THRU MOST
OF THE NIGHT WITHIN THE COOL AND MOIST POST-STORM ENVIRONMENT.

&&

.FIRE WEATHER...
ISSUED AT 206 AM MDT WED OCT 1 2014

NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND DUE TO RECENT HEAVY
RAINFALL AND COOL TEMPERATURES. AN UPPER LEVEL DISTURBANCE WILL
QUICKLY MOVE ACROSS WYOMING AND COLORADO TODAY RESULTING IN MORE
RAIN AND ISOLATED THUNDERSTORMS...MAINLY ALONG THE INTERSTATE 80
CORRIDOR NEAR THE COLORADO BORDER. WETTING RAINS APPEAR LIKELY IN
THIS AREA AS THE SYSTEM WILL QUICKLY MOVE INTO THE GREAT PLAINS
TONIGHT. A DRYING TREND IS EXPECTED FOR LATE THIS WEEK AND INTO
THIS WEEKEND WITH SLIGHTLY WARMER TEMPERATURES AND DAYTIME
HUMIDITIES TRENDING LOWER EACH DAY...BUT REMAINING ABOVE 20
PERCENT THROUGH THE WEEKEND.

&&

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

$$

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







000
FXUS65 KCYS 011213
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
613 AM MDT WED OCT 1 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 206 AM MDT WED OCT 1 2014

CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR TO PARTLY CLOUDY
SKIES ACROSS MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA EARLY
THIS MORNING AS THE LOW PRESSURE SYSTEM WHICH BROUGHT HEAVY RAIN
TO THE AREA YESTERDAY IS NOW ENTERING SOUTHERN SASKATCHEWAN AND
MANITOBA. HOWEVER...THE NEXT UPPER LEVEL TROUGH IS CURRENTLY DIGGING
SOUTH ACROSS THE EASTERN GREAT BASIN REGION...WITH SHOWERS AND
TSTORMS DEVELOPING OVER UTAH AND ENTERING WESTERN COLORADO AT THIS
HOUR. THIS WILL BE OUR NEXT PRECIPITATION PRODUCER TODAY AS THE
UPPER LEVEL SYSTEM CONTINUES TO DIG SOUTHEAST THIS MORNING AND
EVENTUALLY PUSHES EASTWARD THIS AFTERNOON. NOT MUCH DYNAMIC LIFT
AT THE SURFACE WITH THIS SYSTEM...BUT MODELS INDICATE STRONG UPPER
LEVEL DIVERGENCE AS A 100 KT JET LIFT NORTHEAST INTO THE HIGH
PLAINS TODAY. THE GFS AND ECMWF DO INDICATE STRONG 700MB
CONVERGENCE ACROSS NORTHEAST COLORADO AND EXTREME SE WYOMING AS A
700MB LOW TRIES TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING.
THIS MID TO UPPER LEVEL COUPLET WILL ALLOW FOR SOME SUBSTANTIAL
LIFT IN ADDITION TO ANY LLVL INSTABILITY. CONTINUED TO INCREASE
POP BETWEEN 70 TO 90 PERCENT THIS AFTERNOON THROUGH LATE THIS
EVENING. THIS SYSTEM WILL MOVE RATHER QUICK ACROSS THE AREA...SO
ONLY EXPECT PERHAPS 3 TO 6 HOURS OF PRECIPITATION. IN THE
MOUNTAINS AND LOCATIONS ABOVE 7500 FEET...RAIN WILL MIX WITH AND
CHANGE TO SNOW. THIS INCLUDES THE SOUTHERN LARAMIE RANGE AND THE
I80 SUMMIT WHICH MAY RECEIVE 1 TO 3 INCHES OF SNOW BY LATE THIS
AFTERNOON. THE SNOWY AND SIERRA MADRE RANGES MAY SEE A LITTLE
MORE...BUT NO MORE THAN 3 TO 5 INCHES IS EXPECTED INTO THIS
EVENING. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES DUE TO THE
PROGRESSIVE NATURE OF THE TROUGH. FOR THE LOWER ELEVATIONS...THE
HEAVIEST RAINFALL AMOUNTS WILL GENERALLY BE ALONG THE I80 CORRIDOR
FROM LARAMIE...EASTWARD TO CHEYENNE AND SIDNEY NEBRASKA. CAN NOT
RULE OUT SOME RAIN/SNOW MIX AS THE PRECIPITATION COMES TO AN END ACROSS
THE LARAMIE VALLEY THIS AFTERNOON WITH SNOW LEVELS LOWERING
BETWEEN 7000 TO 7500 FEET. TONIGHT WILL BE MUCH COOLER WITH LOWS
IN THE 20S TO LOW 30S ACROSS SOUTHEAST WYOMING DUE TO CLEARING
SKIES AND GOOD RADIATIONAL COOLING.

MODELS ARE STRUGGLING WITH AN ALBERTA CLIPPER POTENTIALLY
IMPACTING THE AREA FOR LATE THURSDAY. CURRENT WATERVAPOR LOOP SHOWS
THIS BROAD TROUGH DIGGING SOUTH INTO WESTERN CANADA EARLY THIS
MORNING...WITH AN INTENSIFYING SHORTWAVE AND ASSOCIATED COLD FRONT
AS IT MOVES SOUTHWARD INTO MONTANA. MODELS WERE NOT SHOWING THIS
FEATURE 24 TO 48 HOURS AGO...AND ARE GENERALLY TRENDING COLDER
WITH MORE PRECIPITATION. THE MAIN CONCERN IS FREEZING TEMPERATURES
THURSDAY NIGHT AFTER RAIN/SNOW MIX OR EVEN A QUICK BURST OF SNOW
AS THE FRONT MOVES ACROSS THE AREA. THIS MAY CREATE PROBLEMS ON
THE ROADWAYS DUE TO BLACK ICE AND SLICK CONDITIONS. INCREASED POP
TO 20 PERCENT...AND STARTED ADDING A MIX OF RAIN/SNOW FOR AREAS
BETWEEN 6000 TO 7000 FEET. WILL HAVE TO CLOSELY MONITOR THIS
CLIPPER...DUE TO POTENTIAL IMPACTS TO TRAVEL ACROSS THE AREA.
OTHERWISE...A DRYING TREND AND SLOW WARMING TREND WILL BEGIN ON
FRIDAY AS AN UPPER LEVEL RIDGE ALONG THE WEST COAST STRENGTHENS
AND DRIFTS EASTWARD.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 301 AM MDT WED OCT 1 2014

THE EXTENDED PERIOD WILL BE DRY AND MILD UNDER PERSISTENT NORTHWEST
FLOW ALOFT. THE MAIN JET CORE WILL REMAIN OVER THE CENTRAL
PLAINS...SEPARATING A DEEP LONG WAVE TROUGH OVER THE EASTERN CONUS
AND A BROAD RIDGE OVER THE WESTERN STATES/EASTERN PACIFIC. THE
POSITION OF THE JET WILL KEEP THE FORECAST AREA ON THE DRY SIDE OF
THE FLOW PATTERN AND ON THE SOUTHWESTERN EDGE OF ANY CLIPPER
SYSTEMS. THUS...NOT EXPECTING ANY PRECIP THRU THE PERIOD. A SOMEWHAT
STRONGER SHORTWAVE MOVING WITHIN THE NORTHWEST FLOW ON SUNDAY COULD
DEEPEN THE LONGWAVE TROUGH ENOUGH TO BRING SOME MOISTURE AND ENERGY
OVER EASTERN PORTIONS OF THE CWA...BUT WILL JUST MAINTAIN
INCREASING CLOUDS THROUGH THE AFTERNOON AS THIS SEEMS A MORE
LIKELY SCENARIO RIGHT NOW. TEMPS THRU THE PERIOD WILL REMAIN AT OR
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR...WITH MAX TEMPS OF
60S/70S EXPECTED FOR THE EASTERN PLAINS AND 50S/60S OUT WEST IN
THE HIGH VALLEYS AND MOUNTAINS. WINDS WILL BE QUITE SIMILAR EACH
DAY AS WELL WITH BREEZY WEST-NORTHWEST WINDS DEVELOPING EACH
AFTERNOON AND EVENING FOR THE MAJORITY OF THE CWA. THESE BREEZY
CONDITIONS WILL PERSIST THRU THE OVERNIGHT HOURS IN THE WIND PRONE
AREAS ALONG AND WEST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 613 AM MDT WED OCT 1 2014

A WEAK SFC FRONT WILL CONTINUE TO SLOWLY MOVE SOUTH ACROSS THE
FORECAST AREA THIS MORNING...WITH WINDS SHIFTING TO THE NORTH TO
NORTHWEST AND BECOMING BREEZY AT TIMES THIS AFTERNOON. SHOWERS
WILL MOVE FROM WEST TO EAST THIS MORNING WITH T-STORMS DEVELOPING
IN THE AFTERNOON AND EVENING AS AN UPPER LEVEL DISTURBANCE MOVES
OVER THE ROCKIES. THE BEST COVERAGE FOR STORMS STILL LOOKS TO BE
FOCUSED TOWARDS AREAS NEAR THE COLORADO BORDER WHERE THE STRONGEST
UPSLOPE FLOW WILL BE IN PLACE. LOOKING AT MAINLY MVFR CONDITIONS
WITH THIS ACTIVITY...WITH SCT-BKN MVFR CIGS LINGERING THRU MOST
OF THE NIGHT WITHIN THE COOL AND MOIST POST-STORM ENVIRONMENT.

&&

.FIRE WEATHER...
ISSUED AT 206 AM MDT WED OCT 1 2014

NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND DUE TO RECENT HEAVY
RAINFALL AND COOL TEMPERATURES. AN UPPER LEVEL DISTURBANCE WILL
QUICKLY MOVE ACROSS WYOMING AND COLORADO TODAY RESULTING IN MORE
RAIN AND ISOLATED THUNDERSTORMS...MAINLY ALONG THE INTERSTATE 80
CORRIDOR NEAR THE COLORADO BORDER. WETTING RAINS APPEAR LIKELY IN
THIS AREA AS THE SYSTEM WILL QUICKLY MOVE INTO THE GREAT PLAINS
TONIGHT. A DRYING TREND IS EXPECTED FOR LATE THIS WEEK AND INTO
THIS WEEKEND WITH SLIGHTLY WARMER TEMPERATURES AND DAYTIME
HUMIDITIES TRENDING LOWER EACH DAY...BUT REMAINING ABOVE 20
PERCENT THROUGH THE WEEKEND.

&&

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

$$

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







000
FXUS65 KCYS 011213
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
613 AM MDT WED OCT 1 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 206 AM MDT WED OCT 1 2014

CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR TO PARTLY CLOUDY
SKIES ACROSS MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA EARLY
THIS MORNING AS THE LOW PRESSURE SYSTEM WHICH BROUGHT HEAVY RAIN
TO THE AREA YESTERDAY IS NOW ENTERING SOUTHERN SASKATCHEWAN AND
MANITOBA. HOWEVER...THE NEXT UPPER LEVEL TROUGH IS CURRENTLY DIGGING
SOUTH ACROSS THE EASTERN GREAT BASIN REGION...WITH SHOWERS AND
TSTORMS DEVELOPING OVER UTAH AND ENTERING WESTERN COLORADO AT THIS
HOUR. THIS WILL BE OUR NEXT PRECIPITATION PRODUCER TODAY AS THE
UPPER LEVEL SYSTEM CONTINUES TO DIG SOUTHEAST THIS MORNING AND
EVENTUALLY PUSHES EASTWARD THIS AFTERNOON. NOT MUCH DYNAMIC LIFT
AT THE SURFACE WITH THIS SYSTEM...BUT MODELS INDICATE STRONG UPPER
LEVEL DIVERGENCE AS A 100 KT JET LIFT NORTHEAST INTO THE HIGH
PLAINS TODAY. THE GFS AND ECMWF DO INDICATE STRONG 700MB
CONVERGENCE ACROSS NORTHEAST COLORADO AND EXTREME SE WYOMING AS A
700MB LOW TRIES TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING.
THIS MID TO UPPER LEVEL COUPLET WILL ALLOW FOR SOME SUBSTANTIAL
LIFT IN ADDITION TO ANY LLVL INSTABILITY. CONTINUED TO INCREASE
POP BETWEEN 70 TO 90 PERCENT THIS AFTERNOON THROUGH LATE THIS
EVENING. THIS SYSTEM WILL MOVE RATHER QUICK ACROSS THE AREA...SO
ONLY EXPECT PERHAPS 3 TO 6 HOURS OF PRECIPITATION. IN THE
MOUNTAINS AND LOCATIONS ABOVE 7500 FEET...RAIN WILL MIX WITH AND
CHANGE TO SNOW. THIS INCLUDES THE SOUTHERN LARAMIE RANGE AND THE
I80 SUMMIT WHICH MAY RECEIVE 1 TO 3 INCHES OF SNOW BY LATE THIS
AFTERNOON. THE SNOWY AND SIERRA MADRE RANGES MAY SEE A LITTLE
MORE...BUT NO MORE THAN 3 TO 5 INCHES IS EXPECTED INTO THIS
EVENING. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES DUE TO THE
PROGRESSIVE NATURE OF THE TROUGH. FOR THE LOWER ELEVATIONS...THE
HEAVIEST RAINFALL AMOUNTS WILL GENERALLY BE ALONG THE I80 CORRIDOR
FROM LARAMIE...EASTWARD TO CHEYENNE AND SIDNEY NEBRASKA. CAN NOT
RULE OUT SOME RAIN/SNOW MIX AS THE PRECIPITATION COMES TO AN END ACROSS
THE LARAMIE VALLEY THIS AFTERNOON WITH SNOW LEVELS LOWERING
BETWEEN 7000 TO 7500 FEET. TONIGHT WILL BE MUCH COOLER WITH LOWS
IN THE 20S TO LOW 30S ACROSS SOUTHEAST WYOMING DUE TO CLEARING
SKIES AND GOOD RADIATIONAL COOLING.

MODELS ARE STRUGGLING WITH AN ALBERTA CLIPPER POTENTIALLY
IMPACTING THE AREA FOR LATE THURSDAY. CURRENT WATERVAPOR LOOP SHOWS
THIS BROAD TROUGH DIGGING SOUTH INTO WESTERN CANADA EARLY THIS
MORNING...WITH AN INTENSIFYING SHORTWAVE AND ASSOCIATED COLD FRONT
AS IT MOVES SOUTHWARD INTO MONTANA. MODELS WERE NOT SHOWING THIS
FEATURE 24 TO 48 HOURS AGO...AND ARE GENERALLY TRENDING COLDER
WITH MORE PRECIPITATION. THE MAIN CONCERN IS FREEZING TEMPERATURES
THURSDAY NIGHT AFTER RAIN/SNOW MIX OR EVEN A QUICK BURST OF SNOW
AS THE FRONT MOVES ACROSS THE AREA. THIS MAY CREATE PROBLEMS ON
THE ROADWAYS DUE TO BLACK ICE AND SLICK CONDITIONS. INCREASED POP
TO 20 PERCENT...AND STARTED ADDING A MIX OF RAIN/SNOW FOR AREAS
BETWEEN 6000 TO 7000 FEET. WILL HAVE TO CLOSELY MONITOR THIS
CLIPPER...DUE TO POTENTIAL IMPACTS TO TRAVEL ACROSS THE AREA.
OTHERWISE...A DRYING TREND AND SLOW WARMING TREND WILL BEGIN ON
FRIDAY AS AN UPPER LEVEL RIDGE ALONG THE WEST COAST STRENGTHENS
AND DRIFTS EASTWARD.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 301 AM MDT WED OCT 1 2014

THE EXTENDED PERIOD WILL BE DRY AND MILD UNDER PERSISTENT NORTHWEST
FLOW ALOFT. THE MAIN JET CORE WILL REMAIN OVER THE CENTRAL
PLAINS...SEPARATING A DEEP LONG WAVE TROUGH OVER THE EASTERN CONUS
AND A BROAD RIDGE OVER THE WESTERN STATES/EASTERN PACIFIC. THE
POSITION OF THE JET WILL KEEP THE FORECAST AREA ON THE DRY SIDE OF
THE FLOW PATTERN AND ON THE SOUTHWESTERN EDGE OF ANY CLIPPER
SYSTEMS. THUS...NOT EXPECTING ANY PRECIP THRU THE PERIOD. A SOMEWHAT
STRONGER SHORTWAVE MOVING WITHIN THE NORTHWEST FLOW ON SUNDAY COULD
DEEPEN THE LONGWAVE TROUGH ENOUGH TO BRING SOME MOISTURE AND ENERGY
OVER EASTERN PORTIONS OF THE CWA...BUT WILL JUST MAINTAIN
INCREASING CLOUDS THROUGH THE AFTERNOON AS THIS SEEMS A MORE
LIKELY SCENARIO RIGHT NOW. TEMPS THRU THE PERIOD WILL REMAIN AT OR
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR...WITH MAX TEMPS OF
60S/70S EXPECTED FOR THE EASTERN PLAINS AND 50S/60S OUT WEST IN
THE HIGH VALLEYS AND MOUNTAINS. WINDS WILL BE QUITE SIMILAR EACH
DAY AS WELL WITH BREEZY WEST-NORTHWEST WINDS DEVELOPING EACH
AFTERNOON AND EVENING FOR THE MAJORITY OF THE CWA. THESE BREEZY
CONDITIONS WILL PERSIST THRU THE OVERNIGHT HOURS IN THE WIND PRONE
AREAS ALONG AND WEST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 613 AM MDT WED OCT 1 2014

A WEAK SFC FRONT WILL CONTINUE TO SLOWLY MOVE SOUTH ACROSS THE
FORECAST AREA THIS MORNING...WITH WINDS SHIFTING TO THE NORTH TO
NORTHWEST AND BECOMING BREEZY AT TIMES THIS AFTERNOON. SHOWERS
WILL MOVE FROM WEST TO EAST THIS MORNING WITH T-STORMS DEVELOPING
IN THE AFTERNOON AND EVENING AS AN UPPER LEVEL DISTURBANCE MOVES
OVER THE ROCKIES. THE BEST COVERAGE FOR STORMS STILL LOOKS TO BE
FOCUSED TOWARDS AREAS NEAR THE COLORADO BORDER WHERE THE STRONGEST
UPSLOPE FLOW WILL BE IN PLACE. LOOKING AT MAINLY MVFR CONDITIONS
WITH THIS ACTIVITY...WITH SCT-BKN MVFR CIGS LINGERING THRU MOST
OF THE NIGHT WITHIN THE COOL AND MOIST POST-STORM ENVIRONMENT.

&&

.FIRE WEATHER...
ISSUED AT 206 AM MDT WED OCT 1 2014

NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND DUE TO RECENT HEAVY
RAINFALL AND COOL TEMPERATURES. AN UPPER LEVEL DISTURBANCE WILL
QUICKLY MOVE ACROSS WYOMING AND COLORADO TODAY RESULTING IN MORE
RAIN AND ISOLATED THUNDERSTORMS...MAINLY ALONG THE INTERSTATE 80
CORRIDOR NEAR THE COLORADO BORDER. WETTING RAINS APPEAR LIKELY IN
THIS AREA AS THE SYSTEM WILL QUICKLY MOVE INTO THE GREAT PLAINS
TONIGHT. A DRYING TREND IS EXPECTED FOR LATE THIS WEEK AND INTO
THIS WEEKEND WITH SLIGHTLY WARMER TEMPERATURES AND DAYTIME
HUMIDITIES TRENDING LOWER EACH DAY...BUT REMAINING ABOVE 20
PERCENT THROUGH THE WEEKEND.

&&

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

$$

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







000
FXUS65 KCYS 011213
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
613 AM MDT WED OCT 1 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 206 AM MDT WED OCT 1 2014

CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR TO PARTLY CLOUDY
SKIES ACROSS MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA EARLY
THIS MORNING AS THE LOW PRESSURE SYSTEM WHICH BROUGHT HEAVY RAIN
TO THE AREA YESTERDAY IS NOW ENTERING SOUTHERN SASKATCHEWAN AND
MANITOBA. HOWEVER...THE NEXT UPPER LEVEL TROUGH IS CURRENTLY DIGGING
SOUTH ACROSS THE EASTERN GREAT BASIN REGION...WITH SHOWERS AND
TSTORMS DEVELOPING OVER UTAH AND ENTERING WESTERN COLORADO AT THIS
HOUR. THIS WILL BE OUR NEXT PRECIPITATION PRODUCER TODAY AS THE
UPPER LEVEL SYSTEM CONTINUES TO DIG SOUTHEAST THIS MORNING AND
EVENTUALLY PUSHES EASTWARD THIS AFTERNOON. NOT MUCH DYNAMIC LIFT
AT THE SURFACE WITH THIS SYSTEM...BUT MODELS INDICATE STRONG UPPER
LEVEL DIVERGENCE AS A 100 KT JET LIFT NORTHEAST INTO THE HIGH
PLAINS TODAY. THE GFS AND ECMWF DO INDICATE STRONG 700MB
CONVERGENCE ACROSS NORTHEAST COLORADO AND EXTREME SE WYOMING AS A
700MB LOW TRIES TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING.
THIS MID TO UPPER LEVEL COUPLET WILL ALLOW FOR SOME SUBSTANTIAL
LIFT IN ADDITION TO ANY LLVL INSTABILITY. CONTINUED TO INCREASE
POP BETWEEN 70 TO 90 PERCENT THIS AFTERNOON THROUGH LATE THIS
EVENING. THIS SYSTEM WILL MOVE RATHER QUICK ACROSS THE AREA...SO
ONLY EXPECT PERHAPS 3 TO 6 HOURS OF PRECIPITATION. IN THE
MOUNTAINS AND LOCATIONS ABOVE 7500 FEET...RAIN WILL MIX WITH AND
CHANGE TO SNOW. THIS INCLUDES THE SOUTHERN LARAMIE RANGE AND THE
I80 SUMMIT WHICH MAY RECEIVE 1 TO 3 INCHES OF SNOW BY LATE THIS
AFTERNOON. THE SNOWY AND SIERRA MADRE RANGES MAY SEE A LITTLE
MORE...BUT NO MORE THAN 3 TO 5 INCHES IS EXPECTED INTO THIS
EVENING. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES DUE TO THE
PROGRESSIVE NATURE OF THE TROUGH. FOR THE LOWER ELEVATIONS...THE
HEAVIEST RAINFALL AMOUNTS WILL GENERALLY BE ALONG THE I80 CORRIDOR
FROM LARAMIE...EASTWARD TO CHEYENNE AND SIDNEY NEBRASKA. CAN NOT
RULE OUT SOME RAIN/SNOW MIX AS THE PRECIPITATION COMES TO AN END ACROSS
THE LARAMIE VALLEY THIS AFTERNOON WITH SNOW LEVELS LOWERING
BETWEEN 7000 TO 7500 FEET. TONIGHT WILL BE MUCH COOLER WITH LOWS
IN THE 20S TO LOW 30S ACROSS SOUTHEAST WYOMING DUE TO CLEARING
SKIES AND GOOD RADIATIONAL COOLING.

MODELS ARE STRUGGLING WITH AN ALBERTA CLIPPER POTENTIALLY
IMPACTING THE AREA FOR LATE THURSDAY. CURRENT WATERVAPOR LOOP SHOWS
THIS BROAD TROUGH DIGGING SOUTH INTO WESTERN CANADA EARLY THIS
MORNING...WITH AN INTENSIFYING SHORTWAVE AND ASSOCIATED COLD FRONT
AS IT MOVES SOUTHWARD INTO MONTANA. MODELS WERE NOT SHOWING THIS
FEATURE 24 TO 48 HOURS AGO...AND ARE GENERALLY TRENDING COLDER
WITH MORE PRECIPITATION. THE MAIN CONCERN IS FREEZING TEMPERATURES
THURSDAY NIGHT AFTER RAIN/SNOW MIX OR EVEN A QUICK BURST OF SNOW
AS THE FRONT MOVES ACROSS THE AREA. THIS MAY CREATE PROBLEMS ON
THE ROADWAYS DUE TO BLACK ICE AND SLICK CONDITIONS. INCREASED POP
TO 20 PERCENT...AND STARTED ADDING A MIX OF RAIN/SNOW FOR AREAS
BETWEEN 6000 TO 7000 FEET. WILL HAVE TO CLOSELY MONITOR THIS
CLIPPER...DUE TO POTENTIAL IMPACTS TO TRAVEL ACROSS THE AREA.
OTHERWISE...A DRYING TREND AND SLOW WARMING TREND WILL BEGIN ON
FRIDAY AS AN UPPER LEVEL RIDGE ALONG THE WEST COAST STRENGTHENS
AND DRIFTS EASTWARD.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 301 AM MDT WED OCT 1 2014

THE EXTENDED PERIOD WILL BE DRY AND MILD UNDER PERSISTENT NORTHWEST
FLOW ALOFT. THE MAIN JET CORE WILL REMAIN OVER THE CENTRAL
PLAINS...SEPARATING A DEEP LONG WAVE TROUGH OVER THE EASTERN CONUS
AND A BROAD RIDGE OVER THE WESTERN STATES/EASTERN PACIFIC. THE
POSITION OF THE JET WILL KEEP THE FORECAST AREA ON THE DRY SIDE OF
THE FLOW PATTERN AND ON THE SOUTHWESTERN EDGE OF ANY CLIPPER
SYSTEMS. THUS...NOT EXPECTING ANY PRECIP THRU THE PERIOD. A SOMEWHAT
STRONGER SHORTWAVE MOVING WITHIN THE NORTHWEST FLOW ON SUNDAY COULD
DEEPEN THE LONGWAVE TROUGH ENOUGH TO BRING SOME MOISTURE AND ENERGY
OVER EASTERN PORTIONS OF THE CWA...BUT WILL JUST MAINTAIN
INCREASING CLOUDS THROUGH THE AFTERNOON AS THIS SEEMS A MORE
LIKELY SCENARIO RIGHT NOW. TEMPS THRU THE PERIOD WILL REMAIN AT OR
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR...WITH MAX TEMPS OF
60S/70S EXPECTED FOR THE EASTERN PLAINS AND 50S/60S OUT WEST IN
THE HIGH VALLEYS AND MOUNTAINS. WINDS WILL BE QUITE SIMILAR EACH
DAY AS WELL WITH BREEZY WEST-NORTHWEST WINDS DEVELOPING EACH
AFTERNOON AND EVENING FOR THE MAJORITY OF THE CWA. THESE BREEZY
CONDITIONS WILL PERSIST THRU THE OVERNIGHT HOURS IN THE WIND PRONE
AREAS ALONG AND WEST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 613 AM MDT WED OCT 1 2014

A WEAK SFC FRONT WILL CONTINUE TO SLOWLY MOVE SOUTH ACROSS THE
FORECAST AREA THIS MORNING...WITH WINDS SHIFTING TO THE NORTH TO
NORTHWEST AND BECOMING BREEZY AT TIMES THIS AFTERNOON. SHOWERS
WILL MOVE FROM WEST TO EAST THIS MORNING WITH T-STORMS DEVELOPING
IN THE AFTERNOON AND EVENING AS AN UPPER LEVEL DISTURBANCE MOVES
OVER THE ROCKIES. THE BEST COVERAGE FOR STORMS STILL LOOKS TO BE
FOCUSED TOWARDS AREAS NEAR THE COLORADO BORDER WHERE THE STRONGEST
UPSLOPE FLOW WILL BE IN PLACE. LOOKING AT MAINLY MVFR CONDITIONS
WITH THIS ACTIVITY...WITH SCT-BKN MVFR CIGS LINGERING THRU MOST
OF THE NIGHT WITHIN THE COOL AND MOIST POST-STORM ENVIRONMENT.

&&

.FIRE WEATHER...
ISSUED AT 206 AM MDT WED OCT 1 2014

NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND DUE TO RECENT HEAVY
RAINFALL AND COOL TEMPERATURES. AN UPPER LEVEL DISTURBANCE WILL
QUICKLY MOVE ACROSS WYOMING AND COLORADO TODAY RESULTING IN MORE
RAIN AND ISOLATED THUNDERSTORMS...MAINLY ALONG THE INTERSTATE 80
CORRIDOR NEAR THE COLORADO BORDER. WETTING RAINS APPEAR LIKELY IN
THIS AREA AS THE SYSTEM WILL QUICKLY MOVE INTO THE GREAT PLAINS
TONIGHT. A DRYING TREND IS EXPECTED FOR LATE THIS WEEK AND INTO
THIS WEEKEND WITH SLIGHTLY WARMER TEMPERATURES AND DAYTIME
HUMIDITIES TRENDING LOWER EACH DAY...BUT REMAINING ABOVE 20
PERCENT THROUGH THE WEEKEND.

&&

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

$$

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







000
FXUS63 KUNR 011046
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
446 AM MDT WED OCT 1 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

08Z SURFACE ANALYSIS HAD LOW OVER NORTH CENTRAL ND WITH UPPER LOW
SPINNING ON TOP...WITH SYSTEM MOVING NORTH/NORTHEAST PER SATELLITE
LOOPS. NEXT SHORTWAVE TROUGH OF INTEREST OVER WESTERN MT/ID PER
WATER VAPOUR. THIS WAVE WILL MOVE SOUTHEAST TODAY ROUNDING BASE OF
MEAN TROUGH OVER CENTRAL NORTH AMERICA. COMBINATION OF CYCLONIC
FLOW AND WEAK FORCING WITH SHORTWAVE TROUGH WILL RESULT IN A FEW
-SHRA OVER THE CWA TODAY...SHIFTING EAST/SOUTH OF THE AREA
TONIGHT. TEMPERATURES WILL BE NEAR GUIDANCE TODAY/TONIGHT.

THURSDAY...FAST MOVING UPPER TROUGH/SHORTWAVE WILL RACE INTO THE
NORTHERN PLAINS BY 00Z FRIDAY DRIVING A SHARP COLD FRONT INTO THE
CWA. A FEW -SHRA MAY OCCUR WITH THE SYSTEM...BUT THE MAIN EFFECT
WILL BE RATHER STRONG COLD AIR ADVECTION AND 30-40KT 850-700MB
WINDS. HAVE BUMPED UP WINDS ON THE SD PLAINS TO ACCOUNT...AND MAY
NEED SOME SORT OF WIND HEADLINES WHEN ALL IS SAID AND DONE. IT/LL BE
COLD ENOUGH EARLY THURSDAY EVENING OVER THE HIGHER ELEVATIONS FOR A
FEW -SHRASN. TEMPERATURES WILL BE NEAR GUIDANCE...AND PROBABLY COLD
ENOUGH FOR FROST/FREEZE OVER PARTS OF THE CWA THURSDAY NIGHT.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 237 AM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS THE LARGE
UPPER TROUGH EXITS INTO THE MIDWEST. LITTLE CHANGE TO THE PATTERN
IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE OVERALL
PROGRESS SLOWS TO A CRAWL. PERSISTENT NORTHWEST FLOW OVER THE AREA
WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS. OCCASIONAL
UPPER WAVES WILL PUSH ACROSS THE NORTHWEST FLOW...WHICH WILL BRING
BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE WINDS FRIDAY AND
PERHAPS SATURDAY WILL BE GUSTIER.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 446 AM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA TODAY...THEN SOUTH CENTRAL
SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY ARE EXPECTED WITH ANY SHOWERS
THAT DEVELOP. IFR CIGS ARE POSSIBLE WITH ANY SHOWER DEVELOPMENT
NEAR THE BLACK HILLS. NORTHWEST WINDS WILL BECOME BREEZY ACROSS
THE PLAINS...ESPECIALLY OVER NORTHWEST SOUTH DAKOTA.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 011046
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
446 AM MDT WED OCT 1 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

08Z SURFACE ANALYSIS HAD LOW OVER NORTH CENTRAL ND WITH UPPER LOW
SPINNING ON TOP...WITH SYSTEM MOVING NORTH/NORTHEAST PER SATELLITE
LOOPS. NEXT SHORTWAVE TROUGH OF INTEREST OVER WESTERN MT/ID PER
WATER VAPOUR. THIS WAVE WILL MOVE SOUTHEAST TODAY ROUNDING BASE OF
MEAN TROUGH OVER CENTRAL NORTH AMERICA. COMBINATION OF CYCLONIC
FLOW AND WEAK FORCING WITH SHORTWAVE TROUGH WILL RESULT IN A FEW
-SHRA OVER THE CWA TODAY...SHIFTING EAST/SOUTH OF THE AREA
TONIGHT. TEMPERATURES WILL BE NEAR GUIDANCE TODAY/TONIGHT.

THURSDAY...FAST MOVING UPPER TROUGH/SHORTWAVE WILL RACE INTO THE
NORTHERN PLAINS BY 00Z FRIDAY DRIVING A SHARP COLD FRONT INTO THE
CWA. A FEW -SHRA MAY OCCUR WITH THE SYSTEM...BUT THE MAIN EFFECT
WILL BE RATHER STRONG COLD AIR ADVECTION AND 30-40KT 850-700MB
WINDS. HAVE BUMPED UP WINDS ON THE SD PLAINS TO ACCOUNT...AND MAY
NEED SOME SORT OF WIND HEADLINES WHEN ALL IS SAID AND DONE. IT/LL BE
COLD ENOUGH EARLY THURSDAY EVENING OVER THE HIGHER ELEVATIONS FOR A
FEW -SHRASN. TEMPERATURES WILL BE NEAR GUIDANCE...AND PROBABLY COLD
ENOUGH FOR FROST/FREEZE OVER PARTS OF THE CWA THURSDAY NIGHT.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 237 AM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS THE LARGE
UPPER TROUGH EXITS INTO THE MIDWEST. LITTLE CHANGE TO THE PATTERN
IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE OVERALL
PROGRESS SLOWS TO A CRAWL. PERSISTENT NORTHWEST FLOW OVER THE AREA
WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS. OCCASIONAL
UPPER WAVES WILL PUSH ACROSS THE NORTHWEST FLOW...WHICH WILL BRING
BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE WINDS FRIDAY AND
PERHAPS SATURDAY WILL BE GUSTIER.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 446 AM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA TODAY...THEN SOUTH CENTRAL
SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY ARE EXPECTED WITH ANY SHOWERS
THAT DEVELOP. IFR CIGS ARE POSSIBLE WITH ANY SHOWER DEVELOPMENT
NEAR THE BLACK HILLS. NORTHWEST WINDS WILL BECOME BREEZY ACROSS
THE PLAINS...ESPECIALLY OVER NORTHWEST SOUTH DAKOTA.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 011046
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
446 AM MDT WED OCT 1 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

08Z SURFACE ANALYSIS HAD LOW OVER NORTH CENTRAL ND WITH UPPER LOW
SPINNING ON TOP...WITH SYSTEM MOVING NORTH/NORTHEAST PER SATELLITE
LOOPS. NEXT SHORTWAVE TROUGH OF INTEREST OVER WESTERN MT/ID PER
WATER VAPOUR. THIS WAVE WILL MOVE SOUTHEAST TODAY ROUNDING BASE OF
MEAN TROUGH OVER CENTRAL NORTH AMERICA. COMBINATION OF CYCLONIC
FLOW AND WEAK FORCING WITH SHORTWAVE TROUGH WILL RESULT IN A FEW
-SHRA OVER THE CWA TODAY...SHIFTING EAST/SOUTH OF THE AREA
TONIGHT. TEMPERATURES WILL BE NEAR GUIDANCE TODAY/TONIGHT.

THURSDAY...FAST MOVING UPPER TROUGH/SHORTWAVE WILL RACE INTO THE
NORTHERN PLAINS BY 00Z FRIDAY DRIVING A SHARP COLD FRONT INTO THE
CWA. A FEW -SHRA MAY OCCUR WITH THE SYSTEM...BUT THE MAIN EFFECT
WILL BE RATHER STRONG COLD AIR ADVECTION AND 30-40KT 850-700MB
WINDS. HAVE BUMPED UP WINDS ON THE SD PLAINS TO ACCOUNT...AND MAY
NEED SOME SORT OF WIND HEADLINES WHEN ALL IS SAID AND DONE. IT/LL BE
COLD ENOUGH EARLY THURSDAY EVENING OVER THE HIGHER ELEVATIONS FOR A
FEW -SHRASN. TEMPERATURES WILL BE NEAR GUIDANCE...AND PROBABLY COLD
ENOUGH FOR FROST/FREEZE OVER PARTS OF THE CWA THURSDAY NIGHT.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 237 AM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS THE LARGE
UPPER TROUGH EXITS INTO THE MIDWEST. LITTLE CHANGE TO THE PATTERN
IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE OVERALL
PROGRESS SLOWS TO A CRAWL. PERSISTENT NORTHWEST FLOW OVER THE AREA
WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS. OCCASIONAL
UPPER WAVES WILL PUSH ACROSS THE NORTHWEST FLOW...WHICH WILL BRING
BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE WINDS FRIDAY AND
PERHAPS SATURDAY WILL BE GUSTIER.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 446 AM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA TODAY...THEN SOUTH CENTRAL
SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY ARE EXPECTED WITH ANY SHOWERS
THAT DEVELOP. IFR CIGS ARE POSSIBLE WITH ANY SHOWER DEVELOPMENT
NEAR THE BLACK HILLS. NORTHWEST WINDS WILL BECOME BREEZY ACROSS
THE PLAINS...ESPECIALLY OVER NORTHWEST SOUTH DAKOTA.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13






000
FXUS63 KUNR 011046
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
446 AM MDT WED OCT 1 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

08Z SURFACE ANALYSIS HAD LOW OVER NORTH CENTRAL ND WITH UPPER LOW
SPINNING ON TOP...WITH SYSTEM MOVING NORTH/NORTHEAST PER SATELLITE
LOOPS. NEXT SHORTWAVE TROUGH OF INTEREST OVER WESTERN MT/ID PER
WATER VAPOUR. THIS WAVE WILL MOVE SOUTHEAST TODAY ROUNDING BASE OF
MEAN TROUGH OVER CENTRAL NORTH AMERICA. COMBINATION OF CYCLONIC
FLOW AND WEAK FORCING WITH SHORTWAVE TROUGH WILL RESULT IN A FEW
-SHRA OVER THE CWA TODAY...SHIFTING EAST/SOUTH OF THE AREA
TONIGHT. TEMPERATURES WILL BE NEAR GUIDANCE TODAY/TONIGHT.

THURSDAY...FAST MOVING UPPER TROUGH/SHORTWAVE WILL RACE INTO THE
NORTHERN PLAINS BY 00Z FRIDAY DRIVING A SHARP COLD FRONT INTO THE
CWA. A FEW -SHRA MAY OCCUR WITH THE SYSTEM...BUT THE MAIN EFFECT
WILL BE RATHER STRONG COLD AIR ADVECTION AND 30-40KT 850-700MB
WINDS. HAVE BUMPED UP WINDS ON THE SD PLAINS TO ACCOUNT...AND MAY
NEED SOME SORT OF WIND HEADLINES WHEN ALL IS SAID AND DONE. IT/LL BE
COLD ENOUGH EARLY THURSDAY EVENING OVER THE HIGHER ELEVATIONS FOR A
FEW -SHRASN. TEMPERATURES WILL BE NEAR GUIDANCE...AND PROBABLY COLD
ENOUGH FOR FROST/FREEZE OVER PARTS OF THE CWA THURSDAY NIGHT.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 237 AM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS THE LARGE
UPPER TROUGH EXITS INTO THE MIDWEST. LITTLE CHANGE TO THE PATTERN
IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE OVERALL
PROGRESS SLOWS TO A CRAWL. PERSISTENT NORTHWEST FLOW OVER THE AREA
WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS. OCCASIONAL
UPPER WAVES WILL PUSH ACROSS THE NORTHWEST FLOW...WHICH WILL BRING
BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE WINDS FRIDAY AND
PERHAPS SATURDAY WILL BE GUSTIER.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 446 AM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA TODAY...THEN SOUTH CENTRAL
SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY ARE EXPECTED WITH ANY SHOWERS
THAT DEVELOP. IFR CIGS ARE POSSIBLE WITH ANY SHOWER DEVELOPMENT
NEAR THE BLACK HILLS. NORTHWEST WINDS WILL BECOME BREEZY ACROSS
THE PLAINS...ESPECIALLY OVER NORTHWEST SOUTH DAKOTA.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13






000
FXUS65 KCYS 010902
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
302 AM MDT WED OCT 1 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 206 AM MDT WED OCT 1 2014

CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR TO PARTLY CLOUDY
SKIES ACROSS MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA EARLY
THIS MORNING AS THE LOW PRESSURE SYSTEM WHICH BROUGHT HEAVY RAIN
TO THE AREA YESTERDAY IS NOW ENTERING SOUTHERN SASKATCHEWAN AND
MANITOBA. HOWEVER...THE NEXT UPPER LEVEL TROUGH IS CURRENTLY DIGGING
SOUTH ACROSS THE EASTERN GREAT BASIN REGION...WITH SHOWERS AND
TSTORMS DEVELOPING OVER UTAH AND ENTERING WESTERN COLORADO AT THIS
HOUR. THIS WILL BE OUR NEXT PRECIPITATION PRODUCER TODAY AS THE
UPPER LEVEL SYSTEM CONTINUES TO DIG SOUTHEAST THIS MORNING AND
EVENTUALLY PUSHES EASTWARD THIS AFTERNOON. NOT MUCH DYNAMIC LIFT
AT THE SURFACE WITH THIS SYSTEM...BUT MODELS INDICATE STRONG UPPER
LEVEL DIVERGENCE AS A 100 KT JET LIFT NORTHEAST INTO THE HIGH
PLAINS TODAY. THE GFS AND ECMWF DO INDICATE STRONG 700MB
CONVERGENCE ACROSS NORTHEAST COLORADO AND EXTREME SE WYOMING AS A
700MB LOW TRIES TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING.
THIS MID TO UPPER LEVEL COUPLET WILL ALLOW FOR SOME SUBSTANTIAL
LIFT IN ADDITION TO ANY LLVL INSTABILITY. CONTINUED TO INCREASE
POP BETWEEN 70 TO 90 PERCENT THIS AFTERNOON THROUGH LATE THIS
EVENING. THIS SYSTEM WILL MOVE RATHER QUICK ACROSS THE AREA...SO
ONLY EXPECT PERHAPS 3 TO 6 HOURS OF PRECIPITATION. IN THE
MOUNTAINS AND LOCATIONS ABOVE 7500 FEET...RAIN WILL MIX WITH AND
CHANGE TO SNOW. THIS INCLUDES THE SOUTHERN LARAMIE RANGE AND THE
I80 SUMMIT WHICH MAY RECEIVE 1 TO 3 INCHES OF SNOW BY LATE THIS
AFTERNOON. THE SNOWY AND SIERRA MADRE RANGES MAY SEE A LITTLE
MORE...BUT NO MORE THAN 3 TO 5 INCHES IS EXPECTED INTO THIS
EVENING. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES DUE TO THE
PROGRESSIVE NATURE OF THE TROUGH. FOR THE LOWER ELEVATIONS...THE
HEAVIEST RAINFALL AMOUNTS WILL GENERALLY BE ALONG THE I80 CORRIDOR
FROM LARAMIE...EASTWARD TO CHEYENNE AND SIDNEY NEBRASKA. CAN NOT
RULE OUT SOME RAIN/SNOW MIX AS THE PRECIPITATION COMES TO AN END ACROSS
THE LARAMIE VALLEY THIS AFTERNOON WITH SNOW LEVELS LOWERING
BETWEEN 7000 TO 7500 FEET. TONIGHT WILL BE MUCH COOLER WITH LOWS
IN THE 20S TO LOW 30S ACROSS SOUTHEAST WYOMING DUE TO CLEARING
SKIES AND GOOD RADIATIONAL COOLING.

MODELS ARE STRUGGLING WITH AN ALBERTA CLIPPER POTENTIALLY
IMPACTING THE AREA FOR LATE THURSDAY. CURRENT WATERVAPOR LOOP SHOWS
THIS BROAD TROUGH DIGGING SOUTH INTO WESTERN CANADA EARLY THIS
MORNING...WITH AN INTENSIFYING SHORTWAVE AND ASSOCIATED COLD FRONT
AS IT MOVES SOUTHWARD INTO MONTANA. MODELS WERE NOT SHOWING THIS
FEATURE 24 TO 48 HOURS AGO...AND ARE GENERALLY TRENDING COLDER
WITH MORE PRECIPITATION. THE MAIN CONCERN IS FREEZING TEMPERATURES
THURSDAY NIGHT AFTER RAIN/SNOW MIX OR EVEN A QUICK BURST OF SNOW
AS THE FRONT MOVES ACROSS THE AREA. THIS MAY CREATE PROBLEMS ON
THE ROADWAYS DUE TO BLACK ICE AND SLICK CONDITIONS. INCREASED POP
TO 20 PERCENT...AND STARTED ADDING A MIX OF RAIN/SNOW FOR AREAS
BETWEEN 6000 TO 7000 FEET. WILL HAVE TO CLOSELY MONITOR THIS
CLIPPER...DUE TO POTENTIAL IMPACTS TO TRAVEL ACROSS THE AREA.
OTHERWISE...A DRYING TREND AND SLOW WARMING TREND WILL BEGIN ON
FRIDAY AS AN UPPER LEVEL RIDGE ALONG THE WEST COAST STRENGTHENS
AND DRIFTS EASTWARD.



.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 301 AM MDT WED OCT 1 2014

THE EXTENDED PERIOD WILL BE DRY AND MILD UNDER PERSISTENT NORTHWEST
FLOW ALOFT. THE MAIN JET CORE WILL REMAIN OVER THE CENTRAL
PLAINS...SEPARATING A DEEP LONG WAVE TROUGH OVER THE EASTERN CONUS
AND A BROAD RIDGE OVER THE WESTERN STATES/EASTERN PACIFIC. THE
POSITION OF THE JET WILL KEEP THE FORECAST AREA ON THE DRY SIDE OF
THE FLOW PATTERN AND ON THE SOUTHWESTERN EDGE OF ANY CLIPPER
SYSTEMS. THUS...NOT EXPECTING ANY PRECIP THRU THE PERIOD. A SOMEWHAT
STRONGER SHORTWAVE MOVING WITHIN THE NORTHWEST FLOW ON SUNDAY COULD
DEEPEN THE LONGWAVE TROUGH ENOUGH TO BRING SOME MOISTURE AND ENERGY
OVER EASTERN PORTIONS OF THE CWA...BUT WILL JUST MAINTAIN
INCREASING CLOUDS THROUGH THE AFTERNOON AS THIS SEEMS A MORE
LIKELY SCENARIO RIGHT NOW. TEMPS THRU THE PERIOD WILL REMAIN AT OR
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR...WITH MAX TEMPS OF
60S/70S EXPECTED FOR THE EASTERN PLAINS AND 50S/60S OUT WEST IN
THE HIGH VALLEYS AND MOUNTAINS. WINDS WILL BE QUITE SIMILAR EACH
DAY AS WELL WITH BREEZY WEST-NORTHWEST WINDS DEVELOPING EACH
AFTERNOON AND EVENING FOR THE MAJORITY OF THE CWA. THESE BREEZY
CONDITIONS WILL PERSIST THRU THE OVERNIGHT HOURS IN THE WIND PRONE
AREAS ALONG AND WEST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1158 PM MDT TUE SEP 30 2014

A FEW SHOWERS LINGER OVER THE CWA AT TAF ISSUANCE...BUT SHOULD NOT
IMPACT THE TERMINALS TONIGHT. WINDS WILL SHIFT TO THE NORTH-
NORTHWEST THRU THE MORNING BEHIND A WEAK FRONT DROPPING SOUTH
ACROSS THE AREA. SHOWERS AND T-STORMS WILL REDEVELOP IN THE
AFTERNOON AND EVENING AS ANOTHER UPPER LEVEL DISTURBANCE MOVES
OVER THE ROCKIES...ESPECIALLY FOR AREAS NEAR THE COLORADO BORDER
WITH THE STRONGEST UPSLOPE FLOW IN PLACE. LOOKING AT MAINLY MVFR
CONDITIONS WITH THIS ACTIVITY.

&&

.FIRE WEATHER...
ISSUED AT 206 AM MDT WED OCT 1 2014

NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND DUE TO RECENT HEAVY
RAINFALL AND COOL TEMPERATURES. AN UPPER LEVEL DISTURBANCE WILL
QUICKLY MOVE ACROSS WYOMING AND COLORADO TODAY RESULTING IN MORE
RAIN AND ISOLATED THUNDERSTORMS...MAINLY ALONG THE INTERSTATE 80
CORRIDOR NEAR THE COLORADO BORDER. WETTING RAINS APPEAR LIKELY IN
THIS AREA AS THE SYSTEM WILL QUICKLY MOVE INTO THE GREAT PLAINS
TONIGHT. A DRYING TREND IS EXPECTED FOR LATE THIS WEEK AND INTO
THIS WEEKEND WITH SLIGHTLY WARMER TEMPERATURES AND DAYTIME
HUMIDITIES TRENDING LOWER EACH DAY...BUT REMAINING ABOVE 20
PERCENT THROUGH THE WEEKEND.

&&

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

$$

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








000
FXUS65 KCYS 010902
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
302 AM MDT WED OCT 1 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 206 AM MDT WED OCT 1 2014

CURRENT IR SATELLITE LOOP SHOWS MOSTLY CLEAR TO PARTLY CLOUDY
SKIES ACROSS MOST OF SOUTHEAST WYOMING AND WESTERN NEBRASKA EARLY
THIS MORNING AS THE LOW PRESSURE SYSTEM WHICH BROUGHT HEAVY RAIN
TO THE AREA YESTERDAY IS NOW ENTERING SOUTHERN SASKATCHEWAN AND
MANITOBA. HOWEVER...THE NEXT UPPER LEVEL TROUGH IS CURRENTLY DIGGING
SOUTH ACROSS THE EASTERN GREAT BASIN REGION...WITH SHOWERS AND
TSTORMS DEVELOPING OVER UTAH AND ENTERING WESTERN COLORADO AT THIS
HOUR. THIS WILL BE OUR NEXT PRECIPITATION PRODUCER TODAY AS THE
UPPER LEVEL SYSTEM CONTINUES TO DIG SOUTHEAST THIS MORNING AND
EVENTUALLY PUSHES EASTWARD THIS AFTERNOON. NOT MUCH DYNAMIC LIFT
AT THE SURFACE WITH THIS SYSTEM...BUT MODELS INDICATE STRONG UPPER
LEVEL DIVERGENCE AS A 100 KT JET LIFT NORTHEAST INTO THE HIGH
PLAINS TODAY. THE GFS AND ECMWF DO INDICATE STRONG 700MB
CONVERGENCE ACROSS NORTHEAST COLORADO AND EXTREME SE WYOMING AS A
700MB LOW TRIES TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING.
THIS MID TO UPPER LEVEL COUPLET WILL ALLOW FOR SOME SUBSTANTIAL
LIFT IN ADDITION TO ANY LLVL INSTABILITY. CONTINUED TO INCREASE
POP BETWEEN 70 TO 90 PERCENT THIS AFTERNOON THROUGH LATE THIS
EVENING. THIS SYSTEM WILL MOVE RATHER QUICK ACROSS THE AREA...SO
ONLY EXPECT PERHAPS 3 TO 6 HOURS OF PRECIPITATION. IN THE
MOUNTAINS AND LOCATIONS ABOVE 7500 FEET...RAIN WILL MIX WITH AND
CHANGE TO SNOW. THIS INCLUDES THE SOUTHERN LARAMIE RANGE AND THE
I80 SUMMIT WHICH MAY RECEIVE 1 TO 3 INCHES OF SNOW BY LATE THIS
AFTERNOON. THE SNOWY AND SIERRA MADRE RANGES MAY SEE A LITTLE
MORE...BUT NO MORE THAN 3 TO 5 INCHES IS EXPECTED INTO THIS
EVENING. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES DUE TO THE
PROGRESSIVE NATURE OF THE TROUGH. FOR THE LOWER ELEVATIONS...THE
HEAVIEST RAINFALL AMOUNTS WILL GENERALLY BE ALONG THE I80 CORRIDOR
FROM LARAMIE...EASTWARD TO CHEYENNE AND SIDNEY NEBRASKA. CAN NOT
RULE OUT SOME RAIN/SNOW MIX AS THE PRECIPITATION COMES TO AN END ACROSS
THE LARAMIE VALLEY THIS AFTERNOON WITH SNOW LEVELS LOWERING
BETWEEN 7000 TO 7500 FEET. TONIGHT WILL BE MUCH COOLER WITH LOWS
IN THE 20S TO LOW 30S ACROSS SOUTHEAST WYOMING DUE TO CLEARING
SKIES AND GOOD RADIATIONAL COOLING.

MODELS ARE STRUGGLING WITH AN ALBERTA CLIPPER POTENTIALLY
IMPACTING THE AREA FOR LATE THURSDAY. CURRENT WATERVAPOR LOOP SHOWS
THIS BROAD TROUGH DIGGING SOUTH INTO WESTERN CANADA EARLY THIS
MORNING...WITH AN INTENSIFYING SHORTWAVE AND ASSOCIATED COLD FRONT
AS IT MOVES SOUTHWARD INTO MONTANA. MODELS WERE NOT SHOWING THIS
FEATURE 24 TO 48 HOURS AGO...AND ARE GENERALLY TRENDING COLDER
WITH MORE PRECIPITATION. THE MAIN CONCERN IS FREEZING TEMPERATURES
THURSDAY NIGHT AFTER RAIN/SNOW MIX OR EVEN A QUICK BURST OF SNOW
AS THE FRONT MOVES ACROSS THE AREA. THIS MAY CREATE PROBLEMS ON
THE ROADWAYS DUE TO BLACK ICE AND SLICK CONDITIONS. INCREASED POP
TO 20 PERCENT...AND STARTED ADDING A MIX OF RAIN/SNOW FOR AREAS
BETWEEN 6000 TO 7000 FEET. WILL HAVE TO CLOSELY MONITOR THIS
CLIPPER...DUE TO POTENTIAL IMPACTS TO TRAVEL ACROSS THE AREA.
OTHERWISE...A DRYING TREND AND SLOW WARMING TREND WILL BEGIN ON
FRIDAY AS AN UPPER LEVEL RIDGE ALONG THE WEST COAST STRENGTHENS
AND DRIFTS EASTWARD.



.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 301 AM MDT WED OCT 1 2014

THE EXTENDED PERIOD WILL BE DRY AND MILD UNDER PERSISTENT NORTHWEST
FLOW ALOFT. THE MAIN JET CORE WILL REMAIN OVER THE CENTRAL
PLAINS...SEPARATING A DEEP LONG WAVE TROUGH OVER THE EASTERN CONUS
AND A BROAD RIDGE OVER THE WESTERN STATES/EASTERN PACIFIC. THE
POSITION OF THE JET WILL KEEP THE FORECAST AREA ON THE DRY SIDE OF
THE FLOW PATTERN AND ON THE SOUTHWESTERN EDGE OF ANY CLIPPER
SYSTEMS. THUS...NOT EXPECTING ANY PRECIP THRU THE PERIOD. A SOMEWHAT
STRONGER SHORTWAVE MOVING WITHIN THE NORTHWEST FLOW ON SUNDAY COULD
DEEPEN THE LONGWAVE TROUGH ENOUGH TO BRING SOME MOISTURE AND ENERGY
OVER EASTERN PORTIONS OF THE CWA...BUT WILL JUST MAINTAIN
INCREASING CLOUDS THROUGH THE AFTERNOON AS THIS SEEMS A MORE
LIKELY SCENARIO RIGHT NOW. TEMPS THRU THE PERIOD WILL REMAIN AT OR
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR...WITH MAX TEMPS OF
60S/70S EXPECTED FOR THE EASTERN PLAINS AND 50S/60S OUT WEST IN
THE HIGH VALLEYS AND MOUNTAINS. WINDS WILL BE QUITE SIMILAR EACH
DAY AS WELL WITH BREEZY WEST-NORTHWEST WINDS DEVELOPING EACH
AFTERNOON AND EVENING FOR THE MAJORITY OF THE CWA. THESE BREEZY
CONDITIONS WILL PERSIST THRU THE OVERNIGHT HOURS IN THE WIND PRONE
AREAS ALONG AND WEST OF THE LARAMIE RANGE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1158 PM MDT TUE SEP 30 2014

A FEW SHOWERS LINGER OVER THE CWA AT TAF ISSUANCE...BUT SHOULD NOT
IMPACT THE TERMINALS TONIGHT. WINDS WILL SHIFT TO THE NORTH-
NORTHWEST THRU THE MORNING BEHIND A WEAK FRONT DROPPING SOUTH
ACROSS THE AREA. SHOWERS AND T-STORMS WILL REDEVELOP IN THE
AFTERNOON AND EVENING AS ANOTHER UPPER LEVEL DISTURBANCE MOVES
OVER THE ROCKIES...ESPECIALLY FOR AREAS NEAR THE COLORADO BORDER
WITH THE STRONGEST UPSLOPE FLOW IN PLACE. LOOKING AT MAINLY MVFR
CONDITIONS WITH THIS ACTIVITY.

&&

.FIRE WEATHER...
ISSUED AT 206 AM MDT WED OCT 1 2014

NO FIRE WEATHER CONCERNS THROUGH THIS WEEKEND DUE TO RECENT HEAVY
RAINFALL AND COOL TEMPERATURES. AN UPPER LEVEL DISTURBANCE WILL
QUICKLY MOVE ACROSS WYOMING AND COLORADO TODAY RESULTING IN MORE
RAIN AND ISOLATED THUNDERSTORMS...MAINLY ALONG THE INTERSTATE 80
CORRIDOR NEAR THE COLORADO BORDER. WETTING RAINS APPEAR LIKELY IN
THIS AREA AS THE SYSTEM WILL QUICKLY MOVE INTO THE GREAT PLAINS
TONIGHT. A DRYING TREND IS EXPECTED FOR LATE THIS WEEK AND INTO
THIS WEEKEND WITH SLIGHTLY WARMER TEMPERATURES AND DAYTIME
HUMIDITIES TRENDING LOWER EACH DAY...BUT REMAINING ABOVE 20
PERCENT THROUGH THE WEEKEND.

&&

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

$$

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









000
FXUS65 KRIW 010852
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
252 AM MDT WED OCT 1 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

LARGE LW TROF ACROSS THE CONUS W OF THE MISSISSIPPI...WITH TWO
EMBEDDED SW TROFS ROTATING THRU THE FLOW...ONE TO THE E AND OVR THE
NRN PLAINS...THE OTHER JUST NOW KNOCKING ON THE DOORSTEP OF THE WRN
FA. FURTHER UPSTREAM...SW RIDGING COMING INTO THE PAC NW WITH SW
TROF ON ITS HEALS COMING OUT OF SRN AK. SFC SHOWS
DEVELOPED/ASSOCIATED CYCLONE OVR THE NRN PLAINS W/ TRAILING FRONT
FROM ERN MT SWD AND THRU CNTRL WY...THEN OFF TO THE SW AND INTO THE
GREAT BASIN...WHILE ANOTHER SFC TROF/DEVELOPING FRONT JUST
APPROACHING THE NW CORNER OF THE STATE.

THIS MORNING/TODAY THRU TONIGHT...SOME MID/UPR LIFT INCREASES AS SW
NEAR WRN CORRIDOR CONTINUES TO TRANSLATE THRU THE LARGE-SCALE FLOW
AND OVR THE WRN HALF OF THE CWA BY MORNING...WITH COLDER AND
MODESTLY DIFLUENT UPR LVLS. ATTM...WV IMAGERY SHOWS TWO PLUMES OF
MOISTURE ASSOCIATED WITH APPROACHING SW TROF...ONE RIDING INTO THE
NW CORNER OF WY WITH THE TROF/FRONT...THE OTHER TO THE S AND RIDING
THRU RATHER FLAT FLOW OUT OF THE SERN ID/NRN UT...WITH DRIER AIR IN
BETWEEN THE TWO. PRECIPITATION...BOTH LIQUID AND FROZEN WILL
CONTINUE ACROSS THE NRN CWA THROUGH THE DAY BEHIND A FRONT...WHILE
THE CNTRL CWA INCLUDING THE WIND RIVER BASIN AND WIND RIVER
MOUNTAINS WILL HAVE TO WAIT A BIT LONGER FOR THE MAIN UPR TROF TO
PUSH FURTHER ACROSS AND FORCE THE FRONT FURTHER SOUTH THROUGH THE
LATE MORNING BEFORE PRECIP THERE GETS GOING. H7 TEMPS WILL CONTINUE
TO FALL FROM AROUND -1 DEG C TO NEAR -4 THRU THE MORNING HRS. WHILE
COLD AIR WILL BE ADVECTING INTO THE FA FROM THE N...CLOUD COVER WILL
KEEP SOME WARMER AIR TRAPPED AT LOWER ELEVATIONS AND WILL HAVE TO
MIX OUT THOROUGHLY...WHICH MAY TAKE A WHILE.
ADDITIONALLY...EVAPORATIVE COOLING FROM ALOFT MAY BE LIMITED AS
CEILINGS CONTINUE TO FALL THIS MORNING...CLOSING THE DRY/MOIST AIR GAP
QUICKLY. SNOW TOTALS FROM EARLY THIS MORNING THROUGH THE EVENING
PERIOD WILL VARY FROM AS MUCH AS 6 INCHES OVER PORTIONS OF THE
ABSAROKAS AND BIGHORN MOUNTAINS...5 INCHES IN THE TETONS...AND UP TO
4 INCHES IN THE WIND RIVERS. RAIN SHOWERS MAY MIX WITH SNOW OR
BECOME ALL SNOW FOR A BRIEF PERIOD AT SOME LOWER ELEVATIONS IN THE
WESTERN BIGHORN BASIN THIS MORNING...WITH MOSTLY AN INCH OR LESS
POSSIBLE AT SOME LOCATIONS...BUT WITH ISOLATED AREAS...SUCH AS
AROUND MEETEETSE RECEIVING 1 TO 2 INCHES OF SNOWFALL...IF THE
CHANGEOVER OCCURS.  TONIGHT...UPR TROF AXIS PUSHES ACROSS THE
FA...QUICKLY CLEARING SKIES AND COOLING THINGS OFF FROM W TO E BY
MIDNIGHT OR SHORTLY THEREAFTER. PATCHY FOG MAY BECOME AN ISSUE
OVERNIGHT AND INTO THURSDAY MORNING WEST OF THE DIVIDE AND OVER
PARTS OF THE BIGHORN BASIN.

THU...QUICK MODEST RIDGING GIVES WAY TO YET ANOTHER AND FINAL UPR SW
TROF THAT WILL SWING THRU THE BACKSIDE OF THE MAIN TROF...DRIVING
ANOTHER COLD FRONT DOWN THRU THE FA EAST OF THE DIVIDE.
HOWEVER...MOISTURE WILL BE AT A PREMIUM WITH THIS FEATURE. WHILE
PRECIP CHANCES WILL INCREASE E OF THE DIVIDE...MAINLY ACROSS THE NRN
MOUNTAINS AND BIGHORN BASIN...QPF WILL REMAIN QUITE LOW. CHANCES FOR
LIGHT SNOW WILL BE POSSIBLE ACROSS THE MOUNTAINS ONCE AGAIN ABOVE
7000 FEET...BUT MEASURABLE AMOUNTS ATTM LOOK TO REMAIN MOSTLY BE AN
INCH. THIS SW TROF WILL QUICKLY MOVE OUT OF THE AREA THROUGH THE
EVENING...WITH ONLY CLEAR COLD AND DRY SKIES LEFT BY FRI
MORNING.

FRI...LARGE MAIN UPR TROF PROGRESSES EWD INTO THE CNTRL CONUS...WITH
RIDGING W SLOWLY INCHES ITS WAY TOWARDS WY...LEAVING THE FA UNDER NW
FLOW ALOFT AND STRONG HIGH PRESSURE AT THE SFC. FRI WILL BE
CHARACTERIZED BY MOSTLY CLEAR AND SUNNY SKIES...AND WARMER AFTER A
RATHER COLD START.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

SYNOPSIS...UPPER RIDGE OF HIGH PRESSURE ALONG THE WEST COAST WILL
BRING A DRY AND MILD NORTHWEST FLOW ACROSS THE AREA THROUGH TUESDAY.

DISCUSSION...THIS PERIOD BEGINS WITH AN UPPER RIDGE ALONG THE WEST
COAST AND DOWNSTREAM LONGWAVE TROUGH ACROSS THE EASTERN U.S.  THIS
PATTERN IS EXPECTED TO SLOWLY DEAMPLIFY EARLY NEXT WEEK AS UPSTREAM
OMEGA BLOCK BUILDS ALONG THE ALEUTIAN CHAIN WITH UPPER LOW OVER THE
CENTRAL PACIFIC (NEAR 43N/165W EARLY THIS MORNING) BECOMING THE
EASTERN ANCHOR OF THIS BLOCK NEAR JUNEAU AK.  GFS AND ECMWF
DETERMINISTIC RUNS BOTH SHOW INCREASING SPREAD FROM THEIR RESPECTIVE
ENSEMBLE MEANS ON HOW THIS BLOCK WILL EVOLVE.  FORECAST PREFERS THE
LEAST AMOUNT OF TRANSITION OFFERED BY THE GEFS MEAN THIS
MORNING...HOLDING ON TO FLATTER WESTERN RIDGE...EASTERN TROUGH
PATTERN THROUGH MIDWEEK AND KEEPING POLAR FRONT NORTH OF THE AREA.
EXPECT TEMPERATURES TO BE 5-8F DEGREES ABOVE NORMAL THROUGH THE
PERIOD WITH A SLIGHT WARMING TREND MONDAY AND TUESDAY.  SLIGHT
CHANCE POPS WERE INTRODUCED TO THE NORTHERN MOUNTAINS ON WEDNESDAY
AS FLOW BECOMES MORE WESTERLY.

&&

.AVIATION.../12Z ISSUANCE/

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

A LARGE AREA OF LOW CEILINGS AND SCATTERED TO LOCALLY WIDESPREAD
PRECIPITATION IS EXPECTED ACROSS NORTHERN WYOMING
/KBYG...KCOD...KWRL/ IN WAKE OF A COLD FRONT THIS MORNING. THIS WILL
RESULT IN WIDESPREAD MVFR CEILINGS...AS WELL AS IFR REDUCTIONS
MAINLY DUE TO LOW VSBY IN PRECIP. ENOUGH COLD AIR IS EXPECTED THAT A
SNOW COULD OCCUR DOWN TO AROUND 5500 FT. FARTHER SOUTH ACROSS
CENTRAL WYOMING /KCPR...KLND...KRIW/ THERE IS LESS CERTAINTY OF
EXTENT/TIMING OF THE STRATUS DEVELOPING THIS MORNING AFTER FRONTAL
PASSAGE. EITHER WAY...THE BULK OF THE PRECIPITATION SHOULD BE NORTH
OF THOSE TERMINALS THIS MORNING. SCATTERED SHOWERS AND POSSIBLY AN
ISOLATED THUNDERSTORM WILL OCCUR IN THE AFTERNOON WITH PERSISTENT
LOW CEILINGS IN THE 020-040 KFT AGL. THE TROUGH EXITS THE AREA THIS
EVENING WITH IMPROVING CONDITIONS...BUT A MOIST NORTHWEST FLOW COULD
RESULT IN SHOWER ACTIVITY FORMING OVER THE MOUNTAINS AND PUSHING
SOUTHEAST INTO THE LOWER ELEVATIONS THROUGH ABOUT 06Z. MOUNTAINS
WILL BE OBSCURED THROUGH MUCH OF THE DAY...WITH IMPROVING CONDITIONS
LATE IN THE DAY INTO THE OVERNIGHT.

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

SHOWER ACTIVITY WILL BE MOST CONCENTRATED ACROSS THE FAR WEST THIS
MORNING IMPACTING KJAC. MVFR AND POSSIBLY IFR CONDITIONS WILL BE
POSSIBLE IN SNOW AT KJAC THIS MORNING. THIS SHOWER ACTIVITY IS THEN
EXPECTED TO OVERSPREAD THE REST OF THE WEST/SOUTHWEST WYOMING
BETWEEN 16Z AND 20Z...AS THE MAIN TROUGH BEGINS TO PUSH THROUGH.
THIS COULD RESULT IN PERIODS OF MVFR CONDITIONS...BUT NOT OF
CONFIDENCE TO PREVAIL MVFR CONDITIONS AT ANY TERMINAL. RAPIDLY
IMPROVING CONDITIONS ARE EXPECTED BETWEEN 22Z AND 02Z...WITH SKIES
TRYING TO CLEAR OUT.  SOME WARM AIR ADVECTION STRATOCU DECK IS THEN
EXPECTED TO DEVELOP OVER PORTIONS OF FAR WEST WYOMING AFTER 06Z.

&&

.FIRE WEATHER...

FIRE DANGER WILL REMAIN LOW ACROSS THE FORECAST AREA THROUGH THE
REST OF THE WEEK. SHOWERS WILL CONTINUE ACROSS WEST AND NORTH
THROUGH THE DAY...ENDING FROM WEST TO EAST LATER THIS AFTERNOON AND
THROUGH THIS EVENING. THE BEST CHANCE FOR WETTING RAINS (OR SNOW)
WILL OCCUR IN THE TETONS EARLY...THEN THE ABSAROKA AND BIGHORN
MOUNTAINS THROUGH THE REST OF THE DAY...WITH BEST CHANCES ACROSS THE
LOWER ELEVATIONS COMING IN THE CODY FOOTHILLS AND SOUTHERN BIGHORN
BASIN. ANOTHER CHANCE FOR LIGHT PRECIPITATION WILL PRESENT ITSELF BY
THURSDAY AFTERNOON OVER THE NORTHEASTERN DISPATCH ZONES...EXITING
QUICKLY BY EVENING.

&&

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

$$

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









000
FXUS65 KRIW 010852
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
252 AM MDT WED OCT 1 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

LARGE LW TROF ACROSS THE CONUS W OF THE MISSISSIPPI...WITH TWO
EMBEDDED SW TROFS ROTATING THRU THE FLOW...ONE TO THE E AND OVR THE
NRN PLAINS...THE OTHER JUST NOW KNOCKING ON THE DOORSTEP OF THE WRN
FA. FURTHER UPSTREAM...SW RIDGING COMING INTO THE PAC NW WITH SW
TROF ON ITS HEALS COMING OUT OF SRN AK. SFC SHOWS
DEVELOPED/ASSOCIATED CYCLONE OVR THE NRN PLAINS W/ TRAILING FRONT
FROM ERN MT SWD AND THRU CNTRL WY...THEN OFF TO THE SW AND INTO THE
GREAT BASIN...WHILE ANOTHER SFC TROF/DEVELOPING FRONT JUST
APPROACHING THE NW CORNER OF THE STATE.

THIS MORNING/TODAY THRU TONIGHT...SOME MID/UPR LIFT INCREASES AS SW
NEAR WRN CORRIDOR CONTINUES TO TRANSLATE THRU THE LARGE-SCALE FLOW
AND OVR THE WRN HALF OF THE CWA BY MORNING...WITH COLDER AND
MODESTLY DIFLUENT UPR LVLS. ATTM...WV IMAGERY SHOWS TWO PLUMES OF
MOISTURE ASSOCIATED WITH APPROACHING SW TROF...ONE RIDING INTO THE
NW CORNER OF WY WITH THE TROF/FRONT...THE OTHER TO THE S AND RIDING
THRU RATHER FLAT FLOW OUT OF THE SERN ID/NRN UT...WITH DRIER AIR IN
BETWEEN THE TWO. PRECIPITATION...BOTH LIQUID AND FROZEN WILL
CONTINUE ACROSS THE NRN CWA THROUGH THE DAY BEHIND A FRONT...WHILE
THE CNTRL CWA INCLUDING THE WIND RIVER BASIN AND WIND RIVER
MOUNTAINS WILL HAVE TO WAIT A BIT LONGER FOR THE MAIN UPR TROF TO
PUSH FURTHER ACROSS AND FORCE THE FRONT FURTHER SOUTH THROUGH THE
LATE MORNING BEFORE PRECIP THERE GETS GOING. H7 TEMPS WILL CONTINUE
TO FALL FROM AROUND -1 DEG C TO NEAR -4 THRU THE MORNING HRS. WHILE
COLD AIR WILL BE ADVECTING INTO THE FA FROM THE N...CLOUD COVER WILL
KEEP SOME WARMER AIR TRAPPED AT LOWER ELEVATIONS AND WILL HAVE TO
MIX OUT THOROUGHLY...WHICH MAY TAKE A WHILE.
ADDITIONALLY...EVAPORATIVE COOLING FROM ALOFT MAY BE LIMITED AS
CEILINGS CONTINUE TO FALL THIS MORNING...CLOSING THE DRY/MOIST AIR GAP
QUICKLY. SNOW TOTALS FROM EARLY THIS MORNING THROUGH THE EVENING
PERIOD WILL VARY FROM AS MUCH AS 6 INCHES OVER PORTIONS OF THE
ABSAROKAS AND BIGHORN MOUNTAINS...5 INCHES IN THE TETONS...AND UP TO
4 INCHES IN THE WIND RIVERS. RAIN SHOWERS MAY MIX WITH SNOW OR
BECOME ALL SNOW FOR A BRIEF PERIOD AT SOME LOWER ELEVATIONS IN THE
WESTERN BIGHORN BASIN THIS MORNING...WITH MOSTLY AN INCH OR LESS
POSSIBLE AT SOME LOCATIONS...BUT WITH ISOLATED AREAS...SUCH AS
AROUND MEETEETSE RECEIVING 1 TO 2 INCHES OF SNOWFALL...IF THE
CHANGEOVER OCCURS.  TONIGHT...UPR TROF AXIS PUSHES ACROSS THE
FA...QUICKLY CLEARING SKIES AND COOLING THINGS OFF FROM W TO E BY
MIDNIGHT OR SHORTLY THEREAFTER. PATCHY FOG MAY BECOME AN ISSUE
OVERNIGHT AND INTO THURSDAY MORNING WEST OF THE DIVIDE AND OVER
PARTS OF THE BIGHORN BASIN.

THU...QUICK MODEST RIDGING GIVES WAY TO YET ANOTHER AND FINAL UPR SW
TROF THAT WILL SWING THRU THE BACKSIDE OF THE MAIN TROF...DRIVING
ANOTHER COLD FRONT DOWN THRU THE FA EAST OF THE DIVIDE.
HOWEVER...MOISTURE WILL BE AT A PREMIUM WITH THIS FEATURE. WHILE
PRECIP CHANCES WILL INCREASE E OF THE DIVIDE...MAINLY ACROSS THE NRN
MOUNTAINS AND BIGHORN BASIN...QPF WILL REMAIN QUITE LOW. CHANCES FOR
LIGHT SNOW WILL BE POSSIBLE ACROSS THE MOUNTAINS ONCE AGAIN ABOVE
7000 FEET...BUT MEASURABLE AMOUNTS ATTM LOOK TO REMAIN MOSTLY BE AN
INCH. THIS SW TROF WILL QUICKLY MOVE OUT OF THE AREA THROUGH THE
EVENING...WITH ONLY CLEAR COLD AND DRY SKIES LEFT BY FRI
MORNING.

FRI...LARGE MAIN UPR TROF PROGRESSES EWD INTO THE CNTRL CONUS...WITH
RIDGING W SLOWLY INCHES ITS WAY TOWARDS WY...LEAVING THE FA UNDER NW
FLOW ALOFT AND STRONG HIGH PRESSURE AT THE SFC. FRI WILL BE
CHARACTERIZED BY MOSTLY CLEAR AND SUNNY SKIES...AND WARMER AFTER A
RATHER COLD START.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

SYNOPSIS...UPPER RIDGE OF HIGH PRESSURE ALONG THE WEST COAST WILL
BRING A DRY AND MILD NORTHWEST FLOW ACROSS THE AREA THROUGH TUESDAY.

DISCUSSION...THIS PERIOD BEGINS WITH AN UPPER RIDGE ALONG THE WEST
COAST AND DOWNSTREAM LONGWAVE TROUGH ACROSS THE EASTERN U.S.  THIS
PATTERN IS EXPECTED TO SLOWLY DEAMPLIFY EARLY NEXT WEEK AS UPSTREAM
OMEGA BLOCK BUILDS ALONG THE ALEUTIAN CHAIN WITH UPPER LOW OVER THE
CENTRAL PACIFIC (NEAR 43N/165W EARLY THIS MORNING) BECOMING THE
EASTERN ANCHOR OF THIS BLOCK NEAR JUNEAU AK.  GFS AND ECMWF
DETERMINISTIC RUNS BOTH SHOW INCREASING SPREAD FROM THEIR RESPECTIVE
ENSEMBLE MEANS ON HOW THIS BLOCK WILL EVOLVE.  FORECAST PREFERS THE
LEAST AMOUNT OF TRANSITION OFFERED BY THE GEFS MEAN THIS
MORNING...HOLDING ON TO FLATTER WESTERN RIDGE...EASTERN TROUGH
PATTERN THROUGH MIDWEEK AND KEEPING POLAR FRONT NORTH OF THE AREA.
EXPECT TEMPERATURES TO BE 5-8F DEGREES ABOVE NORMAL THROUGH THE
PERIOD WITH A SLIGHT WARMING TREND MONDAY AND TUESDAY.  SLIGHT
CHANCE POPS WERE INTRODUCED TO THE NORTHERN MOUNTAINS ON WEDNESDAY
AS FLOW BECOMES MORE WESTERLY.

&&

.AVIATION.../12Z ISSUANCE/

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

A LARGE AREA OF LOW CEILINGS AND SCATTERED TO LOCALLY WIDESPREAD
PRECIPITATION IS EXPECTED ACROSS NORTHERN WYOMING
/KBYG...KCOD...KWRL/ IN WAKE OF A COLD FRONT THIS MORNING. THIS WILL
RESULT IN WIDESPREAD MVFR CEILINGS...AS WELL AS IFR REDUCTIONS
MAINLY DUE TO LOW VSBY IN PRECIP. ENOUGH COLD AIR IS EXPECTED THAT A
SNOW COULD OCCUR DOWN TO AROUND 5500 FT. FARTHER SOUTH ACROSS
CENTRAL WYOMING /KCPR...KLND...KRIW/ THERE IS LESS CERTAINTY OF
EXTENT/TIMING OF THE STRATUS DEVELOPING THIS MORNING AFTER FRONTAL
PASSAGE. EITHER WAY...THE BULK OF THE PRECIPITATION SHOULD BE NORTH
OF THOSE TERMINALS THIS MORNING. SCATTERED SHOWERS AND POSSIBLY AN
ISOLATED THUNDERSTORM WILL OCCUR IN THE AFTERNOON WITH PERSISTENT
LOW CEILINGS IN THE 020-040 KFT AGL. THE TROUGH EXITS THE AREA THIS
EVENING WITH IMPROVING CONDITIONS...BUT A MOIST NORTHWEST FLOW COULD
RESULT IN SHOWER ACTIVITY FORMING OVER THE MOUNTAINS AND PUSHING
SOUTHEAST INTO THE LOWER ELEVATIONS THROUGH ABOUT 06Z. MOUNTAINS
WILL BE OBSCURED THROUGH MUCH OF THE DAY...WITH IMPROVING CONDITIONS
LATE IN THE DAY INTO THE OVERNIGHT.

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

SHOWER ACTIVITY WILL BE MOST CONCENTRATED ACROSS THE FAR WEST THIS
MORNING IMPACTING KJAC. MVFR AND POSSIBLY IFR CONDITIONS WILL BE
POSSIBLE IN SNOW AT KJAC THIS MORNING. THIS SHOWER ACTIVITY IS THEN
EXPECTED TO OVERSPREAD THE REST OF THE WEST/SOUTHWEST WYOMING
BETWEEN 16Z AND 20Z...AS THE MAIN TROUGH BEGINS TO PUSH THROUGH.
THIS COULD RESULT IN PERIODS OF MVFR CONDITIONS...BUT NOT OF
CONFIDENCE TO PREVAIL MVFR CONDITIONS AT ANY TERMINAL. RAPIDLY
IMPROVING CONDITIONS ARE EXPECTED BETWEEN 22Z AND 02Z...WITH SKIES
TRYING TO CLEAR OUT.  SOME WARM AIR ADVECTION STRATOCU DECK IS THEN
EXPECTED TO DEVELOP OVER PORTIONS OF FAR WEST WYOMING AFTER 06Z.

&&

.FIRE WEATHER...

FIRE DANGER WILL REMAIN LOW ACROSS THE FORECAST AREA THROUGH THE
REST OF THE WEEK. SHOWERS WILL CONTINUE ACROSS WEST AND NORTH
THROUGH THE DAY...ENDING FROM WEST TO EAST LATER THIS AFTERNOON AND
THROUGH THIS EVENING. THE BEST CHANCE FOR WETTING RAINS (OR SNOW)
WILL OCCUR IN THE TETONS EARLY...THEN THE ABSAROKA AND BIGHORN
MOUNTAINS THROUGH THE REST OF THE DAY...WITH BEST CHANCES ACROSS THE
LOWER ELEVATIONS COMING IN THE CODY FOOTHILLS AND SOUTHERN BIGHORN
BASIN. ANOTHER CHANCE FOR LIGHT PRECIPITATION WILL PRESENT ITSELF BY
THURSDAY AFTERNOON OVER THE NORTHEASTERN DISPATCH ZONES...EXITING
QUICKLY BY EVENING.

&&

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

$$

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








000
FXUS63 KUNR 010837
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
237 AM MDT WED OCT 1 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

08Z SURFACE ANALYSIS HAD LOW OVER NORTH CENTRAL ND WITH UPPER LOW
SPINNING ON TOP...WITH SYSTEM MOVING NORTH/NORTHEAST PER SATELLITE
LOOPS. NEXT SHORTWAVE TROUGH OF INTEREST OVER WESTERN MT/ID PER
WATER VAPOUR. THIS WAVE WILL MOVE SOUTHEAST TODAY ROUNDING BASE OF
MEAN TROUGH OVER CENTRAL NORTH AMERICA. COMBINATION OF CYCLONIC
FLOW AND WEAK FORCING WITH SHORTWAVE TROUGH WILL RESULT IN A FEW
-SHRA OVER THE CWA TODAY...SHIFTING EAST/SOUTH OF THE AREA
TONIGHT. TEMPERATURES WILL BE NEAR GUIDANCE TODAY/TONIGHT.

THURSDAY...FAST MOVING UPPER TROUGH/SHORTWAVE WILL RACE INTO THE
NORTHERN PLAINS BY 00Z FRIDAY DRIVING A SHARP COLD FRONT INTO THE
CWA. A FEW -SHRA MAY OCCUR WITH THE SYSTEM...BUT THE MAIN EFFECT
WILL BE RATHER STRONG COLD AIR ADVECTION AND 30-40KT 850-700MB
WINDS. HAVE BUMPED UP WINDS ON THE SD PLAINS TO ACCOUNT...AND MAY
NEED SOME SORT OF WIND HEADLINES WHEN ALL IS SAID AND DONE. IT/LL BE
COLD ENOUGH EARLY THURSDAY EVENING OVER THE HIGHER ELEVATIONS FOR A
FEW -SHRASN. TEMPERATURES WILL BE NEAR GUIDANCE...AND PROBABLY COLD
ENOUGH FOR FROST/FREEZE OVER PARTS OF THE CWA THURSDAY NIGHT.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 237 AM MDT WED OCT 1 2014

UPPER RIDGING WILL BUILD ACROSS THE WESTERN CONUS AS THE LARGE
UPPER TROUGH EXITS INTO THE MIDWEST. LITTLE CHANGE TO THE PATTERN
IS EXPECTED THROUGH THE REMAINDER OF EXTENDED AS THE OVERALL
PROGRESS SLOWS TO A CRAWL. PERSISTENT NORTHWEST FLOW OVER THE AREA
WILL BRING DRY WEATHER WITH SOME PASSING MID/HIGH CLOUDS.
TEMPERATURES WILL BE BELOW AVERAGE FRIDAY...BUT THEN WARMER AIR
ADVECTS IN THROUGH THE WEEKEND WITH NEAR AVERAGE TEMPS. OCCASIONAL
UPPER WAVES WILL PUSH ACROSS THE NORTHWEST FLOW...WHICH WILL BRING
BREEZY DAYS TO THE AREA. RIGHT NOW IT LOOKS LIKE WINDS FRIDAY AND
PERHAPS SATURDAY WILL BE GUSTIER.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT
ISSUED AT 237 AM MDT WED OCT 1 2014

ISOLATED TO SCATTERED SHOWERS ARE EXPECTED ACROSS NORTHEAST
WYOMING AND FAR WESTERN SOUTH DAKOTA TODAY...THEN SOUTH CENTRAL
SOUTH DAKOTA TONIGHT. MVFR CIGS/VSBY ARE EXPECTED WITH ANY SHOWERS
THAT DEVELOP. IFR CIGS ARE POSSIBLE WITH ANY SHOWER DEVELOPMENT
NEAR THE BLACK HILLS. NORTHWEST WINDS WILL BECOME BREEZY ACROSS
THE PLAINS...ESPECIALLY OVER NORTHWEST SOUTH DAKOTA.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13





000
FXUS65 KCYS 010558
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1158 PM MDT TUE SEP 30 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 331 PM MDT TUE SEP 30 2014

MAIN STORY THROUGH THE DAY HAS BEEN THE WINDY CONDITIONS ACROSS
THE REGION. THE STRONGEST WINDS THIS AFTN HAVE GENERALLY BEEN
ACROSS THE NORTHERN NEBRASKA PANHANDLE AND ARLINGTON WITH GUSTS
TO 40-45 MPH. WILL KEEP THE WIND ADVISORY GOING FOR THE NORTHERN
PANHANDLE THROUGH 4PM. STARTING TO SEE GUSTS COMING DOWN IN THE PAST
HOUR UP IN DAWES AND BOX BUTTE COUNTIES. WOULD EXPECT THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTN AS THE SFC PRESSURE
GRADIENT WEAKENS IN RESPONSE TO THE SFC LOW SHIFTING QUICKLY OFF
TO THE NORTHEAST. OTHERWISE...HIGHS HAVE BEEN A BIT COOLER THAN
FCSTED TO THE WEST OF THE LARAMIE RANGE WITH WIDESPREAD CLOUD
COVER OUT THERE. WITH WEAK INSTABILITY (LI VALUES AROUND -1C)
COMBINED WITH WESTERLY MID LEVEL WINDS AND SOME OROGRAPHIC
ENHANCEMENT...SCATTERED SHOWERS WILL BE POSSIBLE ESPECIALLY IN THE
MTNS THROUGH THE EVENING. WINDS WILL DECREASE AREAWIDE AFTER
SUNSET WITH THE LOSS OF DAYTIME MIXING.

ATTENTION ON WED WILL TURN TO THE UPPER LEVEL DISTURBANCE THAT IS
PROGGED TO AMPLIFY JUST TO THE WEST OF THE CWA BY MIDDAY. WITH THE
UPPER JET ACROSS COLORADO BY 18Z AND LARGE SCALE QG ASCENT
INCREASING WILL SEE AN INCREASE IN PRECIP CHANCES FROM MID MORNING
THROUGH THE EVENING ESPECIALLY ALONG THE COLORADO BORDER. THE MODELS
CONTINUE TO INDICATE THAT LARGE SCALE ASCENT WILL BE MAXIMIZED
OVER THE NORTHERN HALF OF COLORADO. THUS...WILL KEEP HIGH END
CHANCE TO LIKELY POPS FOR AREAS ALONG THE COLORADO BORDER DURING
THE AFTN. THE SYSTEM IS QUITE PROGRESSIVE SO ONLY EXPECTING A 3-6
HR PERIOD OF PRECIP. WITH 700MB TEMPS OF -2C TO 0C WILL DEFINITELY
SEE A FEW INCHES OF SNOW IN THE SIERRA MADRE AND SNOWY RANGES AT
ELEVATIONS ABOVE 9000 FT OR SO. IF THE SYSTEM WERE SLOWER MOVING
AND THE BEST LIFT WAS LOCATED TO THE NORTH OF THE BORDER WOULD BE
MORE CONCERNED ABOUT A WINTER WEATHER ADVISORY.

IT WILL BE A COOL WED NIGHT WITH MOST LOCATIONS TO THE WEST OF THE
LARAMIE RANGE BELOW FREEZING. MUCH DRIER WEATHER IS EXPECTED ON
THURS BUT IT WILL STILL BE RATHER COOL AND BREEZY. THE MAIN
DISAGREEMENT ON THURS NIGHT BETWEEN THE GFS AND ECMWF INVOLVES HOW
FAR WEST THE SHORTWAVE MOVES AS IT DIVES SOUTHEASTWARD INTO THE
NORTHERN PLAINS. WILL SIDE WITH THE LESS AMPLIFIED AND DRIER GFS
SOLUTION FOR NOW AND KEEP SLIGHT CHANCE POPS OUT...HOWEVER THIS WILL
HAVE TO BE MONITORED BY FUTURE SHIFTS.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 331 PM MDT TUE SEP 30 2014

DRY NORTHWEST FLOW WILL DOMINATE THE PERIOD WITH THE MAIN NRN STREAM
JET STREAM HELD TO THE NORTHEAST EXTENDING FROM ALBERTA INTO THE
MID-MISSISSIPPI RIVER VALLEY. THE TRICKIEST PART OF THE FORECAST IN
TRYING TO TIME ANY BACKDOOR FRONT THAT BRUSHES THE AREA COOLING
TEMPS MAINLY OVER NORTH AND EAST ZONES. FRIDAY WILL BE A TRANSITION
DAY AS THE COOL CANADIAN AIR MASS IS FINALLY REPLACED BY A WARMER
PACIFIC AIR MASS. IT WILL STILL BE COOL BUT DRY AS H7 TEMPS CLIMB
BACK TO AROUND 5C PRODUCING HIGH TEMPS IN THE 60S. A DEVELOPING LEE
SIDE PRESSURE TROUGH FRIDAY NIGHT WILL SLIDE EAST ON SATURDAY
PRODUCING BREEZY WEST/NORTHWEST CONDITIONS WITH GUSTS OF 20 TO 30
MPH COMMON. IT WILL BE WARMER THOUGH WITH H7 TEMPS OF AROUND 7C
PRODUCING HIGHS BACK TO NR OR INTO THE LOWER 70S. A WEAK BOUNDARY
MAY SNEAK INTO NORTH AND EAST ZONES SATURDAY NIGHT...BUT SHOULD ONLY
COOL HIGHS BACK INTO THE 60S FOR SUNDAY. FLOW WILL TURN MORE
WEST/NORTHWEST FOR MONDAY AND TUESDAY WHICH WILL ELIMINATE THE
POSSIBILITY OF AN INTRUDING BOUNDARY NORTH AND EAST. IT STILL LOOKS
DRY EARLY NEXT WEEK...WITH HIGHS CLIMBING BACK INTO THE 70S FOR MOST
LOCALES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1158 PM MDT TUE SEP 30 2014

A FEW SHOWERS LINGER OVER THE CWA AT TAF ISSUANCE...BUT SHOULD NOT
IMPACT THE TERMINALS TONIGHT. WINDS WILL SHIFT TO THE NORTH-
NORTHWEST THRU THE MORNING BEHIND A WEAK FRONT DROPPING SOUTH
ACROSS THE AREA. SHOWERS AND T-STORMS WILL REDEVELOP IN THE
AFTERNOON AND EVENING AS ANOTHER UPPER LEVEL DISTURBANCE MOVES
OVER THE ROCKIES...ESPECIALLY FOR AREAS NEAR THE COLORADO BORDER
WITH THE STRONGEST UPSLOPE FLOW IN PLACE. LOOKING AT MAINLY MVFR
CONDITIONS WITH THIS ACTIVITY.

&&

.FIRE WEATHER...
ISSUED AT 331 PM MDT TUE SEP 30 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH THURSDAY. WINDY CONDITIONS
WILL CONTINUE THROUGH THE AFTERNOON WITH GUSTS TO 40 MPH
POSSIBLE...HOWEVER RELATIVE HUMIDITY VALUES ARE ELEVATED AND
GENERALLY ABOVE 40 PERCENT. TEMPERATURES WILL BE COOLER THAN
NORMAL THROUGH FRIDAY WITH MINIMUM AFTERNOON HUMIDITY VALUES ABOVE
30 PERCENT. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS COLORADO
ON WEDNESDAY AND PROVIDE A GOOD CHANCE OF WETTING PRECIPITATION
IN AREAS NEAR THE COLORADO BORDER DURING THE AFTERNOON AND EVENING.

&&

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

$$

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









000
FXUS65 KCYS 010558
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1158 PM MDT TUE SEP 30 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 331 PM MDT TUE SEP 30 2014

MAIN STORY THROUGH THE DAY HAS BEEN THE WINDY CONDITIONS ACROSS
THE REGION. THE STRONGEST WINDS THIS AFTN HAVE GENERALLY BEEN
ACROSS THE NORTHERN NEBRASKA PANHANDLE AND ARLINGTON WITH GUSTS
TO 40-45 MPH. WILL KEEP THE WIND ADVISORY GOING FOR THE NORTHERN
PANHANDLE THROUGH 4PM. STARTING TO SEE GUSTS COMING DOWN IN THE PAST
HOUR UP IN DAWES AND BOX BUTTE COUNTIES. WOULD EXPECT THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTN AS THE SFC PRESSURE
GRADIENT WEAKENS IN RESPONSE TO THE SFC LOW SHIFTING QUICKLY OFF
TO THE NORTHEAST. OTHERWISE...HIGHS HAVE BEEN A BIT COOLER THAN
FCSTED TO THE WEST OF THE LARAMIE RANGE WITH WIDESPREAD CLOUD
COVER OUT THERE. WITH WEAK INSTABILITY (LI VALUES AROUND -1C)
COMBINED WITH WESTERLY MID LEVEL WINDS AND SOME OROGRAPHIC
ENHANCEMENT...SCATTERED SHOWERS WILL BE POSSIBLE ESPECIALLY IN THE
MTNS THROUGH THE EVENING. WINDS WILL DECREASE AREAWIDE AFTER
SUNSET WITH THE LOSS OF DAYTIME MIXING.

ATTENTION ON WED WILL TURN TO THE UPPER LEVEL DISTURBANCE THAT IS
PROGGED TO AMPLIFY JUST TO THE WEST OF THE CWA BY MIDDAY. WITH THE
UPPER JET ACROSS COLORADO BY 18Z AND LARGE SCALE QG ASCENT
INCREASING WILL SEE AN INCREASE IN PRECIP CHANCES FROM MID MORNING
THROUGH THE EVENING ESPECIALLY ALONG THE COLORADO BORDER. THE MODELS
CONTINUE TO INDICATE THAT LARGE SCALE ASCENT WILL BE MAXIMIZED
OVER THE NORTHERN HALF OF COLORADO. THUS...WILL KEEP HIGH END
CHANCE TO LIKELY POPS FOR AREAS ALONG THE COLORADO BORDER DURING
THE AFTN. THE SYSTEM IS QUITE PROGRESSIVE SO ONLY EXPECTING A 3-6
HR PERIOD OF PRECIP. WITH 700MB TEMPS OF -2C TO 0C WILL DEFINITELY
SEE A FEW INCHES OF SNOW IN THE SIERRA MADRE AND SNOWY RANGES AT
ELEVATIONS ABOVE 9000 FT OR SO. IF THE SYSTEM WERE SLOWER MOVING
AND THE BEST LIFT WAS LOCATED TO THE NORTH OF THE BORDER WOULD BE
MORE CONCERNED ABOUT A WINTER WEATHER ADVISORY.

IT WILL BE A COOL WED NIGHT WITH MOST LOCATIONS TO THE WEST OF THE
LARAMIE RANGE BELOW FREEZING. MUCH DRIER WEATHER IS EXPECTED ON
THURS BUT IT WILL STILL BE RATHER COOL AND BREEZY. THE MAIN
DISAGREEMENT ON THURS NIGHT BETWEEN THE GFS AND ECMWF INVOLVES HOW
FAR WEST THE SHORTWAVE MOVES AS IT DIVES SOUTHEASTWARD INTO THE
NORTHERN PLAINS. WILL SIDE WITH THE LESS AMPLIFIED AND DRIER GFS
SOLUTION FOR NOW AND KEEP SLIGHT CHANCE POPS OUT...HOWEVER THIS WILL
HAVE TO BE MONITORED BY FUTURE SHIFTS.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 331 PM MDT TUE SEP 30 2014

DRY NORTHWEST FLOW WILL DOMINATE THE PERIOD WITH THE MAIN NRN STREAM
JET STREAM HELD TO THE NORTHEAST EXTENDING FROM ALBERTA INTO THE
MID-MISSISSIPPI RIVER VALLEY. THE TRICKIEST PART OF THE FORECAST IN
TRYING TO TIME ANY BACKDOOR FRONT THAT BRUSHES THE AREA COOLING
TEMPS MAINLY OVER NORTH AND EAST ZONES. FRIDAY WILL BE A TRANSITION
DAY AS THE COOL CANADIAN AIR MASS IS FINALLY REPLACED BY A WARMER
PACIFIC AIR MASS. IT WILL STILL BE COOL BUT DRY AS H7 TEMPS CLIMB
BACK TO AROUND 5C PRODUCING HIGH TEMPS IN THE 60S. A DEVELOPING LEE
SIDE PRESSURE TROUGH FRIDAY NIGHT WILL SLIDE EAST ON SATURDAY
PRODUCING BREEZY WEST/NORTHWEST CONDITIONS WITH GUSTS OF 20 TO 30
MPH COMMON. IT WILL BE WARMER THOUGH WITH H7 TEMPS OF AROUND 7C
PRODUCING HIGHS BACK TO NR OR INTO THE LOWER 70S. A WEAK BOUNDARY
MAY SNEAK INTO NORTH AND EAST ZONES SATURDAY NIGHT...BUT SHOULD ONLY
COOL HIGHS BACK INTO THE 60S FOR SUNDAY. FLOW WILL TURN MORE
WEST/NORTHWEST FOR MONDAY AND TUESDAY WHICH WILL ELIMINATE THE
POSSIBILITY OF AN INTRUDING BOUNDARY NORTH AND EAST. IT STILL LOOKS
DRY EARLY NEXT WEEK...WITH HIGHS CLIMBING BACK INTO THE 70S FOR MOST
LOCALES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1158 PM MDT TUE SEP 30 2014

A FEW SHOWERS LINGER OVER THE CWA AT TAF ISSUANCE...BUT SHOULD NOT
IMPACT THE TERMINALS TONIGHT. WINDS WILL SHIFT TO THE NORTH-
NORTHWEST THRU THE MORNING BEHIND A WEAK FRONT DROPPING SOUTH
ACROSS THE AREA. SHOWERS AND T-STORMS WILL REDEVELOP IN THE
AFTERNOON AND EVENING AS ANOTHER UPPER LEVEL DISTURBANCE MOVES
OVER THE ROCKIES...ESPECIALLY FOR AREAS NEAR THE COLORADO BORDER
WITH THE STRONGEST UPSLOPE FLOW IN PLACE. LOOKING AT MAINLY MVFR
CONDITIONS WITH THIS ACTIVITY.

&&

.FIRE WEATHER...
ISSUED AT 331 PM MDT TUE SEP 30 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH THURSDAY. WINDY CONDITIONS
WILL CONTINUE THROUGH THE AFTERNOON WITH GUSTS TO 40 MPH
POSSIBLE...HOWEVER RELATIVE HUMIDITY VALUES ARE ELEVATED AND
GENERALLY ABOVE 40 PERCENT. TEMPERATURES WILL BE COOLER THAN
NORMAL THROUGH FRIDAY WITH MINIMUM AFTERNOON HUMIDITY VALUES ABOVE
30 PERCENT. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS COLORADO
ON WEDNESDAY AND PROVIDE A GOOD CHANCE OF WETTING PRECIPITATION
IN AREAS NEAR THE COLORADO BORDER DURING THE AFTERNOON AND EVENING.

&&

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

$$

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








000
FXUS65 KRIW 010538
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1138 PM MDT TUE SEP 30 2014

.SHORT TERM...TONIGHT AND WEDNESDAY

PART ONE OF OUR TWO PART STORM SYSTEM IS BRINGING WIDESPREAD RAIN
SHOWERS TO THE LOWER ELEVATIONS OF THE WEST WITH SNOW ABOVE 9K OR
SO. OUR SYSTEM FROM THE PAST COUPLE DAYS IS WRAPPING UP OVER WRN SD
WITH THE OUTER SHIELD WRAPPING SOME CLOUDS BACK INTO NRN AND ERN
JOHNSON COUNTY. WEAK INSTABILITY DEVELOPING OVER ERN IDAHO AND IN
SRN WYO WITH A FEW LIGHTNING STRIKES TO OUR WEST EARLY THIS
AFTERNOON. PART TWO OF OUR STORM HAS THE COLDER AIR WITH -25C COLD
POCKET AT H5. NO SIGNIFICANT CHANGE TO THIS SYSTEM YESTERDAY EXCEPT
FOR THE FACT THAT IT LOOKS LIKE IT WILL BE ABOUT 1 TO 1.5C COLDER
AT H7. INSTEAD OF SNOW LEVELS NEAR 6K FEET IN THE CODY FOOTHILLS
STARTING TO LOOK LIKE THEY WILL LOWER TO AROUND 5K BY TOMORROW
MORNING. UPPER LOW TRACKS INTO ERN IDAHO OVERNIGHT AND THEN IS
STILL FORECAST TO WEAKEN AND BECOME MORE DISORGANIZED DURING THE
DAY WEDNESDAY AS IT TRACKS SE ACROSS OUR AREA. MODERATE QG FORCING
IS STILL EXPECTED TO MOVE INTO THE WEST HALF TONIGHT AND SPREAD SE
DURING THE DAY. THE LOW LEVEL UPSLOPE AND UPPER LEVEL SUPPORT
SHOULD PRODUCE WIDESPREAD PCPN IN THE WEST...MOUNTAINS AND CODY
FOOTHILLS WITH LESSER CHANCES FURTHER SOUTH UNTIL ROUND TWO
ARRIVES DURING THE DAY WEDNESDAY. WITH THE NAM...GFS AND WRF ALL
SHOWING H7 TEMPERATURES DROPPING TO AROUND -5 TO -5.5C AROUND CODY
BY 12Z-15Z WEDNESDAY WITH STEADY PCPN...HAVE OPTED TO CHANGE THE
RAIN TO SNOW ABOVE 5K IN THE CODY FOOTHILLS BY TOMORROW MORNING
WITH SOME LIGHT ACCUMULATION. LOOKS LIKE THE ABSAROKAS ABOVE 9K
WILL GET 3 TO 6 INCHES WITH 1 TO 3 INCHES IN THE FOOTHILLS AND A
SKIFF TO 2 INCHES DOWN TO 5K. AS THIS SYSTEM MOVES FURTHER SOUTH
DURING THE DAY WEDNESDAY...IT WILL BE WARMER AT THE SURFACE IN THE
CENTRAL AREAS BUT THE COLD CORE ALOFT MAY END UP AIDING IN SOME
CONVECTIVE SHOWERS WHICH WITH TEMPERATURES ONLY IN THE 40S TO
AROUND 50 MAY END UP BEING SNOW SHOWERS AT TIMES. OTHERWISE...A
CHILLY...UNSETTLED START TO OCTOBER FOR MOST OF THE AREA WITH SOME
EMBEDDED THUNDER POSSIBLE JUST ABOUT ANYWHERE TOMORROW.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

LINGERING PRECIPITATION POSSIBLE THROUGH WEDNESDAY
NIGHT...ASSOCIATED WITH THE PASSING WAVE OF LOW PRESSURE. SHOWER
ACTIVITY IS EXPECTED TO TAPER OFF OVERNIGHT...WITH BUILDING
NORTHWEST FLOW. MODELS INDICATE AN INCREASED PRESSURE
GRADIENT...ESPECIALLY OVER CENTRAL AND NORTHEASTERN WYOMING. THIS
WILL RESULT IN THE POTENTIAL FOR GUSTY NORTHWEST WIND OVER THE AREA
ON THURSDAY AND THURSDAY NIGHT...ESPECIALLY OVER CENTRAL AND EASTERN
WYOMING.

BUILDING HIGH PRESSURE TAKES OVER THE FORECAST AREA LATE
THURSDAY...WITH GENERALLY DRY CONDITIONS EXPECTED THROUGH THE
REMAINDER OF THE FORECAST PERIOD. TEMPERATURES WILL BE
SEASONABLE...WITH HIGH TEMPERATURES IN THE MID TO UPPER 60S. MODELS
LINE UP WELL DURING THE MEDIUM AND EXTENDED RANGES CONCERNING THE
HIGH PRESSURE AND DRY CONDITIONS.

&&

.AVIATION.../06Z ISSUANCE/

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

A LARGE AREA OF LOW CEILINGS AND SCATTERED TO LOCALLY WIDESPREAD
PRECIPITATION IS EXPECTED TO CONTINUE/DEVELOP ACROSS NORTHERN
WYOMING /KBYG...KCOD...KWRL/ IN WAKE OF A COLD FRONT TONIGHT. THIS
WILL RESULT IN WIDESPREAD MVFR CEILINGS...AS WELL AS IFR REDUCTIONS
MAINLY DUE TO LOW VSBY IN PRECIP. ENOUGH COLD AIR IS EXPECTED THAT A
SNOW COULD OCCUR DOWN TO AROUND 5500 FT WEDNESDAY MORNING. FARTHER
SOUTH ACROSS CENTRAL WYOMING /KCPR...KLND...KRIW/ THERE IS LESS
CERTAINTY OF EXTENT/TIMING OF THE STRATUS DEVELOPING THIS MORNING
AFTER FRONTAL PASSAGE. EITHER WAY...THE BULK OF THE PRECIPITATION
SHOULD BE NORTH OF THOSE TERMINALS THIS MORNING. SCATTERED SHOWERS
AND POSSIBLY AN ISOLATED THUNDERSTORM WILL OCCUR IN THE AFTERNOON
WITH PERSISTENT LOW CEILINGS IN THE 020-040 KFT AGL. THE TROUGH
EXITS THE AREA THIS EVENING WITH IMPROVING CONDITIONS...BUT A MOIST
NORTHWEST FLOW COULD RESULT IN SHOWER ACTIVITY FORMING OVER THE
MOUNTAINS AND PUSHING SOUTHEAST INTO THE LOWER ELEVATIONS THROUGH
ABOUT 06Z THURSDAY. MOUNTAINS WILL BE OBSCURED THROUGH MUCH OF THE
DAY...WITH IMPROVING CONDITIONS LATE IN THE DAY INTO THE OVERNIGHT.

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

SHOWER ACTIVITY WILL BE MOST CONCENTRATED ACROSS THE FAR WEST FOR
THE REMAINDER OF TONIGHT INTO WEDNESDAY MORNING IMPACTING KJAC.
MVFR AND POSSIBLY IFR CONDITIONS WILL BE POSSIBLE IN SNOW AT KJAC
THIS MORNING. THIS SHOWER ACTIVITY IS THEN EXPECTED TO OVERSPREAD
THE REST OF THE WEST/SOUTHWEST WYOMING BETWEEN 16Z AND 20Z...AS THE
MAIN TROUGH BEGINS TO PUSH THROUGH. THIS COULD RESULT IN PERIODS OF
MVFR CONDITIONS...BUT NOT OF CONFIDENCE TO PREVAIL MVFR CONDITIONS
AT ANY TERMINAL. RAPIDLY IMPROVING CONDITIONS ARE EXPECTED BETWEEN
22Z AND 02Z...WITH SKIES TRYING TO CLEAR OUT.  SOME WARM AIR
ADVECTION STRATOCU DECK IS THEN EXPECTED TO DEVELOP OVER PORTIONS OF
FAR WEST WYOMING AFTER 06Z THURSDAY.

&&

.FIRE WEATHER...
WIDESPREAD SHOWERS WILL CONTINUE ACROSS WEST INTO THE EARLY EVENING
AND THROUGH THE NIGHT IN THE NORTHWEST WITH LOWERING SNOW LEVELS.
ISOLATED THUNDERSTORMS ARE POSSIBLE IN THE WEST THE REMAINDER OF THE
AFTERNOON AND MAINLY IN THE NORTHWEST OVERNIGHT. A NEW STORM SYSTEM
IS FAST ON THE HEELS OF OUR CURRENT ONE AND WILL BRING LOWERING SNOW
LEVELS TO NOT ONLY THE FAR WEST BUT ALSO CENTRAL WYOMING LATER
TONIGHT INTO WEDNESDAY MORNING DOWN TO BETWEEN 5 AND 6K FEET. THE
BEST CHANCE FOR WETTING RAINS (OR SNOW) WILL BE IN THE CODY
FOOTHILLS AND OF COURSE AROUND ANY OF THE MOUNTAINS TONIGHT INTO
WEDNESDAY. A CHANCE OF SHOWERS WILL CONTINUE FURTHER SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE INTO THE EARLY EVENING AND AGAIN ON
WEDNESDAY.

&&

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

&&

$$

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









000
FXUS65 KRIW 010538
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1138 PM MDT TUE SEP 30 2014

.SHORT TERM...TONIGHT AND WEDNESDAY

PART ONE OF OUR TWO PART STORM SYSTEM IS BRINGING WIDESPREAD RAIN
SHOWERS TO THE LOWER ELEVATIONS OF THE WEST WITH SNOW ABOVE 9K OR
SO. OUR SYSTEM FROM THE PAST COUPLE DAYS IS WRAPPING UP OVER WRN SD
WITH THE OUTER SHIELD WRAPPING SOME CLOUDS BACK INTO NRN AND ERN
JOHNSON COUNTY. WEAK INSTABILITY DEVELOPING OVER ERN IDAHO AND IN
SRN WYO WITH A FEW LIGHTNING STRIKES TO OUR WEST EARLY THIS
AFTERNOON. PART TWO OF OUR STORM HAS THE COLDER AIR WITH -25C COLD
POCKET AT H5. NO SIGNIFICANT CHANGE TO THIS SYSTEM YESTERDAY EXCEPT
FOR THE FACT THAT IT LOOKS LIKE IT WILL BE ABOUT 1 TO 1.5C COLDER
AT H7. INSTEAD OF SNOW LEVELS NEAR 6K FEET IN THE CODY FOOTHILLS
STARTING TO LOOK LIKE THEY WILL LOWER TO AROUND 5K BY TOMORROW
MORNING. UPPER LOW TRACKS INTO ERN IDAHO OVERNIGHT AND THEN IS
STILL FORECAST TO WEAKEN AND BECOME MORE DISORGANIZED DURING THE
DAY WEDNESDAY AS IT TRACKS SE ACROSS OUR AREA. MODERATE QG FORCING
IS STILL EXPECTED TO MOVE INTO THE WEST HALF TONIGHT AND SPREAD SE
DURING THE DAY. THE LOW LEVEL UPSLOPE AND UPPER LEVEL SUPPORT
SHOULD PRODUCE WIDESPREAD PCPN IN THE WEST...MOUNTAINS AND CODY
FOOTHILLS WITH LESSER CHANCES FURTHER SOUTH UNTIL ROUND TWO
ARRIVES DURING THE DAY WEDNESDAY. WITH THE NAM...GFS AND WRF ALL
SHOWING H7 TEMPERATURES DROPPING TO AROUND -5 TO -5.5C AROUND CODY
BY 12Z-15Z WEDNESDAY WITH STEADY PCPN...HAVE OPTED TO CHANGE THE
RAIN TO SNOW ABOVE 5K IN THE CODY FOOTHILLS BY TOMORROW MORNING
WITH SOME LIGHT ACCUMULATION. LOOKS LIKE THE ABSAROKAS ABOVE 9K
WILL GET 3 TO 6 INCHES WITH 1 TO 3 INCHES IN THE FOOTHILLS AND A
SKIFF TO 2 INCHES DOWN TO 5K. AS THIS SYSTEM MOVES FURTHER SOUTH
DURING THE DAY WEDNESDAY...IT WILL BE WARMER AT THE SURFACE IN THE
CENTRAL AREAS BUT THE COLD CORE ALOFT MAY END UP AIDING IN SOME
CONVECTIVE SHOWERS WHICH WITH TEMPERATURES ONLY IN THE 40S TO
AROUND 50 MAY END UP BEING SNOW SHOWERS AT TIMES. OTHERWISE...A
CHILLY...UNSETTLED START TO OCTOBER FOR MOST OF THE AREA WITH SOME
EMBEDDED THUNDER POSSIBLE JUST ABOUT ANYWHERE TOMORROW.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

LINGERING PRECIPITATION POSSIBLE THROUGH WEDNESDAY
NIGHT...ASSOCIATED WITH THE PASSING WAVE OF LOW PRESSURE. SHOWER
ACTIVITY IS EXPECTED TO TAPER OFF OVERNIGHT...WITH BUILDING
NORTHWEST FLOW. MODELS INDICATE AN INCREASED PRESSURE
GRADIENT...ESPECIALLY OVER CENTRAL AND NORTHEASTERN WYOMING. THIS
WILL RESULT IN THE POTENTIAL FOR GUSTY NORTHWEST WIND OVER THE AREA
ON THURSDAY AND THURSDAY NIGHT...ESPECIALLY OVER CENTRAL AND EASTERN
WYOMING.

BUILDING HIGH PRESSURE TAKES OVER THE FORECAST AREA LATE
THURSDAY...WITH GENERALLY DRY CONDITIONS EXPECTED THROUGH THE
REMAINDER OF THE FORECAST PERIOD. TEMPERATURES WILL BE
SEASONABLE...WITH HIGH TEMPERATURES IN THE MID TO UPPER 60S. MODELS
LINE UP WELL DURING THE MEDIUM AND EXTENDED RANGES CONCERNING THE
HIGH PRESSURE AND DRY CONDITIONS.

&&

.AVIATION.../06Z ISSUANCE/

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

A LARGE AREA OF LOW CEILINGS AND SCATTERED TO LOCALLY WIDESPREAD
PRECIPITATION IS EXPECTED TO CONTINUE/DEVELOP ACROSS NORTHERN
WYOMING /KBYG...KCOD...KWRL/ IN WAKE OF A COLD FRONT TONIGHT. THIS
WILL RESULT IN WIDESPREAD MVFR CEILINGS...AS WELL AS IFR REDUCTIONS
MAINLY DUE TO LOW VSBY IN PRECIP. ENOUGH COLD AIR IS EXPECTED THAT A
SNOW COULD OCCUR DOWN TO AROUND 5500 FT WEDNESDAY MORNING. FARTHER
SOUTH ACROSS CENTRAL WYOMING /KCPR...KLND...KRIW/ THERE IS LESS
CERTAINTY OF EXTENT/TIMING OF THE STRATUS DEVELOPING THIS MORNING
AFTER FRONTAL PASSAGE. EITHER WAY...THE BULK OF THE PRECIPITATION
SHOULD BE NORTH OF THOSE TERMINALS THIS MORNING. SCATTERED SHOWERS
AND POSSIBLY AN ISOLATED THUNDERSTORM WILL OCCUR IN THE AFTERNOON
WITH PERSISTENT LOW CEILINGS IN THE 020-040 KFT AGL. THE TROUGH
EXITS THE AREA THIS EVENING WITH IMPROVING CONDITIONS...BUT A MOIST
NORTHWEST FLOW COULD RESULT IN SHOWER ACTIVITY FORMING OVER THE
MOUNTAINS AND PUSHING SOUTHEAST INTO THE LOWER ELEVATIONS THROUGH
ABOUT 06Z THURSDAY. MOUNTAINS WILL BE OBSCURED THROUGH MUCH OF THE
DAY...WITH IMPROVING CONDITIONS LATE IN THE DAY INTO THE OVERNIGHT.

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

SHOWER ACTIVITY WILL BE MOST CONCENTRATED ACROSS THE FAR WEST FOR
THE REMAINDER OF TONIGHT INTO WEDNESDAY MORNING IMPACTING KJAC.
MVFR AND POSSIBLY IFR CONDITIONS WILL BE POSSIBLE IN SNOW AT KJAC
THIS MORNING. THIS SHOWER ACTIVITY IS THEN EXPECTED TO OVERSPREAD
THE REST OF THE WEST/SOUTHWEST WYOMING BETWEEN 16Z AND 20Z...AS THE
MAIN TROUGH BEGINS TO PUSH THROUGH. THIS COULD RESULT IN PERIODS OF
MVFR CONDITIONS...BUT NOT OF CONFIDENCE TO PREVAIL MVFR CONDITIONS
AT ANY TERMINAL. RAPIDLY IMPROVING CONDITIONS ARE EXPECTED BETWEEN
22Z AND 02Z...WITH SKIES TRYING TO CLEAR OUT.  SOME WARM AIR
ADVECTION STRATOCU DECK IS THEN EXPECTED TO DEVELOP OVER PORTIONS OF
FAR WEST WYOMING AFTER 06Z THURSDAY.

&&

.FIRE WEATHER...
WIDESPREAD SHOWERS WILL CONTINUE ACROSS WEST INTO THE EARLY EVENING
AND THROUGH THE NIGHT IN THE NORTHWEST WITH LOWERING SNOW LEVELS.
ISOLATED THUNDERSTORMS ARE POSSIBLE IN THE WEST THE REMAINDER OF THE
AFTERNOON AND MAINLY IN THE NORTHWEST OVERNIGHT. A NEW STORM SYSTEM
IS FAST ON THE HEELS OF OUR CURRENT ONE AND WILL BRING LOWERING SNOW
LEVELS TO NOT ONLY THE FAR WEST BUT ALSO CENTRAL WYOMING LATER
TONIGHT INTO WEDNESDAY MORNING DOWN TO BETWEEN 5 AND 6K FEET. THE
BEST CHANCE FOR WETTING RAINS (OR SNOW) WILL BE IN THE CODY
FOOTHILLS AND OF COURSE AROUND ANY OF THE MOUNTAINS TONIGHT INTO
WEDNESDAY. A CHANCE OF SHOWERS WILL CONTINUE FURTHER SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE INTO THE EARLY EVENING AND AGAIN ON
WEDNESDAY.

&&

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

&&

$$

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










000
FXUS63 KUNR 010516
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1116 PM MDT TUE SEP 30 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1115 PM MDT TUE SEP 30 2014

MVFR CIGS WILL PERSIST ACROSS FAR NORTHWEST SOUTH DAKOTA THROUGH
THE NIGHT. ELSEWHERE...A FEW SHOWERS EXPECTED ACROSS NORTHEAST
WYMOING INTO WESTERN SOUTH DAKOTA TONIGHT INTO WEDNESDAY
AFTERNOON. LCL MVFR CIGS/VSBY POSSIBLE WITH THE SHOWERS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...55
AVIATION...77







000
FXUS63 KUNR 010516
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1116 PM MDT TUE SEP 30 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1115 PM MDT TUE SEP 30 2014

MVFR CIGS WILL PERSIST ACROSS FAR NORTHWEST SOUTH DAKOTA THROUGH
THE NIGHT. ELSEWHERE...A FEW SHOWERS EXPECTED ACROSS NORTHEAST
WYMOING INTO WESTERN SOUTH DAKOTA TONIGHT INTO WEDNESDAY
AFTERNOON. LCL MVFR CIGS/VSBY POSSIBLE WITH THE SHOWERS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...55
AVIATION...77







000
FXUS63 KUNR 010516
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1116 PM MDT TUE SEP 30 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1115 PM MDT TUE SEP 30 2014

MVFR CIGS WILL PERSIST ACROSS FAR NORTHWEST SOUTH DAKOTA THROUGH
THE NIGHT. ELSEWHERE...A FEW SHOWERS EXPECTED ACROSS NORTHEAST
WYMOING INTO WESTERN SOUTH DAKOTA TONIGHT INTO WEDNESDAY
AFTERNOON. LCL MVFR CIGS/VSBY POSSIBLE WITH THE SHOWERS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...55
AVIATION...77







000
FXUS63 KUNR 010516
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1116 PM MDT TUE SEP 30 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1115 PM MDT TUE SEP 30 2014

MVFR CIGS WILL PERSIST ACROSS FAR NORTHWEST SOUTH DAKOTA THROUGH
THE NIGHT. ELSEWHERE...A FEW SHOWERS EXPECTED ACROSS NORTHEAST
WYMOING INTO WESTERN SOUTH DAKOTA TONIGHT INTO WEDNESDAY
AFTERNOON. LCL MVFR CIGS/VSBY POSSIBLE WITH THE SHOWERS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...55
AVIATION...77







000
FXUS63 KUNR 010234
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
834 PM MDT TUE SEP 30 2014

.UPDATE...
ISSUED AT 831 PM MDT TUE SEP 30 2014

MAIN UPPER LOW LIFTING NORTH INTO CANADA...WHILE SECONDARY
SHORTWAVE CROSSING WYOMING. THIS WILL BRING A FEW SHOWERS
OVERNIGHT INTO WEDNESDAY.

&&

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON
ISSUED AT 239 PM MDT TUE SEP 30 2014

MVFR CIGS WILL PERSIST ACROSS FAR NORTHWEST SOUTH DAKOTA THROUGH
THE NIGHT. ELSEWHERE...A FEW SHOWERS EXPECTED ACROSS NORTHEAST
WYMOING INTO WESTERN SOUTH DAKOTA TONIGHT INTO WEDNESDAY
AFTERNOON. LCL MVFR CIGS/VSBY POSSIBLE WITH THE SHOWERS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...77
SHORT TERM...10
LONG TERM...55
AVIATION...77






000
FXUS63 KUNR 010234
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
834 PM MDT TUE SEP 30 2014

.UPDATE...
ISSUED AT 831 PM MDT TUE SEP 30 2014

MAIN UPPER LOW LIFTING NORTH INTO CANADA...WHILE SECONDARY
SHORTWAVE CROSSING WYOMING. THIS WILL BRING A FEW SHOWERS
OVERNIGHT INTO WEDNESDAY.

&&

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON
ISSUED AT 239 PM MDT TUE SEP 30 2014

MVFR CIGS WILL PERSIST ACROSS FAR NORTHWEST SOUTH DAKOTA THROUGH
THE NIGHT. ELSEWHERE...A FEW SHOWERS EXPECTED ACROSS NORTHEAST
WYMOING INTO WESTERN SOUTH DAKOTA TONIGHT INTO WEDNESDAY
AFTERNOON. LCL MVFR CIGS/VSBY POSSIBLE WITH THE SHOWERS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$

UPDATE...77
SHORT TERM...10
LONG TERM...55
AVIATION...77





000
FXUS65 KCYS 302351
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
551 PM MDT TUE SEP 30 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 331 PM MDT TUE SEP 30 2014

MAIN STORY THROUGH THE DAY HAS BEEN THE WINDY CONDITIONS ACROSS
THE REGION. THE STRONGEST WINDS THIS AFTN HAVE GENERALLY BEEN
ACROSS THE NORTHERN NEBRASKA PANHANDLE AND ARLINGTON WITH GUSTS
TO 40-45 MPH. WILL KEEP THE WIND ADVISORY GOING FOR THE NORTHERN
PANHANDLE THROUGH 4PM. STARTING TO SEE GUSTS COMING DOWN IN THE PAST
HOUR UP IN DAWES AND BOX BUTTE COUNTIES. WOULD EXPECT THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTN AS THE SFC PRESSURE
GRADIENT WEAKENS IN RESPONSE TO THE SFC LOW SHIFTING QUICKLY OFF
TO THE NORTHEAST. OTHERWISE...HIGHS HAVE BEEN A BIT COOLER THAN
FCSTED TO THE WEST OF THE LARAMIE RANGE WITH WIDESPREAD CLOUD
COVER OUT THERE. WITH WEAK INSTABILITY (LI VALUES AROUND -1C)
COMBINED WITH WESTERLY MID LEVEL WINDS AND SOME OROGRAPHIC
ENHANCEMENT...SCATTERED SHOWERS WILL BE POSSIBLE ESPECIALLY IN THE
MTNS THROUGH THE EVENING. WINDS WILL DECREASE AREAWIDE AFTER
SUNSET WITH THE LOSS OF DAYTIME MIXING.

ATTENTION ON WED WILL TURN TO THE UPPER LEVEL DISTURBANCE THAT IS
PROGGED TO AMPLIFY JUST TO THE WEST OF THE CWA BY MIDDAY. WITH THE
UPPER JET ACROSS COLORADO BY 18Z AND LARGE SCALE QG ASCENT
INCREASING WILL SEE AN INCREASE IN PRECIP CHANCES FROM MID MORNING
THROUGH THE EVENING ESPECIALLY ALONG THE COLORADO BORDER. THE MODELS
CONTINUE TO INDICATE THAT LARGE SCALE ASCENT WILL BE MAXIMIZED
OVER THE NORTHERN HALF OF COLORADO. THUS...WILL KEEP HIGH END
CHANCE TO LIKELY POPS FOR AREAS ALONG THE COLORADO BORDER DURING
THE AFTN. THE SYSTEM IS QUITE PROGRESSIVE SO ONLY EXPECTING A 3-6
HR PERIOD OF PRECIP. WITH 700MB TEMPS OF -2C TO 0C WILL DEFINITELY
SEE A FEW INCHES OF SNOW IN THE SIERRA MADRE AND SNOWY RANGES AT
ELEVATIONS ABOVE 9000 FT OR SO. IF THE SYSTEM WERE SLOWER MOVING
AND THE BEST LIFT WAS LOCATED TO THE NORTH OF THE BORDER WOULD BE
MORE CONCERNED ABOUT A WINTER WEATHER ADVISORY.

IT WILL BE A COOL WED NIGHT WITH MOST LOCATIONS TO THE WEST OF THE
LARAMIE RANGE BELOW FREEZING. MUCH DRIER WEATHER IS EXPECTED ON
THURS BUT IT WILL STILL BE RATHER COOL AND BREEZY. THE MAIN
DISAGREEMENT ON THURS NIGHT BETWEEN THE GFS AND ECMWF INVOLVES HOW
FAR WEST THE SHORTWAVE MOVES AS IT DIVES SOUTHEASTWARD INTO THE
NORTHERN PLAINS. WILL SIDE WITH THE LESS AMPLIFIED AND DRIER GFS
SOLUTION FOR NOW AND KEEP SLIGHT CHANCE POPS OUT...HOWEVER THIS WILL
HAVE TO BE MONITORED BY FUTURE SHIFTS.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 331 PM MDT TUE SEP 30 2014

DRY NORTHWEST FLOW WILL DOMINATE THE PERIOD WITH THE MAIN NRN STREAM
JET STREAM HELD TO THE NORTHEAST EXTENDING FROM ALBERTA INTO THE
MID-MISSISSIPPI RIVER VALLEY. THE TRICKIEST PART OF THE FORECAST IN
TRYING TO TIME ANY BACKDOOR FRONT THAT BRUSHES THE AREA COOLING
TEMPS MAINLY OVER NORTH AND EAST ZONES. FRIDAY WILL BE A TRANSITION
DAY AS THE COOL CANADIAN AIR MASS IS FINALLY REPLACED BY A WARMER
PACIFIC AIR MASS. IT WILL STILL BE COOL BUT DRY AS H7 TEMPS CLIMB
BACK TO AROUND 5C PRODUCING HIGH TEMPS IN THE 60S. A DEVELOPING LEE
SIDE PRESSURE TROUGH FRIDAY NIGHT WILL SLIDE EAST ON SATURDAY
PRODUCING BREEZY WEST/NORTHWEST CONDITIONS WITH GUSTS OF 20 TO 30
MPH COMMON. IT WILL BE WARMER THOUGH WITH H7 TEMPS OF AROUND 7C
PRODUCING HIGHS BACK TO NR OR INTO THE LOWER 70S. A WEAK BOUNDARY
MAY SNEAK INTO NORTH AND EAST ZONES SATURDAY NIGHT...BUT SHOULD ONLY
COOL HIGHS BACK INTO THE 60S FOR SUNDAY. FLOW WILL TURN MORE
WEST/NORTHWEST FOR MONDAY AND TUESDAY WHICH WILL ELIMINATE THE
POSSIBILITY OF AN INTRUDING BOUNDARY NORTH AND EAST. IT STILL LOOKS
DRY EARLY NEXT WEEK...WITH HIGHS CLIMBING BACK INTO THE 70S FOR MOST
LOCALES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 546 PM MDT TUE SEP 30 2014

VFR CONDITIONS WILL PREVAIL TONIGHT AND MUCH OF WEDNESDAY. GUSTY
WEST WINDS WILL DIMINISH EARLY THIS EVENING...THEN GRADUALLY VEER
TO NORTHWEST LATER TONIGHT AND WEDNESDAY MORNING. WIDELY SCATTERED
LIGHT SHOWERS WILL BE AROUND UNTIL 03Z AT RAWLINS...SARATOGA AND
LARAMIE. CEILINGS WILL LOWER TO MVFR WEST OF THE LARAMIE RANGE
WEDNESDAY AFTERNOON WITH SCATTERED SHOWERS AND A FEW TSTORMS
DEVELOPING.

&&

.FIRE WEATHER...
ISSUED AT 331 PM MDT TUE SEP 30 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH THURSDAY. WINDY CONDITIONS
WILL CONTINUE THROUGH THE AFTERNOON WITH GUSTS TO 40 MPH
POSSIBLE...HOWEVER RELATIVE HUMIDITY VALUES ARE ELEVATED AND
GENERALLY ABOVE 40 PERCENT. TEMPERATURES WILL BE COOLER THAN
NORMAL THROUGH FRIDAY WITH MINIMUM AFTERNOON HUMIDITY VALUES ABOVE
30 PERCENT. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS COLORADO
ON WEDNESDAY AND PROVIDE A GOOD CHANCE OF WETTING PRECIPITATION
IN AREAS NEAR THE COLORADO BORDER DURING THE AFTERNOON AND EVENING.

&&

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

$$

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







000
FXUS65 KCYS 302351
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
551 PM MDT TUE SEP 30 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 331 PM MDT TUE SEP 30 2014

MAIN STORY THROUGH THE DAY HAS BEEN THE WINDY CONDITIONS ACROSS
THE REGION. THE STRONGEST WINDS THIS AFTN HAVE GENERALLY BEEN
ACROSS THE NORTHERN NEBRASKA PANHANDLE AND ARLINGTON WITH GUSTS
TO 40-45 MPH. WILL KEEP THE WIND ADVISORY GOING FOR THE NORTHERN
PANHANDLE THROUGH 4PM. STARTING TO SEE GUSTS COMING DOWN IN THE PAST
HOUR UP IN DAWES AND BOX BUTTE COUNTIES. WOULD EXPECT THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTN AS THE SFC PRESSURE
GRADIENT WEAKENS IN RESPONSE TO THE SFC LOW SHIFTING QUICKLY OFF
TO THE NORTHEAST. OTHERWISE...HIGHS HAVE BEEN A BIT COOLER THAN
FCSTED TO THE WEST OF THE LARAMIE RANGE WITH WIDESPREAD CLOUD
COVER OUT THERE. WITH WEAK INSTABILITY (LI VALUES AROUND -1C)
COMBINED WITH WESTERLY MID LEVEL WINDS AND SOME OROGRAPHIC
ENHANCEMENT...SCATTERED SHOWERS WILL BE POSSIBLE ESPECIALLY IN THE
MTNS THROUGH THE EVENING. WINDS WILL DECREASE AREAWIDE AFTER
SUNSET WITH THE LOSS OF DAYTIME MIXING.

ATTENTION ON WED WILL TURN TO THE UPPER LEVEL DISTURBANCE THAT IS
PROGGED TO AMPLIFY JUST TO THE WEST OF THE CWA BY MIDDAY. WITH THE
UPPER JET ACROSS COLORADO BY 18Z AND LARGE SCALE QG ASCENT
INCREASING WILL SEE AN INCREASE IN PRECIP CHANCES FROM MID MORNING
THROUGH THE EVENING ESPECIALLY ALONG THE COLORADO BORDER. THE MODELS
CONTINUE TO INDICATE THAT LARGE SCALE ASCENT WILL BE MAXIMIZED
OVER THE NORTHERN HALF OF COLORADO. THUS...WILL KEEP HIGH END
CHANCE TO LIKELY POPS FOR AREAS ALONG THE COLORADO BORDER DURING
THE AFTN. THE SYSTEM IS QUITE PROGRESSIVE SO ONLY EXPECTING A 3-6
HR PERIOD OF PRECIP. WITH 700MB TEMPS OF -2C TO 0C WILL DEFINITELY
SEE A FEW INCHES OF SNOW IN THE SIERRA MADRE AND SNOWY RANGES AT
ELEVATIONS ABOVE 9000 FT OR SO. IF THE SYSTEM WERE SLOWER MOVING
AND THE BEST LIFT WAS LOCATED TO THE NORTH OF THE BORDER WOULD BE
MORE CONCERNED ABOUT A WINTER WEATHER ADVISORY.

IT WILL BE A COOL WED NIGHT WITH MOST LOCATIONS TO THE WEST OF THE
LARAMIE RANGE BELOW FREEZING. MUCH DRIER WEATHER IS EXPECTED ON
THURS BUT IT WILL STILL BE RATHER COOL AND BREEZY. THE MAIN
DISAGREEMENT ON THURS NIGHT BETWEEN THE GFS AND ECMWF INVOLVES HOW
FAR WEST THE SHORTWAVE MOVES AS IT DIVES SOUTHEASTWARD INTO THE
NORTHERN PLAINS. WILL SIDE WITH THE LESS AMPLIFIED AND DRIER GFS
SOLUTION FOR NOW AND KEEP SLIGHT CHANCE POPS OUT...HOWEVER THIS WILL
HAVE TO BE MONITORED BY FUTURE SHIFTS.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 331 PM MDT TUE SEP 30 2014

DRY NORTHWEST FLOW WILL DOMINATE THE PERIOD WITH THE MAIN NRN STREAM
JET STREAM HELD TO THE NORTHEAST EXTENDING FROM ALBERTA INTO THE
MID-MISSISSIPPI RIVER VALLEY. THE TRICKIEST PART OF THE FORECAST IN
TRYING TO TIME ANY BACKDOOR FRONT THAT BRUSHES THE AREA COOLING
TEMPS MAINLY OVER NORTH AND EAST ZONES. FRIDAY WILL BE A TRANSITION
DAY AS THE COOL CANADIAN AIR MASS IS FINALLY REPLACED BY A WARMER
PACIFIC AIR MASS. IT WILL STILL BE COOL BUT DRY AS H7 TEMPS CLIMB
BACK TO AROUND 5C PRODUCING HIGH TEMPS IN THE 60S. A DEVELOPING LEE
SIDE PRESSURE TROUGH FRIDAY NIGHT WILL SLIDE EAST ON SATURDAY
PRODUCING BREEZY WEST/NORTHWEST CONDITIONS WITH GUSTS OF 20 TO 30
MPH COMMON. IT WILL BE WARMER THOUGH WITH H7 TEMPS OF AROUND 7C
PRODUCING HIGHS BACK TO NR OR INTO THE LOWER 70S. A WEAK BOUNDARY
MAY SNEAK INTO NORTH AND EAST ZONES SATURDAY NIGHT...BUT SHOULD ONLY
COOL HIGHS BACK INTO THE 60S FOR SUNDAY. FLOW WILL TURN MORE
WEST/NORTHWEST FOR MONDAY AND TUESDAY WHICH WILL ELIMINATE THE
POSSIBILITY OF AN INTRUDING BOUNDARY NORTH AND EAST. IT STILL LOOKS
DRY EARLY NEXT WEEK...WITH HIGHS CLIMBING BACK INTO THE 70S FOR MOST
LOCALES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 546 PM MDT TUE SEP 30 2014

VFR CONDITIONS WILL PREVAIL TONIGHT AND MUCH OF WEDNESDAY. GUSTY
WEST WINDS WILL DIMINISH EARLY THIS EVENING...THEN GRADUALLY VEER
TO NORTHWEST LATER TONIGHT AND WEDNESDAY MORNING. WIDELY SCATTERED
LIGHT SHOWERS WILL BE AROUND UNTIL 03Z AT RAWLINS...SARATOGA AND
LARAMIE. CEILINGS WILL LOWER TO MVFR WEST OF THE LARAMIE RANGE
WEDNESDAY AFTERNOON WITH SCATTERED SHOWERS AND A FEW TSTORMS
DEVELOPING.

&&

.FIRE WEATHER...
ISSUED AT 331 PM MDT TUE SEP 30 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH THURSDAY. WINDY CONDITIONS
WILL CONTINUE THROUGH THE AFTERNOON WITH GUSTS TO 40 MPH
POSSIBLE...HOWEVER RELATIVE HUMIDITY VALUES ARE ELEVATED AND
GENERALLY ABOVE 40 PERCENT. TEMPERATURES WILL BE COOLER THAN
NORMAL THROUGH FRIDAY WITH MINIMUM AFTERNOON HUMIDITY VALUES ABOVE
30 PERCENT. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS COLORADO
ON WEDNESDAY AND PROVIDE A GOOD CHANCE OF WETTING PRECIPITATION
IN AREAS NEAR THE COLORADO BORDER DURING THE AFTERNOON AND EVENING.

&&

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

$$

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






000
FXUS65 KCYS 302131
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
331 PM MDT TUE SEP 30 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 331 PM MDT TUE SEP 30 2014

MAIN STORY THROUGH THE DAY HAS BEEN THE WINDY CONDITIONS ACROSS
THE REGION. THE STRONGEST WINDS THIS AFTN HAVE GENERALLY BEEN
ACROSS THE NORTHERN NEBRASKA PANHANDLE AND ARLINGTON WITH GUSTS
TO 40-45 MPH. WILL KEEP THE WIND ADVISORY GOING FOR THE NORTHERN
PANHANDLE THROUGH 4PM. STARTING TO SEE GUSTS COMING DOWN IN THE PAST
HOUR UP IN DAWES AND BOX BUTTE COUNTIES. WOULD EXPECT THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTN AS THE SFC PRESSURE
GRADIENT WEAKENS IN RESPONSE TO THE SFC LOW SHIFTING QUICKLY OFF
TO THE NORTHEAST. OTHERWISE...HIGHS HAVE BEEN A BIT COOLER THAN
FCSTED TO THE WEST OF THE LARAMIE RANGE WITH WIDESPREAD CLOUD
COVER OUT THERE. WITH WEAK INSTABILITY (LI VALUES AROUND -1C)
COMBINED WITH WESTERLY MIDLVL WINDS AND SOME OROGRAPHIC
ENHANCEMENT...SCATTERED SHOWERS WILL BE POSSIBLE ESPECIALLY IN THE
MTNS THROUGH THE EVENING. WINDS WILL DECREASE AREAWIDE AFTER
SUNSET WITH THE LOSS OF DAYTIME MIXING.

ATTENTION ON WED WILL TURN TO THE UPPER LEVEL DISTURBANCE THAT IS
PROGGED TO AMPLIFY JUST TO THE WEST OF THE CWA BY MIDDAY. WITH THE
UPPER JET ACROSS COLORADO BY 18Z AND LARGE SCALE QG ASCENT
INCREASING WILL SEE AN INCREASE IN PRECIP CHANCES FROM MID MORNING
THROUGH THE EVENING ESPECIALLY ALONG THE COLORADO BORDER. THE MODELS
CONTINUE TO INDICATE THAT LARGE SCALE ASCENT WILL BE MAXIMIZED
OVER THE NORTHERN HALF OF COLORADO. THUS...WILL KEEP HIGH END
CHANCE TO LIKELY POPS FOR AREAS ALONG THE COLORADO BORDER DURING
THE AFTN. THE SYSTEM IS QUITE PROGRESSIVE SO ONLY EXPECTING A 3-6
HR PERIOD OF PRECIP. WITH 700MB TEMPS OF -2C TO 0C WILL DEFINITELY
SEE A FEW INCHES OF SNOW IN THE SIERRA MADRE AND SNOWY RANGES AT
ELEVATIONS ABOVE 9000 FT OR SO. IF THE SYSTEM WERE SLOWER MOVING
AND THE BEST LIFT WAS LOCATED TO THE NORTH OF THE BORDER WOULD BE
MORE CONCERNED ABOUT A WINTER WEATHER ADVISORY.

IT WILL BE A COOL WED NIGHT WITH MOST LOCATIONS TO THE WEST OF THE
LARAMIE RANGE BELOW FREEZING. MUCH DRIER WEATHER IS EXPECTED ON
THURS BUT IT WILL STILL BE RATHER COOL AND BREEZY. THE MAIN
DISAGREEMENT ON THURS NIGHT BETWEEN THE GFS AND ECMWF INVOLVES HOW
FAR WEST THE SHORTWAVE MOVES AS IT DIVES SOUTHEASTWARD INTO THE
NORTHERN PLAINS. WILL SIDE WITH THE LESS AMPLIFIED AND DRIER GFS
SOLN FOR NOW AND KEEP SLIGHT CHANCE POPS OUT...HOWEVER THIS WILL
HAVE TO BE MONITORED BY FUTURE SHIFTS.


.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 331 PM MDT TUE SEP 30 2014

DRY NORTHWEST FLOW WILL DOMINATE THE PERIOD WITH THE MAIN NRN STREAM
JET STREAM HELD TO THE NORTHEAST EXTENDING FROM ALBERTA INTO THE
MID-MISSISSIPPI RIVER VALLEY. THE TRICKIEST PART OF THE FORECAST IN
TRYING TO TIME ANY BACKDOOR FRONT THAT BRUSHES THE AREA COOLING
TEMPS MAINLY OVER NORTH AND EAST ZONES. FRIDAY WILL BE A TRANSITION
DAY AS THE COOL CANADIAN AIR MASS IS FINALLY REPLACED BY A WARMER
PACIFIC AIR MASS. IT WILL STILL BE COOL BUT DRY AS H7 TEMPS CLIMB
BACK TO AROUND 5C PRODUCING HIGH TEMPS IN THE 60S. A DEVELOPING LEE
SIDE PRESSURE TROUGH FRIDAY NIGHT WILL SLIDE EAST ON SATURDAY
PRODUCING BREEZY WEST/NORTHWEST CONDITIONS WITH GUSTS OF 20 TO 30
MPH COMMON. IT WILL BE WARMER THOUGH WITH H7 TEMPS OF AROUND 7C
PRODUCING HIGHS BACK TO NR OR INTO THE LOWER 70S. A WEAK BOUNDARY
MAY SNEAK INTO NORTH AND EAST ZONES SATURDAY NIGHT...BUT SHOULD ONLY
COOL HIGHS BACK INTO THE 60S FOR SUNDAY. FLOW WILL TURN MORE
WEST/NORTHWEST FOR MONDAY AND TUESDAY WHICH WILL ELIMINATE THE
POSSIBILITY OF AN INTRUDING BOUNDARY NORTH AND EAST. IT STILL LOOKS
DRY EARLY NEXT WEEK...WITH HIGHS CLIMBING BACK INTO THE 70S FOR MOST
LOCALES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1209 AM MDT TUE SEP 30 2014

THE MAIN IMPACT FOR THIS PERIOD WILL BE THE BREEZY TO LOCALLY
WINDY CONDITIONS AT ALL SITES THIS AFTERNOON...ALONG WITH THE
POSSIBILITY OF WEAK SHOWERS/STORMS DEVELOPING LATER TODAY AT
KRWL...KLAR AND KCYS. WEST WINDS WILL CONTINUE TO GUST TO 30-35
KNOTS AT ALL SITES THROUGH THE REST OF THE AFTERNOON. HAVE KEPT
TAF SITES IN VFR THRU THE PERIOD...BUT MAY SEE A BRIEF DIP INTO
MVFR AT KLAR AND KCYS WITH THE AFTERNOON SHOWERS. ANY CONVECTION
WILL DISSIPATE THIS EVENING AND SO WILL THE WINDS. MORE CHANCES
FOR PRECIPITATION WILL RETURN TO AREA AIRFIELDS JUST BEYOND THIS
TAF CYCLE...ON WEDNESDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 331 PM MDT TUE SEP 30 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH THURSDAY. WINDY CONDITIONS
WILL CONTINUE THROUGH THE AFTERNOON WITH GUSTS TO 40 MPH
POSSIBLE...HOWEVER RELATIVE HUMIDITY VALUES ARE ELEVATED AND
GENERALLY ABOVE 40 PERCENT. TEMPERATURES WILL BE COOLER THAN
NORMAL THROUGH FRIDAY WITH MINIMUM AFTERNOON HUMIDITY VALUES ABOVE
30 PERCENT. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS COLORADO
ON WEDNESDAY AND PROVIDE A GOOD CHANCE OF WETTING PRECIPITATION
IN AREAS NEAR THE COLORADO BORDER DURING THE AFTERNOON AND EVENING.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR NEZ002-003-095-
     096.

&&

$$

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







000
FXUS65 KCYS 302131
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
331 PM MDT TUE SEP 30 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 331 PM MDT TUE SEP 30 2014

MAIN STORY THROUGH THE DAY HAS BEEN THE WINDY CONDITIONS ACROSS
THE REGION. THE STRONGEST WINDS THIS AFTN HAVE GENERALLY BEEN
ACROSS THE NORTHERN NEBRASKA PANHANDLE AND ARLINGTON WITH GUSTS
TO 40-45 MPH. WILL KEEP THE WIND ADVISORY GOING FOR THE NORTHERN
PANHANDLE THROUGH 4PM. STARTING TO SEE GUSTS COMING DOWN IN THE PAST
HOUR UP IN DAWES AND BOX BUTTE COUNTIES. WOULD EXPECT THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTN AS THE SFC PRESSURE
GRADIENT WEAKENS IN RESPONSE TO THE SFC LOW SHIFTING QUICKLY OFF
TO THE NORTHEAST. OTHERWISE...HIGHS HAVE BEEN A BIT COOLER THAN
FCSTED TO THE WEST OF THE LARAMIE RANGE WITH WIDESPREAD CLOUD
COVER OUT THERE. WITH WEAK INSTABILITY (LI VALUES AROUND -1C)
COMBINED WITH WESTERLY MIDLVL WINDS AND SOME OROGRAPHIC
ENHANCEMENT...SCATTERED SHOWERS WILL BE POSSIBLE ESPECIALLY IN THE
MTNS THROUGH THE EVENING. WINDS WILL DECREASE AREAWIDE AFTER
SUNSET WITH THE LOSS OF DAYTIME MIXING.

ATTENTION ON WED WILL TURN TO THE UPPER LEVEL DISTURBANCE THAT IS
PROGGED TO AMPLIFY JUST TO THE WEST OF THE CWA BY MIDDAY. WITH THE
UPPER JET ACROSS COLORADO BY 18Z AND LARGE SCALE QG ASCENT
INCREASING WILL SEE AN INCREASE IN PRECIP CHANCES FROM MID MORNING
THROUGH THE EVENING ESPECIALLY ALONG THE COLORADO BORDER. THE MODELS
CONTINUE TO INDICATE THAT LARGE SCALE ASCENT WILL BE MAXIMIZED
OVER THE NORTHERN HALF OF COLORADO. THUS...WILL KEEP HIGH END
CHANCE TO LIKELY POPS FOR AREAS ALONG THE COLORADO BORDER DURING
THE AFTN. THE SYSTEM IS QUITE PROGRESSIVE SO ONLY EXPECTING A 3-6
HR PERIOD OF PRECIP. WITH 700MB TEMPS OF -2C TO 0C WILL DEFINITELY
SEE A FEW INCHES OF SNOW IN THE SIERRA MADRE AND SNOWY RANGES AT
ELEVATIONS ABOVE 9000 FT OR SO. IF THE SYSTEM WERE SLOWER MOVING
AND THE BEST LIFT WAS LOCATED TO THE NORTH OF THE BORDER WOULD BE
MORE CONCERNED ABOUT A WINTER WEATHER ADVISORY.

IT WILL BE A COOL WED NIGHT WITH MOST LOCATIONS TO THE WEST OF THE
LARAMIE RANGE BELOW FREEZING. MUCH DRIER WEATHER IS EXPECTED ON
THURS BUT IT WILL STILL BE RATHER COOL AND BREEZY. THE MAIN
DISAGREEMENT ON THURS NIGHT BETWEEN THE GFS AND ECMWF INVOLVES HOW
FAR WEST THE SHORTWAVE MOVES AS IT DIVES SOUTHEASTWARD INTO THE
NORTHERN PLAINS. WILL SIDE WITH THE LESS AMPLIFIED AND DRIER GFS
SOLN FOR NOW AND KEEP SLIGHT CHANCE POPS OUT...HOWEVER THIS WILL
HAVE TO BE MONITORED BY FUTURE SHIFTS.


.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 331 PM MDT TUE SEP 30 2014

DRY NORTHWEST FLOW WILL DOMINATE THE PERIOD WITH THE MAIN NRN STREAM
JET STREAM HELD TO THE NORTHEAST EXTENDING FROM ALBERTA INTO THE
MID-MISSISSIPPI RIVER VALLEY. THE TRICKIEST PART OF THE FORECAST IN
TRYING TO TIME ANY BACKDOOR FRONT THAT BRUSHES THE AREA COOLING
TEMPS MAINLY OVER NORTH AND EAST ZONES. FRIDAY WILL BE A TRANSITION
DAY AS THE COOL CANADIAN AIR MASS IS FINALLY REPLACED BY A WARMER
PACIFIC AIR MASS. IT WILL STILL BE COOL BUT DRY AS H7 TEMPS CLIMB
BACK TO AROUND 5C PRODUCING HIGH TEMPS IN THE 60S. A DEVELOPING LEE
SIDE PRESSURE TROUGH FRIDAY NIGHT WILL SLIDE EAST ON SATURDAY
PRODUCING BREEZY WEST/NORTHWEST CONDITIONS WITH GUSTS OF 20 TO 30
MPH COMMON. IT WILL BE WARMER THOUGH WITH H7 TEMPS OF AROUND 7C
PRODUCING HIGHS BACK TO NR OR INTO THE LOWER 70S. A WEAK BOUNDARY
MAY SNEAK INTO NORTH AND EAST ZONES SATURDAY NIGHT...BUT SHOULD ONLY
COOL HIGHS BACK INTO THE 60S FOR SUNDAY. FLOW WILL TURN MORE
WEST/NORTHWEST FOR MONDAY AND TUESDAY WHICH WILL ELIMINATE THE
POSSIBILITY OF AN INTRUDING BOUNDARY NORTH AND EAST. IT STILL LOOKS
DRY EARLY NEXT WEEK...WITH HIGHS CLIMBING BACK INTO THE 70S FOR MOST
LOCALES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1209 AM MDT TUE SEP 30 2014

THE MAIN IMPACT FOR THIS PERIOD WILL BE THE BREEZY TO LOCALLY
WINDY CONDITIONS AT ALL SITES THIS AFTERNOON...ALONG WITH THE
POSSIBILITY OF WEAK SHOWERS/STORMS DEVELOPING LATER TODAY AT
KRWL...KLAR AND KCYS. WEST WINDS WILL CONTINUE TO GUST TO 30-35
KNOTS AT ALL SITES THROUGH THE REST OF THE AFTERNOON. HAVE KEPT
TAF SITES IN VFR THRU THE PERIOD...BUT MAY SEE A BRIEF DIP INTO
MVFR AT KLAR AND KCYS WITH THE AFTERNOON SHOWERS. ANY CONVECTION
WILL DISSIPATE THIS EVENING AND SO WILL THE WINDS. MORE CHANCES
FOR PRECIPITATION WILL RETURN TO AREA AIRFIELDS JUST BEYOND THIS
TAF CYCLE...ON WEDNESDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 331 PM MDT TUE SEP 30 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH THURSDAY. WINDY CONDITIONS
WILL CONTINUE THROUGH THE AFTERNOON WITH GUSTS TO 40 MPH
POSSIBLE...HOWEVER RELATIVE HUMIDITY VALUES ARE ELEVATED AND
GENERALLY ABOVE 40 PERCENT. TEMPERATURES WILL BE COOLER THAN
NORMAL THROUGH FRIDAY WITH MINIMUM AFTERNOON HUMIDITY VALUES ABOVE
30 PERCENT. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS COLORADO
ON WEDNESDAY AND PROVIDE A GOOD CHANCE OF WETTING PRECIPITATION
IN AREAS NEAR THE COLORADO BORDER DURING THE AFTERNOON AND EVENING.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR NEZ002-003-095-
     096.

&&

$$

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






000
FXUS63 KUNR 302054
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
254 PM MDT TUE SEP 30 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

STORM SYSTEM OVR NCNTRL SD CONTINUES TO MOVE NEWD...W/
SHWRS REMAINING OVER NWRN SD THIS AFTN AND EVEN...THEN DIMINISHING
OVERNIGHT. MVFR/IFR CIGS WITH THE PRECIP...WHILE CIGS ARE LIFTING
OVER SWRN SD WHERE DOWNSLOPE WINDS HAVE INCREASED. GUSTY NORTHWEST
WINDS WL DIMINISH THIS EVEN AND BCM WESTERLY.

&&

.HYDROLOGY...
ISSUED AT 239 PM MDT TUE SEP 30 2014

THE LOW PRESSURE CENTER CURRENTLY LOCATED OVER NORTH CENTRAL SOUTH
DAKOTA WILL CONTINUE TO ACCELERATE OFF TOWARD THE NORTH AND THE BANDS
OF SHOWERS OVER THE FORECAST AREA WILL GRADUALLY DECREASE IN
COVERAGE AN INTENSITY THIS EVENING AS THE LOW MOVES AWAY. A FLOOD
ADVISORY REMAINS IN EFFECT FOR FALL RIVER COUNTY AND PARTS OF
CUSTER...WESTERN PENNINGTON AND FAR WESTERN SHANNON COUNTIES UNTIL
700 PM MDT THIS EVENING. THOSE ARE THE AREAS WHICH RECEIVED THE
MOST RAIN OVER THE PAST COUPLE OF DAYS. SMALL CREEKS AND STREAMS
ARE RUNNING VERY HIGH IN THOSE AREAS. DEBRIS IN THOSE STREAMS CAN
QUICKLY BLOCK CULVERTS WHICH COULD CAUSE MINOR FLOODING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR SDZ026-
     027-030>032-041>044-046-047-049-072>074.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...55
AVIATION...55
HYDROLOGY...10






000
FXUS63 KUNR 302054
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
254 PM MDT TUE SEP 30 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

STORM SYSTEM OVR NCNTRL SD CONTINUES TO MOVE NEWD...W/
SHWRS REMAINING OVER NWRN SD THIS AFTN AND EVEN...THEN DIMINISHING
OVERNIGHT. MVFR/IFR CIGS WITH THE PRECIP...WHILE CIGS ARE LIFTING
OVER SWRN SD WHERE DOWNSLOPE WINDS HAVE INCREASED. GUSTY NORTHWEST
WINDS WL DIMINISH THIS EVEN AND BCM WESTERLY.

&&

.HYDROLOGY...
ISSUED AT 239 PM MDT TUE SEP 30 2014

THE LOW PRESSURE CENTER CURRENTLY LOCATED OVER NORTH CENTRAL SOUTH
DAKOTA WILL CONTINUE TO ACCELERATE OFF TOWARD THE NORTH AND THE BANDS
OF SHOWERS OVER THE FORECAST AREA WILL GRADUALLY DECREASE IN
COVERAGE AN INTENSITY THIS EVENING AS THE LOW MOVES AWAY. A FLOOD
ADVISORY REMAINS IN EFFECT FOR FALL RIVER COUNTY AND PARTS OF
CUSTER...WESTERN PENNINGTON AND FAR WESTERN SHANNON COUNTIES UNTIL
700 PM MDT THIS EVENING. THOSE ARE THE AREAS WHICH RECEIVED THE
MOST RAIN OVER THE PAST COUPLE OF DAYS. SMALL CREEKS AND STREAMS
ARE RUNNING VERY HIGH IN THOSE AREAS. DEBRIS IN THOSE STREAMS CAN
QUICKLY BLOCK CULVERTS WHICH COULD CAUSE MINOR FLOODING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR SDZ026-
     027-030>032-041>044-046-047-049-072>074.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...55
AVIATION...55
HYDROLOGY...10







000
FXUS65 KRIW 302009
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
209 PM MDT TUE SEP 30 2014

.SHORT TERM...TONIGHT AND WEDNESDAY

PART ONE OF OUR TWO PART STORM SYSTEM IS BRINGING WIDESPREAD RAIN
SHOWERS TO THE LOWER ELEVATIONS OF THE WEST WITH SNOW ABOVE 9K OR
SO. OUR SYSTEM FROM THE PAST COUPLE DAYS IS WRAPPING UP OVER WRN SD
WITH THE OUTER SHIELD WRAPPING SOME CLOUDS BACK INTO NRN AND ERN
JOHNSON COUNTY. WEAK INSTABILITY DEVELOPING OVER ERN IDAHO AND IN
SRN WYO WITH A FEW LIGHTNING STRIKES TO OUR WEST EARLY THIS
AFTERNOON. PART TWO OF OUR STORM HAS THE COLDER AIR WITH -25C COLD
POCKET AT H5. NO SIGNIFICANT CHANGE TO THIS SYSTEM YESTERDAY EXCEPT
FOR THE FACT THAT IT LOOKS LIKE IT WILL BE ABOUT 1 TO 1.5C COLDER
AT H7. INSTEAD OF SNOW LEVELS NEAR 6K FEET IN THE CODY FOOTHILLS
STARTING TO LOOK LIKE THEY WILL LOWER TO AROUND 5K BY TOMORROW
MORNING. UPPER LOW TRACKS INTO ERN IDAHO OVERNIGHT AND THEN IS
STILL FORECAST TO WEAKEN AND BECOME MORE DISORGANIZED DURING THE
DAY WEDNESDAY AS IT TRACKS SE ACROSS OUR AREA. MODERATE QG FORCING
IS STILL EXPECTED TO MOVE INTO THE WEST HALF TONIGHT AND SPREAD SE
DURING THE DAY. THE LOW LEVEL UPSLOPE AND UPPER LEVEL SUPPORT
SHOULD PRODUCE WIDESPREAD PCPN IN THE WEST...MOUNTAINS AND CODY
FOOTHILLS WITH LESSER CHANCES FURTHER SOUTH UNTIL ROUND TWO
ARRIVES DURING THE DAY WEDNESDAY. WITH THE NAM...GFS AND WRF ALL
SHOWING H7 TEMPERATURES DROPPING TO AROUND -5 TO -5.5C AROUND CODY
BY 12Z-15Z WEDNESDAY WITH STEADY PCPN...HAVE OPTED TO CHANGE THE
RAIN TO SNOW ABOVE 5K IN THE CODY FOOTHILLS BY TOMORROW MORNING
WITH SOME LIGHT ACCUMULATION. LOOKS LIKE THE ABSAROKAS ABOVE 9K
WILL GET 3 TO 6 INCHES WITH 1 TO 3 INCHES IN THE FOOTHILLS AND A
SKIFF TO 2 INCHES DOWN TO 5K. AS THIS SYSTEM MOVES FURTHER SOUTH
DURING THE DAY WEDNESDAY...IT WILL BE WARMER AT THE SURFACE IN THE
CENTRAL AREAS BUT THE COLD CORE ALOFT MAY END UP AIDING IN SOME
CONVECTIVE SHOWERS WHICH WITH TEMPERATURES ONLY IN THE 40S TO
AROUND 50 MAY END UP BEING SNOW SHOWERS AT TIMES. OTHERWISE...A
CHILLY...UNSETTLED START TO OCTOBER FOR MOST OF THE AREA WITH SOME
EMBEDDED THUNDER POSSIBLE JUST ABOUT ANYWHERE TOMORROW.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

LINGERING PRECIPITATION POSSIBLE THROUGH WEDNESDAY
NIGHT...ASSOCIATED WITH THE PASSING WAVE OF LOW PRESSURE. SHOWER
ACTIVITY IS EXPECTED TO TAPER OFF OVERNIGHT...WITH BUILDING
NORTHWEST FLOW. MODELS INDICATE AN INCREASED PRESSURE
GRADIENT...ESPECIALLY OVER CENTRAL AND NORTHEASTERN WYOMING. THIS
WILL RESULT IN THE POTENTIAL FOR GUSTY NORTHWEST WIND OVER THE AREA
ON THURSDAY AND THURSDAY NIGHT...ESPECIALLY OVER CENTRAL AND EASTERN
WYOMING.

BUILDING HIGH PRESSURE TAKES OVER THE FORECAST AREA LATE
THURSDAY...WITH GENERALLY DRY CONDITIONS EXPECTED THROUGH THE
REMAINDER OF THE FORECAST PERIOD. TEMPERATURES WILL BE
SEASONABLE...WITH HIGH TEMPERATURES IN THE MID TO UPPER 60S. MODELS
LINE UP WELL DURING THE MEDIUM AND EXTENDED RANGES CONCERNING THE
HIGH PRESSURE AND DRY CONDITIONS.

&&

.AVIATION.../00Z ISSUANCE/
EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

A NEW WEATHER SYSTEM WILL PUSH A COLD FRONT SOUTH ACROSS THE AREA
OVERNIGHT INTO WEDNESDAY MORNING WITH LOWERING CEILINGS BEHIND THE
FRONT. WIDESPREAD SHOWERS ARE LIKELY IN AND NEAR THE MOUNTAINS
WITH WIDELY SCATTERED TO SCATTERED SHOWERS IN THE SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE. RAIN WILL LIKELY CHANGE TO SNOW IN THE
CODY FOOTHILLS BY SUNRISE. MVFR CONDITIONS WITH MOUNTAIN AND
HIGHER TERRAIN OBSCURATION WILL INCREASE BEHIND THE COLD FRONT...
ESPECIALLY AROUND KCOD BUT AREAS OF MVFR CONDITIONS WILL OCCUR
ACROSS THE SOUTH TONIGHT AND WEDNESDAY AND WILL DEVELOP BEHIND THE
COLD FRONT SLIDING SOUTH.

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

WIDESPREAD RAIN SHOWERS CAN BE EXPECTED INTO THE EARLY EVENING
ACROSS THE VALLEYS WITH OCCASIONAL MOUNTAIN SNOW AND WIDESPREAD
MOUNTAIN AND FOOTHILL OBSCURATION. LOW VFR TO OCNL MVFR WILL
PREVAIL. A NEW STORM SYSTEM WILL BRING WIDESPREAD SNOW TO THE FAR
NORTHWEST OVERNIGHT AND THEN SPREAD INTO THE SOUTHWEST DURING THE
DAY WEDNESDAY. CONSIDERABLE MOUNTAIN OBSCURATION WILL CONTINUE WITH
MVFR CONDITIONS AT TIMES AND LOCALIZED IFR DURING MODERATE TO
HEAVY SNOW SHOWERS. ISOLATED THUNDERSTORMS ARE POSSIBLE THROUGH
WEDNESDAY.

&&

.FIRE WEATHER...
WIDESPREAD SHOWERS WILL CONTINUE ACROSS WEST INTO THE EARLY EVENING
AND THROUGH THE NIGHT IN THE NORTHWEST WITH LOWERING SNOW LEVELS.
ISOLATED THUNDERSTORMS ARE POSSIBLE IN THE WEST THE REMAINDER OF THE
AFTERNOON AND MAINLY IN THE NORTHWEST OVERNIGHT. A NEW STORM SYSTEM
IS FAST ON THE HEELS OF OUR CURRENT ONE AND WILL BRING LOWERING SNOW
LEVELS TO NOT ONLY THE FAR WEST BUT ALSO CENTRAL WYOMING LATER
TONIGHT INTO WEDNESDAY MORNING DOWN TO BETWEEN 5 AND 6K FEET. THE
BEST CHANCE FOR WETTING RAINS (OR SNOW) WILL BE IN THE CODY
FOOTHILLS AND OF COURSE AROUND ANY OF THE MOUNTAINS TONIGHT INTO
WEDNESDAY. A CHANCE OF SHOWERS WILL CONTINUE FURTHER SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE INTO THE EARLY EVENING AND AGAIN ON
WEDNESDAY.

&&

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

&&

$$

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






000
FXUS65 KRIW 302009
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
209 PM MDT TUE SEP 30 2014

.SHORT TERM...TONIGHT AND WEDNESDAY

PART ONE OF OUR TWO PART STORM SYSTEM IS BRINGING WIDESPREAD RAIN
SHOWERS TO THE LOWER ELEVATIONS OF THE WEST WITH SNOW ABOVE 9K OR
SO. OUR SYSTEM FROM THE PAST COUPLE DAYS IS WRAPPING UP OVER WRN SD
WITH THE OUTER SHIELD WRAPPING SOME CLOUDS BACK INTO NRN AND ERN
JOHNSON COUNTY. WEAK INSTABILITY DEVELOPING OVER ERN IDAHO AND IN
SRN WYO WITH A FEW LIGHTNING STRIKES TO OUR WEST EARLY THIS
AFTERNOON. PART TWO OF OUR STORM HAS THE COLDER AIR WITH -25C COLD
POCKET AT H5. NO SIGNIFICANT CHANGE TO THIS SYSTEM YESTERDAY EXCEPT
FOR THE FACT THAT IT LOOKS LIKE IT WILL BE ABOUT 1 TO 1.5C COLDER
AT H7. INSTEAD OF SNOW LEVELS NEAR 6K FEET IN THE CODY FOOTHILLS
STARTING TO LOOK LIKE THEY WILL LOWER TO AROUND 5K BY TOMORROW
MORNING. UPPER LOW TRACKS INTO ERN IDAHO OVERNIGHT AND THEN IS
STILL FORECAST TO WEAKEN AND BECOME MORE DISORGANIZED DURING THE
DAY WEDNESDAY AS IT TRACKS SE ACROSS OUR AREA. MODERATE QG FORCING
IS STILL EXPECTED TO MOVE INTO THE WEST HALF TONIGHT AND SPREAD SE
DURING THE DAY. THE LOW LEVEL UPSLOPE AND UPPER LEVEL SUPPORT
SHOULD PRODUCE WIDESPREAD PCPN IN THE WEST...MOUNTAINS AND CODY
FOOTHILLS WITH LESSER CHANCES FURTHER SOUTH UNTIL ROUND TWO
ARRIVES DURING THE DAY WEDNESDAY. WITH THE NAM...GFS AND WRF ALL
SHOWING H7 TEMPERATURES DROPPING TO AROUND -5 TO -5.5C AROUND CODY
BY 12Z-15Z WEDNESDAY WITH STEADY PCPN...HAVE OPTED TO CHANGE THE
RAIN TO SNOW ABOVE 5K IN THE CODY FOOTHILLS BY TOMORROW MORNING
WITH SOME LIGHT ACCUMULATION. LOOKS LIKE THE ABSAROKAS ABOVE 9K
WILL GET 3 TO 6 INCHES WITH 1 TO 3 INCHES IN THE FOOTHILLS AND A
SKIFF TO 2 INCHES DOWN TO 5K. AS THIS SYSTEM MOVES FURTHER SOUTH
DURING THE DAY WEDNESDAY...IT WILL BE WARMER AT THE SURFACE IN THE
CENTRAL AREAS BUT THE COLD CORE ALOFT MAY END UP AIDING IN SOME
CONVECTIVE SHOWERS WHICH WITH TEMPERATURES ONLY IN THE 40S TO
AROUND 50 MAY END UP BEING SNOW SHOWERS AT TIMES. OTHERWISE...A
CHILLY...UNSETTLED START TO OCTOBER FOR MOST OF THE AREA WITH SOME
EMBEDDED THUNDER POSSIBLE JUST ABOUT ANYWHERE TOMORROW.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

LINGERING PRECIPITATION POSSIBLE THROUGH WEDNESDAY
NIGHT...ASSOCIATED WITH THE PASSING WAVE OF LOW PRESSURE. SHOWER
ACTIVITY IS EXPECTED TO TAPER OFF OVERNIGHT...WITH BUILDING
NORTHWEST FLOW. MODELS INDICATE AN INCREASED PRESSURE
GRADIENT...ESPECIALLY OVER CENTRAL AND NORTHEASTERN WYOMING. THIS
WILL RESULT IN THE POTENTIAL FOR GUSTY NORTHWEST WIND OVER THE AREA
ON THURSDAY AND THURSDAY NIGHT...ESPECIALLY OVER CENTRAL AND EASTERN
WYOMING.

BUILDING HIGH PRESSURE TAKES OVER THE FORECAST AREA LATE
THURSDAY...WITH GENERALLY DRY CONDITIONS EXPECTED THROUGH THE
REMAINDER OF THE FORECAST PERIOD. TEMPERATURES WILL BE
SEASONABLE...WITH HIGH TEMPERATURES IN THE MID TO UPPER 60S. MODELS
LINE UP WELL DURING THE MEDIUM AND EXTENDED RANGES CONCERNING THE
HIGH PRESSURE AND DRY CONDITIONS.

&&

.AVIATION.../00Z ISSUANCE/
EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

A NEW WEATHER SYSTEM WILL PUSH A COLD FRONT SOUTH ACROSS THE AREA
OVERNIGHT INTO WEDNESDAY MORNING WITH LOWERING CEILINGS BEHIND THE
FRONT. WIDESPREAD SHOWERS ARE LIKELY IN AND NEAR THE MOUNTAINS
WITH WIDELY SCATTERED TO SCATTERED SHOWERS IN THE SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE. RAIN WILL LIKELY CHANGE TO SNOW IN THE
CODY FOOTHILLS BY SUNRISE. MVFR CONDITIONS WITH MOUNTAIN AND
HIGHER TERRAIN OBSCURATION WILL INCREASE BEHIND THE COLD FRONT...
ESPECIALLY AROUND KCOD BUT AREAS OF MVFR CONDITIONS WILL OCCUR
ACROSS THE SOUTH TONIGHT AND WEDNESDAY AND WILL DEVELOP BEHIND THE
COLD FRONT SLIDING SOUTH.

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

WIDESPREAD RAIN SHOWERS CAN BE EXPECTED INTO THE EARLY EVENING
ACROSS THE VALLEYS WITH OCCASIONAL MOUNTAIN SNOW AND WIDESPREAD
MOUNTAIN AND FOOTHILL OBSCURATION. LOW VFR TO OCNL MVFR WILL
PREVAIL. A NEW STORM SYSTEM WILL BRING WIDESPREAD SNOW TO THE FAR
NORTHWEST OVERNIGHT AND THEN SPREAD INTO THE SOUTHWEST DURING THE
DAY WEDNESDAY. CONSIDERABLE MOUNTAIN OBSCURATION WILL CONTINUE WITH
MVFR CONDITIONS AT TIMES AND LOCALIZED IFR DURING MODERATE TO
HEAVY SNOW SHOWERS. ISOLATED THUNDERSTORMS ARE POSSIBLE THROUGH
WEDNESDAY.

&&

.FIRE WEATHER...
WIDESPREAD SHOWERS WILL CONTINUE ACROSS WEST INTO THE EARLY EVENING
AND THROUGH THE NIGHT IN THE NORTHWEST WITH LOWERING SNOW LEVELS.
ISOLATED THUNDERSTORMS ARE POSSIBLE IN THE WEST THE REMAINDER OF THE
AFTERNOON AND MAINLY IN THE NORTHWEST OVERNIGHT. A NEW STORM SYSTEM
IS FAST ON THE HEELS OF OUR CURRENT ONE AND WILL BRING LOWERING SNOW
LEVELS TO NOT ONLY THE FAR WEST BUT ALSO CENTRAL WYOMING LATER
TONIGHT INTO WEDNESDAY MORNING DOWN TO BETWEEN 5 AND 6K FEET. THE
BEST CHANCE FOR WETTING RAINS (OR SNOW) WILL BE IN THE CODY
FOOTHILLS AND OF COURSE AROUND ANY OF THE MOUNTAINS TONIGHT INTO
WEDNESDAY. A CHANCE OF SHOWERS WILL CONTINUE FURTHER SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE INTO THE EARLY EVENING AND AGAIN ON
WEDNESDAY.

&&

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

&&

$$

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







000
FXUS65 KRIW 301830
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1230 PM MDT TUE SEP 30 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

PREVIOUS FORECAST LOOKS TO BE ON TRACK...MOST OF THE ACTIVITY WILL
BE EAST OF THE AREA TODAY AS WE TRANSITION TO MOIST WESTERLY FLOW.
RAPID LEE CYCLOGENESIS IS ALREADY BEGINNING NEAR THE NE/WY/SD TRIPLE
POINT...WHICH WILL TRANSLATE TO A NOTICEABLE INCREASE IN WESTERLY
WINDS ACROSS THE FORECAST AREA... ESPECIALLY ACROSS THE SOUTH EARLY.
THE LOW WILL MOVE NORTH AND EAST DURING THE MORNING...SWITCHING
WINDS TO THE NORTHWEST ACROSS OUR NORTHERN HALF OF THE FORECAST
AREA...AND ENCOURAGING A COLD FRONT TO DIP SOUTH...WHICH COULD LEAD
TO GUSTS OVER 40 MPH WINDS IN NORTHERN JOHNSON COUNTY IF EVERYTHING
LINES UP RIGHT. ASIDE FROM THE WIND...OROGRAPHIC LIFT ACROSS THE
WEST...A COLD FRONT DIPPING INTO THE NORTH...AND A DEFORMATION AXIS
POKING INTO OUR EASTERN ZONES COULD KEEP SOME MORE PERSISTENT RAIN
GOING IN THESE AREAS...WITH SNOW ABOVE 8500FT IN THE WESTERN
MOUNTAINS AND YELLOWSTONE. IT WILL BE VERY WEAKLY UNSTABLE
ELSEWHERE...AND THAT COMBINED WITH DECENT RESIDUAL MOISTURE COULD
ALLOW FOR SOME ISOLATED AFTERNOON SHOWERS IN BETWEEN. IT WILL
DEFINITELY STILL BE A COOL...MOIST AND RAW DAY FOR MUCH OF THE AREA.

INTO WEDNESDAY...A REINFORCING SHOT COULD ARRIVE IN THE WESTERLY
FLOW...WITH YET ANOTHER WEATHER SYSTEM FOR WEDNESDAY KEEPING SHOWERS
IN THE FORECAST AND DIPPING SNOW LEVELS DOWN BELOW 7000FT ACROSS THE
WEST AND NORTH. THESE NEXT COUPLE OF SYSTEMS ARE NOT EXPECTED TO
AMOUNT TO MUCH PRECIPITATION BUT THEY HAVE A BETTER SHOT AT LAYING
DOWN A WETTING RAIN AND A MOUNTAIN SNOW ACROSS THE NORTH...BASICALLY
THE ONLY AREA IN OUR CWA THAT DID NOT GET MUCH OUT OF THE WEEKEND
STORM. COULD SEE A DECENT QUARTER TO HALF INCH OF PCPN IN THE NW
MOUNTAINS WITH 2 TO 4 INCHES OF SNOW ABOVE 9K...MAYBE AN INCH OR TWO
DOWN TO AS LOW AS 7-8K AND A BRIEF CHANGEOVER DOWN TO AS LOW AS 6K
IN THE CODY FOOTHILLS EARLY WEDNESDAY MORNING. OUR LAST WAVE SHOULD
EXIT WEDNESDAY EVENING LEAVING BEHIND A VERY COOL AND FROSTY NIGHT
FOR MUCH OF THE FORECAST AREA.

THE NEXT APPROACHING SHORTWAVE FOR THURSDAY LOOKS TO BE A GLANCING
BLOW WITH JUST A SLIGHT CHANCE OF RAIN IN THE FAR NRN/ERN ZONES
THURSDAY WITH GUSTY NORTH WINDS AND CLOUDS. COULD ALSO SEE SOME
GUSTY WINDS IN THE CODY FOOTHILLS WEDNESDAY NIGHT INTO THURSDAY
MORNING AHEAD OF THIS SYSTEM. ELSEWHERE...IT WILL BE MAINLY DRY AND
REMAINING COOL WITH SWIFT NORTHWEST FLOW ALOFT TRANSLATING TO A FEW
20 TO 35 MPH BREEZES DEVELOPING ACROSS THE SOUTH.

.LONG TERM...FRIDAY THROUGH TUESDAY

THE LONG RANGE MODELS ARE IN GOOD AGREEMENT THROUGH SUNDAY WITH THE
WEATHER PATTERN. ON MONDAY AND TUESDAY THE GFS AND GEM MODELS TRY TO
SAG A COLD FRONT ALONG THE MONTANA/WY BORDER WITH PRECIP GETTING
CLOSE MONDAY NIGHT AND TUESDAY ALONG THE BORDER. THE ECMWF IS
DIFFERENT EARLY NEXT WEEK AND KEEPS THE COOLER AIR IN SOUTHERN
CANADA/NORTHERN MONTANA AND DRY WEATHER ALONG THE NORTHERN WY
BORDER. FOR NOW WILL COMPROMISE AND KEEP THE FORECAST DRY AND KNOCK
A DEGREE OR TWO OFF THE HIGH TEMPS IN THE FAR NORTH MONDAY AND
TUESDAY. THERE WILL BE PERIODS OF MID AND HIGH CLOUDS MOVING THROUGH
THE AREA FRIDAY THROUGH TUESDAY WITH LIMITED AMOUNTS OF CUMULUS
CLOUDS. HIGH TEMPS WILL BE SEASONAL TO SLIGHTLY ABOVE NORMAL FRIDAY
THROUGH NEXT TUESDAY. EXPECT BREEZY AREAS IN THE AFTERNOON THROUGH
SUNSET OVER THE WEEKEND INTO EARLY NEXT WEEK. BOTTOM LINE...GOOD
FALL WEATHER FOR SEEING FALL FOLIAGE OR OTHER OUTDOOR ACTIVITIES.

&

.AVIATION.../18Z ISSUANCE/

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

A NEW WEATHER SYSTEM WILL PUSH A COLD FRONT SOUTH ACROSS THE AREA
OVERNIGHT INTO WEDNESDAY MORNING WITH LOWERING CEILINGS BEHIND THE
FRONT. WIDESPREAD SHOWERS ARE LIKELY IN AND NEAR THE MOUNTAINS
WITH WIDELY SCATTERED TO SCATTERED SHOWERS IN THE SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE. RAIN WILL LIKELY CHANGE TO SNOW IN THE
CODY FOOTHILLS BY SUNRISE. MVFR CONDITIONS WITH MOUNTAIN AND
HIGHER TERRAIN OBSCURATION WILL INCREASE BEHIND THE COLD FRONT...
ESPECIALLY AROUND KCOD BUT AREAS OF MVFR CONDITIONS WILL OCCUR
ACROSS THE SOUTH TONIGHT AND WEDNESDAY AND WILL DEVELOP BEHIND THE
COLD FRONT SLIDING SOUTH.

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

WIDESPREAD RAIN SHOWERS CAN BE EXPECTED INTO THE EARLY EVENING
ACROSS THE VALLEYS WITH OCCASIONAL MOUNTAIN SNOW AND WIDESPREAD
MOUNTAIN AND FOOTHILL OBSCURATION. LOW VFR TO OCNL MVFR WILL
PREVAIL. A NEW STORM SYSTEM WILL BRING WIDESPREAD SNOW TO THE FAR
NORTHWEST OVERNIGHT AND THEN SPREAD INTO THE SOUTHWEST DURING THE
DAY WEDNESDAY. CONSIDERABLE MOUNTAIN OBSCURATION WILL CONTINUE WITH
MVFR CONDITIONS AT TIMES AND LOCALIZED IFR DURING MODERATE TO
HEAVY SNOW SHOWERS.

&

.FIRE WEATHER...

WETTING RAIN POSSIBLE ACROSS WESTERN AND CENTRAL WYOMING AGAIN
TODAY...THOUGH NOT AS MUCH AS THERE WAS THIS WEEKEND. SHOWERS WILL
BE MORE SCATTERED TODAY ACROSS THE NORTH...WEST AND EAST WITH
ISOLATED SHOWERS AND A THUNDERSTORM OR TWO ACROSS THE SOUTH. IT WILL
REMAIN COOL AND CLOUDY THROUGH THURSDAY AS A SERIES OF DISTURBANCES
AND COLD FRONTS MOVE THROUGH THE REGION. IT WILL BE WARMER AND DRIER
ON FRIDAY WITH SWIFT WEST TO NORTHWEST FLOW CONTINUING.

&&

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

&&

$$

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











000
FXUS65 KRIW 301830
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1230 PM MDT TUE SEP 30 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

PREVIOUS FORECAST LOOKS TO BE ON TRACK...MOST OF THE ACTIVITY WILL
BE EAST OF THE AREA TODAY AS WE TRANSITION TO MOIST WESTERLY FLOW.
RAPID LEE CYCLOGENESIS IS ALREADY BEGINNING NEAR THE NE/WY/SD TRIPLE
POINT...WHICH WILL TRANSLATE TO A NOTICEABLE INCREASE IN WESTERLY
WINDS ACROSS THE FORECAST AREA... ESPECIALLY ACROSS THE SOUTH EARLY.
THE LOW WILL MOVE NORTH AND EAST DURING THE MORNING...SWITCHING
WINDS TO THE NORTHWEST ACROSS OUR NORTHERN HALF OF THE FORECAST
AREA...AND ENCOURAGING A COLD FRONT TO DIP SOUTH...WHICH COULD LEAD
TO GUSTS OVER 40 MPH WINDS IN NORTHERN JOHNSON COUNTY IF EVERYTHING
LINES UP RIGHT. ASIDE FROM THE WIND...OROGRAPHIC LIFT ACROSS THE
WEST...A COLD FRONT DIPPING INTO THE NORTH...AND A DEFORMATION AXIS
POKING INTO OUR EASTERN ZONES COULD KEEP SOME MORE PERSISTENT RAIN
GOING IN THESE AREAS...WITH SNOW ABOVE 8500FT IN THE WESTERN
MOUNTAINS AND YELLOWSTONE. IT WILL BE VERY WEAKLY UNSTABLE
ELSEWHERE...AND THAT COMBINED WITH DECENT RESIDUAL MOISTURE COULD
ALLOW FOR SOME ISOLATED AFTERNOON SHOWERS IN BETWEEN. IT WILL
DEFINITELY STILL BE A COOL...MOIST AND RAW DAY FOR MUCH OF THE AREA.

INTO WEDNESDAY...A REINFORCING SHOT COULD ARRIVE IN THE WESTERLY
FLOW...WITH YET ANOTHER WEATHER SYSTEM FOR WEDNESDAY KEEPING SHOWERS
IN THE FORECAST AND DIPPING SNOW LEVELS DOWN BELOW 7000FT ACROSS THE
WEST AND NORTH. THESE NEXT COUPLE OF SYSTEMS ARE NOT EXPECTED TO
AMOUNT TO MUCH PRECIPITATION BUT THEY HAVE A BETTER SHOT AT LAYING
DOWN A WETTING RAIN AND A MOUNTAIN SNOW ACROSS THE NORTH...BASICALLY
THE ONLY AREA IN OUR CWA THAT DID NOT GET MUCH OUT OF THE WEEKEND
STORM. COULD SEE A DECENT QUARTER TO HALF INCH OF PCPN IN THE NW
MOUNTAINS WITH 2 TO 4 INCHES OF SNOW ABOVE 9K...MAYBE AN INCH OR TWO
DOWN TO AS LOW AS 7-8K AND A BRIEF CHANGEOVER DOWN TO AS LOW AS 6K
IN THE CODY FOOTHILLS EARLY WEDNESDAY MORNING. OUR LAST WAVE SHOULD
EXIT WEDNESDAY EVENING LEAVING BEHIND A VERY COOL AND FROSTY NIGHT
FOR MUCH OF THE FORECAST AREA.

THE NEXT APPROACHING SHORTWAVE FOR THURSDAY LOOKS TO BE A GLANCING
BLOW WITH JUST A SLIGHT CHANCE OF RAIN IN THE FAR NRN/ERN ZONES
THURSDAY WITH GUSTY NORTH WINDS AND CLOUDS. COULD ALSO SEE SOME
GUSTY WINDS IN THE CODY FOOTHILLS WEDNESDAY NIGHT INTO THURSDAY
MORNING AHEAD OF THIS SYSTEM. ELSEWHERE...IT WILL BE MAINLY DRY AND
REMAINING COOL WITH SWIFT NORTHWEST FLOW ALOFT TRANSLATING TO A FEW
20 TO 35 MPH BREEZES DEVELOPING ACROSS THE SOUTH.

.LONG TERM...FRIDAY THROUGH TUESDAY

THE LONG RANGE MODELS ARE IN GOOD AGREEMENT THROUGH SUNDAY WITH THE
WEATHER PATTERN. ON MONDAY AND TUESDAY THE GFS AND GEM MODELS TRY TO
SAG A COLD FRONT ALONG THE MONTANA/WY BORDER WITH PRECIP GETTING
CLOSE MONDAY NIGHT AND TUESDAY ALONG THE BORDER. THE ECMWF IS
DIFFERENT EARLY NEXT WEEK AND KEEPS THE COOLER AIR IN SOUTHERN
CANADA/NORTHERN MONTANA AND DRY WEATHER ALONG THE NORTHERN WY
BORDER. FOR NOW WILL COMPROMISE AND KEEP THE FORECAST DRY AND KNOCK
A DEGREE OR TWO OFF THE HIGH TEMPS IN THE FAR NORTH MONDAY AND
TUESDAY. THERE WILL BE PERIODS OF MID AND HIGH CLOUDS MOVING THROUGH
THE AREA FRIDAY THROUGH TUESDAY WITH LIMITED AMOUNTS OF CUMULUS
CLOUDS. HIGH TEMPS WILL BE SEASONAL TO SLIGHTLY ABOVE NORMAL FRIDAY
THROUGH NEXT TUESDAY. EXPECT BREEZY AREAS IN THE AFTERNOON THROUGH
SUNSET OVER THE WEEKEND INTO EARLY NEXT WEEK. BOTTOM LINE...GOOD
FALL WEATHER FOR SEEING FALL FOLIAGE OR OTHER OUTDOOR ACTIVITIES.

&

.AVIATION.../18Z ISSUANCE/

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

A NEW WEATHER SYSTEM WILL PUSH A COLD FRONT SOUTH ACROSS THE AREA
OVERNIGHT INTO WEDNESDAY MORNING WITH LOWERING CEILINGS BEHIND THE
FRONT. WIDESPREAD SHOWERS ARE LIKELY IN AND NEAR THE MOUNTAINS
WITH WIDELY SCATTERED TO SCATTERED SHOWERS IN THE SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE. RAIN WILL LIKELY CHANGE TO SNOW IN THE
CODY FOOTHILLS BY SUNRISE. MVFR CONDITIONS WITH MOUNTAIN AND
HIGHER TERRAIN OBSCURATION WILL INCREASE BEHIND THE COLD FRONT...
ESPECIALLY AROUND KCOD BUT AREAS OF MVFR CONDITIONS WILL OCCUR
ACROSS THE SOUTH TONIGHT AND WEDNESDAY AND WILL DEVELOP BEHIND THE
COLD FRONT SLIDING SOUTH.

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

WIDESPREAD RAIN SHOWERS CAN BE EXPECTED INTO THE EARLY EVENING
ACROSS THE VALLEYS WITH OCCASIONAL MOUNTAIN SNOW AND WIDESPREAD
MOUNTAIN AND FOOTHILL OBSCURATION. LOW VFR TO OCNL MVFR WILL
PREVAIL. A NEW STORM SYSTEM WILL BRING WIDESPREAD SNOW TO THE FAR
NORTHWEST OVERNIGHT AND THEN SPREAD INTO THE SOUTHWEST DURING THE
DAY WEDNESDAY. CONSIDERABLE MOUNTAIN OBSCURATION WILL CONTINUE WITH
MVFR CONDITIONS AT TIMES AND LOCALIZED IFR DURING MODERATE TO
HEAVY SNOW SHOWERS.

&

.FIRE WEATHER...

WETTING RAIN POSSIBLE ACROSS WESTERN AND CENTRAL WYOMING AGAIN
TODAY...THOUGH NOT AS MUCH AS THERE WAS THIS WEEKEND. SHOWERS WILL
BE MORE SCATTERED TODAY ACROSS THE NORTH...WEST AND EAST WITH
ISOLATED SHOWERS AND A THUNDERSTORM OR TWO ACROSS THE SOUTH. IT WILL
REMAIN COOL AND CLOUDY THROUGH THURSDAY AS A SERIES OF DISTURBANCES
AND COLD FRONTS MOVE THROUGH THE REGION. IT WILL BE WARMER AND DRIER
ON FRIDAY WITH SWIFT WEST TO NORTHWEST FLOW CONTINUING.

&&

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

&&

$$

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











000
FXUS65 KRIW 301830
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1230 PM MDT TUE SEP 30 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

PREVIOUS FORECAST LOOKS TO BE ON TRACK...MOST OF THE ACTIVITY WILL
BE EAST OF THE AREA TODAY AS WE TRANSITION TO MOIST WESTERLY FLOW.
RAPID LEE CYCLOGENESIS IS ALREADY BEGINNING NEAR THE NE/WY/SD TRIPLE
POINT...WHICH WILL TRANSLATE TO A NOTICEABLE INCREASE IN WESTERLY
WINDS ACROSS THE FORECAST AREA... ESPECIALLY ACROSS THE SOUTH EARLY.
THE LOW WILL MOVE NORTH AND EAST DURING THE MORNING...SWITCHING
WINDS TO THE NORTHWEST ACROSS OUR NORTHERN HALF OF THE FORECAST
AREA...AND ENCOURAGING A COLD FRONT TO DIP SOUTH...WHICH COULD LEAD
TO GUSTS OVER 40 MPH WINDS IN NORTHERN JOHNSON COUNTY IF EVERYTHING
LINES UP RIGHT. ASIDE FROM THE WIND...OROGRAPHIC LIFT ACROSS THE
WEST...A COLD FRONT DIPPING INTO THE NORTH...AND A DEFORMATION AXIS
POKING INTO OUR EASTERN ZONES COULD KEEP SOME MORE PERSISTENT RAIN
GOING IN THESE AREAS...WITH SNOW ABOVE 8500FT IN THE WESTERN
MOUNTAINS AND YELLOWSTONE. IT WILL BE VERY WEAKLY UNSTABLE
ELSEWHERE...AND THAT COMBINED WITH DECENT RESIDUAL MOISTURE COULD
ALLOW FOR SOME ISOLATED AFTERNOON SHOWERS IN BETWEEN. IT WILL
DEFINITELY STILL BE A COOL...MOIST AND RAW DAY FOR MUCH OF THE AREA.

INTO WEDNESDAY...A REINFORCING SHOT COULD ARRIVE IN THE WESTERLY
FLOW...WITH YET ANOTHER WEATHER SYSTEM FOR WEDNESDAY KEEPING SHOWERS
IN THE FORECAST AND DIPPING SNOW LEVELS DOWN BELOW 7000FT ACROSS THE
WEST AND NORTH. THESE NEXT COUPLE OF SYSTEMS ARE NOT EXPECTED TO
AMOUNT TO MUCH PRECIPITATION BUT THEY HAVE A BETTER SHOT AT LAYING
DOWN A WETTING RAIN AND A MOUNTAIN SNOW ACROSS THE NORTH...BASICALLY
THE ONLY AREA IN OUR CWA THAT DID NOT GET MUCH OUT OF THE WEEKEND
STORM. COULD SEE A DECENT QUARTER TO HALF INCH OF PCPN IN THE NW
MOUNTAINS WITH 2 TO 4 INCHES OF SNOW ABOVE 9K...MAYBE AN INCH OR TWO
DOWN TO AS LOW AS 7-8K AND A BRIEF CHANGEOVER DOWN TO AS LOW AS 6K
IN THE CODY FOOTHILLS EARLY WEDNESDAY MORNING. OUR LAST WAVE SHOULD
EXIT WEDNESDAY EVENING LEAVING BEHIND A VERY COOL AND FROSTY NIGHT
FOR MUCH OF THE FORECAST AREA.

THE NEXT APPROACHING SHORTWAVE FOR THURSDAY LOOKS TO BE A GLANCING
BLOW WITH JUST A SLIGHT CHANCE OF RAIN IN THE FAR NRN/ERN ZONES
THURSDAY WITH GUSTY NORTH WINDS AND CLOUDS. COULD ALSO SEE SOME
GUSTY WINDS IN THE CODY FOOTHILLS WEDNESDAY NIGHT INTO THURSDAY
MORNING AHEAD OF THIS SYSTEM. ELSEWHERE...IT WILL BE MAINLY DRY AND
REMAINING COOL WITH SWIFT NORTHWEST FLOW ALOFT TRANSLATING TO A FEW
20 TO 35 MPH BREEZES DEVELOPING ACROSS THE SOUTH.

.LONG TERM...FRIDAY THROUGH TUESDAY

THE LONG RANGE MODELS ARE IN GOOD AGREEMENT THROUGH SUNDAY WITH THE
WEATHER PATTERN. ON MONDAY AND TUESDAY THE GFS AND GEM MODELS TRY TO
SAG A COLD FRONT ALONG THE MONTANA/WY BORDER WITH PRECIP GETTING
CLOSE MONDAY NIGHT AND TUESDAY ALONG THE BORDER. THE ECMWF IS
DIFFERENT EARLY NEXT WEEK AND KEEPS THE COOLER AIR IN SOUTHERN
CANADA/NORTHERN MONTANA AND DRY WEATHER ALONG THE NORTHERN WY
BORDER. FOR NOW WILL COMPROMISE AND KEEP THE FORECAST DRY AND KNOCK
A DEGREE OR TWO OFF THE HIGH TEMPS IN THE FAR NORTH MONDAY AND
TUESDAY. THERE WILL BE PERIODS OF MID AND HIGH CLOUDS MOVING THROUGH
THE AREA FRIDAY THROUGH TUESDAY WITH LIMITED AMOUNTS OF CUMULUS
CLOUDS. HIGH TEMPS WILL BE SEASONAL TO SLIGHTLY ABOVE NORMAL FRIDAY
THROUGH NEXT TUESDAY. EXPECT BREEZY AREAS IN THE AFTERNOON THROUGH
SUNSET OVER THE WEEKEND INTO EARLY NEXT WEEK. BOTTOM LINE...GOOD
FALL WEATHER FOR SEEING FALL FOLIAGE OR OTHER OUTDOOR ACTIVITIES.

&

.AVIATION.../18Z ISSUANCE/

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

A NEW WEATHER SYSTEM WILL PUSH A COLD FRONT SOUTH ACROSS THE AREA
OVERNIGHT INTO WEDNESDAY MORNING WITH LOWERING CEILINGS BEHIND THE
FRONT. WIDESPREAD SHOWERS ARE LIKELY IN AND NEAR THE MOUNTAINS
WITH WIDELY SCATTERED TO SCATTERED SHOWERS IN THE SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE. RAIN WILL LIKELY CHANGE TO SNOW IN THE
CODY FOOTHILLS BY SUNRISE. MVFR CONDITIONS WITH MOUNTAIN AND
HIGHER TERRAIN OBSCURATION WILL INCREASE BEHIND THE COLD FRONT...
ESPECIALLY AROUND KCOD BUT AREAS OF MVFR CONDITIONS WILL OCCUR
ACROSS THE SOUTH TONIGHT AND WEDNESDAY AND WILL DEVELOP BEHIND THE
COLD FRONT SLIDING SOUTH.

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

WIDESPREAD RAIN SHOWERS CAN BE EXPECTED INTO THE EARLY EVENING
ACROSS THE VALLEYS WITH OCCASIONAL MOUNTAIN SNOW AND WIDESPREAD
MOUNTAIN AND FOOTHILL OBSCURATION. LOW VFR TO OCNL MVFR WILL
PREVAIL. A NEW STORM SYSTEM WILL BRING WIDESPREAD SNOW TO THE FAR
NORTHWEST OVERNIGHT AND THEN SPREAD INTO THE SOUTHWEST DURING THE
DAY WEDNESDAY. CONSIDERABLE MOUNTAIN OBSCURATION WILL CONTINUE WITH
MVFR CONDITIONS AT TIMES AND LOCALIZED IFR DURING MODERATE TO
HEAVY SNOW SHOWERS.

&

.FIRE WEATHER...

WETTING RAIN POSSIBLE ACROSS WESTERN AND CENTRAL WYOMING AGAIN
TODAY...THOUGH NOT AS MUCH AS THERE WAS THIS WEEKEND. SHOWERS WILL
BE MORE SCATTERED TODAY ACROSS THE NORTH...WEST AND EAST WITH
ISOLATED SHOWERS AND A THUNDERSTORM OR TWO ACROSS THE SOUTH. IT WILL
REMAIN COOL AND CLOUDY THROUGH THURSDAY AS A SERIES OF DISTURBANCES
AND COLD FRONTS MOVE THROUGH THE REGION. IT WILL BE WARMER AND DRIER
ON FRIDAY WITH SWIFT WEST TO NORTHWEST FLOW CONTINUING.

&&

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

&&

$$

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











000
FXUS65 KRIW 301830
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1230 PM MDT TUE SEP 30 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT

PREVIOUS FORECAST LOOKS TO BE ON TRACK...MOST OF THE ACTIVITY WILL
BE EAST OF THE AREA TODAY AS WE TRANSITION TO MOIST WESTERLY FLOW.
RAPID LEE CYCLOGENESIS IS ALREADY BEGINNING NEAR THE NE/WY/SD TRIPLE
POINT...WHICH WILL TRANSLATE TO A NOTICEABLE INCREASE IN WESTERLY
WINDS ACROSS THE FORECAST AREA... ESPECIALLY ACROSS THE SOUTH EARLY.
THE LOW WILL MOVE NORTH AND EAST DURING THE MORNING...SWITCHING
WINDS TO THE NORTHWEST ACROSS OUR NORTHERN HALF OF THE FORECAST
AREA...AND ENCOURAGING A COLD FRONT TO DIP SOUTH...WHICH COULD LEAD
TO GUSTS OVER 40 MPH WINDS IN NORTHERN JOHNSON COUNTY IF EVERYTHING
LINES UP RIGHT. ASIDE FROM THE WIND...OROGRAPHIC LIFT ACROSS THE
WEST...A COLD FRONT DIPPING INTO THE NORTH...AND A DEFORMATION AXIS
POKING INTO OUR EASTERN ZONES COULD KEEP SOME MORE PERSISTENT RAIN
GOING IN THESE AREAS...WITH SNOW ABOVE 8500FT IN THE WESTERN
MOUNTAINS AND YELLOWSTONE. IT WILL BE VERY WEAKLY UNSTABLE
ELSEWHERE...AND THAT COMBINED WITH DECENT RESIDUAL MOISTURE COULD
ALLOW FOR SOME ISOLATED AFTERNOON SHOWERS IN BETWEEN. IT WILL
DEFINITELY STILL BE A COOL...MOIST AND RAW DAY FOR MUCH OF THE AREA.

INTO WEDNESDAY...A REINFORCING SHOT COULD ARRIVE IN THE WESTERLY
FLOW...WITH YET ANOTHER WEATHER SYSTEM FOR WEDNESDAY KEEPING SHOWERS
IN THE FORECAST AND DIPPING SNOW LEVELS DOWN BELOW 7000FT ACROSS THE
WEST AND NORTH. THESE NEXT COUPLE OF SYSTEMS ARE NOT EXPECTED TO
AMOUNT TO MUCH PRECIPITATION BUT THEY HAVE A BETTER SHOT AT LAYING
DOWN A WETTING RAIN AND A MOUNTAIN SNOW ACROSS THE NORTH...BASICALLY
THE ONLY AREA IN OUR CWA THAT DID NOT GET MUCH OUT OF THE WEEKEND
STORM. COULD SEE A DECENT QUARTER TO HALF INCH OF PCPN IN THE NW
MOUNTAINS WITH 2 TO 4 INCHES OF SNOW ABOVE 9K...MAYBE AN INCH OR TWO
DOWN TO AS LOW AS 7-8K AND A BRIEF CHANGEOVER DOWN TO AS LOW AS 6K
IN THE CODY FOOTHILLS EARLY WEDNESDAY MORNING. OUR LAST WAVE SHOULD
EXIT WEDNESDAY EVENING LEAVING BEHIND A VERY COOL AND FROSTY NIGHT
FOR MUCH OF THE FORECAST AREA.

THE NEXT APPROACHING SHORTWAVE FOR THURSDAY LOOKS TO BE A GLANCING
BLOW WITH JUST A SLIGHT CHANCE OF RAIN IN THE FAR NRN/ERN ZONES
THURSDAY WITH GUSTY NORTH WINDS AND CLOUDS. COULD ALSO SEE SOME
GUSTY WINDS IN THE CODY FOOTHILLS WEDNESDAY NIGHT INTO THURSDAY
MORNING AHEAD OF THIS SYSTEM. ELSEWHERE...IT WILL BE MAINLY DRY AND
REMAINING COOL WITH SWIFT NORTHWEST FLOW ALOFT TRANSLATING TO A FEW
20 TO 35 MPH BREEZES DEVELOPING ACROSS THE SOUTH.

.LONG TERM...FRIDAY THROUGH TUESDAY

THE LONG RANGE MODELS ARE IN GOOD AGREEMENT THROUGH SUNDAY WITH THE
WEATHER PATTERN. ON MONDAY AND TUESDAY THE GFS AND GEM MODELS TRY TO
SAG A COLD FRONT ALONG THE MONTANA/WY BORDER WITH PRECIP GETTING
CLOSE MONDAY NIGHT AND TUESDAY ALONG THE BORDER. THE ECMWF IS
DIFFERENT EARLY NEXT WEEK AND KEEPS THE COOLER AIR IN SOUTHERN
CANADA/NORTHERN MONTANA AND DRY WEATHER ALONG THE NORTHERN WY
BORDER. FOR NOW WILL COMPROMISE AND KEEP THE FORECAST DRY AND KNOCK
A DEGREE OR TWO OFF THE HIGH TEMPS IN THE FAR NORTH MONDAY AND
TUESDAY. THERE WILL BE PERIODS OF MID AND HIGH CLOUDS MOVING THROUGH
THE AREA FRIDAY THROUGH TUESDAY WITH LIMITED AMOUNTS OF CUMULUS
CLOUDS. HIGH TEMPS WILL BE SEASONAL TO SLIGHTLY ABOVE NORMAL FRIDAY
THROUGH NEXT TUESDAY. EXPECT BREEZY AREAS IN THE AFTERNOON THROUGH
SUNSET OVER THE WEEKEND INTO EARLY NEXT WEEK. BOTTOM LINE...GOOD
FALL WEATHER FOR SEEING FALL FOLIAGE OR OTHER OUTDOOR ACTIVITIES.

&

.AVIATION.../18Z ISSUANCE/

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

A NEW WEATHER SYSTEM WILL PUSH A COLD FRONT SOUTH ACROSS THE AREA
OVERNIGHT INTO WEDNESDAY MORNING WITH LOWERING CEILINGS BEHIND THE
FRONT. WIDESPREAD SHOWERS ARE LIKELY IN AND NEAR THE MOUNTAINS
WITH WIDELY SCATTERED TO SCATTERED SHOWERS IN THE SOUTH. ISOLATED
THUNDERSTORMS ARE POSSIBLE. RAIN WILL LIKELY CHANGE TO SNOW IN THE
CODY FOOTHILLS BY SUNRISE. MVFR CONDITIONS WITH MOUNTAIN AND
HIGHER TERRAIN OBSCURATION WILL INCREASE BEHIND THE COLD FRONT...
ESPECIALLY AROUND KCOD BUT AREAS OF MVFR CONDITIONS WILL OCCUR
ACROSS THE SOUTH TONIGHT AND WEDNESDAY AND WILL DEVELOP BEHIND THE
COLD FRONT SLIDING SOUTH.

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

WIDESPREAD RAIN SHOWERS CAN BE EXPECTED INTO THE EARLY EVENING
ACROSS THE VALLEYS WITH OCCASIONAL MOUNTAIN SNOW AND WIDESPREAD
MOUNTAIN AND FOOTHILL OBSCURATION. LOW VFR TO OCNL MVFR WILL
PREVAIL. A NEW STORM SYSTEM WILL BRING WIDESPREAD SNOW TO THE FAR
NORTHWEST OVERNIGHT AND THEN SPREAD INTO THE SOUTHWEST DURING THE
DAY WEDNESDAY. CONSIDERABLE MOUNTAIN OBSCURATION WILL CONTINUE WITH
MVFR CONDITIONS AT TIMES AND LOCALIZED IFR DURING MODERATE TO
HEAVY SNOW SHOWERS.

&

.FIRE WEATHER...

WETTING RAIN POSSIBLE ACROSS WESTERN AND CENTRAL WYOMING AGAIN
TODAY...THOUGH NOT AS MUCH AS THERE WAS THIS WEEKEND. SHOWERS WILL
BE MORE SCATTERED TODAY ACROSS THE NORTH...WEST AND EAST WITH
ISOLATED SHOWERS AND A THUNDERSTORM OR TWO ACROSS THE SOUTH. IT WILL
REMAIN COOL AND CLOUDY THROUGH THURSDAY AS A SERIES OF DISTURBANCES
AND COLD FRONTS MOVE THROUGH THE REGION. IT WILL BE WARMER AND DRIER
ON FRIDAY WITH SWIFT WEST TO NORTHWEST FLOW CONTINUING.

&&

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

&&

$$

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











000
FXUS65 KCYS 301815
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1215 PM MDT TUE SEP 30 2014

.UPDATE...
ISSUED AT 1058 AM MDT TUE SEP 30 2014

CANCELLED THE HIGH WIND WARNING FOR THE WIND PRONE AREAS OF
SOUTHEAST WYOMING EARLIER THIS MORNING. GUSTS ABOVE 50 MPH HAVE
BEEN LIMITED THIS MORNING ACROSS SOUTHEAST WY AND THE CAG-CPR
GRADIENT IS WEAKENING ALONG WITH WINDSPEEDS ALOFT. WILL KEEP THE
WIND ADVISORY GOING FOR THE NORTHERN PANHANDLE THROUGH THE EARLY
AFTN AS GUSTS TO 45 MPH ARE CURRENTLY BEING OBSERVED MAINLY OVER
DAWES COUNTY AND THE PINE RIDGE. SHOULD SEE WINDS COME DOWN OVER
THE NORTHERN PANHANDLE BY LATE IN THE AFTN AS THE SFC LOW QUICKLY
MOVING OFF TO THE NORTHEAST. FCST LOOKS IN GOOD SHAPE OVERALL WITH
SCATTERED SHOWERS EXPECTED TO DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE DURING THE AFTN.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MDT TUE SEP 30 2014

LOW PRESSURE SYSTEM CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE
WILL CONTINUE ITS TRACK NORTHEAST INTO THE PLAINS THE REST OF THIS
MORNING. MOST RAIN SHOWER ACTIVITY WILL BE OVER THE NORTHERN
NEBRASKA PANHANDLE AND EAST CENTRAL WYOMING. GENERALLY A QUARTER
TO HALF INCH OF ADDITIONAL RAINFALL CAN BE EXPECTED THROUGH MID
MORNING AS THE RAIN SHIELD LIFTS NORTHEASTWARD ALONG WITH THE
LOW. COULD SEE ADDITIONAL RAIN SHOWERS DEVELOP IN THE WESTERN CWA
THIS AFTERNOON AND COOL AIR ALOFT AND MORNING SUNSHINE
DESTABILIZES THE BOUNDARY LAYER. NOT EXPECTING MUCH IN THE WAY OF
MEASURABLE PRECIPITATION THIS AFTERNOON WITH MAINLY ISOLATED
SHOWERS. CAN NOT RULE OUT A FEW LIGHTNING STRIKES BUT GENERALLY
LOOKING FOR SHOWERS IF ANYTHING.

HIGH WIND WARNING REMAINS IN EFFECT FOR WIND PRONE AREAS OF
SOUTHEAST WYOMING. WINDS HAVE INCREASED OVER THE LAST SEVERAL
HOURS WITH A FEW SITES CLOSE TO HIGH WIND WARNING SPEEDS. LOOKING
MARGINAL AT BEST TO HIT HIGH WIND WARNING AT THIS POINT...BUT
CLOSE ENOUGH TO KEEP THE WARNING GOING FOR NOW. THE OTHER WIND
CONCERN IS INTO THE NORTHERN NEBRASKA PANHANDLE. 40 TO 50 KT WINDS
WILL BE IN PLACE NOT TOO FAR OFF THE SURFACE THIS MORNING. AS LOW
PRESSURE WRAPS UP SOME OF THESE WINDS WILL MAKE THEIR WAY TO THE
SURFACE SO ISSUED A WIND ADVISORY FOR THE NORTHERN PANHANDLE
THROUGH EARLY AFTERNOON. TOUGH CALL WITH SO MUCH CLOUD COVER
AROUND THIS MORNING BUT THEN AGAIN ALLIANCE REPORTED A WIND GUST
OVER 60 MPH AT 3 AM.

SHORTWAVE WILL DROP ACROSS THE AREA WEDNESDAY. THIS WAVE SHOULD
BRING SOME SHOWERS AND A FEW THUNDERSTORMS WEDNESDAY...AT LEAST
GIVEN THE EXPECTED TRACK. HIGHEST CHANCES FOR MEASUREABLE RAIN
LOOKS TO BE NEAR THE COLORADO BORDER. SKIES WILL CLEAR OUT FROM
WEST TO EAST WEDNESDAY NIGHT WITH SUNNY SKIES FOR THURSDAY UNDER
NORTHWEST FLOW ALOFT.

.LONG TERM...(THURSDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 315 AM MDT TUE SEP 30 2014

ALL LONG RANGE MODELS SHOW QUIET WEATHER FOR THE EXTENDED WITH NO
CONCERNS THROUGH NEXT WEEKEND. PERSISTENT DRY NORTHWESTERLY FLOW
WILL CONTINUE ACROSS THE AREA THROUGH THE PERIOD. JET STREAM WILL
RETREAT NORTHWARD TOWARDS THE CANADIAN BORDER WITH ONLY ONE WEAK
WAVE EXPECTED TO IMPACT THE AREA ON SUNDAY...WHICH WILL RESULT IN
THE POLAR JET STREAM DIGGING A LITTLE FURTHER SOUTH INTO THE
CENTRAL PLAINS...BRIEFLY. NO PRECIPITATION IS EXPECTED THROUGH THE
PERIOD WITH POP BELOW 10 PERCENT AND EVEN AROUND ZERO PERCENT FOR
SEVERAL DAYS. A SLOW WARMING TREND IS EXPECTED INTO THIS WEEKEND
WITH DAYTIME HIGHS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE
YEAR. HIGHS IN THE MID 60S TO MID 70S ARE EXPECTED ON
SATURDAY...WARMEST OVER THE HIGH PLAINS. TEMPERATURES WILL BE
SLIGHTLY COOLER ON SUNDAY AS A WEAK WAVE AND ASSOCIATED FRONT
ALOFT PUSH ACROSS THE AREA...BUT ABOVE AVERAGE TEMPS WILL CONTINUE
INTO EARLY NEXT WEEK. BREEZY CONDITIONS CAN BE EXPECTED ON MOST
DAYS...WHICH IS TYPICAL OF PROGRESSIVE NORTHWEST FLOW ALOFT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1209 AM MDT TUE SEP 30 2014

THE MAIN IMPACT FOR THIS PERIOD WILL BE THE BREEZY TO LOCALLY
WINDY CONDITIONS AT ALL SITES THIS AFTERNOON...ALONG WITH THE
POSSIBILITY OF WEAK SHOWERS/STORMS DEVELOPING LATER TODAY AT
KRWL...KLAR AND KCYS. WEST WINDS WILL CONTINUE TO GUST TO 30-35
KNOTS AT ALL SITES THROUGH THE REST OF THE AFTERNOON. HAVE KEPT
TAF SITES IN VFR THRU THE PERIOD...BUT MAY SEE A BRIEF DIP INTO
MVFR AT KLAR AND KCYS WITH THE AFTERNOON SHOWERS. ANY CONVECTION
WILL DISSIPATE THIS EVENING AND SO WILL THE WINDS. MORE CHANCES
FOR PRECIPITATION WILL RETURN TO AREA AIRFIELDS JUST BEYOND THIS
TAF CYCLE...ON WEDNESDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 404 AM MDT TUE SEP 30 2014

LOW PRESSURE WILL MOVE INTO THE NORTHERN PLAINS TODAY. WINDY
CONDITIONS WILL PREVAIL OVER FORECAST AREA AS THE PRESSURE
GRADIENT INCREASES THIS MORNING. RAIN SHOWERS WILL BE FOUND
OVER NORTHERN NEBRASKA PANHANDLE AND INTO EAST CENTRAL WYOMING
EARLY THIS MORNING BUT SHOWERS WILL MOVE TO THE NORTHEAST BY
THIS AFTERNOON. A FEW ISOLATED AFTERNOON SHOWERS POSSIBLE FOR
SOUTHEAST WYOMING THIS AFTERNOON. ANOTHER QUICK MOVING SYSTEM WILL
BRING SOME RAIN SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY.
OTHERWISE A DRY WEEK WITH WARMING TEMPERATURES THE LATTER HALF OF
THE WEEK.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR NEZ002-003-095-
     096.

&&

$$

UPDATE...FINCH
SHORT TERM...SML
LONG TERM...TJT
AVIATION...HAHN
FIRE WEATHER...SML






000
FXUS65 KCYS 301815
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1215 PM MDT TUE SEP 30 2014

.UPDATE...
ISSUED AT 1058 AM MDT TUE SEP 30 2014

CANCELLED THE HIGH WIND WARNING FOR THE WIND PRONE AREAS OF
SOUTHEAST WYOMING EARLIER THIS MORNING. GUSTS ABOVE 50 MPH HAVE
BEEN LIMITED THIS MORNING ACROSS SOUTHEAST WY AND THE CAG-CPR
GRADIENT IS WEAKENING ALONG WITH WINDSPEEDS ALOFT. WILL KEEP THE
WIND ADVISORY GOING FOR THE NORTHERN PANHANDLE THROUGH THE EARLY
AFTN AS GUSTS TO 45 MPH ARE CURRENTLY BEING OBSERVED MAINLY OVER
DAWES COUNTY AND THE PINE RIDGE. SHOULD SEE WINDS COME DOWN OVER
THE NORTHERN PANHANDLE BY LATE IN THE AFTN AS THE SFC LOW QUICKLY
MOVING OFF TO THE NORTHEAST. FCST LOOKS IN GOOD SHAPE OVERALL WITH
SCATTERED SHOWERS EXPECTED TO DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE DURING THE AFTN.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MDT TUE SEP 30 2014

LOW PRESSURE SYSTEM CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE
WILL CONTINUE ITS TRACK NORTHEAST INTO THE PLAINS THE REST OF THIS
MORNING. MOST RAIN SHOWER ACTIVITY WILL BE OVER THE NORTHERN
NEBRASKA PANHANDLE AND EAST CENTRAL WYOMING. GENERALLY A QUARTER
TO HALF INCH OF ADDITIONAL RAINFALL CAN BE EXPECTED THROUGH MID
MORNING AS THE RAIN SHIELD LIFTS NORTHEASTWARD ALONG WITH THE
LOW. COULD SEE ADDITIONAL RAIN SHOWERS DEVELOP IN THE WESTERN CWA
THIS AFTERNOON AND COOL AIR ALOFT AND MORNING SUNSHINE
DESTABILIZES THE BOUNDARY LAYER. NOT EXPECTING MUCH IN THE WAY OF
MEASURABLE PRECIPITATION THIS AFTERNOON WITH MAINLY ISOLATED
SHOWERS. CAN NOT RULE OUT A FEW LIGHTNING STRIKES BUT GENERALLY
LOOKING FOR SHOWERS IF ANYTHING.

HIGH WIND WARNING REMAINS IN EFFECT FOR WIND PRONE AREAS OF
SOUTHEAST WYOMING. WINDS HAVE INCREASED OVER THE LAST SEVERAL
HOURS WITH A FEW SITES CLOSE TO HIGH WIND WARNING SPEEDS. LOOKING
MARGINAL AT BEST TO HIT HIGH WIND WARNING AT THIS POINT...BUT
CLOSE ENOUGH TO KEEP THE WARNING GOING FOR NOW. THE OTHER WIND
CONCERN IS INTO THE NORTHERN NEBRASKA PANHANDLE. 40 TO 50 KT WINDS
WILL BE IN PLACE NOT TOO FAR OFF THE SURFACE THIS MORNING. AS LOW
PRESSURE WRAPS UP SOME OF THESE WINDS WILL MAKE THEIR WAY TO THE
SURFACE SO ISSUED A WIND ADVISORY FOR THE NORTHERN PANHANDLE
THROUGH EARLY AFTERNOON. TOUGH CALL WITH SO MUCH CLOUD COVER
AROUND THIS MORNING BUT THEN AGAIN ALLIANCE REPORTED A WIND GUST
OVER 60 MPH AT 3 AM.

SHORTWAVE WILL DROP ACROSS THE AREA WEDNESDAY. THIS WAVE SHOULD
BRING SOME SHOWERS AND A FEW THUNDERSTORMS WEDNESDAY...AT LEAST
GIVEN THE EXPECTED TRACK. HIGHEST CHANCES FOR MEASUREABLE RAIN
LOOKS TO BE NEAR THE COLORADO BORDER. SKIES WILL CLEAR OUT FROM
WEST TO EAST WEDNESDAY NIGHT WITH SUNNY SKIES FOR THURSDAY UNDER
NORTHWEST FLOW ALOFT.

.LONG TERM...(THURSDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 315 AM MDT TUE SEP 30 2014

ALL LONG RANGE MODELS SHOW QUIET WEATHER FOR THE EXTENDED WITH NO
CONCERNS THROUGH NEXT WEEKEND. PERSISTENT DRY NORTHWESTERLY FLOW
WILL CONTINUE ACROSS THE AREA THROUGH THE PERIOD. JET STREAM WILL
RETREAT NORTHWARD TOWARDS THE CANADIAN BORDER WITH ONLY ONE WEAK
WAVE EXPECTED TO IMPACT THE AREA ON SUNDAY...WHICH WILL RESULT IN
THE POLAR JET STREAM DIGGING A LITTLE FURTHER SOUTH INTO THE
CENTRAL PLAINS...BRIEFLY. NO PRECIPITATION IS EXPECTED THROUGH THE
PERIOD WITH POP BELOW 10 PERCENT AND EVEN AROUND ZERO PERCENT FOR
SEVERAL DAYS. A SLOW WARMING TREND IS EXPECTED INTO THIS WEEKEND
WITH DAYTIME HIGHS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE
YEAR. HIGHS IN THE MID 60S TO MID 70S ARE EXPECTED ON
SATURDAY...WARMEST OVER THE HIGH PLAINS. TEMPERATURES WILL BE
SLIGHTLY COOLER ON SUNDAY AS A WEAK WAVE AND ASSOCIATED FRONT
ALOFT PUSH ACROSS THE AREA...BUT ABOVE AVERAGE TEMPS WILL CONTINUE
INTO EARLY NEXT WEEK. BREEZY CONDITIONS CAN BE EXPECTED ON MOST
DAYS...WHICH IS TYPICAL OF PROGRESSIVE NORTHWEST FLOW ALOFT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1209 AM MDT TUE SEP 30 2014

THE MAIN IMPACT FOR THIS PERIOD WILL BE THE BREEZY TO LOCALLY
WINDY CONDITIONS AT ALL SITES THIS AFTERNOON...ALONG WITH THE
POSSIBILITY OF WEAK SHOWERS/STORMS DEVELOPING LATER TODAY AT
KRWL...KLAR AND KCYS. WEST WINDS WILL CONTINUE TO GUST TO 30-35
KNOTS AT ALL SITES THROUGH THE REST OF THE AFTERNOON. HAVE KEPT
TAF SITES IN VFR THRU THE PERIOD...BUT MAY SEE A BRIEF DIP INTO
MVFR AT KLAR AND KCYS WITH THE AFTERNOON SHOWERS. ANY CONVECTION
WILL DISSIPATE THIS EVENING AND SO WILL THE WINDS. MORE CHANCES
FOR PRECIPITATION WILL RETURN TO AREA AIRFIELDS JUST BEYOND THIS
TAF CYCLE...ON WEDNESDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 404 AM MDT TUE SEP 30 2014

LOW PRESSURE WILL MOVE INTO THE NORTHERN PLAINS TODAY. WINDY
CONDITIONS WILL PREVAIL OVER FORECAST AREA AS THE PRESSURE
GRADIENT INCREASES THIS MORNING. RAIN SHOWERS WILL BE FOUND
OVER NORTHERN NEBRASKA PANHANDLE AND INTO EAST CENTRAL WYOMING
EARLY THIS MORNING BUT SHOWERS WILL MOVE TO THE NORTHEAST BY
THIS AFTERNOON. A FEW ISOLATED AFTERNOON SHOWERS POSSIBLE FOR
SOUTHEAST WYOMING THIS AFTERNOON. ANOTHER QUICK MOVING SYSTEM WILL
BRING SOME RAIN SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY.
OTHERWISE A DRY WEEK WITH WARMING TEMPERATURES THE LATTER HALF OF
THE WEEK.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR NEZ002-003-095-
     096.

&&

$$

UPDATE...FINCH
SHORT TERM...SML
LONG TERM...TJT
AVIATION...HAHN
FIRE WEATHER...SML







000
FXUS63 KUNR 301732
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1132 AM MDT TUE SEP 30 2014

.UPDATE...
ISSUED AT 1109 AM MDT TUE SEP 30 2014

MADE SOME ADJUSTMENTS TO THE FLOOD HEADLINES. SEE THE HYDROLOGY
SECTION BELOW.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 236 AM MDT TUE SEP 30 2014

08Z SURFACE ANALYSIS HAD LOW BETWEEN KAIA/KCDR/KIEN. UPPER LOW
NOW STACKED ON TOP OF SURFACE LOW PER WATER VAPOR. FORCING AHEAD
OF SYSTEM PRONOUNCED WITH CONVECTION FIRING ALONG WARM FRONT FROM
LOW INTO CENTRAL SD. CONVECTION FEEDING STRONG DEFORMATION ZONE
FROM SOUTHWEST ND THROUGH THE BLACK HILLS INTO THE NE PANHANDLE.
00Z NAM A BIT FURTHER EAST WITH HEAVIEST BAND OF PRECIPITATION
THIS MORNING AND THE 00Z GFS FARTHEST WEST. SPLIT THE DIFFERENCE
AND YOU END UP WITH THE BEST RAINS OCCURRING IN THE CURRENT FLOOD
WATCH AREA. HEAVIEST RAIN SHOULD FALL THIS MORNING AS LOW LEVEL
UPSLOPE FEEDS INTO STRONG SYNOPTIC LIFT/DEFORMATION ZONE. AS LOW
PASSES...RAPID SHIFT TO WEST/NORTHWEST WINDS EXPECTED AND WELL-
DEFINED ISALLOBARIC FORCING. COLD AIR ADVECTION NOT THAT
STRONG...BUT SUBSIDENCE/PRESSURE RISES BEHIND LOW SHOULD BE
SUFFICIENT FOR A PERIOD OF ADVISORY CRITERIA WINDS FROM WEST
CENTRAL/SOUTHWEST INTO SOUTH CENTRAL SD TODAY. TEMPERATURES WILL
BE ALL OVER THE PLACE...BUT LIKELY LOWER THAN GUIDANCE OVER
CENTRAL PORTIONS OF THE CWA.

TONIGHT...STACKED SYSTEM RACES INTO SOUTHERN SK/MB AS IT WEAKENS.
CYCLONIC FLOW WILL SUPPORT SOME -SHRA OVER THE CWA. TEMPERATURES
WILL BE NEAR GUIDANCE.

WEDNESDAY...SECONDARY UPPER TROUGH SLICES THROUGH THE REGION WITH
BEST FORCING ACROSS SOUTHERN PORTIONS OF THE CWA AND THUS HAVE
PAINTED BETTER POPS TOWARD THE SD/NE BORDER. TEMPERATURES WILL BE
NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 236 AM MDT TUE SEP 30 2014

CYCLONIC FLOW WILL CONTINUE OVER THE REGION THURSDAY. A STRONG
UPPER WAVE IS PROGGED TO DIVE DOWN THE BACKSIDE OF THE TROUGH
THURSDAY AND THURSDAY NIGHT...BRINGING A STRONG COLD FRONT TO THE
AREA. GUSTY NW WINDS ARE EXPECTED BEHIND THE FRONT AS A TIGHT
PRESSURE GRADIENT DEVELOPS. ISOLATED SHOWERS WILL BE POSSIBLE WITH
THE FROPA. HIGH PRESSURE WILL QUICKLY BUILD IN WITH UPPER RIDGING
DEVELOPING ACROSS THE WESTERN CONUS. DRY WEATHER IS EXPECTED
THROUGH THE END OF THIS WEEK INTO EARLY NEXT WEEK. TEMPS WILL BE
COOLER THAN AVERAGE THU/FRI...THEN WARM BACK TO SEASONAL AVERAGES
BY THE WEEKEND.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 1136 AM MDT TUE SEP 30 2014

STORM SYSTEM NR KPHP MOVG NEWD...W/ WIDESPREAD SHWRS...ISOLD
TSTMS...AND MVFR CIGS/VSBY...ESP OVR WRN SD THIS AFTN. GUSTY
NORTHWEST WINDS WL INCRS OVER NERN WY/SWRN INTO S CNTRL SD THIS
AFTN. CIGS WL IMPROVE THIS EVNG...WHILE WNDS DIMINISH AND BCM
WESTERLY.

&&

.HYDROLOGY...
ISSUED AT 1109 AM MDT TUE SEP 30 2014

THE LOW PRESSURE CENTER CURRENTLY LOCATED OVER HAAKON COUNTY WILL
CONTINUE TO ACCELERATE OFF TOWARD THE NORTHEAST THIS AFTERNOON.
BANDS OF SHOWERS WILL CONTINUE OVER MUCH OF THE FORECAST AREA
THROUGH THE AFTERNOON BUT WILL SHIFT NORTHEASTWARD AS WELL. THE
FLOOD WATCH THAT WAS IN EFFECT FOR PARTS OF NORTHEASTERN WYOMING
AND WESTERN SOUTH DAKOTA WAS SET TO EXPIRE AT NOON. ALTHOUGH RAIN
SHOWERS WILL CONTINUE TO BE FOUND OVER THE AREA...IT LOOKS LIKE
THE THREAT OF WIDESPREAD HEAVY RAIN IS ENDING...SO HAVE CANCELLED
THAT FLOOD WATCH. A FLOOD ADVISORY REMAINS IN EFFECT FOR FALL
RIVER COUNTY AND PARTS OF CUSTER...WESTERN PENNINGTON AND FAR
WESTERN SHANNON COUNTIES UNTIL 700 PM MDT THIS EVENING. THOSE ARE
THE AREAS WHICH RECEIVED THE MOST RAIN OVER THE PAST COUPLE OF
DAYS. SMALL CREEKS AND STREAMS ARE RUNNING VERY HIGH IN THOSE
AREAS. DEBRIS IN THOSE STREAMS CAN QUICKLY BLOCK CULVERTS WHICH
COULD CAUSE MINOR FLOODING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR SDZ026-
     027-030>032-041>044-046-047-049-072>074.

WY...NONE.
&&

$$

UPDATE...10
SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13
HYDROLOGY...10






000
FXUS63 KUNR 301732
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1132 AM MDT TUE SEP 30 2014

.UPDATE...
ISSUED AT 1109 AM MDT TUE SEP 30 2014

MADE SOME ADJUSTMENTS TO THE FLOOD HEADLINES. SEE THE HYDROLOGY
SECTION BELOW.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 236 AM MDT TUE SEP 30 2014

08Z SURFACE ANALYSIS HAD LOW BETWEEN KAIA/KCDR/KIEN. UPPER LOW
NOW STACKED ON TOP OF SURFACE LOW PER WATER VAPOR. FORCING AHEAD
OF SYSTEM PRONOUNCED WITH CONVECTION FIRING ALONG WARM FRONT FROM
LOW INTO CENTRAL SD. CONVECTION FEEDING STRONG DEFORMATION ZONE
FROM SOUTHWEST ND THROUGH THE BLACK HILLS INTO THE NE PANHANDLE.
00Z NAM A BIT FURTHER EAST WITH HEAVIEST BAND OF PRECIPITATION
THIS MORNING AND THE 00Z GFS FARTHEST WEST. SPLIT THE DIFFERENCE
AND YOU END UP WITH THE BEST RAINS OCCURRING IN THE CURRENT FLOOD
WATCH AREA. HEAVIEST RAIN SHOULD FALL THIS MORNING AS LOW LEVEL
UPSLOPE FEEDS INTO STRONG SYNOPTIC LIFT/DEFORMATION ZONE. AS LOW
PASSES...RAPID SHIFT TO WEST/NORTHWEST WINDS EXPECTED AND WELL-
DEFINED ISALLOBARIC FORCING. COLD AIR ADVECTION NOT THAT
STRONG...BUT SUBSIDENCE/PRESSURE RISES BEHIND LOW SHOULD BE
SUFFICIENT FOR A PERIOD OF ADVISORY CRITERIA WINDS FROM WEST
CENTRAL/SOUTHWEST INTO SOUTH CENTRAL SD TODAY. TEMPERATURES WILL
BE ALL OVER THE PLACE...BUT LIKELY LOWER THAN GUIDANCE OVER
CENTRAL PORTIONS OF THE CWA.

TONIGHT...STACKED SYSTEM RACES INTO SOUTHERN SK/MB AS IT WEAKENS.
CYCLONIC FLOW WILL SUPPORT SOME -SHRA OVER THE CWA. TEMPERATURES
WILL BE NEAR GUIDANCE.

WEDNESDAY...SECONDARY UPPER TROUGH SLICES THROUGH THE REGION WITH
BEST FORCING ACROSS SOUTHERN PORTIONS OF THE CWA AND THUS HAVE
PAINTED BETTER POPS TOWARD THE SD/NE BORDER. TEMPERATURES WILL BE
NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 236 AM MDT TUE SEP 30 2014

CYCLONIC FLOW WILL CONTINUE OVER THE REGION THURSDAY. A STRONG
UPPER WAVE IS PROGGED TO DIVE DOWN THE BACKSIDE OF THE TROUGH
THURSDAY AND THURSDAY NIGHT...BRINGING A STRONG COLD FRONT TO THE
AREA. GUSTY NW WINDS ARE EXPECTED BEHIND THE FRONT AS A TIGHT
PRESSURE GRADIENT DEVELOPS. ISOLATED SHOWERS WILL BE POSSIBLE WITH
THE FROPA. HIGH PRESSURE WILL QUICKLY BUILD IN WITH UPPER RIDGING
DEVELOPING ACROSS THE WESTERN CONUS. DRY WEATHER IS EXPECTED
THROUGH THE END OF THIS WEEK INTO EARLY NEXT WEEK. TEMPS WILL BE
COOLER THAN AVERAGE THU/FRI...THEN WARM BACK TO SEASONAL AVERAGES
BY THE WEEKEND.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 1136 AM MDT TUE SEP 30 2014

STORM SYSTEM NR KPHP MOVG NEWD...W/ WIDESPREAD SHWRS...ISOLD
TSTMS...AND MVFR CIGS/VSBY...ESP OVR WRN SD THIS AFTN. GUSTY
NORTHWEST WINDS WL INCRS OVER NERN WY/SWRN INTO S CNTRL SD THIS
AFTN. CIGS WL IMPROVE THIS EVNG...WHILE WNDS DIMINISH AND BCM
WESTERLY.

&&

.HYDROLOGY...
ISSUED AT 1109 AM MDT TUE SEP 30 2014

THE LOW PRESSURE CENTER CURRENTLY LOCATED OVER HAAKON COUNTY WILL
CONTINUE TO ACCELERATE OFF TOWARD THE NORTHEAST THIS AFTERNOON.
BANDS OF SHOWERS WILL CONTINUE OVER MUCH OF THE FORECAST AREA
THROUGH THE AFTERNOON BUT WILL SHIFT NORTHEASTWARD AS WELL. THE
FLOOD WATCH THAT WAS IN EFFECT FOR PARTS OF NORTHEASTERN WYOMING
AND WESTERN SOUTH DAKOTA WAS SET TO EXPIRE AT NOON. ALTHOUGH RAIN
SHOWERS WILL CONTINUE TO BE FOUND OVER THE AREA...IT LOOKS LIKE
THE THREAT OF WIDESPREAD HEAVY RAIN IS ENDING...SO HAVE CANCELLED
THAT FLOOD WATCH. A FLOOD ADVISORY REMAINS IN EFFECT FOR FALL
RIVER COUNTY AND PARTS OF CUSTER...WESTERN PENNINGTON AND FAR
WESTERN SHANNON COUNTIES UNTIL 700 PM MDT THIS EVENING. THOSE ARE
THE AREAS WHICH RECEIVED THE MOST RAIN OVER THE PAST COUPLE OF
DAYS. SMALL CREEKS AND STREAMS ARE RUNNING VERY HIGH IN THOSE
AREAS. DEBRIS IN THOSE STREAMS CAN QUICKLY BLOCK CULVERTS WHICH
COULD CAUSE MINOR FLOODING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR SDZ026-
     027-030>032-041>044-046-047-049-072>074.

WY...NONE.
&&

$$

UPDATE...10
SHORT TERM...HELGESON
LONG TERM...13
AVIATION...13
HYDROLOGY...10







000
FXUS65 KCYS 301705
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1105 AM MDT TUE SEP 30 2014

.UPDATE...
ISSUED AT 1058 AM MDT TUE SEP 30 2014

CANCELLED THE HIGH WIND WARNING FOR THE WIND PRONE AREAS OF
SOUTHEAST WYOMING EARLIER THIS MORNING. GUSTS ABOVE 50 MPH HAVE
BEEN LIMITED THIS MORNING ACROSS SOUTHEAST WY AND THE CAG-CPR
GRADIENT IS WEAKENING ALONG WITH WINDSPEEDS ALOFT. WILL KEEP THE
WIND ADVISORY GOING FOR THE NORTHERN PANHANDLE THROUGH THE EARLY
AFTN AS GUSTS TO 45 MPH ARE CURRENTLY BEING OBSERVED MAINLY OVER
DAWES COUNTY AND THE PINE RIDGE. SHOULD SEE WINDS COME DOWN OVER
THE NORTHERN PANHANDLE BY LATE IN THE AFTN AS THE SFC LOW QUICKLY
MOVING OFF TO THE NORTHEAST. FCST LOOKS IN GOOD SHAPE OVERALL WITH
SCATTERED SHOWERS EXPECTED TO DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE DURING THE AFTN.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MDT TUE SEP 30 2014

LOW PRESSURE SYSTEM CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE
WILL CONTINUE ITS TRACK NORTHEAST INTO THE PLAINS THE REST OF THIS
MORNING. MOST RAIN SHOWER ACTIVITY WILL BE OVER THE NORTHERN
NEBRASKA PANHANDLE AND EAST CENTRAL WYOMING. GENERALLY A QUARTER
TO HALF INCH OF ADDITIONAL RAINFALL CAN BE EXPECTED THROUGH MID
MORNING AS THE RAIN SHIELD LIFTS NORTHEASTWARD ALONG WITH THE
LOW. COULD SEE ADDITIONAL RAIN SHOWERS DEVELOP IN THE WESTERN CWA
THIS AFTERNOON AND COOL AIR ALOFT AND MORNING SUNSHINE
DESTABILIZES THE BOUNDARY LAYER. NOT EXPECTING MUCH IN THE WAY OF
MEASURABLE PRECIPITATION THIS AFTERNOON WITH MAINLY ISOLATED
SHOWERS. CAN NOT RULE OUT A FEW LIGHTNING STRIKES BUT GENERALLY
LOOKING FOR SHOWERS IF ANYTHING.

HIGH WIND WARNING REMAINS IN EFFECT FOR WIND PRONE AREAS OF
SOUTHEAST WYOMING. WINDS HAVE INCREASED OVER THE LAST SEVERAL
HOURS WITH A FEW SITES CLOSE TO HIGH WIND WARNING SPEEDS. LOOKING
MARGINAL AT BEST TO HIT HIGH WIND WARNING AT THIS POINT...BUT
CLOSE ENOUGH TO KEEP THE WARNING GOING FOR NOW. THE OTHER WIND
CONCERN IS INTO THE NORTHERN NEBRASKA PANHANDLE. 40 TO 50 KT WINDS
WILL BE IN PLACE NOT TOO FAR OFF THE SURFACE THIS MORNING. AS LOW
PRESSURE WRAPS UP SOME OF THESE WINDS WILL MAKE THEIR WAY TO THE
SURFACE SO ISSUED A WIND ADVISORY FOR THE NORTHERN PANHANDLE
THROUGH EARLY AFTERNOON. TOUGH CALL WITH SO MUCH CLOUD COVER
AROUND THIS MORNING BUT THEN AGAIN ALLIANCE REPORTED A WIND GUST
OVER 60 MPH AT 3 AM.

SHORTWAVE WILL DROP ACROSS THE AREA WEDNESDAY. THIS WAVE SHOULD
BRING SOME SHOWERS AND A FEW THUNDERSTORMS WEDNESDAY...AT LEAST
GIVEN THE EXPECTED TRACK. HIGHEST CHANCES FOR MEASUREABLE RAIN
LOOKS TO BE NEAR THE COLORADO BORDER. SKIES WILL CLEAR OUT FROM
WEST TO EAST WEDNESDAY NIGHT WITH SUNNY SKIES FOR THURSDAY UNDER
NORTHWEST FLOW ALOFT.

.LONG TERM...(THURSDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 315 AM MDT TUE SEP 30 2014

ALL LONG RANGE MODELS SHOW QUIET WEATHER FOR THE EXTENDED WITH NO
CONCERNS THROUGH NEXT WEEKEND. PERSISTENT DRY NORTHWESTERLY FLOW
WILL CONTINUE ACROSS THE AREA THROUGH THE PERIOD. JET STREAM WILL
RETREAT NORTHWARD TOWARDS THE CANADIAN BORDER WITH ONLY ONE WEAK
WAVE EXPECTED TO IMPACT THE AREA ON SUNDAY...WHICH WILL RESULT IN
THE POLAR JET STREAM DIGGING A LITTLE FURTHER SOUTH INTO THE
CENTRAL PLAINS...BRIEFLY. NO PRECIPITATION IS EXPECTED THROUGH THE
PERIOD WITH POP BELOW 10 PERCENT AND EVEN AROUND ZERO PERCENT FOR
SEVERAL DAYS. A SLOW WARMING TREND IS EXPECTED INTO THIS WEEKEND
WITH DAYTIME HIGHS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE
YEAR. HIGHS IN THE MID 60S TO MID 70S ARE EXPECTED ON
SATURDAY...WARMEST OVER THE HIGH PLAINS. TEMPERATURES WILL BE
SLIGHTLY COOLER ON SUNDAY AS A WEAK WAVE AND ASSOCIATED FRONT
ALOFT PUSH ACROSS THE AREA...BUT ABOVE AVERAGE TEMPS WILL CONTINUE
INTO EARLY NEXT WEEK. BREEZY CONDITIONS CAN BE EXPECTED ON MOST
DAYS...WHICH IS TYPICAL OF PROGRESSIVE NORTHWEST FLOW ALOFT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH TUESDAY NIGHT)
ISSUED AT 235 AM MDT TUE SEP 30 2014

STRONG SURFACE LOW PRESSURE WILL CONTINUE TO MOVE NORTHWARD THIS
MORNING...WITH THE CENTER OF THE LOW JUST PASSING THROUGH ALLIANCE
AT THIS HOUR. RAINFALL HAS SLOWLY DECREASED IN INTENSITY...WITH
MAINLY LIGHT TO MODERATE RAINFALL EXPECTED TO PERSIST NORTHEAST OF A
LINE EXTENDING FROM KDGW TO KSNY. BY SUNRISE...THIS AREA OF RAIN
IS EXPECTED TO BE NORTH OF KSNY AND KAIA WITH CONDITIONS IMPROVING
TO VFR. STRONG GUSTY WINDS ARE EXPECTED BEHIND THIS LOW AS IT
TRACKS NORTH OF THE AREA TODAY...WITH GUSTS UP TO 55 MPH POSSIBLE.
IFR CONDITIONS WILL GRADUALLY IMPROVE TO MVFR THIS MORNING ACROSS
WESTERN NEBRASKA...WITH VFR OVER SOUTHEAST WYOMING.


&&

.FIRE WEATHER...
ISSUED AT 404 AM MDT TUE SEP 30 2014

LOW PRESSURE WILL MOVE INTO THE NORTHERN PLAINS TODAY. WINDY
CONDITIONS WILL PREVAIL OVER FORECAST AREA AS THE PRESSURE
GRADIENT INCREASES THIS MORNING. RAIN SHOWERS WILL BE FOUND
OVER NORTHERN NEBRASKA PANHANDLE AND INTO EAST CENTRAL WYOMING
EARLY THIS MORNING BUT SHOWERS WILL MOVE TO THE NORTHEAST BY
THIS AFTERNOON. A FEW ISOLATED AFTERNOON SHOWERS POSSIBLE FOR
SOUTHEAST WYOMING THIS AFTERNOON. ANOTHER QUICK MOVING SYSTEM WILL
BRING SOME RAIN SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY.
OTHERWISE A DRY WEEK WITH WARMING TEMPERATURES THE LATTER HALF OF
THE WEEK.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR NEZ002-003-095-
     096.

&&

$$

UPDATE...FINCH
SHORT TERM...SML
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...SML






000
FXUS65 KCYS 301705
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1105 AM MDT TUE SEP 30 2014

.UPDATE...
ISSUED AT 1058 AM MDT TUE SEP 30 2014

CANCELLED THE HIGH WIND WARNING FOR THE WIND PRONE AREAS OF
SOUTHEAST WYOMING EARLIER THIS MORNING. GUSTS ABOVE 50 MPH HAVE
BEEN LIMITED THIS MORNING ACROSS SOUTHEAST WY AND THE CAG-CPR
GRADIENT IS WEAKENING ALONG WITH WINDSPEEDS ALOFT. WILL KEEP THE
WIND ADVISORY GOING FOR THE NORTHERN PANHANDLE THROUGH THE EARLY
AFTN AS GUSTS TO 45 MPH ARE CURRENTLY BEING OBSERVED MAINLY OVER
DAWES COUNTY AND THE PINE RIDGE. SHOULD SEE WINDS COME DOWN OVER
THE NORTHERN PANHANDLE BY LATE IN THE AFTN AS THE SFC LOW QUICKLY
MOVING OFF TO THE NORTHEAST. FCST LOOKS IN GOOD SHAPE OVERALL WITH
SCATTERED SHOWERS EXPECTED TO DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE DURING THE AFTN.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MDT TUE SEP 30 2014

LOW PRESSURE SYSTEM CURRENTLY CENTERED OVER THE NEBRASKA PANHANDLE
WILL CONTINUE ITS TRACK NORTHEAST INTO THE PLAINS THE REST OF THIS
MORNING. MOST RAIN SHOWER ACTIVITY WILL BE OVER THE NORTHERN
NEBRASKA PANHANDLE AND EAST CENTRAL WYOMING. GENERALLY A QUARTER
TO HALF INCH OF ADDITIONAL RAINFALL CAN BE EXPECTED THROUGH MID
MORNING AS THE RAIN SHIELD LIFTS NORTHEASTWARD ALONG WITH THE
LOW. COULD SEE ADDITIONAL RAIN SHOWERS DEVELOP IN THE WESTERN CWA
THIS AFTERNOON AND COOL AIR ALOFT AND MORNING SUNSHINE
DESTABILIZES THE BOUNDARY LAYER. NOT EXPECTING MUCH IN THE WAY OF
MEASURABLE PRECIPITATION THIS AFTERNOON WITH MAINLY ISOLATED
SHOWERS. CAN NOT RULE OUT A FEW LIGHTNING STRIKES BUT GENERALLY
LOOKING FOR SHOWERS IF ANYTHING.

HIGH WIND WARNING REMAINS IN EFFECT FOR WIND PRONE AREAS OF
SOUTHEAST WYOMING. WINDS HAVE INCREASED OVER THE LAST SEVERAL
HOURS WITH A FEW SITES CLOSE TO HIGH WIND WARNING SPEEDS. LOOKING
MARGINAL AT BEST TO HIT HIGH WIND WARNING AT THIS POINT...BUT
CLOSE ENOUGH TO KEEP THE WARNING GOING FOR NOW. THE OTHER WIND
CONCERN IS INTO THE NORTHERN NEBRASKA PANHANDLE. 40 TO 50 KT WINDS
WILL BE IN PLACE NOT TOO FAR OFF THE SURFACE THIS MORNING. AS LOW
PRESSURE WRAPS UP SOME OF THESE WINDS WILL MAKE THEIR WAY TO THE
SURFACE SO ISSUED A WIND ADVISORY FOR THE NORTHERN PANHANDLE
THROUGH EARLY AFTERNOON. TOUGH CALL WITH SO MUCH CLOUD COVER
AROUND THIS MORNING BUT THEN AGAIN ALLIANCE REPORTED A WIND GUST
OVER 60 MPH AT 3 AM.

SHORTWAVE WILL DROP ACROSS THE AREA WEDNESDAY. THIS WAVE SHOULD
BRING SOME SHOWERS AND A FEW THUNDERSTORMS WEDNESDAY...AT LEAST
GIVEN THE EXPECTED TRACK. HIGHEST CHANCES FOR MEASUREABLE RAIN
LOOKS TO BE NEAR THE COLORADO BORDER. SKIES WILL CLEAR OUT FROM
WEST TO EAST WEDNESDAY NIGHT WITH SUNNY SKIES FOR THURSDAY UNDER
NORTHWEST FLOW ALOFT.

.LONG TERM...(THURSDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 315 AM MDT TUE SEP 30 2014

ALL LONG RANGE MODELS SHOW QUIET WEATHER FOR THE EXTENDED WITH NO
CONCERNS THROUGH NEXT WEEKEND. PERSISTENT DRY NORTHWESTERLY FLOW
WILL CONTINUE ACROSS THE AREA THROUGH THE PERIOD. JET STREAM WILL
RETREAT NORTHWARD TOWARDS THE CANADIAN BORDER WITH ONLY ONE WEAK
WAVE EXPECTED TO IMPACT THE AREA ON SUNDAY...WHICH WILL RESULT IN
THE POLAR JET STREAM DIGGING A LITTLE FURTHER SOUTH INTO THE
CENTRAL PLAINS...BRIEFLY. NO PRECIPITATION IS EXPECTED THROUGH THE
PERIOD WITH POP BELOW 10 PERCENT AND EVEN AROUND ZERO PERCENT FOR
SEVERAL DAYS. A SLOW WARMING TREND IS EXPECTED INTO THIS WEEKEND
WITH DAYTIME HIGHS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE
YEAR. HIGHS IN THE MID 60S TO MID 70S ARE EXPECTED ON
SATURDAY...WARMEST OVER THE HIGH PLAINS. TEMPERATURES WILL BE
SLIGHTLY COOLER ON SUNDAY AS A WEAK WAVE AND ASSOCIATED FRONT
ALOFT PUSH ACROSS THE AREA...BUT ABOVE AVERAGE TEMPS WILL CONTINUE
INTO EARLY NEXT WEEK. BREEZY CONDITIONS CAN BE EXPECTED ON MOST
DAYS...WHICH IS TYPICAL OF PROGRESSIVE NORTHWEST FLOW ALOFT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH TUESDAY NIGHT)
ISSUED AT 235 AM MDT TUE SEP 30 2014

STRONG SURFACE LOW PRESSURE WILL CONTINUE TO MOVE NORTHWARD THIS
MORNING...WITH THE CENTER OF THE LOW JUST PASSING THROUGH ALLIANCE
AT THIS HOUR. RAINFALL HAS SLOWLY DECREASED IN INTENSITY...WITH
MAINLY LIGHT TO MODERATE RAINFALL EXPECTED TO PERSIST NORTHEAST OF A
LINE EXTENDING FROM KDGW TO KSNY. BY SUNRISE...THIS AREA OF RAIN
IS EXPECTED TO BE NORTH OF KSNY AND KAIA WITH CONDITIONS IMPROVING
TO VFR. STRONG GUSTY WINDS ARE EXPECTED BEHIND THIS LOW AS IT
TRACKS NORTH OF THE AREA TODAY...WITH GUSTS UP TO 55 MPH POSSIBLE.
IFR CONDITIONS WILL GRADUALLY IMPROVE TO MVFR THIS MORNING ACROSS
WESTERN NEBRASKA...WITH VFR OVER SOUTHEAST WYOMING.


&&

.FIRE WEATHER...
ISSUED AT 404 AM MDT TUE SEP 30 2014

LOW PRESSURE WILL MOVE INTO THE NORTHERN PLAINS TODAY. WINDY
CONDITIONS WILL PREVAIL OVER FORECAST AREA AS THE PRESSURE
GRADIENT INCREASES THIS MORNING. RAIN SHOWERS WILL BE FOUND
OVER NORTHERN NEBRASKA PANHANDLE AND INTO EAST CENTRAL WYOMING
EARLY THIS MORNING BUT SHOWERS WILL MOVE TO THE NORTHEAST BY
THIS AFTERNOON. A FEW ISOLATED AFTERNOON SHOWERS POSSIBLE FOR
SOUTHEAST WYOMING THIS AFTERNOON. ANOTHER QUICK MOVING SYSTEM WILL
BRING SOME RAIN SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY.
OTHERWISE A DRY WEEK WITH WARMING TEMPERATURES THE LATTER HALF OF
THE WEEK.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR NEZ002-003-095-
     096.

&&

$$

UPDATE...FINCH
SHORT TERM...SML
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...SML







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