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000
FXUS63 KUNR 191013
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
313 AM MST FRI DEC 19 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 312 AM MST FRI DEC 19 2014

LOW AMPLITUDE UPPER TROUGH IS CROSSING THE CENTRAL CONUS WITH A
COMPACT WAVE NOW MOVING THROUGH THE WRN DAKOTAS. THIS WAVE IS NOT
BRINGING MORE THAN SOME MID/HIGH CLOUDS TO NWRD SD ATTM. STRONG
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS MINNESOTA/GREAT LAKES
WITH WEAK LOW PRESSURE OVER ERN MT INTO THE CWA. A QUIET DAY IS
EXPECTED TODAY. A SECONDARY WAVE WILL CROSS THE CWA DURING THE
DAY...BUT ASIDE FROM SOME PASSING MID/HIGH CLOUDS...SUNSHINE IS
STILL EXPECTED ACROSS MOST AREAS. TEMPS WILL RISE INTO THE MID 30S
TO MID 40S WITH THE WARMEST SPOTS ACROSS THE DOWNSLOPING NE FTHLS.
LOWS TONIGHT WILL DROP INTO THE MID TEENS TO MID 20S. EVENING SKIES
WILL BE MOSTLY CLEAR...BUT CLOUDS WILL INCREASE LATER AT NIGHT AHEAD
OF THE NEXT FAST MOVING SHORTWAVE. THIS WAVE IS EXPECTED TO HAVE A
LITTLE MORE MOISTURE TO WORK WITH. HAVE EXPANDED AREAL COVERAGE OF
POPS OVER NRN TWO THIRDS OF THE CWA...BUT WILL LEAVE AT 20 POPS AS
MOST AREAS WILL NOT SEE ANY MEASURABLE QPF. LIGHT PRECIP WILL MOVE
EAST OF THE CWA BY SAT EVNG. TEMPS SAT WILL BE SIMILAR TO
TODAYS...PERHAPS A TOUCH COOLER WITH GREAT CLOUD COVER.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 312 AM MST FRI DEC 19 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR SUNDAY-TUESDAY...WITH
RIDGE BUILDING ALONG THE PACIFIC COAST AND DOWNSTREAM TROF CLOSING
OFF OVER THE UPPER MIDWEST/WESTERN GREAT LAKES. MAIN SHORTWAVE
RESPONSIBLE FOR TROF CLOSING OFF TRACKS ACROSS THE DAKOTAS LATE
SUNDAY/MONDAY. .WITH SCATTERED RAIN/SNOW. TEMPERATURES SLIGHTLY
ABOVE AVERAGE FOR SUNDAY. GUSTY NORTHWEST WINDS ON MONDAY IN THE
WAKE OF COLD FRONT. STRONG NORTHWEST FLOW ALOFT FOR MID
WEEK...WITH SERIES OF WEAK SHORTWAVES. MAINLY DRY WEATHER
EXPECTED. EXCEPTION WOULD BE NORTHERN BLACK HILLS...WHERE STEEP
LOW LEVEL LAPSE RATES AND MARGINAL 0-2KM RELATIVE HUMIDITY WOULD
RESULT IN SOME LIGHT UPSLOPE SNOW. MODELS CONTINUE TO SHOW STRONG
UPPER TROF DIGGING INTO THE WESTERN CONUS FOR THE END OF THE
WEEK...BUT DIFFER SOME ON TIMING/PLACEMENT OF BEST FORCING.
POTENTIAL FOR WIDESPREAD SNOW LATE CHRISTMAS DAY INTO
FRIDAY...ESPECIALLY ACROSS SOUTHERN PORTIONS OF FORECAST AREA.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING
ISSUED AT 312 AM MST FRI DEC 19 2014

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7








000
FXUS63 KUNR 191013
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
313 AM MST FRI DEC 19 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 312 AM MST FRI DEC 19 2014

LOW AMPLITUDE UPPER TROUGH IS CROSSING THE CENTRAL CONUS WITH A
COMPACT WAVE NOW MOVING THROUGH THE WRN DAKOTAS. THIS WAVE IS NOT
BRINGING MORE THAN SOME MID/HIGH CLOUDS TO NWRD SD ATTM. STRONG
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS MINNESOTA/GREAT LAKES
WITH WEAK LOW PRESSURE OVER ERN MT INTO THE CWA. A QUIET DAY IS
EXPECTED TODAY. A SECONDARY WAVE WILL CROSS THE CWA DURING THE
DAY...BUT ASIDE FROM SOME PASSING MID/HIGH CLOUDS...SUNSHINE IS
STILL EXPECTED ACROSS MOST AREAS. TEMPS WILL RISE INTO THE MID 30S
TO MID 40S WITH THE WARMEST SPOTS ACROSS THE DOWNSLOPING NE FTHLS.
LOWS TONIGHT WILL DROP INTO THE MID TEENS TO MID 20S. EVENING SKIES
WILL BE MOSTLY CLEAR...BUT CLOUDS WILL INCREASE LATER AT NIGHT AHEAD
OF THE NEXT FAST MOVING SHORTWAVE. THIS WAVE IS EXPECTED TO HAVE A
LITTLE MORE MOISTURE TO WORK WITH. HAVE EXPANDED AREAL COVERAGE OF
POPS OVER NRN TWO THIRDS OF THE CWA...BUT WILL LEAVE AT 20 POPS AS
MOST AREAS WILL NOT SEE ANY MEASURABLE QPF. LIGHT PRECIP WILL MOVE
EAST OF THE CWA BY SAT EVNG. TEMPS SAT WILL BE SIMILAR TO
TODAYS...PERHAPS A TOUCH COOLER WITH GREAT CLOUD COVER.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 312 AM MST FRI DEC 19 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR SUNDAY-TUESDAY...WITH
RIDGE BUILDING ALONG THE PACIFIC COAST AND DOWNSTREAM TROF CLOSING
OFF OVER THE UPPER MIDWEST/WESTERN GREAT LAKES. MAIN SHORTWAVE
RESPONSIBLE FOR TROF CLOSING OFF TRACKS ACROSS THE DAKOTAS LATE
SUNDAY/MONDAY. .WITH SCATTERED RAIN/SNOW. TEMPERATURES SLIGHTLY
ABOVE AVERAGE FOR SUNDAY. GUSTY NORTHWEST WINDS ON MONDAY IN THE
WAKE OF COLD FRONT. STRONG NORTHWEST FLOW ALOFT FOR MID
WEEK...WITH SERIES OF WEAK SHORTWAVES. MAINLY DRY WEATHER
EXPECTED. EXCEPTION WOULD BE NORTHERN BLACK HILLS...WHERE STEEP
LOW LEVEL LAPSE RATES AND MARGINAL 0-2KM RELATIVE HUMIDITY WOULD
RESULT IN SOME LIGHT UPSLOPE SNOW. MODELS CONTINUE TO SHOW STRONG
UPPER TROF DIGGING INTO THE WESTERN CONUS FOR THE END OF THE
WEEK...BUT DIFFER SOME ON TIMING/PLACEMENT OF BEST FORCING.
POTENTIAL FOR WIDESPREAD SNOW LATE CHRISTMAS DAY INTO
FRIDAY...ESPECIALLY ACROSS SOUTHERN PORTIONS OF FORECAST AREA.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING
ISSUED AT 312 AM MST FRI DEC 19 2014

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7









000
FXUS63 KUNR 191013
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
313 AM MST FRI DEC 19 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 312 AM MST FRI DEC 19 2014

LOW AMPLITUDE UPPER TROUGH IS CROSSING THE CENTRAL CONUS WITH A
COMPACT WAVE NOW MOVING THROUGH THE WRN DAKOTAS. THIS WAVE IS NOT
BRINGING MORE THAN SOME MID/HIGH CLOUDS TO NWRD SD ATTM. STRONG
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS MINNESOTA/GREAT LAKES
WITH WEAK LOW PRESSURE OVER ERN MT INTO THE CWA. A QUIET DAY IS
EXPECTED TODAY. A SECONDARY WAVE WILL CROSS THE CWA DURING THE
DAY...BUT ASIDE FROM SOME PASSING MID/HIGH CLOUDS...SUNSHINE IS
STILL EXPECTED ACROSS MOST AREAS. TEMPS WILL RISE INTO THE MID 30S
TO MID 40S WITH THE WARMEST SPOTS ACROSS THE DOWNSLOPING NE FTHLS.
LOWS TONIGHT WILL DROP INTO THE MID TEENS TO MID 20S. EVENING SKIES
WILL BE MOSTLY CLEAR...BUT CLOUDS WILL INCREASE LATER AT NIGHT AHEAD
OF THE NEXT FAST MOVING SHORTWAVE. THIS WAVE IS EXPECTED TO HAVE A
LITTLE MORE MOISTURE TO WORK WITH. HAVE EXPANDED AREAL COVERAGE OF
POPS OVER NRN TWO THIRDS OF THE CWA...BUT WILL LEAVE AT 20 POPS AS
MOST AREAS WILL NOT SEE ANY MEASURABLE QPF. LIGHT PRECIP WILL MOVE
EAST OF THE CWA BY SAT EVNG. TEMPS SAT WILL BE SIMILAR TO
TODAYS...PERHAPS A TOUCH COOLER WITH GREAT CLOUD COVER.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 312 AM MST FRI DEC 19 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR SUNDAY-TUESDAY...WITH
RIDGE BUILDING ALONG THE PACIFIC COAST AND DOWNSTREAM TROF CLOSING
OFF OVER THE UPPER MIDWEST/WESTERN GREAT LAKES. MAIN SHORTWAVE
RESPONSIBLE FOR TROF CLOSING OFF TRACKS ACROSS THE DAKOTAS LATE
SUNDAY/MONDAY. .WITH SCATTERED RAIN/SNOW. TEMPERATURES SLIGHTLY
ABOVE AVERAGE FOR SUNDAY. GUSTY NORTHWEST WINDS ON MONDAY IN THE
WAKE OF COLD FRONT. STRONG NORTHWEST FLOW ALOFT FOR MID
WEEK...WITH SERIES OF WEAK SHORTWAVES. MAINLY DRY WEATHER
EXPECTED. EXCEPTION WOULD BE NORTHERN BLACK HILLS...WHERE STEEP
LOW LEVEL LAPSE RATES AND MARGINAL 0-2KM RELATIVE HUMIDITY WOULD
RESULT IN SOME LIGHT UPSLOPE SNOW. MODELS CONTINUE TO SHOW STRONG
UPPER TROF DIGGING INTO THE WESTERN CONUS FOR THE END OF THE
WEEK...BUT DIFFER SOME ON TIMING/PLACEMENT OF BEST FORCING.
POTENTIAL FOR WIDESPREAD SNOW LATE CHRISTMAS DAY INTO
FRIDAY...ESPECIALLY ACROSS SOUTHERN PORTIONS OF FORECAST AREA.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING
ISSUED AT 312 AM MST FRI DEC 19 2014

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7








000
FXUS63 KUNR 191013
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
313 AM MST FRI DEC 19 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 312 AM MST FRI DEC 19 2014

LOW AMPLITUDE UPPER TROUGH IS CROSSING THE CENTRAL CONUS WITH A
COMPACT WAVE NOW MOVING THROUGH THE WRN DAKOTAS. THIS WAVE IS NOT
BRINGING MORE THAN SOME MID/HIGH CLOUDS TO NWRD SD ATTM. STRONG
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS MINNESOTA/GREAT LAKES
WITH WEAK LOW PRESSURE OVER ERN MT INTO THE CWA. A QUIET DAY IS
EXPECTED TODAY. A SECONDARY WAVE WILL CROSS THE CWA DURING THE
DAY...BUT ASIDE FROM SOME PASSING MID/HIGH CLOUDS...SUNSHINE IS
STILL EXPECTED ACROSS MOST AREAS. TEMPS WILL RISE INTO THE MID 30S
TO MID 40S WITH THE WARMEST SPOTS ACROSS THE DOWNSLOPING NE FTHLS.
LOWS TONIGHT WILL DROP INTO THE MID TEENS TO MID 20S. EVENING SKIES
WILL BE MOSTLY CLEAR...BUT CLOUDS WILL INCREASE LATER AT NIGHT AHEAD
OF THE NEXT FAST MOVING SHORTWAVE. THIS WAVE IS EXPECTED TO HAVE A
LITTLE MORE MOISTURE TO WORK WITH. HAVE EXPANDED AREAL COVERAGE OF
POPS OVER NRN TWO THIRDS OF THE CWA...BUT WILL LEAVE AT 20 POPS AS
MOST AREAS WILL NOT SEE ANY MEASURABLE QPF. LIGHT PRECIP WILL MOVE
EAST OF THE CWA BY SAT EVNG. TEMPS SAT WILL BE SIMILAR TO
TODAYS...PERHAPS A TOUCH COOLER WITH GREAT CLOUD COVER.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 312 AM MST FRI DEC 19 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR SUNDAY-TUESDAY...WITH
RIDGE BUILDING ALONG THE PACIFIC COAST AND DOWNSTREAM TROF CLOSING
OFF OVER THE UPPER MIDWEST/WESTERN GREAT LAKES. MAIN SHORTWAVE
RESPONSIBLE FOR TROF CLOSING OFF TRACKS ACROSS THE DAKOTAS LATE
SUNDAY/MONDAY. .WITH SCATTERED RAIN/SNOW. TEMPERATURES SLIGHTLY
ABOVE AVERAGE FOR SUNDAY. GUSTY NORTHWEST WINDS ON MONDAY IN THE
WAKE OF COLD FRONT. STRONG NORTHWEST FLOW ALOFT FOR MID
WEEK...WITH SERIES OF WEAK SHORTWAVES. MAINLY DRY WEATHER
EXPECTED. EXCEPTION WOULD BE NORTHERN BLACK HILLS...WHERE STEEP
LOW LEVEL LAPSE RATES AND MARGINAL 0-2KM RELATIVE HUMIDITY WOULD
RESULT IN SOME LIGHT UPSLOPE SNOW. MODELS CONTINUE TO SHOW STRONG
UPPER TROF DIGGING INTO THE WESTERN CONUS FOR THE END OF THE
WEEK...BUT DIFFER SOME ON TIMING/PLACEMENT OF BEST FORCING.
POTENTIAL FOR WIDESPREAD SNOW LATE CHRISTMAS DAY INTO
FRIDAY...ESPECIALLY ACROSS SOUTHERN PORTIONS OF FORECAST AREA.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING
ISSUED AT 312 AM MST FRI DEC 19 2014

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7









000
FXUS63 KUNR 190423
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
923 PM MST THU DEC 18 2014

.UPDATE...
ISSUED AT 731 PM MST THU DEC 18 2014

PATCHY FOG IS FORMING NEAR THE WRN EDGE OF STRATUS THAT IS SLOWLY
PUSHING EAST OF THE CWFA. WILL ADD PATCHY FOG TO OUR FAR ERN ZONES
FOR THE REST OF THE NIGHT...ALTHOUGH IT MAY CLEAR A BIT EARLIER
WITH DRIER SW/W FLOW EXPECTED TO DEVELOP OVERNIGHT.

&&

.SHORT TERM...TONIGHT AND TOMORROW
ISSUED AT 238 PM MST THU DEC 18 2014

UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE NORTHERN
PLAINS...WITH THE TROUGH AXIS SLIDING INTO THE EASTERN DAKOTAS.
ERODING OF THE LOW CLOUDS CONTINUES TO SPREAD ACROSS WESTERN S
DAKOTA...WITH MOST OF THE CWA NOW SEEING MOSTLY SUNNY SKIES AND
TEMPS ABOVE FREEZING. WITH MOSTLY CLEAR SKIES CONTINUING INTO THE
EVENING HOURS TEMPS WILL FALL QUICKLY INTO THE 20S AFTER SUNSET.
TEMPS BOTTOM OUT IN THE TEENS TO LOWER 20S. TOMORROW A WEEK
DISTURBANCE WILL MOVE ACROSS THE AREA. SOUNDINGS ARE FAIRLY DRY IN
THE LOWER LEVELS AND EXPECT ONLY SOME PASSING MID/HIGH CLOUDS. THIS
SHOULD NOT IMPEDE MUCH ON WARMING WITH HIGHS IN THE 30S TO LOWER 40S.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 238 PM MST THU DEC 18 2014

PRIMARY FORECAST CONCERNS IN THE MID RANGE OF THE FORECAST DEAL WITH
LIGHT SNOW CHANCES OVER NORTHEAST WYOMING SATURDAY MORNING AND WITH
A SLIGHT WARMING TREND IN TEMPERATURES THROUGH THE WEEKEND. FOCUS
THEN TURNS TO THE PATTERN SHIFT FOR NEXT WEEK AS IT TURNS ACTIVE FOR
MUCH OF NEXT WEEK.

A SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS SOUTH DAKOTA FRIDAY NIGHT
WITH ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC CROSSING THE NORTHERN
ROCKIES AND INTO NORTHEAST WYOMING BY 12Z SATURDAY. THE FIRST SYSTEM
WILL MOVE THROUGH DRY AS THERE IS A LARGE LACK OF MOISTURE TO WORK
WITH...BUT THERE MAY BE ENOUGH MOISTURE STILL WITH THE SECOND SYSTEM
AFTER CROSSING THE MOUNTAINS TO BRING SOME LIGHT PRECIPITATION TO
THE NORTHEAST CORNER OF WYOMING SATURDAY MORNING. THE GFS HAS A
CLEAR DRY LAYER JUST OFF THE SURFACE SO MAY NOT BE ENOUGH MOISTURE
TO MAKE IT THROUGH THE BOUNDARY LAYER FOR MEASURABLE PRECIPITATION.
THE NAM IS NOT AS ROBUST WITH THE DRY AIR BUT WOULD INDICATE THERE
MAY BE ENOUGH LIFT AND MOISTURE TO AT LEAST INCLUDE A SLIGHT MENTION
OF SNOW SATURDAY MORNING.

TEMPERATURES WILL SEE A SLIGHT MODERATION THROUGH THE WEEKEND.
BEHIND THE WEAK PACIFIC FRONT THAT MOVES THOUGH SATURDAY MORNING
WARMER AIR WILL BEGIN TO PUSH NORTH AS LONGWAVE RIDGING BUILDS OVER
THE EASTERN PACIFIC. BY SUNDAY...A LARGE AREA OF LOW PRESSURE AT THE
SURFACE DEVELOPS OVER SOUTHWEST CANADA WITH A TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE OF THE ROCKY MOUNTAINS. SOUTHERLY FLOW IN THE
LOWER LEVELS WILL BRING WARMER AIR NORTHWARD...WITH HIGHS EXPECTED
TO RISE INTO THE LOW AND MID 40S ACROSS PORTIONS OF THE FORECAST
AREA ON BOTH SATURDAY AND SUNDAY. A QUESTION WITH TEMPERATURES WILL
BE IF AND/OR HOW MUCH OF AN IMPACT THE SNOW COVER WILL IMPACT
TEMPERATURES. KEPT HIGHS A BIT COOLER WHERE SNOWPACK EXISTS...WHILE
OTHER AREAS SHOULD EASILY RISE INTO THE 30S AND 40S.

BY MONDAY...NORTHWEST FLOW ALOFT HAS BEEN ESTABLISHED ACROSS THE
NORTH CENTRAL PART OF THE CONUS AS THE UPPER LEVEL PATTERN CHANGES
WITH A LONGWAVE RIDGE OVER THE EASTERN PACIFIC AND A FAIRLY DEEP
TROUGH CENTERED ACROSS THE PLAINS AND MISSISSIPPI RIVER VALLEY. THE
MODELS ARE IN GOOD AGREEMENT WITH THIS PATTERN CHANGE WHICH LOOKS TO
STAY IN PLACE THROUGH THE WEEK. THIS PATTERN WILL KEEP THE WEATHER
ACTIVE THROUGH THE REMAINDER OF THE PERIOD AS MULTIPLE WEAK
SHORTWAVE TROUGHS PUSH OVER THE RIDGE AND PASS ACROSS THE LOCAL
AREA. TIMING OF THE INDIVIDUAL SYSTEMS IS PROBLEMATIC AS IS
TYPICALLY SEEN IN THESE PATTERNS SO IT IS QUITE DIFFICULT TRYING TO
PINPOINT WHEN THE HIGHER CHANCES FOR PRECIPITATION WILL BE. THIS
LEADS TO PRECIPITATION CHANCES THROUGH MOST DAYS MONDAY THROUGH
THURSDAY. WITH THE NORTHWEST FLOW THOUGH...WILL GET UPSLOPE FLOW
OVER THE BLACK HILLS MUCH OF THE PERIOD SO AS LONG AS THERE IS SOME
MOISTURE TO WORK WITH WILL GET SNOW TO DEVELOP AND THESE AREAS WILL
MAINTAIN THE MORE CONSISTENT AND HIGHER PRECIPITATION CHANCES.
AMOUNTS DON/T LOOK SIGNIFICANT WITH ANY OF THESE QUICK HITTING
SYSTEMS AT THIS POINT SO THE CURRENT FORECAST JUST HAS LIGHT AMOUNTS
CURRENTLY. BY WEDNESDAY NIGHT AND THURSDAY THE MODELS ARE DIGGING A
SLIGHTLY MORE SIGNIFICANT SHORTWAVE DOWN THROUGH THE CENTRAL
ROCKIES. IF THIS HOLDS OUT...THE PRECIPITATION WILL BE MOSTLY ACROSS
THE SOUTHWEST PART OF THE FORECAST AREA.

ONE THING THAT IS FAIRLY CERTAIN IS AS THE NORTHWEST FLOW IS
ESTABLISHED THAT TEMPERATURES WILL BE COOLING OFF BACK TO NEAR
NORMAL LEVELS...AND COLDER BY LATE NEXT WEEK WITH HIGHS LIKELY IN
THE LOW TO MID 20S BY THURSDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 921 PM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
MVFR CIGS ALONG WITH PATCHY IFR FOG ACROSS PARTS OF NWRN THROUGH
CNTRL SD WILL SHIFT EAST OF THE AREA OVERNIGHT.

&&

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

$$

UPDATE...JOHNSON
SHORT TERM...MASEK
LONG TERM...BROOKS
AVIATION...JOHNSON








000
FXUS63 KUNR 190423
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
923 PM MST THU DEC 18 2014

.UPDATE...
ISSUED AT 731 PM MST THU DEC 18 2014

PATCHY FOG IS FORMING NEAR THE WRN EDGE OF STRATUS THAT IS SLOWLY
PUSHING EAST OF THE CWFA. WILL ADD PATCHY FOG TO OUR FAR ERN ZONES
FOR THE REST OF THE NIGHT...ALTHOUGH IT MAY CLEAR A BIT EARLIER
WITH DRIER SW/W FLOW EXPECTED TO DEVELOP OVERNIGHT.

&&

.SHORT TERM...TONIGHT AND TOMORROW
ISSUED AT 238 PM MST THU DEC 18 2014

UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE NORTHERN
PLAINS...WITH THE TROUGH AXIS SLIDING INTO THE EASTERN DAKOTAS.
ERODING OF THE LOW CLOUDS CONTINUES TO SPREAD ACROSS WESTERN S
DAKOTA...WITH MOST OF THE CWA NOW SEEING MOSTLY SUNNY SKIES AND
TEMPS ABOVE FREEZING. WITH MOSTLY CLEAR SKIES CONTINUING INTO THE
EVENING HOURS TEMPS WILL FALL QUICKLY INTO THE 20S AFTER SUNSET.
TEMPS BOTTOM OUT IN THE TEENS TO LOWER 20S. TOMORROW A WEEK
DISTURBANCE WILL MOVE ACROSS THE AREA. SOUNDINGS ARE FAIRLY DRY IN
THE LOWER LEVELS AND EXPECT ONLY SOME PASSING MID/HIGH CLOUDS. THIS
SHOULD NOT IMPEDE MUCH ON WARMING WITH HIGHS IN THE 30S TO LOWER 40S.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 238 PM MST THU DEC 18 2014

PRIMARY FORECAST CONCERNS IN THE MID RANGE OF THE FORECAST DEAL WITH
LIGHT SNOW CHANCES OVER NORTHEAST WYOMING SATURDAY MORNING AND WITH
A SLIGHT WARMING TREND IN TEMPERATURES THROUGH THE WEEKEND. FOCUS
THEN TURNS TO THE PATTERN SHIFT FOR NEXT WEEK AS IT TURNS ACTIVE FOR
MUCH OF NEXT WEEK.

A SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS SOUTH DAKOTA FRIDAY NIGHT
WITH ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC CROSSING THE NORTHERN
ROCKIES AND INTO NORTHEAST WYOMING BY 12Z SATURDAY. THE FIRST SYSTEM
WILL MOVE THROUGH DRY AS THERE IS A LARGE LACK OF MOISTURE TO WORK
WITH...BUT THERE MAY BE ENOUGH MOISTURE STILL WITH THE SECOND SYSTEM
AFTER CROSSING THE MOUNTAINS TO BRING SOME LIGHT PRECIPITATION TO
THE NORTHEAST CORNER OF WYOMING SATURDAY MORNING. THE GFS HAS A
CLEAR DRY LAYER JUST OFF THE SURFACE SO MAY NOT BE ENOUGH MOISTURE
TO MAKE IT THROUGH THE BOUNDARY LAYER FOR MEASURABLE PRECIPITATION.
THE NAM IS NOT AS ROBUST WITH THE DRY AIR BUT WOULD INDICATE THERE
MAY BE ENOUGH LIFT AND MOISTURE TO AT LEAST INCLUDE A SLIGHT MENTION
OF SNOW SATURDAY MORNING.

TEMPERATURES WILL SEE A SLIGHT MODERATION THROUGH THE WEEKEND.
BEHIND THE WEAK PACIFIC FRONT THAT MOVES THOUGH SATURDAY MORNING
WARMER AIR WILL BEGIN TO PUSH NORTH AS LONGWAVE RIDGING BUILDS OVER
THE EASTERN PACIFIC. BY SUNDAY...A LARGE AREA OF LOW PRESSURE AT THE
SURFACE DEVELOPS OVER SOUTHWEST CANADA WITH A TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE OF THE ROCKY MOUNTAINS. SOUTHERLY FLOW IN THE
LOWER LEVELS WILL BRING WARMER AIR NORTHWARD...WITH HIGHS EXPECTED
TO RISE INTO THE LOW AND MID 40S ACROSS PORTIONS OF THE FORECAST
AREA ON BOTH SATURDAY AND SUNDAY. A QUESTION WITH TEMPERATURES WILL
BE IF AND/OR HOW MUCH OF AN IMPACT THE SNOW COVER WILL IMPACT
TEMPERATURES. KEPT HIGHS A BIT COOLER WHERE SNOWPACK EXISTS...WHILE
OTHER AREAS SHOULD EASILY RISE INTO THE 30S AND 40S.

BY MONDAY...NORTHWEST FLOW ALOFT HAS BEEN ESTABLISHED ACROSS THE
NORTH CENTRAL PART OF THE CONUS AS THE UPPER LEVEL PATTERN CHANGES
WITH A LONGWAVE RIDGE OVER THE EASTERN PACIFIC AND A FAIRLY DEEP
TROUGH CENTERED ACROSS THE PLAINS AND MISSISSIPPI RIVER VALLEY. THE
MODELS ARE IN GOOD AGREEMENT WITH THIS PATTERN CHANGE WHICH LOOKS TO
STAY IN PLACE THROUGH THE WEEK. THIS PATTERN WILL KEEP THE WEATHER
ACTIVE THROUGH THE REMAINDER OF THE PERIOD AS MULTIPLE WEAK
SHORTWAVE TROUGHS PUSH OVER THE RIDGE AND PASS ACROSS THE LOCAL
AREA. TIMING OF THE INDIVIDUAL SYSTEMS IS PROBLEMATIC AS IS
TYPICALLY SEEN IN THESE PATTERNS SO IT IS QUITE DIFFICULT TRYING TO
PINPOINT WHEN THE HIGHER CHANCES FOR PRECIPITATION WILL BE. THIS
LEADS TO PRECIPITATION CHANCES THROUGH MOST DAYS MONDAY THROUGH
THURSDAY. WITH THE NORTHWEST FLOW THOUGH...WILL GET UPSLOPE FLOW
OVER THE BLACK HILLS MUCH OF THE PERIOD SO AS LONG AS THERE IS SOME
MOISTURE TO WORK WITH WILL GET SNOW TO DEVELOP AND THESE AREAS WILL
MAINTAIN THE MORE CONSISTENT AND HIGHER PRECIPITATION CHANCES.
AMOUNTS DON/T LOOK SIGNIFICANT WITH ANY OF THESE QUICK HITTING
SYSTEMS AT THIS POINT SO THE CURRENT FORECAST JUST HAS LIGHT AMOUNTS
CURRENTLY. BY WEDNESDAY NIGHT AND THURSDAY THE MODELS ARE DIGGING A
SLIGHTLY MORE SIGNIFICANT SHORTWAVE DOWN THROUGH THE CENTRAL
ROCKIES. IF THIS HOLDS OUT...THE PRECIPITATION WILL BE MOSTLY ACROSS
THE SOUTHWEST PART OF THE FORECAST AREA.

ONE THING THAT IS FAIRLY CERTAIN IS AS THE NORTHWEST FLOW IS
ESTABLISHED THAT TEMPERATURES WILL BE COOLING OFF BACK TO NEAR
NORMAL LEVELS...AND COLDER BY LATE NEXT WEEK WITH HIGHS LIKELY IN
THE LOW TO MID 20S BY THURSDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 921 PM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
MVFR CIGS ALONG WITH PATCHY IFR FOG ACROSS PARTS OF NWRN THROUGH
CNTRL SD WILL SHIFT EAST OF THE AREA OVERNIGHT.

&&

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

$$

UPDATE...JOHNSON
SHORT TERM...MASEK
LONG TERM...BROOKS
AVIATION...JOHNSON









000
FXUS63 KUNR 190236
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
736 PM MST THU DEC 18 2014

.UPDATE...
ISSUED AT 731 PM MST THU DEC 18 2014

PATCHY FOG IS FORMING NEAR THE WRN EDGE OF STRATUS THAT IS SLOWLY
PUSHING EAST OF THE CWFA. WILL ADD PATCHY FOG TO OUR FAR ERN ZONES
FOR THE REST OF THE NIGHT...ALTHOUGH IT MAY CLEAR A BIT EARLIER
WITH DRIER SW/W FLOW EXPECTED TO DEVELOP OVERNIGHT.

&&

.SHORT TERM...TONIGHT AND TOMORROW
ISSUED AT 238 PM MST THU DEC 18 2014

UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE NORTHERN
PLAINS...WITH THE TROUGH AXIS SLIDING INTO THE EASTERN DAKOTAS.
ERODING OF THE LOW CLOUDS CONTINUES TO SPREAD ACROSS WESTERN S
DAKOTA...WITH MOST OF THE CWA NOW SEEING MOSTLY SUNNY SKIES AND
TEMPS ABOVE FREEZING. WITH MOSTLY CLEAR SKIES CONTINUING INTO THE
EVENING HOURS TEMPS WILL FALL QUICKLY INTO THE 20S AFTER SUNSET.
TEMPS BOTTOM OUT IN THE TEENS TO LOWER 20S. TOMORROW A WEEK
DISTURBANCE WILL MOVE ACROSS THE AREA. SOUNDINGS ARE FAIRLY DRY IN
THE LOWER LEVELS AND EXPECT ONLY SOME PASSING MID/HIGH CLOUDS. THIS
SHOULD NOT IMPEDE MUCH ON WARMING WITH HIGHS IN THE 30S TO LOWER 40S.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 238 PM MST THU DEC 18 2014

PRIMARY FORECAST CONCERNS IN THE MID RANGE OF THE FORECAST DEAL WITH
LIGHT SNOW CHANCES OVER NORTHEAST WYOMING SATURDAY MORNING AND WITH
A SLIGHT WARMING TREND IN TEMPERATURES THROUGH THE WEEKEND. FOCUS
THEN TURNS TO THE PATTERN SHIFT FOR NEXT WEEK AS IT TURNS ACTIVE FOR
MUCH OF NEXT WEEK.

A SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS SOUTH DAKOTA FRIDAY NIGHT
WITH ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC CROSSING THE NORTHERN
ROCKIES AND INTO NORTHEAST WYOMING BY 12Z SATURDAY. THE FIRST SYSTEM
WILL MOVE THROUGH DRY AS THERE IS A LARGE LACK OF MOISTURE TO WORK
WITH...BUT THERE MAY BE ENOUGH MOISTURE STILL WITH THE SECOND SYSTEM
AFTER CROSSING THE MOUNTAINS TO BRING SOME LIGHT PRECIPITATION TO
THE NORTHEAST CORNER OF WYOMING SATURDAY MORNING. THE GFS HAS A
CLEAR DRY LAYER JUST OFF THE SURFACE SO MAY NOT BE ENOUGH MOISTURE
TO MAKE IT THROUGH THE BOUNDARY LAYER FOR MEASURABLE PRECIPITATION.
THE NAM IS NOT AS ROBUST WITH THE DRY AIR BUT WOULD INDICATE THERE
MAY BE ENOUGH LIFT AND MOISTURE TO AT LEAST INCLUDE A SLIGHT MENTION
OF SNOW SATURDAY MORNING.

TEMPERATURES WILL SEE A SLIGHT MODERATION THROUGH THE WEEKEND.
BEHIND THE WEAK PACIFIC FRONT THAT MOVES THOUGH SATURDAY MORNING
WARMER AIR WILL BEGIN TO PUSH NORTH AS LONGWAVE RIDGING BUILDS OVER
THE EASTERN PACIFIC. BY SUNDAY...A LARGE AREA OF LOW PRESSURE AT THE
SURFACE DEVELOPS OVER SOUTHWEST CANADA WITH A TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE OF THE ROCKY MOUNTAINS. SOUTHERLY FLOW IN THE
LOWER LEVELS WILL BRING WARMER AIR NORTHWARD...WITH HIGHS EXPECTED
TO RISE INTO THE LOW AND MID 40S ACROSS PORTIONS OF THE FORECAST
AREA ON BOTH SATURDAY AND SUNDAY. A QUESTION WITH TEMPERATURES WILL
BE IF AND/OR HOW MUCH OF AN IMPACT THE SNOW COVER WILL IMPACT
TEMPERATURES. KEPT HIGHS A BIT COOLER WHERE SNOWPACK EXISTS...WHILE
OTHER AREAS SHOULD EASILY RISE INTO THE 30S AND 40S.

BY MONDAY...NORTHWEST FLOW ALOFT HAS BEEN ESTABLISHED ACROSS THE
NORTH CENTRAL PART OF THE CONUS AS THE UPPER LEVEL PATTERN CHANGES
WITH A LONGWAVE RIDGE OVER THE EASTERN PACIFIC AND A FAIRLY DEEP
TROUGH CENTERED ACROSS THE PLAINS AND MISSISSIPPI RIVER VALLEY. THE
MODELS ARE IN GOOD AGREEMENT WITH THIS PATTERN CHANGE WHICH LOOKS TO
STAY IN PLACE THROUGH THE WEEK. THIS PATTERN WILL KEEP THE WEATHER
ACTIVE THROUGH THE REMAINDER OF THE PERIOD AS MULTIPLE WEAK
SHORTWAVE TROUGHS PUSH OVER THE RIDGE AND PASS ACROSS THE LOCAL
AREA. TIMING OF THE INDIVIDUAL SYSTEMS IS PROBLEMATIC AS IS
TYPICALLY SEEN IN THESE PATTERNS SO IT IS QUITE DIFFICULT TRYING TO
PINPOINT WHEN THE HIGHER CHANCES FOR PRECIPITATION WILL BE. THIS
LEADS TO PRECIPITATION CHANCES THROUGH MOST DAYS MONDAY THROUGH
THURSDAY. WITH THE NORTHWEST FLOW THOUGH...WILL GET UPSLOPE FLOW
OVER THE BLACK HILLS MUCH OF THE PERIOD SO AS LONG AS THERE IS SOME
MOISTURE TO WORK WITH WILL GET SNOW TO DEVELOP AND THESE AREAS WILL
MAINTAIN THE MORE CONSISTENT AND HIGHER PRECIPITATION CHANCES.
AMOUNTS DON/T LOOK SIGNIFICANT WITH ANY OF THESE QUICK HITTING
SYSTEMS AT THIS POINT SO THE CURRENT FORECAST JUST HAS LIGHT AMOUNTS
CURRENTLY. BY WEDNESDAY NIGHT AND THURSDAY THE MODELS ARE DIGGING A
SLIGHTLY MORE SIGNIFICANT SHORTWAVE DOWN THROUGH THE CENTRAL
ROCKIES. IF THIS HOLDS OUT...THE PRECIPITATION WILL BE MOSTLY ACROSS
THE SOUTHWEST PART OF THE FORECAST AREA.

ONE THING THAT IS FAIRLY CERTAIN IS AS THE NORTHWEST FLOW IS
ESTABLISHED THAT TEMPERATURES WILL BE COOLING OFF BACK TO NEAR
NORMAL LEVELS...AND COLDER BY LATE NEXT WEEK WITH HIGHS LIKELY IN
THE LOW TO MID 20S BY THURSDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 731 PM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
MVFR CIGS ALONG WITH PATCHY IFR FOG ACROSS PARTS OF NWRN THROUGH
CNTRL SD WILL SHIFT EAST OF THE AREA OVERNIGHT.

&&

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

$$

UPDATE...JOHNSON
SHORT TERM...MASEK
LONG TERM...BROOKS
AVIATION...JOHNSON








000
FXUS63 KUNR 190236
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
736 PM MST THU DEC 18 2014

.UPDATE...
ISSUED AT 731 PM MST THU DEC 18 2014

PATCHY FOG IS FORMING NEAR THE WRN EDGE OF STRATUS THAT IS SLOWLY
PUSHING EAST OF THE CWFA. WILL ADD PATCHY FOG TO OUR FAR ERN ZONES
FOR THE REST OF THE NIGHT...ALTHOUGH IT MAY CLEAR A BIT EARLIER
WITH DRIER SW/W FLOW EXPECTED TO DEVELOP OVERNIGHT.

&&

.SHORT TERM...TONIGHT AND TOMORROW
ISSUED AT 238 PM MST THU DEC 18 2014

UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE NORTHERN
PLAINS...WITH THE TROUGH AXIS SLIDING INTO THE EASTERN DAKOTAS.
ERODING OF THE LOW CLOUDS CONTINUES TO SPREAD ACROSS WESTERN S
DAKOTA...WITH MOST OF THE CWA NOW SEEING MOSTLY SUNNY SKIES AND
TEMPS ABOVE FREEZING. WITH MOSTLY CLEAR SKIES CONTINUING INTO THE
EVENING HOURS TEMPS WILL FALL QUICKLY INTO THE 20S AFTER SUNSET.
TEMPS BOTTOM OUT IN THE TEENS TO LOWER 20S. TOMORROW A WEEK
DISTURBANCE WILL MOVE ACROSS THE AREA. SOUNDINGS ARE FAIRLY DRY IN
THE LOWER LEVELS AND EXPECT ONLY SOME PASSING MID/HIGH CLOUDS. THIS
SHOULD NOT IMPEDE MUCH ON WARMING WITH HIGHS IN THE 30S TO LOWER 40S.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 238 PM MST THU DEC 18 2014

PRIMARY FORECAST CONCERNS IN THE MID RANGE OF THE FORECAST DEAL WITH
LIGHT SNOW CHANCES OVER NORTHEAST WYOMING SATURDAY MORNING AND WITH
A SLIGHT WARMING TREND IN TEMPERATURES THROUGH THE WEEKEND. FOCUS
THEN TURNS TO THE PATTERN SHIFT FOR NEXT WEEK AS IT TURNS ACTIVE FOR
MUCH OF NEXT WEEK.

A SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS SOUTH DAKOTA FRIDAY NIGHT
WITH ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC CROSSING THE NORTHERN
ROCKIES AND INTO NORTHEAST WYOMING BY 12Z SATURDAY. THE FIRST SYSTEM
WILL MOVE THROUGH DRY AS THERE IS A LARGE LACK OF MOISTURE TO WORK
WITH...BUT THERE MAY BE ENOUGH MOISTURE STILL WITH THE SECOND SYSTEM
AFTER CROSSING THE MOUNTAINS TO BRING SOME LIGHT PRECIPITATION TO
THE NORTHEAST CORNER OF WYOMING SATURDAY MORNING. THE GFS HAS A
CLEAR DRY LAYER JUST OFF THE SURFACE SO MAY NOT BE ENOUGH MOISTURE
TO MAKE IT THROUGH THE BOUNDARY LAYER FOR MEASURABLE PRECIPITATION.
THE NAM IS NOT AS ROBUST WITH THE DRY AIR BUT WOULD INDICATE THERE
MAY BE ENOUGH LIFT AND MOISTURE TO AT LEAST INCLUDE A SLIGHT MENTION
OF SNOW SATURDAY MORNING.

TEMPERATURES WILL SEE A SLIGHT MODERATION THROUGH THE WEEKEND.
BEHIND THE WEAK PACIFIC FRONT THAT MOVES THOUGH SATURDAY MORNING
WARMER AIR WILL BEGIN TO PUSH NORTH AS LONGWAVE RIDGING BUILDS OVER
THE EASTERN PACIFIC. BY SUNDAY...A LARGE AREA OF LOW PRESSURE AT THE
SURFACE DEVELOPS OVER SOUTHWEST CANADA WITH A TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE OF THE ROCKY MOUNTAINS. SOUTHERLY FLOW IN THE
LOWER LEVELS WILL BRING WARMER AIR NORTHWARD...WITH HIGHS EXPECTED
TO RISE INTO THE LOW AND MID 40S ACROSS PORTIONS OF THE FORECAST
AREA ON BOTH SATURDAY AND SUNDAY. A QUESTION WITH TEMPERATURES WILL
BE IF AND/OR HOW MUCH OF AN IMPACT THE SNOW COVER WILL IMPACT
TEMPERATURES. KEPT HIGHS A BIT COOLER WHERE SNOWPACK EXISTS...WHILE
OTHER AREAS SHOULD EASILY RISE INTO THE 30S AND 40S.

BY MONDAY...NORTHWEST FLOW ALOFT HAS BEEN ESTABLISHED ACROSS THE
NORTH CENTRAL PART OF THE CONUS AS THE UPPER LEVEL PATTERN CHANGES
WITH A LONGWAVE RIDGE OVER THE EASTERN PACIFIC AND A FAIRLY DEEP
TROUGH CENTERED ACROSS THE PLAINS AND MISSISSIPPI RIVER VALLEY. THE
MODELS ARE IN GOOD AGREEMENT WITH THIS PATTERN CHANGE WHICH LOOKS TO
STAY IN PLACE THROUGH THE WEEK. THIS PATTERN WILL KEEP THE WEATHER
ACTIVE THROUGH THE REMAINDER OF THE PERIOD AS MULTIPLE WEAK
SHORTWAVE TROUGHS PUSH OVER THE RIDGE AND PASS ACROSS THE LOCAL
AREA. TIMING OF THE INDIVIDUAL SYSTEMS IS PROBLEMATIC AS IS
TYPICALLY SEEN IN THESE PATTERNS SO IT IS QUITE DIFFICULT TRYING TO
PINPOINT WHEN THE HIGHER CHANCES FOR PRECIPITATION WILL BE. THIS
LEADS TO PRECIPITATION CHANCES THROUGH MOST DAYS MONDAY THROUGH
THURSDAY. WITH THE NORTHWEST FLOW THOUGH...WILL GET UPSLOPE FLOW
OVER THE BLACK HILLS MUCH OF THE PERIOD SO AS LONG AS THERE IS SOME
MOISTURE TO WORK WITH WILL GET SNOW TO DEVELOP AND THESE AREAS WILL
MAINTAIN THE MORE CONSISTENT AND HIGHER PRECIPITATION CHANCES.
AMOUNTS DON/T LOOK SIGNIFICANT WITH ANY OF THESE QUICK HITTING
SYSTEMS AT THIS POINT SO THE CURRENT FORECAST JUST HAS LIGHT AMOUNTS
CURRENTLY. BY WEDNESDAY NIGHT AND THURSDAY THE MODELS ARE DIGGING A
SLIGHTLY MORE SIGNIFICANT SHORTWAVE DOWN THROUGH THE CENTRAL
ROCKIES. IF THIS HOLDS OUT...THE PRECIPITATION WILL BE MOSTLY ACROSS
THE SOUTHWEST PART OF THE FORECAST AREA.

ONE THING THAT IS FAIRLY CERTAIN IS AS THE NORTHWEST FLOW IS
ESTABLISHED THAT TEMPERATURES WILL BE COOLING OFF BACK TO NEAR
NORMAL LEVELS...AND COLDER BY LATE NEXT WEEK WITH HIGHS LIKELY IN
THE LOW TO MID 20S BY THURSDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 731 PM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
MVFR CIGS ALONG WITH PATCHY IFR FOG ACROSS PARTS OF NWRN THROUGH
CNTRL SD WILL SHIFT EAST OF THE AREA OVERNIGHT.

&&

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

$$

UPDATE...JOHNSON
SHORT TERM...MASEK
LONG TERM...BROOKS
AVIATION...JOHNSON







000
FXUS63 KUNR 182306
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
406 PM MST THU DEC 18 2014

.SHORT TERM...TONIGHT AND TOMORROW
ISSUED AT 238 PM MST THU DEC 18 2014

UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE NORTHERN
PLAINS...WITH THE TROUGH AXIS SLIDING INTO THE EASTERN DAKOTAS.
ERODING OF THE LOW CLOUDS CONTINUES TO SPREAD ACROSS WESTERN S
DAKOTA...WITH MOST OF THE CWA NOW SEEING MOSTLY SUNNY SKIES AND
TEMPS ABOVE FREEZING. WITH MOSTLY CLEAR SKIES CONTINUING INTO THE
EVENING HOURS TEMPS WILL FALL QUICKLY INTO THE 20S AFTER SUNSET.
TEMPS BOTTOM OUT IN THE TEENS TO LOWER 20S. TOMORROW A WEEK
DISTURBANCE WILL MOVE ACROSS THE AREA. SOUNDINGS ARE FAIRLY DRY IN
THE LOWER LEVELS AND EXPECT ONLY SOME PASSING MID/HIGH CLOUDS. THIS
SHOULD NOT IMPEDE MUCH ON WARMING WITH HIGHS IN THE 30S TO LOWER 40S.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 238 PM MST THU DEC 18 2014

PRIMARY FORECAST CONCERNS IN THE MID RANGE OF THE FORECAST DEAL WITH
LIGHT SNOW CHANCES OVER NORTHEAST WYOMING SATURDAY MORNING AND WITH
A SLIGHT WARMING TREND IN TEMPERATURES THROUGH THE WEEKEND. FOCUS
THEN TURNS TO THE PATTERN SHIFT FOR NEXT WEEK AS IT TURNS ACTIVE FOR
MUCH OF NEXT WEEK.

A SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS SOUTH DAKOTA FRIDAY NIGHT
WITH ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC CROSSING THE NORTHERN
ROCKIES AND INTO NORTHEAST WYOMING BY 12Z SATURDAY. THE FIRST SYSTEM
WILL MOVE THROUGH DRY AS THERE IS A LARGE LACK OF MOISTURE TO WORK
WITH...BUT THERE MAY BE ENOUGH MOISTURE STILL WITH THE SECOND SYSTEM
AFTER CROSSING THE MOUNTAINS TO BRING SOME LIGHT PRECIPITATION TO
THE NORTHEAST CORNER OF WYOMING SATURDAY MORNING. THE GFS HAS A
CLEAR DRY LAYER JUST OFF THE SURFACE SO MAY NOT BE ENOUGH MOISTURE
TO MAKE IT THROUGH THE BOUNDARY LAYER FOR MEASURABLE PRECIPITATION.
THE NAM IS NOT AS ROBUST WITH THE DRY AIR BUT WOULD INDICATE THERE
MAY BE ENOUGH LIFT AND MOISTURE TO AT LEAST INCLUDE A SLIGHT MENTION
OF SNOW SATURDAY MORNING.

TEMPERATURES WILL SEE A SLIGHT MODERATION THROUGH THE WEEKEND.
BEHIND THE WEAK PACIFIC FRONT THAT MOVES THOUGH SATURDAY MORNING
WARMER AIR WILL BEGIN TO PUSH NORTH AS LONGWAVE RIDGING BUILDS OVER
THE EASTERN PACIFIC. BY SUNDAY...A LARGE AREA OF LOW PRESSURE AT THE
SURFACE DEVELOPS OVER SOUTHWEST CANADA WITH A TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE OF THE ROCKY MOUNTAINS. SOUTHERLY FLOW IN THE
LOWER LEVELS WILL BRING WARMER AIR NORTHWARD...WITH HIGHS EXPECTED
TO RISE INTO THE LOW AND MID 40S ACROSS PORTIONS OF THE FORECAST
AREA ON BOTH SATURDAY AND SUNDAY. A QUESTION WITH TEMPERATURES WILL
BE IF AND/OR HOW MUCH OF AN IMPACT THE SNOW COVER WILL IMPACT
TEMPERATURES. KEPT HIGHS A BIT COOLER WHERE SNOWPACK EXISTS...WHILE
OTHER AREAS SHOULD EASILY RISE INTO THE 30S AND 40S.

BY MONDAY...NORTHWEST FLOW ALOFT HAS BEEN ESTABLISHED ACROSS THE
NORTH CENTRAL PART OF THE CONUS AS THE UPPER LEVEL PATTERN CHANGES
WITH A LONGWAVE RIDGE OVER THE EASTERN PACIFIC AND A FAIRLY DEEP
TROUGH CENTERED ACROSS THE PLAINS AND MISSISSIPPI RIVER VALLEY. THE
MODELS ARE IN GOOD AGREEMENT WITH THIS PATTERN CHANGE WHICH LOOKS TO
STAY IN PLACE THROUGH THE WEEK. THIS PATTERN WILL KEEP THE WEATHER
ACTIVE THROUGH THE REMAINDER OF THE PERIOD AS MULTIPLE WEAK
SHORTWAVE TROUGHS PUSH OVER THE RIDGE AND PASS ACROSS THE LOCAL
AREA. TIMING OF THE INDIVIDUAL SYSTEMS IS PROBLEMATIC AS IS
TYPICALLY SEEN IN THESE PATTERNS SO IT IS QUITE DIFFICULT TRYING TO
PINPOINT WHEN THE HIGHER CHANCES FOR PRECIPITATION WILL BE. THIS
LEADS TO PRECIPITATION CHANCES THROUGH MOST DAYS MONDAY THROUGH
THURSDAY. WITH THE NORTHWEST FLOW THOUGH...WILL GET UPSLOPE FLOW
OVER THE BLACK HILLS MUCH OF THE PERIOD SO AS LONG AS THERE IS SOME
MOISTURE TO WORK WITH WILL GET SNOW TO DEVELOP AND THESE AREAS WILL
MAINTAIN THE MORE CONSISTENT AND HIGHER PRECIPITATION CHANCES.
AMOUNTS DON/T LOOK SIGNIFICANT WITH ANY OF THESE QUICK HITTING
SYSTEMS AT THIS POINT SO THE CURRENT FORECAST JUST HAS LIGHT AMOUNTS
CURRENTLY. BY WEDNESDAY NIGHT AND THURSDAY THE MODELS ARE DIGGING A
SLIGHTLY MORE SIGNIFICANT SHORTWAVE DOWN THROUGH THE CENTRAL
ROCKIES. IF THIS HOLDS OUT...THE PRECIPITATION WILL BE MOSTLY ACROSS
THE SOUTHWEST PART OF THE FORECAST AREA.

ONE THING THAT IS FAIRLY CERTAIN IS AS THE NORTHWEST FLOW IS
ESTABLISHED THAT TEMPERATURES WILL BE COOLING OFF BACK TO NEAR
NORMAL LEVELS...AND COLDER BY LATE NEXT WEEK WITH HIGHS LIKELY IN
THE LOW TO MID 20S BY THURSDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 403 PM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
MVFR CIGS ACROSS PARTS OF CNTRL SD WILL SHIFT EAST OF THE AREA BY
EARLY THIS EVENING.

&&

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

$$

SHORT TERM...MASEK
LONG TERM...BROOKS
AVIATION...JOHNSON







000
FXUS63 KUNR 182306
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
406 PM MST THU DEC 18 2014

.SHORT TERM...TONIGHT AND TOMORROW
ISSUED AT 238 PM MST THU DEC 18 2014

UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE NORTHERN
PLAINS...WITH THE TROUGH AXIS SLIDING INTO THE EASTERN DAKOTAS.
ERODING OF THE LOW CLOUDS CONTINUES TO SPREAD ACROSS WESTERN S
DAKOTA...WITH MOST OF THE CWA NOW SEEING MOSTLY SUNNY SKIES AND
TEMPS ABOVE FREEZING. WITH MOSTLY CLEAR SKIES CONTINUING INTO THE
EVENING HOURS TEMPS WILL FALL QUICKLY INTO THE 20S AFTER SUNSET.
TEMPS BOTTOM OUT IN THE TEENS TO LOWER 20S. TOMORROW A WEEK
DISTURBANCE WILL MOVE ACROSS THE AREA. SOUNDINGS ARE FAIRLY DRY IN
THE LOWER LEVELS AND EXPECT ONLY SOME PASSING MID/HIGH CLOUDS. THIS
SHOULD NOT IMPEDE MUCH ON WARMING WITH HIGHS IN THE 30S TO LOWER 40S.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 238 PM MST THU DEC 18 2014

PRIMARY FORECAST CONCERNS IN THE MID RANGE OF THE FORECAST DEAL WITH
LIGHT SNOW CHANCES OVER NORTHEAST WYOMING SATURDAY MORNING AND WITH
A SLIGHT WARMING TREND IN TEMPERATURES THROUGH THE WEEKEND. FOCUS
THEN TURNS TO THE PATTERN SHIFT FOR NEXT WEEK AS IT TURNS ACTIVE FOR
MUCH OF NEXT WEEK.

A SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS SOUTH DAKOTA FRIDAY NIGHT
WITH ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC CROSSING THE NORTHERN
ROCKIES AND INTO NORTHEAST WYOMING BY 12Z SATURDAY. THE FIRST SYSTEM
WILL MOVE THROUGH DRY AS THERE IS A LARGE LACK OF MOISTURE TO WORK
WITH...BUT THERE MAY BE ENOUGH MOISTURE STILL WITH THE SECOND SYSTEM
AFTER CROSSING THE MOUNTAINS TO BRING SOME LIGHT PRECIPITATION TO
THE NORTHEAST CORNER OF WYOMING SATURDAY MORNING. THE GFS HAS A
CLEAR DRY LAYER JUST OFF THE SURFACE SO MAY NOT BE ENOUGH MOISTURE
TO MAKE IT THROUGH THE BOUNDARY LAYER FOR MEASURABLE PRECIPITATION.
THE NAM IS NOT AS ROBUST WITH THE DRY AIR BUT WOULD INDICATE THERE
MAY BE ENOUGH LIFT AND MOISTURE TO AT LEAST INCLUDE A SLIGHT MENTION
OF SNOW SATURDAY MORNING.

TEMPERATURES WILL SEE A SLIGHT MODERATION THROUGH THE WEEKEND.
BEHIND THE WEAK PACIFIC FRONT THAT MOVES THOUGH SATURDAY MORNING
WARMER AIR WILL BEGIN TO PUSH NORTH AS LONGWAVE RIDGING BUILDS OVER
THE EASTERN PACIFIC. BY SUNDAY...A LARGE AREA OF LOW PRESSURE AT THE
SURFACE DEVELOPS OVER SOUTHWEST CANADA WITH A TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE OF THE ROCKY MOUNTAINS. SOUTHERLY FLOW IN THE
LOWER LEVELS WILL BRING WARMER AIR NORTHWARD...WITH HIGHS EXPECTED
TO RISE INTO THE LOW AND MID 40S ACROSS PORTIONS OF THE FORECAST
AREA ON BOTH SATURDAY AND SUNDAY. A QUESTION WITH TEMPERATURES WILL
BE IF AND/OR HOW MUCH OF AN IMPACT THE SNOW COVER WILL IMPACT
TEMPERATURES. KEPT HIGHS A BIT COOLER WHERE SNOWPACK EXISTS...WHILE
OTHER AREAS SHOULD EASILY RISE INTO THE 30S AND 40S.

BY MONDAY...NORTHWEST FLOW ALOFT HAS BEEN ESTABLISHED ACROSS THE
NORTH CENTRAL PART OF THE CONUS AS THE UPPER LEVEL PATTERN CHANGES
WITH A LONGWAVE RIDGE OVER THE EASTERN PACIFIC AND A FAIRLY DEEP
TROUGH CENTERED ACROSS THE PLAINS AND MISSISSIPPI RIVER VALLEY. THE
MODELS ARE IN GOOD AGREEMENT WITH THIS PATTERN CHANGE WHICH LOOKS TO
STAY IN PLACE THROUGH THE WEEK. THIS PATTERN WILL KEEP THE WEATHER
ACTIVE THROUGH THE REMAINDER OF THE PERIOD AS MULTIPLE WEAK
SHORTWAVE TROUGHS PUSH OVER THE RIDGE AND PASS ACROSS THE LOCAL
AREA. TIMING OF THE INDIVIDUAL SYSTEMS IS PROBLEMATIC AS IS
TYPICALLY SEEN IN THESE PATTERNS SO IT IS QUITE DIFFICULT TRYING TO
PINPOINT WHEN THE HIGHER CHANCES FOR PRECIPITATION WILL BE. THIS
LEADS TO PRECIPITATION CHANCES THROUGH MOST DAYS MONDAY THROUGH
THURSDAY. WITH THE NORTHWEST FLOW THOUGH...WILL GET UPSLOPE FLOW
OVER THE BLACK HILLS MUCH OF THE PERIOD SO AS LONG AS THERE IS SOME
MOISTURE TO WORK WITH WILL GET SNOW TO DEVELOP AND THESE AREAS WILL
MAINTAIN THE MORE CONSISTENT AND HIGHER PRECIPITATION CHANCES.
AMOUNTS DON/T LOOK SIGNIFICANT WITH ANY OF THESE QUICK HITTING
SYSTEMS AT THIS POINT SO THE CURRENT FORECAST JUST HAS LIGHT AMOUNTS
CURRENTLY. BY WEDNESDAY NIGHT AND THURSDAY THE MODELS ARE DIGGING A
SLIGHTLY MORE SIGNIFICANT SHORTWAVE DOWN THROUGH THE CENTRAL
ROCKIES. IF THIS HOLDS OUT...THE PRECIPITATION WILL BE MOSTLY ACROSS
THE SOUTHWEST PART OF THE FORECAST AREA.

ONE THING THAT IS FAIRLY CERTAIN IS AS THE NORTHWEST FLOW IS
ESTABLISHED THAT TEMPERATURES WILL BE COOLING OFF BACK TO NEAR
NORMAL LEVELS...AND COLDER BY LATE NEXT WEEK WITH HIGHS LIKELY IN
THE LOW TO MID 20S BY THURSDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 403 PM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
MVFR CIGS ACROSS PARTS OF CNTRL SD WILL SHIFT EAST OF THE AREA BY
EARLY THIS EVENING.

&&

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

$$

SHORT TERM...MASEK
LONG TERM...BROOKS
AVIATION...JOHNSON








000
FXUS63 KUNR 182139
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
ISSUED BY NATIONAL WEATHER SERVICE NORTH PLATTE NE
239 PM MST THU DEC 18 2014

.SHORT TERM...TONIGHT AND TOMORROW
ISSUED AT 238 PM MST THU DEC 18 2014

UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE NORTHERN
PLAINS...WITH THE TROUGH AXIS SLIDING INTO THE EASTERN DAKOTAS.
ERODING OF THE LOW CLOUDS CONTINUES TO SPREAD ACROSS WESTERN S
DAKOTA...WITH MOST OF THE CWA NOW SEEING MOSTLY SUNNY SKIES AND
TEMPS ABOVE FREEZING. WITH MOSTLY CLEAR SKIES CONTINUING INTO THE
EVENING HOURS TEMPS WILL FALL QUICKLY INTO THE 20S AFTER SUNSET.
TEMPS BOTTOM OUT IN THE TEENS TO LOWER 20S. TOMORROW A WEEK
DISTURBANCE WILL MOVE ACROSS THE AREA. SOUNDINGS ARE FAIRLY DRY IN
THE LOWER LEVELS AND EXPECT ONLY SOME PASSING MID/HIGH CLOUDS. THIS
SHOULD NOT IMPEDE MUCH ON WARMING WITH HIGHS IN THE 30S TO LOWER 40S.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 238 PM MST THU DEC 18 2014

PRIMARY FORECAST CONCERNS IN THE MID RANGE OF THE FORECAST DEAL WITH
LIGHT SNOW CHANCES OVER NORTHEAST WYOMING SATURDAY MORNING AND WITH
A SLIGHT WARMING TREND IN TEMPERATURES THROUGH THE WEEKEND. FOCUS
THEN TURNS TO THE PATTERN SHIFT FOR NEXT WEEK AS IT TURNS ACTIVE FOR
MUCH OF NEXT WEEK.

A SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS SOUTH DAKOTA FRIDAY NIGHT
WITH ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC CROSSING THE NORTHERN
ROCKIES AND INTO NORTHEAST WYOMING BY 12Z SATURDAY. THE FIRST SYSTEM
WILL MOVE THROUGH DRY AS THERE IS A LARGE LACK OF MOISTURE TO WORK
WITH...BUT THERE MAY BE ENOUGH MOISTURE STILL WITH THE SECOND SYSTEM
AFTER CROSSING THE MOUNTAINS TO BRING SOME LIGHT PRECIPITATION TO
THE NORTHEAST CORNER OF WYOMING SATURDAY MORNING. THE GFS HAS A
CLEAR DRY LAYER JUST OFF THE SURFACE SO MAY NOT BE ENOUGH MOISTURE
TO MAKE IT THROUGH THE BOUNDARY LAYER FOR MEASURABLE PRECIPITATION.
THE NAM IS NOT AS ROBUST WITH THE DRY AIR BUT WOULD INDICATE THERE
MAY BE ENOUGH LIFT AND MOISTURE TO AT LEAST INCLUDE A SLIGHT MENTION
OF SNOW SATURDAY MORNING.

TEMPERATURES WILL SEE A SLIGHT MODERATION THROUGH THE WEEKEND.
BEHIND THE WEAK PACIFIC FRONT THAT MOVES THOUGH SATURDAY MORNING
WARMER AIR WILL BEGIN TO PUSH NORTH AS LONGWAVE RIDGING BUILDS OVER
THE EASTERN PACIFIC. BY SUNDAY...A LARGE AREA OF LOW PRESSURE AT THE
SURFACE DEVELOPS OVER SOUTHWEST CANADA WITH A TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE OF THE ROCKY MOUNTAINS. SOUTHERLY FLOW IN THE
LOWER LEVELS WILL BRING WARMER AIR NORTHWARD...WITH HIGHS EXPECTED
TO RISE INTO THE LOW AND MID 40S ACROSS PORTIONS OF THE FORECAST
AREA ON BOTH SATURDAY AND SUNDAY. A QUESTION WITH TEMPERATURES WILL
BE IF AND/OR HOW MUCH OF AN IMPACT THE SNOW COVER WILL IMPACT
TEMPERATURES. KEPT HIGHS A BIT COOLER WHERE SNOWPACK EXISTS...WHILE
OTHER AREAS SHOULD EASILY RISE INTO THE 30S AND 40S.

BY MONDAY...NORTHWEST FLOW ALOFT HAS BEEN ESTABLISHED ACROSS THE
NORTH CENTRAL PART OF THE CONUS AS THE UPPER LEVEL PATTERN CHANGES
WITH A LONGWAVE RIDGE OVER THE EASTERN PACIFIC AND A FAIRLY DEEP
TROUGH CENTERED ACROSS THE PLAINS AND MISSISSIPPI RIVER VALLEY. THE
MODELS ARE IN GOOD AGREEMENT WITH THIS PATTERN CHANGE WHICH LOOKS TO
STAY IN PLACE THROUGH THE WEEK. THIS PATTERN WILL KEEP THE WEATHER
ACTIVE THROUGH THE REMAINDER OF THE PERIOD AS MULTIPLE WEAK
SHORTWAVE TROUGHS PUSH OVER THE RIDGE AND PASS ACROSS THE LOCAL
AREA. TIMING OF THE INDIVIDUAL SYSTEMS IS PROBLEMATIC AS IS
TYPICALLY SEEN IN THESE PATTERNS SO IT IS QUITE DIFFICULT TRYING TO
PINPOINT WHEN THE HIGHER CHANCES FOR PRECIPITATION WILL BE. THIS
LEADS TO PRECIPITATION CHANCES THROUGH MOST DAYS MONDAY THROUGH
THURSDAY. WITH THE NORTHWEST FLOW THOUGH...WILL GET UPSLOPE FLOW
OVER THE BLACK HILLS MUCH OF THE PERIOD SO AS LONG AS THERE IS SOME
MOISTURE TO WORK WITH WILL GET SNOW TO DEVELOP AND THESE AREAS WILL
MAINTAIN THE MORE CONSISTENT AND HIGHER PRECIPITATION CHANCES.
AMOUNTS DON/T LOOK SIGNIFICANT WITH ANY OF THESE QUICK HITTING
SYSTEMS AT THIS POINT SO THE CURRENT FORECAST JUST HAS LIGHT AMOUNTS
CURRENTLY. BY WEDNESDAY NIGHT AND THURSDAY THE MODELS ARE DIGGING A
SLIGHTLY MORE SIGNIFICANT SHORTWAVE DOWN THROUGH THE CENTRAL
ROCKIES. IF THIS HOLDS OUT...THE PRECIPITATION WILL BE MOSTLY ACROSS
THE SOUTHWEST PART OF THE FORECAST AREA.

ONE THING THAT IS FAIRLY CERTAIN IS AS THE NORTHWEST FLOW IS
ESTABLISHED THAT TEMPERATURES WILL BE COOLING OFF BACK TO NEAR
NORMAL LEVELS...AND COLDER BY LATE NEXT WEEK WITH HIGHS LIKELY IN
THE LOW TO MID 20S BY THURSDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1044 AM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
STRATUS/FOG HAS LIFTED THIS MORNING AND EXPECT THE STRATUS/FOG TO
REMAIN EAST OF THE KRAP OVERNIGHT AS WINDS BECOME LIGHT
NORTHWESTERLY.


&&

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

$$

SHORT TERM...MASEK
LONG TERM...BROOKS
AVIATION...MASEK











000
FXUS63 KUNR 182139
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
ISSUED BY NATIONAL WEATHER SERVICE NORTH PLATTE NE
239 PM MST THU DEC 18 2014

.SHORT TERM...TONIGHT AND TOMORROW
ISSUED AT 238 PM MST THU DEC 18 2014

UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE NORTHERN
PLAINS...WITH THE TROUGH AXIS SLIDING INTO THE EASTERN DAKOTAS.
ERODING OF THE LOW CLOUDS CONTINUES TO SPREAD ACROSS WESTERN S
DAKOTA...WITH MOST OF THE CWA NOW SEEING MOSTLY SUNNY SKIES AND
TEMPS ABOVE FREEZING. WITH MOSTLY CLEAR SKIES CONTINUING INTO THE
EVENING HOURS TEMPS WILL FALL QUICKLY INTO THE 20S AFTER SUNSET.
TEMPS BOTTOM OUT IN THE TEENS TO LOWER 20S. TOMORROW A WEEK
DISTURBANCE WILL MOVE ACROSS THE AREA. SOUNDINGS ARE FAIRLY DRY IN
THE LOWER LEVELS AND EXPECT ONLY SOME PASSING MID/HIGH CLOUDS. THIS
SHOULD NOT IMPEDE MUCH ON WARMING WITH HIGHS IN THE 30S TO LOWER 40S.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 238 PM MST THU DEC 18 2014

PRIMARY FORECAST CONCERNS IN THE MID RANGE OF THE FORECAST DEAL WITH
LIGHT SNOW CHANCES OVER NORTHEAST WYOMING SATURDAY MORNING AND WITH
A SLIGHT WARMING TREND IN TEMPERATURES THROUGH THE WEEKEND. FOCUS
THEN TURNS TO THE PATTERN SHIFT FOR NEXT WEEK AS IT TURNS ACTIVE FOR
MUCH OF NEXT WEEK.

A SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS SOUTH DAKOTA FRIDAY NIGHT
WITH ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC CROSSING THE NORTHERN
ROCKIES AND INTO NORTHEAST WYOMING BY 12Z SATURDAY. THE FIRST SYSTEM
WILL MOVE THROUGH DRY AS THERE IS A LARGE LACK OF MOISTURE TO WORK
WITH...BUT THERE MAY BE ENOUGH MOISTURE STILL WITH THE SECOND SYSTEM
AFTER CROSSING THE MOUNTAINS TO BRING SOME LIGHT PRECIPITATION TO
THE NORTHEAST CORNER OF WYOMING SATURDAY MORNING. THE GFS HAS A
CLEAR DRY LAYER JUST OFF THE SURFACE SO MAY NOT BE ENOUGH MOISTURE
TO MAKE IT THROUGH THE BOUNDARY LAYER FOR MEASURABLE PRECIPITATION.
THE NAM IS NOT AS ROBUST WITH THE DRY AIR BUT WOULD INDICATE THERE
MAY BE ENOUGH LIFT AND MOISTURE TO AT LEAST INCLUDE A SLIGHT MENTION
OF SNOW SATURDAY MORNING.

TEMPERATURES WILL SEE A SLIGHT MODERATION THROUGH THE WEEKEND.
BEHIND THE WEAK PACIFIC FRONT THAT MOVES THOUGH SATURDAY MORNING
WARMER AIR WILL BEGIN TO PUSH NORTH AS LONGWAVE RIDGING BUILDS OVER
THE EASTERN PACIFIC. BY SUNDAY...A LARGE AREA OF LOW PRESSURE AT THE
SURFACE DEVELOPS OVER SOUTHWEST CANADA WITH A TROUGH EXTENDING SOUTH
ALONG THE FRONT RANGE OF THE ROCKY MOUNTAINS. SOUTHERLY FLOW IN THE
LOWER LEVELS WILL BRING WARMER AIR NORTHWARD...WITH HIGHS EXPECTED
TO RISE INTO THE LOW AND MID 40S ACROSS PORTIONS OF THE FORECAST
AREA ON BOTH SATURDAY AND SUNDAY. A QUESTION WITH TEMPERATURES WILL
BE IF AND/OR HOW MUCH OF AN IMPACT THE SNOW COVER WILL IMPACT
TEMPERATURES. KEPT HIGHS A BIT COOLER WHERE SNOWPACK EXISTS...WHILE
OTHER AREAS SHOULD EASILY RISE INTO THE 30S AND 40S.

BY MONDAY...NORTHWEST FLOW ALOFT HAS BEEN ESTABLISHED ACROSS THE
NORTH CENTRAL PART OF THE CONUS AS THE UPPER LEVEL PATTERN CHANGES
WITH A LONGWAVE RIDGE OVER THE EASTERN PACIFIC AND A FAIRLY DEEP
TROUGH CENTERED ACROSS THE PLAINS AND MISSISSIPPI RIVER VALLEY. THE
MODELS ARE IN GOOD AGREEMENT WITH THIS PATTERN CHANGE WHICH LOOKS TO
STAY IN PLACE THROUGH THE WEEK. THIS PATTERN WILL KEEP THE WEATHER
ACTIVE THROUGH THE REMAINDER OF THE PERIOD AS MULTIPLE WEAK
SHORTWAVE TROUGHS PUSH OVER THE RIDGE AND PASS ACROSS THE LOCAL
AREA. TIMING OF THE INDIVIDUAL SYSTEMS IS PROBLEMATIC AS IS
TYPICALLY SEEN IN THESE PATTERNS SO IT IS QUITE DIFFICULT TRYING TO
PINPOINT WHEN THE HIGHER CHANCES FOR PRECIPITATION WILL BE. THIS
LEADS TO PRECIPITATION CHANCES THROUGH MOST DAYS MONDAY THROUGH
THURSDAY. WITH THE NORTHWEST FLOW THOUGH...WILL GET UPSLOPE FLOW
OVER THE BLACK HILLS MUCH OF THE PERIOD SO AS LONG AS THERE IS SOME
MOISTURE TO WORK WITH WILL GET SNOW TO DEVELOP AND THESE AREAS WILL
MAINTAIN THE MORE CONSISTENT AND HIGHER PRECIPITATION CHANCES.
AMOUNTS DON/T LOOK SIGNIFICANT WITH ANY OF THESE QUICK HITTING
SYSTEMS AT THIS POINT SO THE CURRENT FORECAST JUST HAS LIGHT AMOUNTS
CURRENTLY. BY WEDNESDAY NIGHT AND THURSDAY THE MODELS ARE DIGGING A
SLIGHTLY MORE SIGNIFICANT SHORTWAVE DOWN THROUGH THE CENTRAL
ROCKIES. IF THIS HOLDS OUT...THE PRECIPITATION WILL BE MOSTLY ACROSS
THE SOUTHWEST PART OF THE FORECAST AREA.

ONE THING THAT IS FAIRLY CERTAIN IS AS THE NORTHWEST FLOW IS
ESTABLISHED THAT TEMPERATURES WILL BE COOLING OFF BACK TO NEAR
NORMAL LEVELS...AND COLDER BY LATE NEXT WEEK WITH HIGHS LIKELY IN
THE LOW TO MID 20S BY THURSDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1044 AM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
STRATUS/FOG HAS LIFTED THIS MORNING AND EXPECT THE STRATUS/FOG TO
REMAIN EAST OF THE KRAP OVERNIGHT AS WINDS BECOME LIGHT
NORTHWESTERLY.


&&

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

$$

SHORT TERM...MASEK
LONG TERM...BROOKS
AVIATION...MASEK










000
FXUS63 KUNR 181746
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
ISSUED BY NATIONAL WEATHER SERVICE NORTH PLATTE NE
1046 AM MST THU DEC 18 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 208 AM MST THU DEC 18 2014

WATER VAPOR IMAGERY SHOWS THE SHORTWAVE MAKING ITS WAY
THROUGH THE WESTERN DAKOTAS. SURFACE LOW IS OVER SOUTHEASTERN
MT...AND WINDS ACROSS THE CWA ARE LIGHT AND SOUTHERLY. LOW CLOUDS
PERSIST ACROSS THE REGION...ALTHOUGH THE FOG AROUND THE HILLS SEEMS
TO BE RETREATING A BIT. WILL LEAVE AREAS OF FOG AROUND THE HILLS
THROUGH EARLY MORNING IN CASE IT FILLS IN. ALSO ADDED SOME PATCHY
FOG FOR THE SD PLAINS EARLY THIS MORNING. SKIES ARE CLEAR OVER
NORTHEAST WY AND THE BLACK HILLS. TEMPS ARE IN THE TEENS TO LOWER
20S.

FOG/LOW CLOUDS WILL BE PUSHED EASTWARD TODAY AS WESTERLY BL WINDS
INCREASE BEHIND THE EXITING SHORTWAVE. SURFACE WINDS WILL BECOME
SOUTHWESTERLY...AND WARMER AIR WILL ADVECT INTO THE REGION.
TEMPERATURES WILL WARM IN TO THE SEASONABLE 30S...WITH SOME 40S ON
THE DOWNSLOPING EASTERN FOOTHILLS. LOWS TONIGHT WILL BE IN THE TEENS.

AN UPPER WAVE WILL PASS THROUGH THE NORTHERN PLAINS ON FRIDAY.
MOISTURE PROFILES LOOK FAIRLY DRY...AND SO EXPECT NOTHING MORE THAN
SOME CLOUDS FROM THE WAVE. WINDS WILL REMAIN LIGHT AND
SOUTHWESTERLY...AND TEMPERATURES WILL WARM INTO THE UPPER 30S AND
LOWER 40S. LOWS FRIDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S.

&&

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 208 AM MST THU DEC 18 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER
SCALE FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF DIGGING
AND CLOSING OFF ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS. INITIAL
DIGGING SHORTWAVE CROSSES THE AREA SUNDAY/MONDAY WITH SOME RAIN/SNOW
POSSIBLE. FAVORABLE CONDITIONS FOR UPSLOPE SNOW TUESDAY/WEDNESDAY
FOR THE BLACK HILLS...WITH DRY WEATHER ELSEWHERE. LATE WEDNESDAY
INTO CHRISTMAS DAY...SIGNIFICANT DIGGING TROF ACROSS THE WESTERN
CONUS CLOSES OFF OVER THE GREAT BASIN. ECMWF/GFS DIFFER SOME IN
STRENGTH/TRACK AND RUN TO RUN CONSISTENCY...BUT BOTH OFFER UP
POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1044 AM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
STRATUS/FOG HAS LIFTED THIS MORNING AND EXPECT THE STRATUS/FOG TO
REMAIN EAST OF THE KRAP OVERNIGHT AS WINDS BECOME LIGHT
NORTHWESTERLY.

&&

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

&&

$$

SHORT TERM...POJORLIE
LONG TERM...7
AVIATION...MASEK







000
FXUS63 KUNR 181746
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
ISSUED BY NATIONAL WEATHER SERVICE NORTH PLATTE NE
1046 AM MST THU DEC 18 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 208 AM MST THU DEC 18 2014

WATER VAPOR IMAGERY SHOWS THE SHORTWAVE MAKING ITS WAY
THROUGH THE WESTERN DAKOTAS. SURFACE LOW IS OVER SOUTHEASTERN
MT...AND WINDS ACROSS THE CWA ARE LIGHT AND SOUTHERLY. LOW CLOUDS
PERSIST ACROSS THE REGION...ALTHOUGH THE FOG AROUND THE HILLS SEEMS
TO BE RETREATING A BIT. WILL LEAVE AREAS OF FOG AROUND THE HILLS
THROUGH EARLY MORNING IN CASE IT FILLS IN. ALSO ADDED SOME PATCHY
FOG FOR THE SD PLAINS EARLY THIS MORNING. SKIES ARE CLEAR OVER
NORTHEAST WY AND THE BLACK HILLS. TEMPS ARE IN THE TEENS TO LOWER
20S.

FOG/LOW CLOUDS WILL BE PUSHED EASTWARD TODAY AS WESTERLY BL WINDS
INCREASE BEHIND THE EXITING SHORTWAVE. SURFACE WINDS WILL BECOME
SOUTHWESTERLY...AND WARMER AIR WILL ADVECT INTO THE REGION.
TEMPERATURES WILL WARM IN TO THE SEASONABLE 30S...WITH SOME 40S ON
THE DOWNSLOPING EASTERN FOOTHILLS. LOWS TONIGHT WILL BE IN THE TEENS.

AN UPPER WAVE WILL PASS THROUGH THE NORTHERN PLAINS ON FRIDAY.
MOISTURE PROFILES LOOK FAIRLY DRY...AND SO EXPECT NOTHING MORE THAN
SOME CLOUDS FROM THE WAVE. WINDS WILL REMAIN LIGHT AND
SOUTHWESTERLY...AND TEMPERATURES WILL WARM INTO THE UPPER 30S AND
LOWER 40S. LOWS FRIDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S.

&&

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 208 AM MST THU DEC 18 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER
SCALE FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF DIGGING
AND CLOSING OFF ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS. INITIAL
DIGGING SHORTWAVE CROSSES THE AREA SUNDAY/MONDAY WITH SOME RAIN/SNOW
POSSIBLE. FAVORABLE CONDITIONS FOR UPSLOPE SNOW TUESDAY/WEDNESDAY
FOR THE BLACK HILLS...WITH DRY WEATHER ELSEWHERE. LATE WEDNESDAY
INTO CHRISTMAS DAY...SIGNIFICANT DIGGING TROF ACROSS THE WESTERN
CONUS CLOSES OFF OVER THE GREAT BASIN. ECMWF/GFS DIFFER SOME IN
STRENGTH/TRACK AND RUN TO RUN CONSISTENCY...BUT BOTH OFFER UP
POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1044 AM MST THU DEC 18 2014

VFR CONDITIONS FOR BOTH KRAP AND KGCC EXPECTED THE NEXT 24 HOURS.
STRATUS/FOG HAS LIFTED THIS MORNING AND EXPECT THE STRATUS/FOG TO
REMAIN EAST OF THE KRAP OVERNIGHT AS WINDS BECOME LIGHT
NORTHWESTERLY.

&&

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

&&

$$

SHORT TERM...POJORLIE
LONG TERM...7
AVIATION...MASEK






000
FXUS63 KUNR 180911
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
211 AM MST THU DEC 18 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 208 AM MST THU DEC 18 2014

WATER VAPOR IMAGERY SHOWS THE SHORTWAVE MAKING ITS WAY
THROUGH THE WESTERN DAKOTAS. SURFACE LOW IS OVER SOUTHEASTERN
MT...AND WINDS ACROSS THE CWA ARE LIGHT AND SOUTHERLY. LOW CLOUDS
PERSIST ACROSS THE REGION...ALTHOUGH THE FOG AROUND THE HILLS SEEMS
TO BE RETREATING A BIT. WILL LEAVE AREAS OF FOG AROUND THE HILLS
THROUGH EARLY MORNING IN CASE IT FILLS IN. ALSO ADDED SOME PATCHY
FOG FOR THE SD PLAINS EARLY THIS MORNING. SKIES ARE CLEAR OVER
NORTHEAST WY AND THE BLACK HILLS. TEMPS ARE IN THE TEENS TO LOWER
20S.

FOG/LOW CLOUDS WILL BE PUSHED EASTWARD TODAY AS WESTERLY BL WINDS
INCREASE BEHIND THE EXITING SHORTWAVE. SURFACE WINDS WILL BECOME
SOUTHWESTERLY...AND WARMER AIR WILL ADVECT INTO THE REGION.
TEMPERATURES WILL WARM IN TO THE SEASONABLE 30S...WITH SOME 40S ON
THE DOWNSLOPING EASTERN FOOTHILLS. LOWS TONIGHT WILL BE IN THE TEENS.

AN UPPER WAVE WILL PASS THROUGH THE NORTHERN PLAINS ON FRIDAY.
MOISTURE PROFILES LOOK FAIRLY DRY...AND SO EXPECT NOTHING MORE THAN
SOME CLOUDS FROM THE WAVE. WINDS WILL REMAIN LIGHT AND
SOUTHWESTERLY...AND TEMPERATURES WILL WARM INTO THE UPPER 30S AND
LOWER 40S. LOWS FRIDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 208 AM MST THU DEC 18 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER
SCALE FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF DIGGING
AND CLOSING OFF ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS. INITIAL
DIGGING SHORTWAVE CROSSES THE AREA SUNDAY/MONDAY WITH SOME RAIN/SNOW
POSSIBLE. FAVORABLE CONDITIONS FOR UPSLOPE SNOW TUESDAY/WEDNESDAY
FOR THE BLACK HILLS...WITH DRY WEATHER ELSEWHERE. LATE WEDNESDAY
INTO CHRISTMAS DAY...SIGNIFICANT DIGGING TROF ACROSS THE WESTERN
CONUS CLOSES OFF OVER THE GREAT BASIN. ECMWF/GFS DIFFER SOME IN
STRENGTH/TRACK AND RUN TO RUN CONSISTENCY...BUT BOTH OFFER UP
POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING
ISSUED AT 208 AM MST THU DEC 18 2014

WIDESPREAD MVFR CIGS ACROSS WESTERN SOUTH DAKOTA WILL
PERSIST THROUGH MUCH OF THE DAY...WITH GRADUAL DISSIPATION ALONG
WESTERN EDGE. FOG ADJACENT TO WEST/SOUTH SIDE OF BLACK HILLS WITH
LIFR VSBY WILL ALSO DISSIPATE THIS MORNING. VFR FOR KGCC TERMINAL
THROUGH TONIGHT WITH MID/HIGH CLOUDS. THE IFR CIGS AT KRAP MY
DISSIPATE PRIOR TO 14Z...WHICH WOULD ALLOW SOME FOG TO DEVELOP
AROUND SUNRISE. ANY FOG AT KRAP SHOULD BE SHORT LIVED. VFR
CONDITIONS EXPECTED AT KRAP BY LATE MORNING THROUGH TONIGHT.

&&

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

$$

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








000
FXUS63 KUNR 180911
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
211 AM MST THU DEC 18 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 208 AM MST THU DEC 18 2014

WATER VAPOR IMAGERY SHOWS THE SHORTWAVE MAKING ITS WAY
THROUGH THE WESTERN DAKOTAS. SURFACE LOW IS OVER SOUTHEASTERN
MT...AND WINDS ACROSS THE CWA ARE LIGHT AND SOUTHERLY. LOW CLOUDS
PERSIST ACROSS THE REGION...ALTHOUGH THE FOG AROUND THE HILLS SEEMS
TO BE RETREATING A BIT. WILL LEAVE AREAS OF FOG AROUND THE HILLS
THROUGH EARLY MORNING IN CASE IT FILLS IN. ALSO ADDED SOME PATCHY
FOG FOR THE SD PLAINS EARLY THIS MORNING. SKIES ARE CLEAR OVER
NORTHEAST WY AND THE BLACK HILLS. TEMPS ARE IN THE TEENS TO LOWER
20S.

FOG/LOW CLOUDS WILL BE PUSHED EASTWARD TODAY AS WESTERLY BL WINDS
INCREASE BEHIND THE EXITING SHORTWAVE. SURFACE WINDS WILL BECOME
SOUTHWESTERLY...AND WARMER AIR WILL ADVECT INTO THE REGION.
TEMPERATURES WILL WARM IN TO THE SEASONABLE 30S...WITH SOME 40S ON
THE DOWNSLOPING EASTERN FOOTHILLS. LOWS TONIGHT WILL BE IN THE TEENS.

AN UPPER WAVE WILL PASS THROUGH THE NORTHERN PLAINS ON FRIDAY.
MOISTURE PROFILES LOOK FAIRLY DRY...AND SO EXPECT NOTHING MORE THAN
SOME CLOUDS FROM THE WAVE. WINDS WILL REMAIN LIGHT AND
SOUTHWESTERLY...AND TEMPERATURES WILL WARM INTO THE UPPER 30S AND
LOWER 40S. LOWS FRIDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 208 AM MST THU DEC 18 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER
SCALE FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF DIGGING
AND CLOSING OFF ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS. INITIAL
DIGGING SHORTWAVE CROSSES THE AREA SUNDAY/MONDAY WITH SOME RAIN/SNOW
POSSIBLE. FAVORABLE CONDITIONS FOR UPSLOPE SNOW TUESDAY/WEDNESDAY
FOR THE BLACK HILLS...WITH DRY WEATHER ELSEWHERE. LATE WEDNESDAY
INTO CHRISTMAS DAY...SIGNIFICANT DIGGING TROF ACROSS THE WESTERN
CONUS CLOSES OFF OVER THE GREAT BASIN. ECMWF/GFS DIFFER SOME IN
STRENGTH/TRACK AND RUN TO RUN CONSISTENCY...BUT BOTH OFFER UP
POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING
ISSUED AT 208 AM MST THU DEC 18 2014

WIDESPREAD MVFR CIGS ACROSS WESTERN SOUTH DAKOTA WILL
PERSIST THROUGH MUCH OF THE DAY...WITH GRADUAL DISSIPATION ALONG
WESTERN EDGE. FOG ADJACENT TO WEST/SOUTH SIDE OF BLACK HILLS WITH
LIFR VSBY WILL ALSO DISSIPATE THIS MORNING. VFR FOR KGCC TERMINAL
THROUGH TONIGHT WITH MID/HIGH CLOUDS. THE IFR CIGS AT KRAP MY
DISSIPATE PRIOR TO 14Z...WHICH WOULD ALLOW SOME FOG TO DEVELOP
AROUND SUNRISE. ANY FOG AT KRAP SHOULD BE SHORT LIVED. VFR
CONDITIONS EXPECTED AT KRAP BY LATE MORNING THROUGH TONIGHT.

&&

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

$$

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







000
FXUS63 KUNR 180911
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
211 AM MST THU DEC 18 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 208 AM MST THU DEC 18 2014

WATER VAPOR IMAGERY SHOWS THE SHORTWAVE MAKING ITS WAY
THROUGH THE WESTERN DAKOTAS. SURFACE LOW IS OVER SOUTHEASTERN
MT...AND WINDS ACROSS THE CWA ARE LIGHT AND SOUTHERLY. LOW CLOUDS
PERSIST ACROSS THE REGION...ALTHOUGH THE FOG AROUND THE HILLS SEEMS
TO BE RETREATING A BIT. WILL LEAVE AREAS OF FOG AROUND THE HILLS
THROUGH EARLY MORNING IN CASE IT FILLS IN. ALSO ADDED SOME PATCHY
FOG FOR THE SD PLAINS EARLY THIS MORNING. SKIES ARE CLEAR OVER
NORTHEAST WY AND THE BLACK HILLS. TEMPS ARE IN THE TEENS TO LOWER
20S.

FOG/LOW CLOUDS WILL BE PUSHED EASTWARD TODAY AS WESTERLY BL WINDS
INCREASE BEHIND THE EXITING SHORTWAVE. SURFACE WINDS WILL BECOME
SOUTHWESTERLY...AND WARMER AIR WILL ADVECT INTO THE REGION.
TEMPERATURES WILL WARM IN TO THE SEASONABLE 30S...WITH SOME 40S ON
THE DOWNSLOPING EASTERN FOOTHILLS. LOWS TONIGHT WILL BE IN THE TEENS.

AN UPPER WAVE WILL PASS THROUGH THE NORTHERN PLAINS ON FRIDAY.
MOISTURE PROFILES LOOK FAIRLY DRY...AND SO EXPECT NOTHING MORE THAN
SOME CLOUDS FROM THE WAVE. WINDS WILL REMAIN LIGHT AND
SOUTHWESTERLY...AND TEMPERATURES WILL WARM INTO THE UPPER 30S AND
LOWER 40S. LOWS FRIDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 208 AM MST THU DEC 18 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER
SCALE FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF DIGGING
AND CLOSING OFF ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS. INITIAL
DIGGING SHORTWAVE CROSSES THE AREA SUNDAY/MONDAY WITH SOME RAIN/SNOW
POSSIBLE. FAVORABLE CONDITIONS FOR UPSLOPE SNOW TUESDAY/WEDNESDAY
FOR THE BLACK HILLS...WITH DRY WEATHER ELSEWHERE. LATE WEDNESDAY
INTO CHRISTMAS DAY...SIGNIFICANT DIGGING TROF ACROSS THE WESTERN
CONUS CLOSES OFF OVER THE GREAT BASIN. ECMWF/GFS DIFFER SOME IN
STRENGTH/TRACK AND RUN TO RUN CONSISTENCY...BUT BOTH OFFER UP
POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING
ISSUED AT 208 AM MST THU DEC 18 2014

WIDESPREAD MVFR CIGS ACROSS WESTERN SOUTH DAKOTA WILL
PERSIST THROUGH MUCH OF THE DAY...WITH GRADUAL DISSIPATION ALONG
WESTERN EDGE. FOG ADJACENT TO WEST/SOUTH SIDE OF BLACK HILLS WITH
LIFR VSBY WILL ALSO DISSIPATE THIS MORNING. VFR FOR KGCC TERMINAL
THROUGH TONIGHT WITH MID/HIGH CLOUDS. THE IFR CIGS AT KRAP MY
DISSIPATE PRIOR TO 14Z...WHICH WOULD ALLOW SOME FOG TO DEVELOP
AROUND SUNRISE. ANY FOG AT KRAP SHOULD BE SHORT LIVED. VFR
CONDITIONS EXPECTED AT KRAP BY LATE MORNING THROUGH TONIGHT.

&&

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

$$

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








000
FXUS63 KUNR 180911
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
211 AM MST THU DEC 18 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 208 AM MST THU DEC 18 2014

WATER VAPOR IMAGERY SHOWS THE SHORTWAVE MAKING ITS WAY
THROUGH THE WESTERN DAKOTAS. SURFACE LOW IS OVER SOUTHEASTERN
MT...AND WINDS ACROSS THE CWA ARE LIGHT AND SOUTHERLY. LOW CLOUDS
PERSIST ACROSS THE REGION...ALTHOUGH THE FOG AROUND THE HILLS SEEMS
TO BE RETREATING A BIT. WILL LEAVE AREAS OF FOG AROUND THE HILLS
THROUGH EARLY MORNING IN CASE IT FILLS IN. ALSO ADDED SOME PATCHY
FOG FOR THE SD PLAINS EARLY THIS MORNING. SKIES ARE CLEAR OVER
NORTHEAST WY AND THE BLACK HILLS. TEMPS ARE IN THE TEENS TO LOWER
20S.

FOG/LOW CLOUDS WILL BE PUSHED EASTWARD TODAY AS WESTERLY BL WINDS
INCREASE BEHIND THE EXITING SHORTWAVE. SURFACE WINDS WILL BECOME
SOUTHWESTERLY...AND WARMER AIR WILL ADVECT INTO THE REGION.
TEMPERATURES WILL WARM IN TO THE SEASONABLE 30S...WITH SOME 40S ON
THE DOWNSLOPING EASTERN FOOTHILLS. LOWS TONIGHT WILL BE IN THE TEENS.

AN UPPER WAVE WILL PASS THROUGH THE NORTHERN PLAINS ON FRIDAY.
MOISTURE PROFILES LOOK FAIRLY DRY...AND SO EXPECT NOTHING MORE THAN
SOME CLOUDS FROM THE WAVE. WINDS WILL REMAIN LIGHT AND
SOUTHWESTERLY...AND TEMPERATURES WILL WARM INTO THE UPPER 30S AND
LOWER 40S. LOWS FRIDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 208 AM MST THU DEC 18 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER
SCALE FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF DIGGING
AND CLOSING OFF ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS. INITIAL
DIGGING SHORTWAVE CROSSES THE AREA SUNDAY/MONDAY WITH SOME RAIN/SNOW
POSSIBLE. FAVORABLE CONDITIONS FOR UPSLOPE SNOW TUESDAY/WEDNESDAY
FOR THE BLACK HILLS...WITH DRY WEATHER ELSEWHERE. LATE WEDNESDAY
INTO CHRISTMAS DAY...SIGNIFICANT DIGGING TROF ACROSS THE WESTERN
CONUS CLOSES OFF OVER THE GREAT BASIN. ECMWF/GFS DIFFER SOME IN
STRENGTH/TRACK AND RUN TO RUN CONSISTENCY...BUT BOTH OFFER UP
POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING
ISSUED AT 208 AM MST THU DEC 18 2014

WIDESPREAD MVFR CIGS ACROSS WESTERN SOUTH DAKOTA WILL
PERSIST THROUGH MUCH OF THE DAY...WITH GRADUAL DISSIPATION ALONG
WESTERN EDGE. FOG ADJACENT TO WEST/SOUTH SIDE OF BLACK HILLS WITH
LIFR VSBY WILL ALSO DISSIPATE THIS MORNING. VFR FOR KGCC TERMINAL
THROUGH TONIGHT WITH MID/HIGH CLOUDS. THE IFR CIGS AT KRAP MY
DISSIPATE PRIOR TO 14Z...WHICH WOULD ALLOW SOME FOG TO DEVELOP
AROUND SUNRISE. ANY FOG AT KRAP SHOULD BE SHORT LIVED. VFR
CONDITIONS EXPECTED AT KRAP BY LATE MORNING THROUGH TONIGHT.

&&

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

$$

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







000
FXUS63 KUNR 180535
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1035 PM MST WED DEC 17 2014

.UPDATE...
ISSUED AT 926 PM MST WED DEC 17 2014

UPPER LEVEL SHORTWAVE IN MONTANA WILL SLIDE EAST INTO NORTH DAKOTA
OVERNIGHT. WEAK RETURNS ACROSS SOUTHEAST MONTANA SHOULD PROGRESS
EASTWARD INTO FAR NORTHWEST SOUTH DAKOTA BY MIDNIGHT. HAVE ADDED
SOME SCATTERED FLURRIES TO THE FORECAST FOR THAT AREA. HAVE ALSO
EXPANDED AREAS OF FOG OVERNIGHT ACROSS FAR SOUTHWEST SOUTH DAKOTA.
UPDATES HAVE BEEN SENT.

&&

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1034 PM MST WED DEC 17 2014

CURRENT IR SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND FOG WITH IFR/LIFR CIGS AND VSBYS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP...AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT THROUGH THURSDAY MORNING. A SURFACE TROF WILL SLOWLY SHIFT
OUT OF NORTHEAST WYOMING INTO WESTERN SOUTH DAKOTA THURSDAY
MORNING...PUSHING THE LOW STRATUS DECK EAST THROUGH THE DAY. VFR
CONDITIONS ARE NOT EXPECTED AT KRAP UNTIL AT LEAST MID MORNING ON
THURSDAY.

MEANWHILE...NORTHEAST WY WILL SEE MAINLY VFR CONDITIONS EXCEPT FOR
LOW CLOUDS/STRATUS/AND FOG IN THE VICINITY OF THE BLACK HILLS. WHILE
PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT ACROSS THE WYOMING
PLAINS...DO NOT EXPECT IT TO BE WIDESPREAD...AND HAVE LEFT IT OUT
OF KGCC TAF FOR THE CURRENT TIME.


&&

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

$$

UPDATE...15
SHORT TERM...15
LONG TERM...10
AVIATION...7








000
FXUS63 KUNR 180535
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1035 PM MST WED DEC 17 2014

.UPDATE...
ISSUED AT 926 PM MST WED DEC 17 2014

UPPER LEVEL SHORTWAVE IN MONTANA WILL SLIDE EAST INTO NORTH DAKOTA
OVERNIGHT. WEAK RETURNS ACROSS SOUTHEAST MONTANA SHOULD PROGRESS
EASTWARD INTO FAR NORTHWEST SOUTH DAKOTA BY MIDNIGHT. HAVE ADDED
SOME SCATTERED FLURRIES TO THE FORECAST FOR THAT AREA. HAVE ALSO
EXPANDED AREAS OF FOG OVERNIGHT ACROSS FAR SOUTHWEST SOUTH DAKOTA.
UPDATES HAVE BEEN SENT.

&&

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1034 PM MST WED DEC 17 2014

CURRENT IR SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND FOG WITH IFR/LIFR CIGS AND VSBYS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP...AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT THROUGH THURSDAY MORNING. A SURFACE TROF WILL SLOWLY SHIFT
OUT OF NORTHEAST WYOMING INTO WESTERN SOUTH DAKOTA THURSDAY
MORNING...PUSHING THE LOW STRATUS DECK EAST THROUGH THE DAY. VFR
CONDITIONS ARE NOT EXPECTED AT KRAP UNTIL AT LEAST MID MORNING ON
THURSDAY.

MEANWHILE...NORTHEAST WY WILL SEE MAINLY VFR CONDITIONS EXCEPT FOR
LOW CLOUDS/STRATUS/AND FOG IN THE VICINITY OF THE BLACK HILLS. WHILE
PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT ACROSS THE WYOMING
PLAINS...DO NOT EXPECT IT TO BE WIDESPREAD...AND HAVE LEFT IT OUT
OF KGCC TAF FOR THE CURRENT TIME.


&&

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

$$

UPDATE...15
SHORT TERM...15
LONG TERM...10
AVIATION...7







000
FXUS63 KUNR 180431
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
931 PM MST WED DEC 17 2014

.UPDATE...
ISSUED AT 926 PM MST WED DEC 17 2014

UPPER LEVEL SHORTWAVE IN MONTANA WILL SLIDE EAST INTO NORTH DAKOTA
OVERNIGHT. WEAK RETURNS ACROSS SOUTHEAST MONTANA SHOULD PROGRESS
EASTWARD INTO FAR NORTHWEST SOUTH DAKOTA BY MIDNIGHT. HAVE ADDED
SOME SCATTERED FLURRIES TO THE FORECAST FOR THAT AREA. HAVE ALSO
EXPANDED AREAS OF FOG OVERNIGHT ACROSS FAR SOUTHWEST SOUTH DAKOTA.
UPDATES HAVE BEEN SENT.

&&

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 510 PM MST WED DEC 17 2014

CURRENT IR SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND FOG WITH IFR/LIFR CIGS AND VSBYS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP...AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT THROUGH THURSDAY MORNING. A SURFACE TROF WILL SLOWLY SHIFT
OUT OF NORTHEAST WYOMING INTO WESTERN SOUTH DAKOTA THURSDAY
MORNING...PUSHING THE LOW STRATUS DECK EAST THROUGH THE DAY. VFR
CONDITIONS ARE NOT EXPECTED AT KRAP UNTIL AT LEAST MID MORNING ON
THURSDAY.

MEANWHILE...NORTHEAST WY WILL SEE MAINLY VFR CONDITIONS EXCEPT FOR
LOW CLOUDS/STRATUS/AND FOG IN THE VICINITY OF THE BLACK HILLS. WHILE
PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT ACROSS THE WYOMING
PLAINS...DO NOT EXPECT IT TO BE WIDESPREAD...AND HAVE LEFT IT OUT
OF KGCC TAF FOR THE CURRENT TIME.


&&

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

$$

UPDATE...15
SHORT TERM...15
LONG TERM...10
AVIATION...15








000
FXUS63 KUNR 180017 CCA
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
516 PM MST WED DEC 17 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 510 PM MST WED DEC 17 2014

CURRENT IR SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND FOG WITH IFR/LIFR CIGS AND VSBYS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP...AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT THROUGH THURSDAY MORNING. A SURFACE TROF WILL SLOWLY SHIFT
OUT OF NORTHEAST WYOMING INTO WESTERN SOUTH DAKOTA THURSDAY
MORNING...PUSHING THE LOW STRATUS DECK EAST THROUGH THE DAY. VFR
CONDITIONS ARE NOT EXPECTED AT KRAP UNTIL AT LEAST MID MORNING ON
THURSDAY.

MEANWHILE...NORTHEAST WY WILL SEE MAINLY VFR CONDITIONS EXCEPT FOR
LOW CLOUDS/STRATUS/AND FOG IN THE VICINITY OF THE BLACK HILLS. WHILE
PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT ACROSS THE WYOMING
PLAINS...DO NOT EXPECT IT TO BE WIDESPREAD...AND HAVE LEFT IT OUT
OF KGCC TAF FOR THE CURRENT TIME.

&&

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

$$

SHORT TERM...15
LONG TERM...10
AVIATION...15










000
FXUS63 KUNR 180017 CCA
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
516 PM MST WED DEC 17 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 510 PM MST WED DEC 17 2014

CURRENT IR SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND FOG WITH IFR/LIFR CIGS AND VSBYS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP...AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT THROUGH THURSDAY MORNING. A SURFACE TROF WILL SLOWLY SHIFT
OUT OF NORTHEAST WYOMING INTO WESTERN SOUTH DAKOTA THURSDAY
MORNING...PUSHING THE LOW STRATUS DECK EAST THROUGH THE DAY. VFR
CONDITIONS ARE NOT EXPECTED AT KRAP UNTIL AT LEAST MID MORNING ON
THURSDAY.

MEANWHILE...NORTHEAST WY WILL SEE MAINLY VFR CONDITIONS EXCEPT FOR
LOW CLOUDS/STRATUS/AND FOG IN THE VICINITY OF THE BLACK HILLS. WHILE
PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT ACROSS THE WYOMING
PLAINS...DO NOT EXPECT IT TO BE WIDESPREAD...AND HAVE LEFT IT OUT
OF KGCC TAF FOR THE CURRENT TIME.

&&

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

$$

SHORT TERM...15
LONG TERM...10
AVIATION...15











000
FXUS63 KUNR 180016
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
516 PM MST WED DEC 17 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 510 PM MST WED DEC 17 2014

FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 248 PM MST WED DEC 17 2014

CURRENT IR SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND FOG WITH IFR/LIFR CIGS AND
VSBYS. MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO
WESTERN SD... INCLUDING KRAP...AND SURFACE WINDS MAINTAIN AN
EASTERLY COMPONENT THROUGH THURSDAY MORNING. A SURFACE TROF WILL
SLOWLY SHIFT OUT OF NORTHEAST WYOMING INTO WESTERN SOUTH DAKOTA
THURSDAY MORNING...PUSHING THE LOW STRATUS DECK EAST THROUGH THE
DAY. VFR CONDITIONS ARE NOT EXPECTED AT KRAP UNTIL AT LEAST MID
MORNING ON THURSDAY.

MEANWHILE...NORTHEAST WY WILL SEE MAINLY VFR CONDITIONS EXCEPT FOR
LOW CLOUDS/STRATUS/AND FOG IN THE VICINITY OF THE BLACK HILLS. WHILE
PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT ACROSS THE WYOMING
PLAINS...DO NOT EXPECT IT TO BE WIDESPREAD...AND HAVE LEFT IT OUT
OF KGCC TAF FOR THE CURRENT TIME.

&&

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

$$

SHORT TERM...15
LONG TERM...10
AVIATION...15







000
FXUS63 KUNR 180016
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
516 PM MST WED DEC 17 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 510 PM MST WED DEC 17 2014

FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 248 PM MST WED DEC 17 2014

CURRENT IR SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND FOG WITH IFR/LIFR CIGS AND
VSBYS. MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO
WESTERN SD... INCLUDING KRAP...AND SURFACE WINDS MAINTAIN AN
EASTERLY COMPONENT THROUGH THURSDAY MORNING. A SURFACE TROF WILL
SLOWLY SHIFT OUT OF NORTHEAST WYOMING INTO WESTERN SOUTH DAKOTA
THURSDAY MORNING...PUSHING THE LOW STRATUS DECK EAST THROUGH THE
DAY. VFR CONDITIONS ARE NOT EXPECTED AT KRAP UNTIL AT LEAST MID
MORNING ON THURSDAY.

MEANWHILE...NORTHEAST WY WILL SEE MAINLY VFR CONDITIONS EXCEPT FOR
LOW CLOUDS/STRATUS/AND FOG IN THE VICINITY OF THE BLACK HILLS. WHILE
PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT ACROSS THE WYOMING
PLAINS...DO NOT EXPECT IT TO BE WIDESPREAD...AND HAVE LEFT IT OUT
OF KGCC TAF FOR THE CURRENT TIME.

&&

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

$$

SHORT TERM...15
LONG TERM...10
AVIATION...15








000
FXUS63 KUNR 172209
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
309 PM MST WED DEC 17 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 248 PM MST WED DEC 17 2014

CURRENT SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND CLOUDS WITH IFR/LIFR CIGS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP... AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT FOR THE REST OF THE FORECAST PERIOD. THESE CONDITIONS
ARE CONDUCIVE FOR PERSISTENT LOW CLOUDS/STRATUS... AND AS A
RESULT... HAVE GONE WITH IFR/LIFR CIGS FOR REST OF
AFTERNOON AND EVENING IN WESTERN SD.

MEANWHILE... NORTHEAST WY WILL CONTINUE TO SEE CLEARING OF LOW
CLOUDS/STRATUS THIS AFTERNOON WITH A FEW HIGH CLOUDS MOVING IN.
WHILE PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT... DO NOT EXPECT
IT TO BE WIDESPREAD... AND HAVE LEFT IT OUT OF KGCC TAF FOR THE
CURRENT TIME.

&&

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

$$

SHORT TERM...15
LONG TERM...10
AVIATION...MCKEMY








000
FXUS63 KUNR 172209
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
309 PM MST WED DEC 17 2014

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 248 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH EASTERN MONTANA
WITH WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE
MOSTLY CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL
IN PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS PARTS OF NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE
BLACK HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE
EASTERN DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK
EAST TO SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN
CONTRIBUTING FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT
3PM ARE MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK
HILLS.

TONIGHT...UPPER LEVEL SHORTWAVE WILL SLIDE INTO CENTRAL NORTH
DAKOTA AS FLOW ALOFT REMAINS WEAK OUT OF THE WEST. SURFACE HIGH
PRESSURE SHIFTS EAST WITH SOUTHEAST BOUNDARY LAYER FLOW
CONTINUING. THIS WILL KEEP LOW CLOUD DECK/FOG AROUND THE SOUTH
DAKOTA PLAINS FOR MUCH OF THE NIGHT. LOW TEMPERATURES WILL FALL
INTO THE 10 TO 20 DEGREE RANGE.

ON THURSDAY...UPPER TROF SHIFTS EAST OF THE DAKOTAS AS RIDGE
BUILDS INTO THE WEST COAST. SURFACE HIGH SHIFTS INTO THE GREAT
LAKES AS LOW PRESSURE TROF STRENGTHENS ACROSS MONTANA AND WYOMING.
WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE TROUGH PASSES
THROUGH...AND CLOUDS WILL SLOWLY BE PUSHED OUT OF THE CWA FROM
WEST TO EAST. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S
POSSIBLE ACROSS THE EASTERN FOOTHILLS. SKIES WILL BE PARTLY CLOUDY
THURSDAY NIGHT...WITH LOW TEMPERATURES FALLING INTO THE TEENS TO
MID 20S.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 248 PM MST WED DEC 17 2014

EXTENDED MODEL SOLUTIONS REMAIN SIMILAR WITH THE LARGER SCALE
FEATURES THROUGH THE WEEKEND INTO EARLY NEXT WEEK...SHOWING A
RIDGE BUILDING ALONG THE PACIFIC COAST AND A DOWNSTREAM TROF
DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS PATTERN WILL
RESULT IN NORTHWEST FLOW ALOFT OVER THE NORTHERN PLAINS...WITH
SERIES OF SHORTWAVES TRACKING ACROSS THE AREA. DRY WEATHER IS
STILL EXPECTED FRIDAY AND SATURDAY WITH TEMPERATURES NEAR AVERAGE.
A SHORTWAVE WILL AFFECT THE FORECAST AREA LATE SUNDAY AND ON
MONDAY AS A LOW LEVEL BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL
PROFILES SUPPORT SOME RAIN/SNOW. INCREASING NORTHWEST BL-850MB
FLOW WILL LEAD TO UPSLOPE ENHANCEMENT ACROSS THE NRN BLKHLS. AS
THE DEEP UPPER TROF MOVES EASTWARD MID-WEEK...THE SIGNIFICANT WEST
COAST TROF STARTS DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT
BASIN. ECMWF/GFS DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH
OFFER UP POTENTIAL FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 248 PM MST WED DEC 17 2014

CURRENT SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND CLOUDS WITH IFR/LIFR CIGS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP... AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT FOR THE REST OF THE FORECAST PERIOD. THESE CONDITIONS
ARE CONDUCIVE FOR PERSISTENT LOW CLOUDS/STRATUS... AND AS A
RESULT... HAVE GONE WITH IFR/LIFR CIGS FOR REST OF
AFTERNOON AND EVENING IN WESTERN SD.

MEANWHILE... NORTHEAST WY WILL CONTINUE TO SEE CLEARING OF LOW
CLOUDS/STRATUS THIS AFTERNOON WITH A FEW HIGH CLOUDS MOVING IN.
WHILE PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT... DO NOT EXPECT
IT TO BE WIDESPREAD... AND HAVE LEFT IT OUT OF KGCC TAF FOR THE
CURRENT TIME.

&&

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

$$

SHORT TERM...15
LONG TERM...10
AVIATION...MCKEMY







000
FXUS63 KUNR 171926
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1226 PM MST WED DEC 17 2014

.UPDATE...
ISSUED AT 1208 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH MONTANA WITH
WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE MOSTLY
CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL IN
PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE BLACK
HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE EASTERN
DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK EAST TO
SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN CONTRIBUTING
FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT NOON ARE
MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK HILLS.

EASTERLY UPSLOPE FLOW WILL PERSIST THROUGH THE REST OF THE
DAY...WITH LOW CLOUDS AND FOG NOT ERODING AWAY ANY TIME SOON.
TEMPERATURES WILL NOT RISE BUT A FEW MORE DEGREES BEFORE LEVELING
OFF AND FALLING LATER THIS AFTERNOON. HAVE ADJUSTED HIGH TEMPS FOR
TODAY IN THE OVERCAST/FOG AREAS. ADDITIONALLY...RAISED TEMPS A FEW
DEGREES IN THE HIGHER ELEVATIONS OF THE BLACK HILLS WHERE
INSOLATION IS HARD AT WORK. REMAINDER OF FORECAST IN GOOD SHAPE.
UPDATES HAVE BEEN SENT.

&&

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 201 AM MST WED DEC 17 2014

LARGE UPPER TROUGH COVERS THE WESTERN CONUS. WATER VAPOR IMAGERY
SHOWS AN EMBEDDED SHORTWAVE MOVING THROUGH MT/WY. SURFACE LOW IS
OVER CENTRAL WY...AND WINDS ACROSS THE CWA ARE FROM THE SOUTHEAST.
FOG/LOW STRATUS COVERS MUCH OF THE NORTHERN PLAINS...WITH MID/HIGH
CLOUDS DRIFTING IN AHEAD OF THE SHORTWAVE. KRCA REPORTED FREEZING
DRIZZLE A BIT AGO...AND THERE MAY BE A LITTLE ICING FORMING OUT OF
THE FOG...SO UPDATED WEATHER GRIDS FOR FREEZING FOG EARLY THIS
MORNING. TEMPS ARE MAINLY IN THE TEENS.

SHORTWAVE/WEAK TROUGH WILL PASS THROUGH THE REGION TODAY...PUSHING
IN SOME WARMER AIR. STILL LOOKS LIKE THERE MAY BE A FEW LIGHT SNOW
SHOWERS ALONG THE BAROCLINIC ZONE TODAY...POSSIBLY LINGERING A BIT
INTO THE EVENING. BEST FORCING SHOULD BE EAST OF THE AREA BY
MIDNIGHT...SO EXPECT THE REST OF THE NIGHT TO BE DRY...ALTHOUGH
HARDLY ANY PRECIPITATION IS EXPECTED FROM WHAT DOES FALL. SOUTHEAST
WINDS WILL CONTINUE THROUGH THE DAY AND OVERNIGHT...AND SO EXPECT LOW
CLOUDS TO STICK AROUND THROUGH THE NIGHT...ESPECIALLY ACROSS THE SD
PLAINS. MAY BE SOME CLEARING ACROSS NORTHEASTERN WY. LOWERED HIGHS
A BIT TO ACCOUNT FOR CLOUDS...RANGING FROM THE LOWER 20S IN THE
EAST TO THE LOWER 30S FARTHER WEST. LOWS WILL BE IN THE TEENS.

ON THURSDAY...WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE
TROUGH PASSES THROUGH...AND CLOUDS WILL FINALLY BE PUSHED OUT OF THE
CWA. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S POSSIBLE
ACROSS THE EASTERN FOOTHILLS.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 201 AM MST WED DEC 17 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR THE WEEKEND INTO EARLY
NEXT WEEK...WITH RIDGE BUILDING ALONG THE PACIFIC COAST AND
DOWNSTREAM TROF DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS
LEAVES NORTHWEST FLOW ALOFT FOR THE NORTHERN PLAINS...WITH SERIES
OF SHORTWAVES TRACKING ACROSS THE AREA. WEEKEND STILL ON TRACK FOR
DRY WEATHER WITH TEMPERATURES NEAR AVERAGE. STRONGEST SHORTWAVE
CROSSES THE NORTHERN PLAINS LATE SUNDAY/MONDAY AS LOW LEVEL
BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL PROFILES SUPPORT SOME
RAIN/SNOW. INCREASING NORTHWEST BL-850MB FLOW WILL ALLOW FOR
UPSLOPE ENHANCEMENT ACROSS THE BLACK HILLS. AS DEEP UPPER TROF
MOVES INTO EASTERN CONUS MID-WEEK...SIGNIFICANT TROF STARTS
DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT BASIN. ECMWF/GFS
DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH OFFER UP POTENTIAL
FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1014 AM MST WED DEC 17 2014

CURRENT SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND CLOUDS WITH IFR/LIFR CIGS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP... AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT FOR THE REST OF THE FORECAST PERIOD. THESE CONDITIONS
ARE CONDUCIVE FOR PERSISTENT LOW CLOUDS/STRATUS... AND AS A
RESULT... HAVE GONE WITH IFR/LIFR CIGS FOR REST OF
AFTERNOON AND EVENING IN WESTERN SD.

MEANWHILE... NORTHEAST WY WILL CONTINUE TO SEE CLEARING OF LOW
CLOUDS/STRATUS THIS AFTERNOON WITH A FEW HIGH CLOUDS MOVING IN.
WHILE PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT... DO NOT EXPECT
IT TO BE WIDESPREAD... AND HAVE LEFT IT OUT OF KGCC TAF FOR THE
CURRENT TIME.


&&

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

$$

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







000
FXUS63 KUNR 171926
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1226 PM MST WED DEC 17 2014

.UPDATE...
ISSUED AT 1208 PM MST WED DEC 17 2014

UPPER LEVEL ANALYSIS HAS SHORTWAVE LIFTING THROUGH MONTANA WITH
WEAK SOUTHWEST FLOW ACROSS THE NORTHERN PLAINS. SKIES ARE MOSTLY
CLOUDY ACROSS THE SOUTH DAKOTA PLAINS...WITH SOME FOG STILL IN
PLACE ALONG THE FOOTHILLS OF THE BLACK HILLS. SKIES ARE SUNNY
ACROSS NORTHEAST WYOMING AND THE HIGHER ELEVATIONS OF THE BLACK
HILLS. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE EASTERN
DAKOTAS WITH WEAK LOW PRESSURE ACROSS THE ROCKIES. WEAK EAST TO
SOUTHEAST UPSLOPE FLOW CONTINUES...AND IS THE MAIN CONTRIBUTING
FACTOR FOR THE LOW CLOUDS AND FOG. TEMPERATURES AT NOON ARE
MAINLY IN THE TEENS AND 20S...WITH 30S IN THE BLACK HILLS.

EASTERLY UPSLOPE FLOW WILL PERSIST THROUGH THE REST OF THE
DAY...WITH LOW CLOUDS AND FOG NOT ERODING AWAY ANY TIME SOON.
TEMPERATURES WILL NOT RISE BUT A FEW MORE DEGREES BEFORE LEVELING
OFF AND FALLING LATER THIS AFTERNOON. HAVE ADJUSTED HIGH TEMPS FOR
TODAY IN THE OVERCAST/FOG AREAS. ADDITIONALLY...RAISED TEMPS A FEW
DEGREES IN THE HIGHER ELEVATIONS OF THE BLACK HILLS WHERE
INSOLATION IS HARD AT WORK. REMAINDER OF FORECAST IN GOOD SHAPE.
UPDATES HAVE BEEN SENT.

&&

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 201 AM MST WED DEC 17 2014

LARGE UPPER TROUGH COVERS THE WESTERN CONUS. WATER VAPOR IMAGERY
SHOWS AN EMBEDDED SHORTWAVE MOVING THROUGH MT/WY. SURFACE LOW IS
OVER CENTRAL WY...AND WINDS ACROSS THE CWA ARE FROM THE SOUTHEAST.
FOG/LOW STRATUS COVERS MUCH OF THE NORTHERN PLAINS...WITH MID/HIGH
CLOUDS DRIFTING IN AHEAD OF THE SHORTWAVE. KRCA REPORTED FREEZING
DRIZZLE A BIT AGO...AND THERE MAY BE A LITTLE ICING FORMING OUT OF
THE FOG...SO UPDATED WEATHER GRIDS FOR FREEZING FOG EARLY THIS
MORNING. TEMPS ARE MAINLY IN THE TEENS.

SHORTWAVE/WEAK TROUGH WILL PASS THROUGH THE REGION TODAY...PUSHING
IN SOME WARMER AIR. STILL LOOKS LIKE THERE MAY BE A FEW LIGHT SNOW
SHOWERS ALONG THE BAROCLINIC ZONE TODAY...POSSIBLY LINGERING A BIT
INTO THE EVENING. BEST FORCING SHOULD BE EAST OF THE AREA BY
MIDNIGHT...SO EXPECT THE REST OF THE NIGHT TO BE DRY...ALTHOUGH
HARDLY ANY PRECIPITATION IS EXPECTED FROM WHAT DOES FALL. SOUTHEAST
WINDS WILL CONTINUE THROUGH THE DAY AND OVERNIGHT...AND SO EXPECT LOW
CLOUDS TO STICK AROUND THROUGH THE NIGHT...ESPECIALLY ACROSS THE SD
PLAINS. MAY BE SOME CLEARING ACROSS NORTHEASTERN WY. LOWERED HIGHS
A BIT TO ACCOUNT FOR CLOUDS...RANGING FROM THE LOWER 20S IN THE
EAST TO THE LOWER 30S FARTHER WEST. LOWS WILL BE IN THE TEENS.

ON THURSDAY...WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE
TROUGH PASSES THROUGH...AND CLOUDS WILL FINALLY BE PUSHED OUT OF THE
CWA. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S POSSIBLE
ACROSS THE EASTERN FOOTHILLS.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 201 AM MST WED DEC 17 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR THE WEEKEND INTO EARLY
NEXT WEEK...WITH RIDGE BUILDING ALONG THE PACIFIC COAST AND
DOWNSTREAM TROF DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS
LEAVES NORTHWEST FLOW ALOFT FOR THE NORTHERN PLAINS...WITH SERIES
OF SHORTWAVES TRACKING ACROSS THE AREA. WEEKEND STILL ON TRACK FOR
DRY WEATHER WITH TEMPERATURES NEAR AVERAGE. STRONGEST SHORTWAVE
CROSSES THE NORTHERN PLAINS LATE SUNDAY/MONDAY AS LOW LEVEL
BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL PROFILES SUPPORT SOME
RAIN/SNOW. INCREASING NORTHWEST BL-850MB FLOW WILL ALLOW FOR
UPSLOPE ENHANCEMENT ACROSS THE BLACK HILLS. AS DEEP UPPER TROF
MOVES INTO EASTERN CONUS MID-WEEK...SIGNIFICANT TROF STARTS
DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT BASIN. ECMWF/GFS
DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH OFFER UP POTENTIAL
FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1014 AM MST WED DEC 17 2014

CURRENT SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND CLOUDS WITH IFR/LIFR CIGS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP... AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT FOR THE REST OF THE FORECAST PERIOD. THESE CONDITIONS
ARE CONDUCIVE FOR PERSISTENT LOW CLOUDS/STRATUS... AND AS A
RESULT... HAVE GONE WITH IFR/LIFR CIGS FOR REST OF
AFTERNOON AND EVENING IN WESTERN SD.

MEANWHILE... NORTHEAST WY WILL CONTINUE TO SEE CLEARING OF LOW
CLOUDS/STRATUS THIS AFTERNOON WITH A FEW HIGH CLOUDS MOVING IN.
WHILE PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT... DO NOT EXPECT
IT TO BE WIDESPREAD... AND HAVE LEFT IT OUT OF KGCC TAF FOR THE
CURRENT TIME.


&&

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

$$

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








000
FXUS63 KUNR 171725
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1025 AM MST WED DEC 17 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 201 AM MST WED DEC 17 2014

LARGE UPPER TROUGH COVERS THE WESTERN CONUS. WATER VAPOR IMAGERY
SHOWS AN EMBEDDED SHORTWAVE MOVING THROUGH MT/WY. SURFACE LOW IS
OVER CENTRAL WY...AND WINDS ACROSS THE CWA ARE FROM THE SOUTHEAST.
FOG/LOW STRATUS COVERS MUCH OF THE NORTHERN PLAINS...WITH MID/HIGH
CLOUDS DRIFTING IN AHEAD OF THE SHORTWAVE. KRCA REPORTED FREEZING
DRIZZLE A BIT AGO...AND THERE MAY BE A LITTLE ICING FORMING OUT OF
THE FOG...SO UPDATED WEATHER GRIDS FOR FREEZING FOG EARLY THIS
MORNING. TEMPS ARE MAINLY IN THE TEENS.

SHORTWAVE/WEAK TROUGH WILL PASS THROUGH THE REGION TODAY...PUSHING
IN SOME WARMER AIR. STILL LOOKS LIKE THERE MAY BE A FEW LIGHT SNOW
SHOWERS ALONG THE BAROCLINIC ZONE TODAY...POSSIBLY LINGERING A BIT
INTO THE EVENING. BEST FORCING SHOULD BE EAST OF THE AREA BY
MIDNIGHT...SO EXPECT THE REST OF THE NIGHT TO BE DRY...ALTHOUGH
HARDLY ANY PRECIPITATION IS EXPECTED FROM WHAT DOES FALL. SOUTHEAST
WINDS WILL CONTINUE THROUGH THE DAY AND OVERNIGHT...AND SO EXPECT LOW
CLOUDS TO STICK AROUND THROUGH THE NIGHT...ESPECIALLY ACROSS THE SD
PLAINS. MAY BE SOME CLEARING ACROSS NORTHEASTERN WY. LOWERED HIGHS
A BIT TO ACCOUNT FOR CLOUDS...RANGING FROM THE LOWER 20S IN THE
EAST TO THE LOWER 30S FARTHER WEST. LOWS WILL BE IN THE TEENS.

ON THURSDAY...WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE
TROUGH PASSES THROUGH...AND CLOUDS WILL FINALLY BE PUSHED OUT OF THE
CWA. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S POSSIBLE
ACROSS THE EASTERN FOOTHILLS.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 201 AM MST WED DEC 17 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR THE WEEKEND INTO EARLY
NEXT WEEK...WITH RIDGE BUILDING ALONG THE PACIFIC COAST AND
DOWNSTREAM TROF DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS
LEAVES NORTHWEST FLOW ALOFT FOR THE NORTHERN PLAINS...WITH SERIES
OF SHORTWAVES TRACKING ACROSS THE AREA. WEEKEND STILL ON TRACK FOR
DRY WEATHER WITH TEMPERATURES NEAR AVERAGE. STRONGEST SHORTWAVE
CROSSES THE NORTHERN PLAINS LATE SUNDAY/MONDAY AS LOW LEVEL
BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL PROFILES SUPPORT SOME
RAIN/SNOW. INCREASING NORTHWEST BL-850MB FLOW WILL ALLOW FOR
UPSLOPE ENHANCEMENT ACROSS THE BLACK HILLS. AS DEEP UPPER TROF
MOVES INTO EASTERN CONUS MID-WEEK...SIGNIFICANT TROF STARTS
DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT BASIN. ECMWF/GFS
DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH OFFER UP POTENTIAL
FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1014 AM MST WED DEC 17 2014

CURRENT SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND CLOUDS WITH IFR/LIFR CIGS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP... AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT FOR THE REST OF THE FORECAST PERIOD. THESE CONDITIONS
ARE CONDUCIVE FOR PERSISTENT LOW CLOUDS/STRATUS... AND AS A
RESULT... HAVE GONE WITH IFR/LIFR CIGS FOR REST OF
AFTERNOON AND EVENING IN WESTERN SD.

MEANWHILE... NORTHEAST WY WILL CONTINUE TO SEE CLEARING OF LOW
CLOUDS/STRATUS THIS AFTERNOON WITH A FEW HIGH CLOUDS MOVING IN.
WHILE PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT... DO NOT EXPECT
IT TO BE WIDESPREAD... AND HAVE LEFT IT OUT OF KGCC TAF FOR THE
CURRENT TIME.

&&

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

$$

SHORT TERM...POJORLIE
LONG TERM...7
AVIATION...MCKEMY







000
FXUS63 KUNR 171725
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1025 AM MST WED DEC 17 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 201 AM MST WED DEC 17 2014

LARGE UPPER TROUGH COVERS THE WESTERN CONUS. WATER VAPOR IMAGERY
SHOWS AN EMBEDDED SHORTWAVE MOVING THROUGH MT/WY. SURFACE LOW IS
OVER CENTRAL WY...AND WINDS ACROSS THE CWA ARE FROM THE SOUTHEAST.
FOG/LOW STRATUS COVERS MUCH OF THE NORTHERN PLAINS...WITH MID/HIGH
CLOUDS DRIFTING IN AHEAD OF THE SHORTWAVE. KRCA REPORTED FREEZING
DRIZZLE A BIT AGO...AND THERE MAY BE A LITTLE ICING FORMING OUT OF
THE FOG...SO UPDATED WEATHER GRIDS FOR FREEZING FOG EARLY THIS
MORNING. TEMPS ARE MAINLY IN THE TEENS.

SHORTWAVE/WEAK TROUGH WILL PASS THROUGH THE REGION TODAY...PUSHING
IN SOME WARMER AIR. STILL LOOKS LIKE THERE MAY BE A FEW LIGHT SNOW
SHOWERS ALONG THE BAROCLINIC ZONE TODAY...POSSIBLY LINGERING A BIT
INTO THE EVENING. BEST FORCING SHOULD BE EAST OF THE AREA BY
MIDNIGHT...SO EXPECT THE REST OF THE NIGHT TO BE DRY...ALTHOUGH
HARDLY ANY PRECIPITATION IS EXPECTED FROM WHAT DOES FALL. SOUTHEAST
WINDS WILL CONTINUE THROUGH THE DAY AND OVERNIGHT...AND SO EXPECT LOW
CLOUDS TO STICK AROUND THROUGH THE NIGHT...ESPECIALLY ACROSS THE SD
PLAINS. MAY BE SOME CLEARING ACROSS NORTHEASTERN WY. LOWERED HIGHS
A BIT TO ACCOUNT FOR CLOUDS...RANGING FROM THE LOWER 20S IN THE
EAST TO THE LOWER 30S FARTHER WEST. LOWS WILL BE IN THE TEENS.

ON THURSDAY...WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE
TROUGH PASSES THROUGH...AND CLOUDS WILL FINALLY BE PUSHED OUT OF THE
CWA. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S POSSIBLE
ACROSS THE EASTERN FOOTHILLS.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 201 AM MST WED DEC 17 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR THE WEEKEND INTO EARLY
NEXT WEEK...WITH RIDGE BUILDING ALONG THE PACIFIC COAST AND
DOWNSTREAM TROF DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS
LEAVES NORTHWEST FLOW ALOFT FOR THE NORTHERN PLAINS...WITH SERIES
OF SHORTWAVES TRACKING ACROSS THE AREA. WEEKEND STILL ON TRACK FOR
DRY WEATHER WITH TEMPERATURES NEAR AVERAGE. STRONGEST SHORTWAVE
CROSSES THE NORTHERN PLAINS LATE SUNDAY/MONDAY AS LOW LEVEL
BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL PROFILES SUPPORT SOME
RAIN/SNOW. INCREASING NORTHWEST BL-850MB FLOW WILL ALLOW FOR
UPSLOPE ENHANCEMENT ACROSS THE BLACK HILLS. AS DEEP UPPER TROF
MOVES INTO EASTERN CONUS MID-WEEK...SIGNIFICANT TROF STARTS
DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT BASIN. ECMWF/GFS
DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH OFFER UP POTENTIAL
FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1014 AM MST WED DEC 17 2014

CURRENT SATELLITE AND OBS SHOW MUCH OF WESTERN SD AND PARTS OF
NORTHEASTERN WY IN LOW STRATUS AND CLOUDS WITH IFR/LIFR CIGS.
MODEL SOUNDINGS KEEP THE LOW LEVEL MOISTURE LOCKED INTO WESTERN
SD... INCLUDING KRAP... AND SURFACE WINDS MAINTAIN AN EASTERLY
COMPONENT FOR THE REST OF THE FORECAST PERIOD. THESE CONDITIONS
ARE CONDUCIVE FOR PERSISTENT LOW CLOUDS/STRATUS... AND AS A
RESULT... HAVE GONE WITH IFR/LIFR CIGS FOR REST OF
AFTERNOON AND EVENING IN WESTERN SD.

MEANWHILE... NORTHEAST WY WILL CONTINUE TO SEE CLEARING OF LOW
CLOUDS/STRATUS THIS AFTERNOON WITH A FEW HIGH CLOUDS MOVING IN.
WHILE PATCHY FOG/STRATUS COULD DEVELOP OVERNIGHT... DO NOT EXPECT
IT TO BE WIDESPREAD... AND HAVE LEFT IT OUT OF KGCC TAF FOR THE
CURRENT TIME.

&&

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

$$

SHORT TERM...POJORLIE
LONG TERM...7
AVIATION...MCKEMY








000
FXUS63 KUNR 170906
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
206 AM MST WED DEC 17 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 201 AM MST WED DEC 17 2014

LARGE UPPER TROUGH COVERS THE WESTERN CONUS. WATER VAPOR IMAGERY
SHOWS AN EMBEDDED SHORTWAVE MOVING THROUGH MT/WY. SURFACE LOW IS
OVER CENTRAL WY...AND WINDS ACROSS THE CWA ARE FROM THE SOUTHEAST.
FOG/LOW STRATUS COVERS MUCH OF THE NORTHERN PLAINS...WITH MID/HIGH
CLOUDS DRIFTING IN AHEAD OF THE SHORTWAVE. KRCA REPORTED FREEZING
DRIZZLE A BIT AGO...AND THERE MAY BE A LITTLE ICING FORMING OUT OF
THE FOG...SO UPDATED WEATHER GRIDS FOR FREEZING FOG EARLY THIS
MORNING. TEMPS ARE MAINLY IN THE TEENS.

SHORTWAVE/WEAK TROUGH WILL PASS THROUGH THE REGION TODAY...PUSHING
IN SOME WARMER AIR. STILL LOOKS LIKE THERE MAY BE A FEW LIGHT SNOW
SHOWERS ALONG THE BAROCLINIC ZONE TODAY...POSSIBLY LINGERING A BIT
INTO THE EVENING. BEST FORCING SHOULD BE EAST OF THE AREA BY
MIDNIGHT...SO EXPECT THE REST OF THE NIGHT TO BE DRY...ALTHOUGH
HARDLY ANY PRECIPITATION IS EXPECTED FROM WHAT DOES FALL. SOUTHEAST
WINDS WILL CONTINUE THROUGH THE DAY AND OVERNIGHT...AND SO EXPECT LOW
CLOUDS TO STICK AROUND THROUGH THE NIGHT...ESPECIALLY ACROSS THE SD
PLAINS. MAY BE SOME CLEARING ACROSS NORTHEASTERN WY. LOWERED HIGHS
A BIT TO ACCOUNT FOR CLOUDS...RANGING FROM THE LOWER 20S IN THE
EAST TO THE LOWER 30S FARTHER WEST. LOWS WILL BE IN THE TEENS.

ON THURSDAY...WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE
TROUGH PASSES THROUGH...AND CLOUDS WILL FINALLY BE PUSHED OUT OF THE
CWA. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S POSSIBLE
ACROSS THE EASTERN FOOTHILLS.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 201 AM MST WED DEC 17 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR THE WEEKEND INTO EARLY
NEXT WEEK...WITH RIDGE BUILDING ALONG THE PACIFIC COAST AND
DOWNSTREAM TROF DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS
LEAVES NORTHWEST FLOW ALOFT FOR THE NORTHERN PLAINS...WITH SERIES
OF SHORTWAVES TRACKING ACROSS THE AREA. WEEKEND STILL ON TRACK FOR
DRY WEATHER WITH TEMPERATURES NEAR AVERAGE. STRONGEST SHORTWAVE
CROSSES THE NORTHERN PLAINS LATE SUNDAY/MONDAY AS LOW LEVEL
BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL PROFILES SUPPORT SOME
RAIN/SNOW. INCREASING NORTHWEST BL-850MB FLOW WILL ALLOW FOR
UPSLOPE ENHANCEMENT ACROSS THE BLACK HILLS. AS DEEP UPPER TROF
MOVES INTO EASTERN CONUS MID-WEEK...SIGNIFICANT TROF STARTS
DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT BASIN. ECMWF/GFS
DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH OFFER UP POTENTIAL
FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 201 AM MST WED DEC 17 2014

WIDESPREAD IFR/LIFR CIGS WILL CONTINUE ACROSS WESTERN
SOUTH DAKOTA INTO NORTHEASTERN WYOMING THROUGH MUCH OF TODAY. SOME
CLEARING POSSIBLE OVER PORTIONS OF NORTHEAST WYOMING...INCLUDING
KGCC TERMINAL LATE THIS MORNING/EARLY AFTERNOON. HIGHER ELEVATIONS
OF BLACK HILLS WILL ALSO REMAIN CLOUD FREE. WITH THE SHALLOW
SUPERCOOLED CLOUDS...SOME FZFG POSSIBLE. LOW CLOUDS WILL REMAIN
ACROSS THE WESTERN SOUTH DAKOTA PLAINS THROUGH TONIGHT.

&&

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

$$

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








000
FXUS63 KUNR 170906
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
206 AM MST WED DEC 17 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 201 AM MST WED DEC 17 2014

LARGE UPPER TROUGH COVERS THE WESTERN CONUS. WATER VAPOR IMAGERY
SHOWS AN EMBEDDED SHORTWAVE MOVING THROUGH MT/WY. SURFACE LOW IS
OVER CENTRAL WY...AND WINDS ACROSS THE CWA ARE FROM THE SOUTHEAST.
FOG/LOW STRATUS COVERS MUCH OF THE NORTHERN PLAINS...WITH MID/HIGH
CLOUDS DRIFTING IN AHEAD OF THE SHORTWAVE. KRCA REPORTED FREEZING
DRIZZLE A BIT AGO...AND THERE MAY BE A LITTLE ICING FORMING OUT OF
THE FOG...SO UPDATED WEATHER GRIDS FOR FREEZING FOG EARLY THIS
MORNING. TEMPS ARE MAINLY IN THE TEENS.

SHORTWAVE/WEAK TROUGH WILL PASS THROUGH THE REGION TODAY...PUSHING
IN SOME WARMER AIR. STILL LOOKS LIKE THERE MAY BE A FEW LIGHT SNOW
SHOWERS ALONG THE BAROCLINIC ZONE TODAY...POSSIBLY LINGERING A BIT
INTO THE EVENING. BEST FORCING SHOULD BE EAST OF THE AREA BY
MIDNIGHT...SO EXPECT THE REST OF THE NIGHT TO BE DRY...ALTHOUGH
HARDLY ANY PRECIPITATION IS EXPECTED FROM WHAT DOES FALL. SOUTHEAST
WINDS WILL CONTINUE THROUGH THE DAY AND OVERNIGHT...AND SO EXPECT LOW
CLOUDS TO STICK AROUND THROUGH THE NIGHT...ESPECIALLY ACROSS THE SD
PLAINS. MAY BE SOME CLEARING ACROSS NORTHEASTERN WY. LOWERED HIGHS
A BIT TO ACCOUNT FOR CLOUDS...RANGING FROM THE LOWER 20S IN THE
EAST TO THE LOWER 30S FARTHER WEST. LOWS WILL BE IN THE TEENS.

ON THURSDAY...WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE
TROUGH PASSES THROUGH...AND CLOUDS WILL FINALLY BE PUSHED OUT OF THE
CWA. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S POSSIBLE
ACROSS THE EASTERN FOOTHILLS.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 201 AM MST WED DEC 17 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR THE WEEKEND INTO EARLY
NEXT WEEK...WITH RIDGE BUILDING ALONG THE PACIFIC COAST AND
DOWNSTREAM TROF DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS
LEAVES NORTHWEST FLOW ALOFT FOR THE NORTHERN PLAINS...WITH SERIES
OF SHORTWAVES TRACKING ACROSS THE AREA. WEEKEND STILL ON TRACK FOR
DRY WEATHER WITH TEMPERATURES NEAR AVERAGE. STRONGEST SHORTWAVE
CROSSES THE NORTHERN PLAINS LATE SUNDAY/MONDAY AS LOW LEVEL
BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL PROFILES SUPPORT SOME
RAIN/SNOW. INCREASING NORTHWEST BL-850MB FLOW WILL ALLOW FOR
UPSLOPE ENHANCEMENT ACROSS THE BLACK HILLS. AS DEEP UPPER TROF
MOVES INTO EASTERN CONUS MID-WEEK...SIGNIFICANT TROF STARTS
DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT BASIN. ECMWF/GFS
DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH OFFER UP POTENTIAL
FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 201 AM MST WED DEC 17 2014

WIDESPREAD IFR/LIFR CIGS WILL CONTINUE ACROSS WESTERN
SOUTH DAKOTA INTO NORTHEASTERN WYOMING THROUGH MUCH OF TODAY. SOME
CLEARING POSSIBLE OVER PORTIONS OF NORTHEAST WYOMING...INCLUDING
KGCC TERMINAL LATE THIS MORNING/EARLY AFTERNOON. HIGHER ELEVATIONS
OF BLACK HILLS WILL ALSO REMAIN CLOUD FREE. WITH THE SHALLOW
SUPERCOOLED CLOUDS...SOME FZFG POSSIBLE. LOW CLOUDS WILL REMAIN
ACROSS THE WESTERN SOUTH DAKOTA PLAINS THROUGH TONIGHT.

&&

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

$$

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









000
FXUS63 KUNR 170906
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
206 AM MST WED DEC 17 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 201 AM MST WED DEC 17 2014

LARGE UPPER TROUGH COVERS THE WESTERN CONUS. WATER VAPOR IMAGERY
SHOWS AN EMBEDDED SHORTWAVE MOVING THROUGH MT/WY. SURFACE LOW IS
OVER CENTRAL WY...AND WINDS ACROSS THE CWA ARE FROM THE SOUTHEAST.
FOG/LOW STRATUS COVERS MUCH OF THE NORTHERN PLAINS...WITH MID/HIGH
CLOUDS DRIFTING IN AHEAD OF THE SHORTWAVE. KRCA REPORTED FREEZING
DRIZZLE A BIT AGO...AND THERE MAY BE A LITTLE ICING FORMING OUT OF
THE FOG...SO UPDATED WEATHER GRIDS FOR FREEZING FOG EARLY THIS
MORNING. TEMPS ARE MAINLY IN THE TEENS.

SHORTWAVE/WEAK TROUGH WILL PASS THROUGH THE REGION TODAY...PUSHING
IN SOME WARMER AIR. STILL LOOKS LIKE THERE MAY BE A FEW LIGHT SNOW
SHOWERS ALONG THE BAROCLINIC ZONE TODAY...POSSIBLY LINGERING A BIT
INTO THE EVENING. BEST FORCING SHOULD BE EAST OF THE AREA BY
MIDNIGHT...SO EXPECT THE REST OF THE NIGHT TO BE DRY...ALTHOUGH
HARDLY ANY PRECIPITATION IS EXPECTED FROM WHAT DOES FALL. SOUTHEAST
WINDS WILL CONTINUE THROUGH THE DAY AND OVERNIGHT...AND SO EXPECT LOW
CLOUDS TO STICK AROUND THROUGH THE NIGHT...ESPECIALLY ACROSS THE SD
PLAINS. MAY BE SOME CLEARING ACROSS NORTHEASTERN WY. LOWERED HIGHS
A BIT TO ACCOUNT FOR CLOUDS...RANGING FROM THE LOWER 20S IN THE
EAST TO THE LOWER 30S FARTHER WEST. LOWS WILL BE IN THE TEENS.

ON THURSDAY...WINDS WILL SHIFT TO THE SOUTHWEST AS THE SURFACE
TROUGH PASSES THROUGH...AND CLOUDS WILL FINALLY BE PUSHED OUT OF THE
CWA. HIGHS WILL WARM INTO THE 30S...WITH SOME LOWER 40S POSSIBLE
ACROSS THE EASTERN FOOTHILLS.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 201 AM MST WED DEC 17 2014

EXTENDED MODELS IN DECENT AGREEMENT FOR THE WEEKEND INTO EARLY
NEXT WEEK...WITH RIDGE BUILDING ALONG THE PACIFIC COAST AND
DOWNSTREAM TROF DIGGING ACROSS THE UPPER MIDWEST/GREAT LAKES. THIS
LEAVES NORTHWEST FLOW ALOFT FOR THE NORTHERN PLAINS...WITH SERIES
OF SHORTWAVES TRACKING ACROSS THE AREA. WEEKEND STILL ON TRACK FOR
DRY WEATHER WITH TEMPERATURES NEAR AVERAGE. STRONGEST SHORTWAVE
CROSSES THE NORTHERN PLAINS LATE SUNDAY/MONDAY AS LOW LEVEL
BAROCLINIC ZONE SLIPS INTO THE AREA. THERMAL PROFILES SUPPORT SOME
RAIN/SNOW. INCREASING NORTHWEST BL-850MB FLOW WILL ALLOW FOR
UPSLOPE ENHANCEMENT ACROSS THE BLACK HILLS. AS DEEP UPPER TROF
MOVES INTO EASTERN CONUS MID-WEEK...SIGNIFICANT TROF STARTS
DIGGING THROUGH PACIFIC NORTHWEST INTO THE GREAT BASIN. ECMWF/GFS
DIFFER SOME IN STRENGTH AND TRACK...BUT BOTH OFFER UP POTENTIAL
FOR SNOW ON CHRISTMAS DAY.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING
ISSUED AT 201 AM MST WED DEC 17 2014

WIDESPREAD IFR/LIFR CIGS WILL CONTINUE ACROSS WESTERN
SOUTH DAKOTA INTO NORTHEASTERN WYOMING THROUGH MUCH OF TODAY. SOME
CLEARING POSSIBLE OVER PORTIONS OF NORTHEAST WYOMING...INCLUDING
KGCC TERMINAL LATE THIS MORNING/EARLY AFTERNOON. HIGHER ELEVATIONS
OF BLACK HILLS WILL ALSO REMAIN CLOUD FREE. WITH THE SHALLOW
SUPERCOOLED CLOUDS...SOME FZFG POSSIBLE. LOW CLOUDS WILL REMAIN
ACROSS THE WESTERN SOUTH DAKOTA PLAINS THROUGH TONIGHT.

&&

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

$$

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








000
FXUS63 KUNR 170441
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
941 PM MST TUE DEC 16 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 241 PM MST TUE DEC 16 2014

WATER VAPOR IMAGERY SHOWS UPPER TROUGH ACROSS THE GREAT LAKES WITH
SECONDARY UPPER LOW OVER MINNESOTA. THE NEXT STRONG TROUGH IS
PUSHING INTO THE PACIFIC COAST...AND IN BETWEEN THE NRN PLAINS ARE
SITTING IN WEAK RIDGING. SURFACE ANALYSIS SHOWS THE FRONTAL BOUNDARY
SITTING OVER CNTRL MT TO THE BLKHLS AREA AND SOUTH INTO WRN/CNTRL
NEB. TEMPS HAVE RISEN INTO THE 20S ACROSS MOST LOCATIONS. LOW CLOUDS
ARE MAINLY AFFECTING THE WRN SD PLAINS THOUGH SOME BREAKING APART OF
THE CLOUD DECK HAS OCCURRED IN THE LAST HOUR OR TWO OVER NE WY AND
WRN SD FTHLLS. CLOUDS WILL BUILD BACK IN TONIGHT OVER THE WRN SD
PLAINS AND NE WY AS S/SE RETURN FLOW CONTINUES ACROSS THE AREA. THE
BKLHLS WILL REMAIN CLEAR OVERNIGHT AS THE MOISTURE REMAINS LIMITED
TO THE LOW LEVELS.

MODELS SHOW AN UPPER WAVE CROSSING THE MT/WY BORDER TOMORROW WITH
LOW LEVEL RETURN FLOW CONTINUING OVER THE REGION. LOW CLOUDS ARE
EXPECTED TO CONTINUE OVER THE WRN SD PLAINS THROUGH THE DAY...WHILE
SOME DECREASING IN CLOUD COVERAGE IS POSSIBLE OVER THE NE WY PLAINS.
WEAK FORCING FROM THE UPPER WAVE MAY BRING SOME FLURRIES/-SHSN TO
PORTIONS OF NE WY INTO NW SD THROUGH THE DAY...BUT LITTLE TO NO
ACCUMULATION IS EXPECTED. TEMPS WILL BE NEAR OR SLIGHTLY WARMER THAN
TODAY WITH HIGHS IN THE 20S TO MID 30S. WAVE WILL CROSS THE AREA
LATE WEDNESDAY SO HAVE REMOVED MENTION OF -SHSN WED NIGHT.

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 241 PM MST TUE DEC 16 2014

SPLIT FLOW WILL REMAIN IN THE PERIOD...WITH SEASONAL WESTERLY
FLOW. WEAK SHORTWAVE IMPULSES WILL CROSS REGION THROUGH THE
WEEKEND...BRINGING NOTHING MORE THAN SOME MID CLOUDS AND A WIND
SHIFT. A MORE ORGANIZED SYSTEM IS ON TRACK FOR THE FIRST PART OF
NEXT WEEK AS THE WESTERN NOAM RIDGE BUILDS AND ACTIVE NW FLOW
DEVELOPS. INCREASING LL PAC ORIGIN MOISTURE COUPLED WITH NW FLOW
IMPULSES WILL BRING CHANCES FOR RAIN OR SNOW SHOWERS...WITH THE
BEST CHANCES FOR ANY PRECIP IN NE WY AND THE NORTHERN BLACK HILLS
PER UPSLOPE PROCESSES. WARMER WEATHER IS ALSO EXPECTED FRI-SUN AS
THE UPPER RIDGE SPREADS EAST SOME AND WAA ENSUES.
HOWEVER...CONTINUED TRAIN OF IMPULSE WILL EVENTUALLY SETTLE COOLER
AIR INTO THE REGION EARLY NEXT WEEK. TENDENCIES FOR A STRONG
WESTERN NOAM TROUGH REMAIN PRESENT IN MEAN ENSEMBLES AND
DETERMINISTIC SOLUTIONS PER ANOTHER EXTENSION OF THE EAST ASIAN
UPPER JET. THIS TROUGH WOULD LIKELY LEAD TO VIGOROUS CYCLOGENSIS
ON THE PLAINS NEXT WEEK...WITH THE LATITUDINAL LOCATION HINGING ON
THE DEGREE OF UPPER JET DIGGING OVER THE SW CONUS AND POSSIBLE
DOWNSTREAM RIDGE AMPLIFICATION. THIS SYSTEM COULD POTENTIALLY
BRING SIG SNOW AND WIND TO A PORTION OF THE PLAINS TOWARD THE
MIDDLE OR END OF NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 939 PM MST TUE DEC 16 2014

WIDESPREAD IFR/LIFR CIGS WILL CONTINUE ACROSS WRN SD AND INTO
NERN WY OVERNIGHT AND THROUGH MUCH OF WEDNESDAY. LOW CLOUDS WILL
BE IN AND OUT OF THE KGCC AREA ON THE WRN EXTENT...AND THE BLKHLS
SHOULD REMAIN ABOVE THE LOW CLOUDS FOR THE MOST PART. ALSO...WITH
THE SHALLOW SUPERCOOLED CLOUDS THERE MAY BE SOME FZFG...BUT LACK
OF SHEAR IN THE CLOUD LAYER SHOULD PREVENT FZDZ FROM OCCURRING.
GRADUAL CLEARING IS EXPECTED OVER NERN WY ON WEDNESDAY...BUT
CLOUDS WILL HANG TOUGH OVER THE WRN/CNTRL SD THROUGH MOST IF NOT
ALL OF THE DAY.

&&

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

$$

SHORT TERM...13
LONG TERM...JC
AVIATION...BUNKERS






000
FXUS63 KUNR 170441
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
941 PM MST TUE DEC 16 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 241 PM MST TUE DEC 16 2014

WATER VAPOR IMAGERY SHOWS UPPER TROUGH ACROSS THE GREAT LAKES WITH
SECONDARY UPPER LOW OVER MINNESOTA. THE NEXT STRONG TROUGH IS
PUSHING INTO THE PACIFIC COAST...AND IN BETWEEN THE NRN PLAINS ARE
SITTING IN WEAK RIDGING. SURFACE ANALYSIS SHOWS THE FRONTAL BOUNDARY
SITTING OVER CNTRL MT TO THE BLKHLS AREA AND SOUTH INTO WRN/CNTRL
NEB. TEMPS HAVE RISEN INTO THE 20S ACROSS MOST LOCATIONS. LOW CLOUDS
ARE MAINLY AFFECTING THE WRN SD PLAINS THOUGH SOME BREAKING APART OF
THE CLOUD DECK HAS OCCURRED IN THE LAST HOUR OR TWO OVER NE WY AND
WRN SD FTHLLS. CLOUDS WILL BUILD BACK IN TONIGHT OVER THE WRN SD
PLAINS AND NE WY AS S/SE RETURN FLOW CONTINUES ACROSS THE AREA. THE
BKLHLS WILL REMAIN CLEAR OVERNIGHT AS THE MOISTURE REMAINS LIMITED
TO THE LOW LEVELS.

MODELS SHOW AN UPPER WAVE CROSSING THE MT/WY BORDER TOMORROW WITH
LOW LEVEL RETURN FLOW CONTINUING OVER THE REGION. LOW CLOUDS ARE
EXPECTED TO CONTINUE OVER THE WRN SD PLAINS THROUGH THE DAY...WHILE
SOME DECREASING IN CLOUD COVERAGE IS POSSIBLE OVER THE NE WY PLAINS.
WEAK FORCING FROM THE UPPER WAVE MAY BRING SOME FLURRIES/-SHSN TO
PORTIONS OF NE WY INTO NW SD THROUGH THE DAY...BUT LITTLE TO NO
ACCUMULATION IS EXPECTED. TEMPS WILL BE NEAR OR SLIGHTLY WARMER THAN
TODAY WITH HIGHS IN THE 20S TO MID 30S. WAVE WILL CROSS THE AREA
LATE WEDNESDAY SO HAVE REMOVED MENTION OF -SHSN WED NIGHT.

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 241 PM MST TUE DEC 16 2014

SPLIT FLOW WILL REMAIN IN THE PERIOD...WITH SEASONAL WESTERLY
FLOW. WEAK SHORTWAVE IMPULSES WILL CROSS REGION THROUGH THE
WEEKEND...BRINGING NOTHING MORE THAN SOME MID CLOUDS AND A WIND
SHIFT. A MORE ORGANIZED SYSTEM IS ON TRACK FOR THE FIRST PART OF
NEXT WEEK AS THE WESTERN NOAM RIDGE BUILDS AND ACTIVE NW FLOW
DEVELOPS. INCREASING LL PAC ORIGIN MOISTURE COUPLED WITH NW FLOW
IMPULSES WILL BRING CHANCES FOR RAIN OR SNOW SHOWERS...WITH THE
BEST CHANCES FOR ANY PRECIP IN NE WY AND THE NORTHERN BLACK HILLS
PER UPSLOPE PROCESSES. WARMER WEATHER IS ALSO EXPECTED FRI-SUN AS
THE UPPER RIDGE SPREADS EAST SOME AND WAA ENSUES.
HOWEVER...CONTINUED TRAIN OF IMPULSE WILL EVENTUALLY SETTLE COOLER
AIR INTO THE REGION EARLY NEXT WEEK. TENDENCIES FOR A STRONG
WESTERN NOAM TROUGH REMAIN PRESENT IN MEAN ENSEMBLES AND
DETERMINISTIC SOLUTIONS PER ANOTHER EXTENSION OF THE EAST ASIAN
UPPER JET. THIS TROUGH WOULD LIKELY LEAD TO VIGOROUS CYCLOGENSIS
ON THE PLAINS NEXT WEEK...WITH THE LATITUDINAL LOCATION HINGING ON
THE DEGREE OF UPPER JET DIGGING OVER THE SW CONUS AND POSSIBLE
DOWNSTREAM RIDGE AMPLIFICATION. THIS SYSTEM COULD POTENTIALLY
BRING SIG SNOW AND WIND TO A PORTION OF THE PLAINS TOWARD THE
MIDDLE OR END OF NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 939 PM MST TUE DEC 16 2014

WIDESPREAD IFR/LIFR CIGS WILL CONTINUE ACROSS WRN SD AND INTO
NERN WY OVERNIGHT AND THROUGH MUCH OF WEDNESDAY. LOW CLOUDS WILL
BE IN AND OUT OF THE KGCC AREA ON THE WRN EXTENT...AND THE BLKHLS
SHOULD REMAIN ABOVE THE LOW CLOUDS FOR THE MOST PART. ALSO...WITH
THE SHALLOW SUPERCOOLED CLOUDS THERE MAY BE SOME FZFG...BUT LACK
OF SHEAR IN THE CLOUD LAYER SHOULD PREVENT FZDZ FROM OCCURRING.
GRADUAL CLEARING IS EXPECTED OVER NERN WY ON WEDNESDAY...BUT
CLOUDS WILL HANG TOUGH OVER THE WRN/CNTRL SD THROUGH MOST IF NOT
ALL OF THE DAY.

&&

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

$$

SHORT TERM...13
LONG TERM...JC
AVIATION...BUNKERS







000
FXUS63 KUNR 162328
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
428 PM MST TUE DEC 16 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 241 PM MST TUE DEC 16 2014

WATER VAPOR IMAGERY SHOWS UPPER TROUGH ACROSS THE GREAT LAKES WITH
SECONDARY UPPER LOW OVER MINNESOTA. THE NEXT STRONG TROUGH IS
PUSHING INTO THE PACIFIC COAST...AND IN BETWEEN THE NRN PLAINS ARE
SITTING IN WEAK RIDGING. SURFACE ANALYSIS SHOWS THE FRONTAL BOUNDARY
SITTING OVER CNTRL MT TO THE BLKHLS AREA AND SOUTH INTO WRN/CNTRL
NEB. TEMPS HAVE RISEN INTO THE 20S ACROSS MOST LOCATIONS. LOW CLOUDS
ARE MAINLY AFFECTING THE WRN SD PLAINS THOUGH SOME BREAKING APART OF
THE CLOUD DECK HAS OCCURRED IN THE LAST HOUR OR TWO OVER NE WY AND
WRN SD FTHLLS. CLOUDS WILL BUILD BACK IN TONIGHT OVER THE WRN SD
PLAINS AND NE WY AS S/SE RETURN FLOW CONTINUES ACROSS THE AREA. THE
BKLHLS WILL REMAIN CLEAR OVERNIGHT AS THE MOISTURE REMAINS LIMITED
TO THE LOW LEVELS.

MODELS SHOW AN UPPER WAVE CROSSING THE MT/WY BORDER TOMORROW WITH
LOW LEVEL RETURN FLOW CONTINUING OVER THE REGION. LOW CLOUDS ARE
EXPECTED TO CONTINUE OVER THE WRN SD PLAINS THROUGH THE DAY...WHILE
SOME DECREASING IN CLOUD COVERAGE IS POSSIBLE OVER THE NE WY PLAINS.
WEAK FORCING FROM THE UPPER WAVE MAY BRING SOME FLURRIES/-SHSN TO
PORTIONS OF NE WY INTO NW SD THROUGH THE DAY...BUT LITTLE TO NO
ACCUMULATION IS EXPECTED. TEMPS WILL BE NEAR OR SLIGHTLY WARMER THAN
TODAY WITH HIGHS IN THE 20S TO MID 30S. WAVE WILL CROSS THE AREA
LATE WEDNESDAY SO HAVE REMOVED MENTION OF -SHSN WED NIGHT.

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 241 PM MST TUE DEC 16 2014

SPLIT FLOW WILL REMAIN IN THE PERIOD...WITH SEASONAL WESTERLY
FLOW. WEAK SHORTWAVE IMPULSES WILL CROSS REGION THROUGH THE
WEEKEND...BRINGING NOTHING MORE THAN SOME MID CLOUDS AND A WIND
SHIFT. A MORE ORGANIZED SYSTEM IS ON TRACK FOR THE FIRST PART OF
NEXT WEEK AS THE WESTERN NOAM RIDGE BUILDS AND ACTIVE NW FLOW
DEVELOPS. INCREASING LL PAC ORIGIN MOISTURE COUPLED WITH NW FLOW
IMPULSES WILL BRING CHANCES FOR RAIN OR SNOW SHOWERS...WITH THE
BEST CHANCES FOR ANY PRECIP IN NE WY AND THE NORTHERN BLACK HILLS
PER UPSLOPE PROCESSES. WARMER WEATHER IS ALSO EXPECTED FRI-SUN AS
THE UPPER RIDGE SPREADS EAST SOME AND WAA ENSUES.
HOWEVER...CONTINUED TRAIN OF IMPULSE WILL EVENTUALLY SETTLE COOLER
AIR INTO THE REGION EARLY NEXT WEEK. TENDENCIES FOR A STRONG
WESTERN NOAM TROUGH REMAIN PRESENT IN MEAN ENSEMBLES AND
DETERMINISTIC SOLUTIONS PER ANOTHER EXTENSION OF THE EAST ASIAN
UPPER JET. THIS TROUGH WOULD LIKELY LEAD TO VIGOROUS CYCLOGENSIS
ON THE PLAINS NEXT WEEK...WITH THE LATITUDINAL LOCATION HINGING ON
THE DEGREE OF UPPER JET DIGGING OVER THE SW CONUS AND POSSIBLE
DOWNSTREAM RIDGE AMPLIFICATION. THIS SYSTEM COULD POTENTIALLY
BRING SIG SNOW AND WIND TO A PORTION OF THE PLAINS TOWARD THE
MIDDLE OR END OF NEXT WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 423 PM MST TUE DEC 16 2014

WIDESPREAD IFR/LIFR CIGS WILL CONTINUE ACROSS WRN SD AND INTO
NERN WY OVERNIGHT...WITH LOW CLOUDS POSSIBLY SPREADING ALL THE WAY
BACK TO KGCC. HOWEVER...THE BLKHLS SHOULD REMAIN ABOVE THE CLOUDS
FOR THE MOST PART. THERE IS A QUESTION OF THE WRN EXTENT OF THE
STRATUS BECAUSE OF MID AND HIGH CLOUDS THAT WILL LIMIT SFC
COOLING. ALSO...WITH THE SHALLOW SUPERCOOLED CLOUDS THERE MAY BE
SOME FZFG. LACK OF SHEAR IN THE CLOUD LAYER SHOULD PREVENT FZDZ
FROM OCCURRING. GRADUAL CLEARING IS EXPECTED OVER NERN WY AND FAR
WRN SD ON WEDNESDAY...BUT CLOUDS WILL HANG TOUGH OVER THE REST OF
THE WRN/CNTRL SD PLAINS.

&&

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

$$

SHORT TERM...13
LONG TERM...JC
AVIATION...BUNKERS








000
FXUS63 KUNR 162328
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
428 PM MST TUE DEC 16 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 241 PM MST TUE DEC 16 2014

WATER VAPOR IMAGERY SHOWS UPPER TROUGH ACROSS THE GREAT LAKES WITH
SECONDARY UPPER LOW OVER MINNESOTA. THE NEXT STRONG TROUGH IS
PUSHING INTO THE PACIFIC COAST...AND IN BETWEEN THE NRN PLAINS ARE
SITTING IN WEAK RIDGING. SURFACE ANALYSIS SHOWS THE FRONTAL BOUNDARY
SITTING OVER CNTRL MT TO THE BLKHLS AREA AND SOUTH INTO WRN/CNTRL
NEB. TEMPS HAVE RISEN INTO THE 20S ACROSS MOST LOCATIONS. LOW CLOUDS
ARE MAINLY AFFECTING THE WRN SD PLAINS THOUGH SOME BREAKING APART OF
THE CLOUD DECK HAS OCCURRED IN THE LAST HOUR OR TWO OVER NE WY AND
WRN SD FTHLLS. CLOUDS WILL BUILD BACK IN TONIGHT OVER THE WRN SD
PLAINS AND NE WY AS S/SE RETURN FLOW CONTINUES ACROSS THE AREA. THE
BKLHLS WILL REMAIN CLEAR OVERNIGHT AS THE MOISTURE REMAINS LIMITED
TO THE LOW LEVELS.

MODELS SHOW AN UPPER WAVE CROSSING THE MT/WY BORDER TOMORROW WITH
LOW LEVEL RETURN FLOW CONTINUING OVER THE REGION. LOW CLOUDS ARE
EXPECTED TO CONTINUE OVER THE WRN SD PLAINS THROUGH THE DAY...WHILE
SOME DECREASING IN CLOUD COVERAGE IS POSSIBLE OVER THE NE WY PLAINS.
WEAK FORCING FROM THE UPPER WAVE MAY BRING SOME FLURRIES/-SHSN TO
PORTIONS OF NE WY INTO NW SD THROUGH THE DAY...BUT LITTLE TO NO
ACCUMULATION IS EXPECTED. TEMPS WILL BE NEAR OR SLIGHTLY WARMER THAN
TODAY WITH HIGHS IN THE 20S TO MID 30S. WAVE WILL CROSS THE AREA
LATE WEDNESDAY SO HAVE REMOVED MENTION OF -SHSN WED NIGHT.

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 241 PM MST TUE DEC 16 2014

SPLIT FLOW WILL REMAIN IN THE PERIOD...WITH SEASONAL WESTERLY
FLOW. WEAK SHORTWAVE IMPULSES WILL CROSS REGION THROUGH THE
WEEKEND...BRINGING NOTHING MORE THAN SOME MID CLOUDS AND A WIND
SHIFT. A MORE ORGANIZED SYSTEM IS ON TRACK FOR THE FIRST PART OF
NEXT WEEK AS THE WESTERN NOAM RIDGE BUILDS AND ACTIVE NW FLOW
DEVELOPS. INCREASING LL PAC ORIGIN MOISTURE COUPLED WITH NW FLOW
IMPULSES WILL BRING CHANCES FOR RAIN OR SNOW SHOWERS...WITH THE
BEST CHANCES FOR ANY PRECIP IN NE WY AND THE NORTHERN BLACK HILLS
PER UPSLOPE PROCESSES. WARMER WEATHER IS ALSO EXPECTED FRI-SUN AS
THE UPPER RIDGE SPREADS EAST SOME AND WAA ENSUES.
HOWEVER...CONTINUED TRAIN OF IMPULSE WILL EVENTUALLY SETTLE COOLER
AIR INTO THE REGION EARLY NEXT WEEK. TENDENCIES FOR A STRONG
WESTERN NOAM TROUGH REMAIN PRESENT IN MEAN ENSEMBLES AND
DETERMINISTIC SOLUTIONS PER ANOTHER EXTENSION OF THE EAST ASIAN
UPPER JET. THIS TROUGH WOULD LIKELY LEAD TO VIGOROUS CYCLOGENSIS
ON THE PLAINS NEXT WEEK...WITH THE LATITUDINAL LOCATION HINGING ON
THE DEGREE OF UPPER JET DIGGING OVER THE SW CONUS AND POSSIBLE
DOWNSTREAM RIDGE AMPLIFICATION. THIS SYSTEM COULD POTENTIALLY
BRING SIG SNOW AND WIND TO A PORTION OF THE PLAINS TOWARD THE
MIDDLE OR END OF NEXT WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 423 PM MST TUE DEC 16 2014

WIDESPREAD IFR/LIFR CIGS WILL CONTINUE ACROSS WRN SD AND INTO
NERN WY OVERNIGHT...WITH LOW CLOUDS POSSIBLY SPREADING ALL THE WAY
BACK TO KGCC. HOWEVER...THE BLKHLS SHOULD REMAIN ABOVE THE CLOUDS
FOR THE MOST PART. THERE IS A QUESTION OF THE WRN EXTENT OF THE
STRATUS BECAUSE OF MID AND HIGH CLOUDS THAT WILL LIMIT SFC
COOLING. ALSO...WITH THE SHALLOW SUPERCOOLED CLOUDS THERE MAY BE
SOME FZFG. LACK OF SHEAR IN THE CLOUD LAYER SHOULD PREVENT FZDZ
FROM OCCURRING. GRADUAL CLEARING IS EXPECTED OVER NERN WY AND FAR
WRN SD ON WEDNESDAY...BUT CLOUDS WILL HANG TOUGH OVER THE REST OF
THE WRN/CNTRL SD PLAINS.

&&

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

$$

SHORT TERM...13
LONG TERM...JC
AVIATION...BUNKERS









000
FXUS63 KUNR 162142
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
242 PM MST TUE DEC 16 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 241 PM MST TUE DEC 16 2014

WATER VAPOR IMAGERY SHOWS UPPER TROUGH ACROSS THE GREAT LAKES WITH
SECONDARY UPPER LOW OVER MINNESOTA. THE NEXT STRONG TROUGH IS
PUSHING INTO THE PACIFIC COAST...AND IN BETWEEN THE NRN PLAINS ARE
SITTING IN WEAK RIDGING. SURFACE ANALYSIS SHOWS THE FRONTAL BOUNDARY
SITTING OVER CNTRL MT TO THE BLKHLS AREA AND SOUTH INTO WRN/CNTRL
NEB. TEMPS HAVE RISEN INTO THE 20S ACROSS MOST LOCATIONS. LOW CLOUDS
ARE MAINLY AFFECTING THE WRN SD PLAINS THOUGH SOME BREAKING APART OF
THE CLOUD DECK HAS OCCURRED IN THE LAST HOUR OR TWO OVER NE WY AND
WRN SD FTHLLS. CLOUDS WILL BUILD BACK IN TONIGHT OVER THE WRN SD
PLAINS AND NE WY AS S/SE RETURN FLOW CONTINUES ACROSS THE AREA. THE
BKLHLS WILL REMAIN CLEAR OVERNIGHT AS THE MOISTURE REMAINS LIMITED
TO THE LOW LEVELS.

MODELS SHOW AN UPPER WAVE CROSSING THE MT/WY BORDER TOMORROW WITH
LOW LEVEL RETURN FLOW CONTINUING OVER THE REGION. LOW CLOUDS ARE
EXPECTED TO CONTINUE OVER THE WRN SD PLAINS THROUGH THE DAY...WHILE
SOME DECREASING IN CLOUD COVERAGE IS POSSIBLE OVER THE NE WY PLAINS.
WEAK FORCING FROM THE UPPER WAVE MAY BRING SOME FLURRIES/-SHSN TO
PORTIONS OF NE WY INTO NW SD THROUGH THE DAY...BUT LITTLE TO NO
ACCUMULATION IS EXPECTED. TEMPS WILL BE NEAR OR SLIGHTLY WARMER THAN
TODAY WITH HIGHS IN THE 20S TO MID 30S. WAVE WILL CROSS THE AREA
LATE WEDNESDAY SO HAVE REMOVED MENTION OF -SHSN WED NIGHT.

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 241 PM MST TUE DEC 16 2014

SPLIT FLOW WILL REMAIN IN THE PERIOD...WITH SEASONAL
WESTERLY FLOW. WEAK SHORTWAVE IMPULSES WILL CROSS REGION THROUGH THE
WEEKEND...BRINGING NOTHING MORE THAN SOME MID CLOUDS AND A WIND
SHIFT. A MORE ORGANIZED SYSTEM IS ON TRACK FOR THE FIRST PART OF
NEXT WEEK AS THE WESTERN NOAM RIDGE BUILDS AND ACTIVE NW FLOW
DEVELOPS. INCREASING LL PAC ORIGIN MOISTURE COUPLED WITH NW FLOW
IMPULSES WILL BRING CHANCES FOR RAIN OR SNOW SHOWERS...WITH
THE BEST CHANCES FOR ANY PRECIP IN NE WY AND THE NORTHERN BLACK
HILLS PER UPSLOPE PROCESSES. WARMER WEATHER IS ALSO EXPECTED FRI-SUN
AS THE UPPER RIDGE SPREADS EAST SOME AND WAA ENSUES.
HOWEVER...CONTINUED TRAIN OF IMPULSE WILL EVENTUALLY SETTLE COOLER
AIR INTO THE REGION EARLY NEXT WEEK. TENDENCIES FOR A STRONG WESTERN
NOAM TROUGH REMAIN PRESENT IN MEAN ENSEMBLES AND DETERMINISTIC
SOLUTIONS PER ANOTHER EXTENSION OF THE EAST ASIAN UPPER JET. THIS
TROUGH WOULD LIKELY LEAD TO VIGOROUS CYCLOGENSIS ON THE PLAINS NEXT
WEEK...WITH THE LATITUDINAL LOCATION HINGING ON THE DEGREE OF UPPER
JET DIGGING OVER THE SW CONUS AND POSSIBLE DOWNSTREAM RIDGE
AMPLIFICATION. THIS SYSTEM COULD POTENTIALLY BRING SIG SNOW AND WIND
TO A PORTION OF THE PLAINS TOWARD THE MIDDLE OR END OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1001 AM MST TUE DEC 16 2014

WIDESPREAD IFR/LIFR CIGS ACROSS WESTERN SD AND NORTHEAST WY AT THIS
TIME. EXPECT MOST OF WESTERN SD... INCLUDING KRAP... TO STAY
SOCKED IN WITH LOW CLOUDS AND IFR/LIFR CIGS THROUGH THE AFTERNOON...
WHILE NORTHEASTERN WY WILL SEE SOME CLEARING OF LOW CLOUDS BEFORE
MOVING BACK IN THIS EVENING.

&&

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

$$

SHORT TERM...13
LONG TERM...JC
AVIATION...MCKEMY







000
FXUS63 KUNR 162142
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
242 PM MST TUE DEC 16 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 241 PM MST TUE DEC 16 2014

WATER VAPOR IMAGERY SHOWS UPPER TROUGH ACROSS THE GREAT LAKES WITH
SECONDARY UPPER LOW OVER MINNESOTA. THE NEXT STRONG TROUGH IS
PUSHING INTO THE PACIFIC COAST...AND IN BETWEEN THE NRN PLAINS ARE
SITTING IN WEAK RIDGING. SURFACE ANALYSIS SHOWS THE FRONTAL BOUNDARY
SITTING OVER CNTRL MT TO THE BLKHLS AREA AND SOUTH INTO WRN/CNTRL
NEB. TEMPS HAVE RISEN INTO THE 20S ACROSS MOST LOCATIONS. LOW CLOUDS
ARE MAINLY AFFECTING THE WRN SD PLAINS THOUGH SOME BREAKING APART OF
THE CLOUD DECK HAS OCCURRED IN THE LAST HOUR OR TWO OVER NE WY AND
WRN SD FTHLLS. CLOUDS WILL BUILD BACK IN TONIGHT OVER THE WRN SD
PLAINS AND NE WY AS S/SE RETURN FLOW CONTINUES ACROSS THE AREA. THE
BKLHLS WILL REMAIN CLEAR OVERNIGHT AS THE MOISTURE REMAINS LIMITED
TO THE LOW LEVELS.

MODELS SHOW AN UPPER WAVE CROSSING THE MT/WY BORDER TOMORROW WITH
LOW LEVEL RETURN FLOW CONTINUING OVER THE REGION. LOW CLOUDS ARE
EXPECTED TO CONTINUE OVER THE WRN SD PLAINS THROUGH THE DAY...WHILE
SOME DECREASING IN CLOUD COVERAGE IS POSSIBLE OVER THE NE WY PLAINS.
WEAK FORCING FROM THE UPPER WAVE MAY BRING SOME FLURRIES/-SHSN TO
PORTIONS OF NE WY INTO NW SD THROUGH THE DAY...BUT LITTLE TO NO
ACCUMULATION IS EXPECTED. TEMPS WILL BE NEAR OR SLIGHTLY WARMER THAN
TODAY WITH HIGHS IN THE 20S TO MID 30S. WAVE WILL CROSS THE AREA
LATE WEDNESDAY SO HAVE REMOVED MENTION OF -SHSN WED NIGHT.

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 241 PM MST TUE DEC 16 2014

SPLIT FLOW WILL REMAIN IN THE PERIOD...WITH SEASONAL
WESTERLY FLOW. WEAK SHORTWAVE IMPULSES WILL CROSS REGION THROUGH THE
WEEKEND...BRINGING NOTHING MORE THAN SOME MID CLOUDS AND A WIND
SHIFT. A MORE ORGANIZED SYSTEM IS ON TRACK FOR THE FIRST PART OF
NEXT WEEK AS THE WESTERN NOAM RIDGE BUILDS AND ACTIVE NW FLOW
DEVELOPS. INCREASING LL PAC ORIGIN MOISTURE COUPLED WITH NW FLOW
IMPULSES WILL BRING CHANCES FOR RAIN OR SNOW SHOWERS...WITH
THE BEST CHANCES FOR ANY PRECIP IN NE WY AND THE NORTHERN BLACK
HILLS PER UPSLOPE PROCESSES. WARMER WEATHER IS ALSO EXPECTED FRI-SUN
AS THE UPPER RIDGE SPREADS EAST SOME AND WAA ENSUES.
HOWEVER...CONTINUED TRAIN OF IMPULSE WILL EVENTUALLY SETTLE COOLER
AIR INTO THE REGION EARLY NEXT WEEK. TENDENCIES FOR A STRONG WESTERN
NOAM TROUGH REMAIN PRESENT IN MEAN ENSEMBLES AND DETERMINISTIC
SOLUTIONS PER ANOTHER EXTENSION OF THE EAST ASIAN UPPER JET. THIS
TROUGH WOULD LIKELY LEAD TO VIGOROUS CYCLOGENSIS ON THE PLAINS NEXT
WEEK...WITH THE LATITUDINAL LOCATION HINGING ON THE DEGREE OF UPPER
JET DIGGING OVER THE SW CONUS AND POSSIBLE DOWNSTREAM RIDGE
AMPLIFICATION. THIS SYSTEM COULD POTENTIALLY BRING SIG SNOW AND WIND
TO A PORTION OF THE PLAINS TOWARD THE MIDDLE OR END OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1001 AM MST TUE DEC 16 2014

WIDESPREAD IFR/LIFR CIGS ACROSS WESTERN SD AND NORTHEAST WY AT THIS
TIME. EXPECT MOST OF WESTERN SD... INCLUDING KRAP... TO STAY
SOCKED IN WITH LOW CLOUDS AND IFR/LIFR CIGS THROUGH THE AFTERNOON...
WHILE NORTHEASTERN WY WILL SEE SOME CLEARING OF LOW CLOUDS BEFORE
MOVING BACK IN THIS EVENING.

&&

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

$$

SHORT TERM...13
LONG TERM...JC
AVIATION...MCKEMY








000
FXUS63 KUNR 161714
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1014 AM MST TUE DEC 16 2014

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 150 AM MST TUE DEC 16 2014

UPPER RIDGE IS MOVING OVER THE CENTRAL CONUS...WITH A
TROUGH MOVING INTO THE WEST COAST. SURFACE HIGH IS DRAPED OVER THE
NORTHERN PLAINS...RESULTING IN GENERALLY LIGHT WINDS. LOW CLOUDS AND
FOG BLANKET MUCH OF THE REGION...AND TEMPS ARE IN THE TEENS TO LOW
20S.

RETURN FLOW WILL DEVELOP ACROSS THE CWA TODAY AS THE SURFACE HIGH
SHIFTS EAST. WITH LIGHT SOUTHEAST WINDS...EXPECT LOW CLOUDS TO STICK
AROUND FOR MUCH OF THE DAY...ESPECIALLY IN THE WESTERN ZONES. MAY BE
SOME CLEARING ACROSS THE EAST LATER THIS EVENING. UNDER MOSTLY
CLOUDY SKIES...HIGHS WILL BE ONLY IN THE 20S TO LOW 30S. CLOUDS WILL
INCREASE OVERNIGHT AHEAD OF AN APPROACHING WEAK TROUGH. LOWS WILL BE
AROUND 10 TO 20.

SOUTHEAST WINDS WILL INCREASE ON WEDNESDAY AS THE PRESSURE GRADIENT
TIGHTENS...BRINGING IN A BIT OF MOISTURE. AN AREA OF Q-VECTOR
CONVERGENCE WILL MAKE ITS WAY ACROSS THE CWA WITH THE PASSING
TROUGH. SOME LIGHT SNOW SHOWERS MAY DEVELOP ALONG THE BAROCLINIC
ZONE ACROSS PORTIONS OF NORTHEAST WYOMING AND NORTHWEST SOUTH DAKOTA
DURING THE DAY. ADDED SOME VERY SLIGHT CHANCE POPS FOR WEDNESDAY
NIGHT WHEN THE BAROCLINIC ZONE/WARM FRONT SHIFTS NORTHEASTWARD AND
LAPSE RATES INCREASE TO 7 C/KM...ALTHOUGH EXPECT MOISTURE TO BE
LIMITED AFTER MIDNIGHT. HIGHS WILL RANGE FROM THE LOW 20S IN THE
EASTERN CWA TO THE MID 30S FARTHER WEST...WITH LOWS AROUND 10 TO 20
AGAIN.

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 150 AM MST TUE DEC 16 2014

PROGRESSIVE SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE END OF
THE WEEK. WEAK NORTHERN STREAM TROF SLIDES THROUGH THE AREA
THURSDAY/FRIDAY. WITH LACK OF FORCING/MOISTURE...WILL MAINTAIN DRY
FORECAST. TEMPERATURES NEAR TO SLIGHTLY ABOVE AVERAGE...ESPECIALLY
AREAS LACKING SNOW COVER. ECMWF/GFS/GEFS TRENDING TOWARDS BUILDING
RIDGE ALONG THE PACIFIC COAST...WITH LONG WAVE TROF THROUGH THE
CENTRAL CONUS. WILL RESULT IN COOLER TEMPERATURES WITH INCREASING
CHANCES OF PRECIPITATION.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1001 AM MST TUE DEC 16 2014

WIDESPREAD IFR/LIFR CIGS ACROSS WESTERN SD AND NORTHEAST WY AT THIS
TIME. EXPECT MOST OF WESTERN SD... INCLUDING KRAP... TO STAY
SOCKED IN WITH LOW CLOUDS AND IFR/LIFR CIGS THROUGH THE AFTERNOON...
WHILE NORTHEASTERN WY WILL SEE SOME CLEARING OF LOW CLOUDS BEFORE
MOVING BACK IN THIS EVENING.

&&

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

$$

SHORT TERM...POJORLIE
LONG TERM...7
AVIATION...MCKEMY







000
FXUS63 KUNR 161714
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1014 AM MST TUE DEC 16 2014

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 150 AM MST TUE DEC 16 2014

UPPER RIDGE IS MOVING OVER THE CENTRAL CONUS...WITH A
TROUGH MOVING INTO THE WEST COAST. SURFACE HIGH IS DRAPED OVER THE
NORTHERN PLAINS...RESULTING IN GENERALLY LIGHT WINDS. LOW CLOUDS AND
FOG BLANKET MUCH OF THE REGION...AND TEMPS ARE IN THE TEENS TO LOW
20S.

RETURN FLOW WILL DEVELOP ACROSS THE CWA TODAY AS THE SURFACE HIGH
SHIFTS EAST. WITH LIGHT SOUTHEAST WINDS...EXPECT LOW CLOUDS TO STICK
AROUND FOR MUCH OF THE DAY...ESPECIALLY IN THE WESTERN ZONES. MAY BE
SOME CLEARING ACROSS THE EAST LATER THIS EVENING. UNDER MOSTLY
CLOUDY SKIES...HIGHS WILL BE ONLY IN THE 20S TO LOW 30S. CLOUDS WILL
INCREASE OVERNIGHT AHEAD OF AN APPROACHING WEAK TROUGH. LOWS WILL BE
AROUND 10 TO 20.

SOUTHEAST WINDS WILL INCREASE ON WEDNESDAY AS THE PRESSURE GRADIENT
TIGHTENS...BRINGING IN A BIT OF MOISTURE. AN AREA OF Q-VECTOR
CONVERGENCE WILL MAKE ITS WAY ACROSS THE CWA WITH THE PASSING
TROUGH. SOME LIGHT SNOW SHOWERS MAY DEVELOP ALONG THE BAROCLINIC
ZONE ACROSS PORTIONS OF NORTHEAST WYOMING AND NORTHWEST SOUTH DAKOTA
DURING THE DAY. ADDED SOME VERY SLIGHT CHANCE POPS FOR WEDNESDAY
NIGHT WHEN THE BAROCLINIC ZONE/WARM FRONT SHIFTS NORTHEASTWARD AND
LAPSE RATES INCREASE TO 7 C/KM...ALTHOUGH EXPECT MOISTURE TO BE
LIMITED AFTER MIDNIGHT. HIGHS WILL RANGE FROM THE LOW 20S IN THE
EASTERN CWA TO THE MID 30S FARTHER WEST...WITH LOWS AROUND 10 TO 20
AGAIN.

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 150 AM MST TUE DEC 16 2014

PROGRESSIVE SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE END OF
THE WEEK. WEAK NORTHERN STREAM TROF SLIDES THROUGH THE AREA
THURSDAY/FRIDAY. WITH LACK OF FORCING/MOISTURE...WILL MAINTAIN DRY
FORECAST. TEMPERATURES NEAR TO SLIGHTLY ABOVE AVERAGE...ESPECIALLY
AREAS LACKING SNOW COVER. ECMWF/GFS/GEFS TRENDING TOWARDS BUILDING
RIDGE ALONG THE PACIFIC COAST...WITH LONG WAVE TROF THROUGH THE
CENTRAL CONUS. WILL RESULT IN COOLER TEMPERATURES WITH INCREASING
CHANCES OF PRECIPITATION.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1001 AM MST TUE DEC 16 2014

WIDESPREAD IFR/LIFR CIGS ACROSS WESTERN SD AND NORTHEAST WY AT THIS
TIME. EXPECT MOST OF WESTERN SD... INCLUDING KRAP... TO STAY
SOCKED IN WITH LOW CLOUDS AND IFR/LIFR CIGS THROUGH THE AFTERNOON...
WHILE NORTHEASTERN WY WILL SEE SOME CLEARING OF LOW CLOUDS BEFORE
MOVING BACK IN THIS EVENING.

&&

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

$$

SHORT TERM...POJORLIE
LONG TERM...7
AVIATION...MCKEMY








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