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000
FXUS65 KRIW 250523
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1123 PM MDT FRI OCT 24 2014

.SHORT TERM...TONIGHT THROUGH SATURDAY

MID LEVEL CLOUDS WILL MOVE NORTH OF OUR CWA TONIGHT. TRAPPED MTN
WAVES ARE EVIDENT ON SATL WITHIN THOSE CLOUDS OVER NORTHERN WY.
WINDS AT CHIEF JOSEPH HAVE BEEN GUSTING TO OVER 50 MPH BUT WILL
CONTINUE TO DECREASE FOR THE REMAINDER OF THIS AFTERNOON.
HOWEVER...THE FAST WESTERLY FLOW WILL CONTROL THE WEATHER THROUGH
SATURDAY. THIS WILL RESULT IN FAIRLY BREEZY WEST SOUTHWESTERLY
WINDS ...MILD AND DRY CONDITIONS THROUGH THE PERIOD. HIGH
TEMPERATURES WILL LIKELY RUN ABOUT 15 DEGREES ABOVE NORMAL. THE
WINDS WILL GRADUALLY INCREASE LATER SATURDAY AFTERNOON AS THE NEXT
PACIFIC TROUGH APPROACHES WITHIN THE BACKING STEERING WINDS.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

ANOTHER WIND EVENT IS POSSIBLE IN THE ABSAROKAS AND CODY FOOTHILLS
SATURDAY NIGHT AS INCREASING H7 FLOW TO 35-45KTS POTENTIALLY COMBINE
WITH AN ENCROACHING JET...JUST ABOVE MTN TOP INVERSION AND
EVEN SOME MODERATE GAP FLOW SIGNATURE TO AT LEAST WARRANT A WATCH.
THE WRF IS SHOWING 35KT AT H7 UPSTREAM OF THE ABSAROKA PLATEAU WITH
80KTS ON THE EAST SLOPE LATER SUNDAY NIGHT WITH 35-40KT BOUNDARY
LAYER WINDS SURFACING ON HIGHWAY 120 WITH 60-70KTS ALONG THE
FOOTHILLS. WRF CROSS SECTION IS NOT SHOWING ANY CRITICAL LAYER BUT
ENOUGH PARAMETERS PRESENT TO AT LEAST PUT UP THE WATCH AND ALLOW
LATER SHIFTS TO MONITOR THE POTENTIAL. OTHERWISE...QUITE A BIT OF
WIND IN MUCH OF THE AREA SATURDAY NIGHT AND SUNDAY AS ERN PACIFIC/
GULF OF ALASKA LOW MOVES INLAND. SRN UPPER LOW LIFTS NE FIRST
SATURDAY NIGHT WITH FIRST SHOT OF LIGHT PCPN IN THE FAR WEST BEFORE
THE COLDER TROUGH TO THE NW MOVES IN. MAIN CHANGE TODAY IS LESS
SUPPORT FROM THE NRN PART OF THIS TROUGH ON MONDAY. MORE SHEARING
AND FURTHER NORTH TRACK BEING SHOWN WITH LESS SUPPORT IN WYO FOR
PCPN ON MONDAY. STILL LOOKING AT SNOW IN THE WRN MOUNTAINS SUNDAY
INTO SUNDAY NIGHT WITH A CHANCE OF RAIN EAST OF THE DIVIDE...MAINLY
NORTH SUNDAY NIGHT INTO MONDAY. RAIN COULD MIX WITH OR BRIEFLY
CHANGE TO SNOW LATER SUNDAY NIGHT OR EARLY MONDAY BUT LITTLE OR NO
ACCUMULATION IS EXPECTED. EVEN LESS OF A CHANCE OF PCPN FURTHER WEST
IN THE WIND RIVER BASIN. STILL A MILD DAY EAST OF THE DIVIDE BEFORE
COLD FRONT MOVES EAST AND SE ACROSS THE AREA. MUCH COOLER MONDAY.

BRIEF RIDGING WITH TEMPS RECOVERING TUESDAY BUT THEN A FAST MOVING
SYSTEM HITS THE FAR WEST TUESDAY NIGHT WITH SOME MOIST...ISENTROPIC
UPGLIDE. THE SHORTWAVE THEN MOVES ACROSS THE AREA ON WEDNESDAY WITH
A DECENT CHANCE OF HIGHER ELEVATION SNOW AND LOWER ELEVATIONS RAIN
IN THE WEST AND FAR NORTH. FURTHER SOUTH...THE MAIN EFFECT WILL BE
CLOUDS AND STRONG TO HIGH WINDS. SHORTWAVE MOVES OFF WEDNESDAY NIGHT
WITH A RIDGE MOVING BACK IN THURSDAY AND FRIDAY. GFS HAS COME IN
LINE WITH THE ECMWF TODAY WITH A MORE SIGNIFICANT RIDGE HOLDING
ACROSS THE AREA THROUGH NEXT FRIDAY AT LEAST. MID LEVEL TEMPERATURES
RISE TO BETWEEN +6 AND +8 ACROSS THE SOUTH HALF BY FRIDAY AFTERNOON.
RIDGE AXIS NEARLY OVERHEAD ON FRIDAY MAY HAMPER FULL MIXING BUT
STILL A MILD END TO A ABNORMALLY WARM OCTOBER.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS UNDER SKC CONDITIONS ARE EXPECTED THROUGH 00Z SUNDAY.
BREEZY TO WINDY SOUTH TO SOUTHWEST WIND IN TYPICAL AREAS DURING THE
DAY SATURDAY...WITH AN APPROACH OF A STORM SYSTEM. AFTER 00Z...AREAS
WEST OF THE DIVIDE WILL SEE QUICKLY INCREASING MID LEVEL CLOUDINESS
WITH SOME SHOWER ACTIVITY POSSIBLE AFTER 03Z. MOUNTAIN TOPS WILL
BECOME OBSCURED OVER THE FAR WEST BETWEEN 03Z AND 06Z. SOME MVFR
CONDITIONS COULD OCCUR IN OR NEAR THIS CONVECTION.  HOWEVER OF MORE
CONCERN...WILL BE CONSIDERABLE MOUNTAIN TURBULENCE SATURDAY NIGHT AS
WELL AS...LLWS ON THE LEE SIDE OF MOUNTAIN RANGES...ESPECIALLY AT
COD AND LND.

PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON
TURBULENCE FORECASTS.

&&

.FIRE WEATHER...

FIRE DANGER WILL BECOME SOMEWHAT ENHANCED THROUGH
SATURDAY...PRIMARILY ACROSS BASINS AND VALLEYS EAST OF THE DIVIDE ON
SATURDAY AS WELL AS ACROSS NATRONA COUNTY. MINIMUM RH VALUES ACROSS
THESE AREAS WILL FALL INTO THE MID AND UPPER TEENS WHILE WINDS
INCREASE OUT OF THE SOUTHWEST TO 15 TO 25 MPH WITH HIGHER GUSTS AT
TIMES. VERY WINDY CONDITIONS ARE EXPECTED IN SOME OF THE ZONES
SATURDAY NIGHT. SUNDAY...MOISTURE WILL INCREASE ACROSS THE ENTIRE
REGION WITH A BETTER CHANCE FOR SHOWERS ACROSS THE NORTH AND
WEST...LOWERING FIRE DANGER ONCE AGAIN.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
WYZ002-003.

&&

$$

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










000
FXUS65 KRIW 242032
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
232 PM MDT FRI OCT 24 2014

.SHORT TERM...TONIGHT THROUGH SATURDAY
MID LEVEL CLOUDS WILL MOVE NORTH OF OUR CWA TONIGHT. TRAPPED MTN
WAVES ARE EVIDENT ON SATL WITHIN THOSE CLOUDS OVER NORTHERN WY.
WINDS AT CHIEF JOSEPH HAVE BEEN GUSTING TO OVER 50 MPH BUT WILL
CONTINUE TO DECREASE FOR THE REMAINDER OF THIS AFTERNOON.
HOWEVER...THE FAST WESTERLY FLOW WILL CONTROL THE WEATHER THROUGH
SATURDAY. THIS WILL RESULT IN FAIRLY BREEZY WEST SOUTHWESTERLY
WINDS ...MILD AND DRY CONDITIONS THROUGH THE PERIOD. HIGH
TEMPERATURES WILL LIKELY RUN ABOUT 15 DEGREES ABOVE NORMAL. THE
WINDS WILL GRADUALLY INCREASE LATER SATURDAY AFTERNOON AS THE NEXT
PACIFIC TROUGH APPROACHES WITHIN THE BACKING STEERING WINDS.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ANOTHER WIND EVENT IS POSSIBLE IN THE ABSAROKAS AND CODY FOOTHILLS
SATURDAY NIGHT AS INCREASING H7 FLOW TO 35-45KTS POTENTIALLY COMBINE
WITH AN ENCROACHING JET...JUST ABOVE MTN TOP INVERSION AND
EVEN SOME MODERATE GAP FLOW SIGNATURE TO AT LEAST WARRANT A WATCH.
THE WRF IS SHOWING 35KT AT H7 UPSTREAM OF THE ABSAROKA PLATEAU WITH
80KTS ON THE EAST SLOPE LATER SUNDAY NIGHT WITH 35-40KT BOUNDARY
LAYER WINDS SURFACING ON HIGHWAY 120 WITH 60-70KTS ALONG THE
FOOTHILLS. WRF CROSS SECTION IS NOT SHOWING ANY CRITICAL LAYER BUT
ENOUGH PARAMETERS PRESENT TO AT LEAST PUT UP THE WATCH AND ALLOW
LATER SHIFTS TO MONITOR THE POTENTIAL. OTHERWISE...QUITE A BIT OF
WIND IN MUCH OF THE AREA SATURDAY NIGHT AND SUNDAY AS ERN PACIFIC/
GULF OF ALASKA LOW MOVES INLAND. SRN UPPER LOW LIFTS NE FIRST
SATURDAY NIGHT WITH FIRST SHOT OF LIGHT PCPN IN THE FAR WEST BEFORE
THE COLDER TROUGH TO THE NW MOVES IN. MAIN CHANGE TODAY IS LESS
SUPPORT FROM THE NRN PART OF THIS TROUGH ON MONDAY. MORE SHEARING
AND FURTHER NORTH TRACK BEING SHOWN WITH LESS SUPPORT IN WYO FOR
PCPN ON MONDAY. STILL LOOKING AT SNOW IN THE WRN MOUNTAINS SUNDAY
INTO SUNDAY NIGHT WITH A CHANCE OF RAIN EAST OF THE DIVIDE...MAINLY
NORTH SUNDAY NIGHT INTO MONDAY. RAIN COULD MIX WITH OR BRIEFLY
CHANGE TO SNOW LATER SUNDAY NIGHT OR EARLY MONDAY BUT LITTLE OR NO
ACCUMULATION IS EXPECTED. EVEN LESS OF A CHANCE OF PCPN FURTHER WEST
IN THE WIND RIVER BASIN. STILL A MILD DAY EAST OF THE DIVIDE BEFORE
COLD FRONT MOVES EAST AND SE ACROSS THE AREA. MUCH COOLER MONDAY.

BRIEF RIDGING WITH TEMPS RECOVERING TUESDAY BUT THEN A FAST MOVING
SYSTEM HITS THE FAR WEST TUESDAY NIGHT WITH SOME MOIST...ISENTROPIC
UPGLIDE. THE SHORTWAVE THEN MOVES ACROSS THE AREA ON WEDNESDAY WITH
A DECENT CHANCE OF HIGHER ELEVATION SNOW AND LOWER ELEVATIONS RAIN
IN THE WEST AND FAR NORTH. FURTHER SOUTH...THE MAIN EFFECT WILL BE
CLOUDS AND STRONG TO HIGH WINDS. SHORTWAVE MOVES OFF WEDNESDAY NIGHT
WITH A RIDGE MOVING BACK IN THURSDAY AND FRIDAY. GFS HAS COME IN
LINE WITH THE ECMWF TODAY WITH A MORE SIGNIFICANT RIDGE HOLDING
ACROSS THE AREA THROUGH NEXT FRIDAY AT LEAST. MID LEVEL TEMPERATURES
RISE TO BETWEEN +6 AND +8 ACROSS THE SOUTH HALF BY FRIDAY AFTERNOON.
RIDGE AXIS NEARLY OVERHEAD ON FRIDAY MAY HAMPER FULL MIXING BUT
STILL A MILD END TO A ABNORMALLY WARM OCTOBER.

&&

.AVIATION.../00Z ISSUANCE/
CONSIDERABLE HIGH AND MID LEVEL CLOUDINESS ARE EXPECTED TO BECOME
MAINLY SKC BY 00Z IN NORTHERN WY. OTHERWISE...VFR AND DRY CONDITIONS WILL OCCUR
AT AREA TERMINALS THROUGH TAF VALID PERIOD...WITH BREEZY TO WINDY
CONDITIONS BEING THE MAIN CONCERN THROUGH SATURDAY.

&&

.FIRE WEATHER...
FIRE DANGER WILL BECOME SOMEWHAT ENHANCED THROUGH SATURDAY...PRIMARILY
ACROSS BASINS AND VALLEYS EAST OF THE DIVIDE ON SATURDAY AS WELL
AS ACROSS NATRONA COUNTY. MINIMUM RH VALUES ACROSS THESE AREAS WILL
FALL INTO THE MID AND UPPER TEENS WHILE WINDS INCREASE OUT OF THE
SOUTHWEST TO 15 TO 25 MPH WITH HIGHER GUSTS AT TIMES. VERY WINDY
CONDITIONS ARE EXPECTED IN SOME OF THE ZONES SATURDAY NIGHT.
SUNDAY...MOISTURE WILL INCREASE ACROSS THE ENTIRE REGION WITH A
BETTER CHANCE FOR SHOWERS ACROSS THE NORTH AND WEST...LOWERING
FIRE DANGER ONCE AGAIN.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
WYZ002-003.

&&

$$

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







000
FXUS65 KRIW 241716
AFDRIW

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1115 AM MDT FRI OCT 24 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

IMAGERY SHOWS FLAT RIDGING WITH BROAD TROUGHING TO BOTH THE WEST AND
EAST. VERY STRONG JET OFF TO THE N AND ACROSS THE BORDER REGION OF
THE NW CONUS AND CA. AT THE SFC...WEAK TROF ACROSS NRN ROCKIES AND
ACROSS THE NRN PLAINS W/ A WEAK FRONT SPLITTING MT THEN SWD THRU ERN
ID AND EVENTUALLY INTO NV.

STRONG WINDS AND SOME MOUNTAIN WAVE ACTION PINNED AND BREAKING JUST
EAST OF THE HIGH MOUNTAINS OF THE NRN ABSAROKAS TONIGHT. THESE WILL
BEGIN TO DECREASE LATER THIS MORNING. OTHERWISE...STRONG FLOW
ALOFT...WARM LL TEMPS WITH GOOD LAPSE RATES UP THRU 600 MB WILL
CONTINUE TO ALLOW FOR VARIOUS WIND SCENARIOS OVER THE NEXT COUPLE OF
DAYS. AFTERNOON WINDS WILL COME UP ACROSS THE SRN/SERN WIND
CORRIDOR...WHILE NOCTURNAL WINDS INCREASE OVER/NEAR THE LEE PORTIONS
OF THE MAJOR MOUNTAIN RANGES...WITH PERHAPS SOME OCCASIONAL SPILL
INTO THE LOWER ELEVATIONS...PARTICULARLY SATURDAY NIGHT AS
CONDITIONS BECOME MUCH MORE FAVORABLE FOR MOUNTAIN WAVE PRODUCTION.
THE UPR LVLS TRANSITION INTO A MORE SOUTHWEST UPR FLOW PATTERN BY
SATURDAY WITH THE APPROACHING TROF AXIS...AND MOISTURE WILL START
TO FEED INTO THE WRN FA ALONG WITH INCREASING VORTICITY AND LIFT.
THIS WILL PUSH A COLD FRONT THRU AND ALLOW BOTH RAIN AND SNOW
SHOWERS TO DEVELOP SAT NIGHT AND SPREAD ACROSS MUCH OF THE WRN FA
THRU THE REST OF THE DAY ON SUNDAY. ATTM...DEEP RELATIVELY WARM
TEMPS WILL KEEP THE SNOW ON THE WET AND ON THE LOWER END OF THE
ACCUMULATION SCALE...MAXING OUT AT 6 INCHES OVER THE HIGHEST
PEAKS.

.LONG TERM...MONDAY THROUGH FRIDAY

MONDAY WILL SEE THE WEATHER SYSTEM PASS THROUGH WY PRODUCING
SCATTERED RAIN SHOWERS WITH SNOW FOR MOST MOUNTAINS. BRISK WIND IN
PLACES AND COOL HIGH TEMPS. THE SHOWERS END MONDAY EVENING. TUESDAY
LOOKS DRY FOR MOST AREAS...ISOLATED SHOWERS MAY DEVELOP OVER THE NW
WY MOUNTAINS LATE TUE PM WITH INCREASING SHOWERS IN THE NW WY
MOUNTAINS TUE NIGHT. THE NEXT WEATHER SYSTEM PASSES THROUGH THE
REGION ON WEDNESDAY. A CHANCE OF RAIN SHOWERS IN THE WEST WITH SNOW
IN THE HIGHER MOUNTAINS. EAST OF THE DIVIDE...ISOLATED SHOWERS AT
BEST WITH SOME RAIN AND SNOW SHOWERS IN THE BIGHORN MOUNTAINS. THE
PRECIP ENDS WED NIGHT. AS FOR NEXT THURSDAY AND FRIDAY...THE ECMWF
MODEL IS DRY WITH UPPER RIDGE OVER THE REGION. THE GFS HAS THURSDAY
DRY BUT THEN HAS SOME PRECIP IN THE WEST ON FRIDAY AHEAD OF THE NEXT
WEATHER SYSTEM. THIS MAY BE TOO FAST AND WILL NOT ADD ANY PRECIP TO
THE WEST AT THIS TIME. HIGH TEMPS TO BE ON THE COOL SIDE TUESDAY
WITH ONLY SLIGHT WARMING ON WED. NEXT THURSDAY AND FRIDAY WILL BE
MILDER.

&&

.AVIATION.../18Z ISSUANCE/

CONSIDERABLE HIGH AND MID LEVEL CLOUDINESS ARE EXPECTED TO BECOME
MAINLY SKC BETWEEN 20Z AND 00Z. VFR AND DRY CONDITIONS WILL OCCUR AT
AREA TERMINALS THROUGH TAF VALID PERIOD...WITH BREEZY TO WINDY
CONDITIONS BEING THE MAIN CONCERN TODAY.

PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON
TURBULENCE FORECASTS.

&&

.FIRE WEATHER...

FIRE DANGER WILL BECOME SOMEWHAT ENHANCED TODAY THROUGH
SATURDAY...PRIMARILY ACROSS THE NATRONA COUNTY TODAY...THEN OVER
MOST BASINS AND VALLEYS EAST OF THE DIVIDE ON SATURDAY. MINIMUM RH
VALUES ACROSS THESE AREAS WILL FALL INTO THE MID AND UPPER TEENS
WHILE WINDS INCREASE OUT OF THE SOUTHWEST TO 15 TO 25 MPH WITH
HIGHER GUSTS AT TIMES. SUNDAY...MOISTURE WILL INCREASE ACROSS THE
ENTIRE REGION WITH A BETTER CHANCE FOR SHOWERS ACROSS THE NORTH AND
WEST...LOWERING FIRE DANGER ONCE AGAIN.

&&

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

&&

$$

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










000
FXUS65 KRIW 240933
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
333 AM MDT FRI OCT 24 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

IMAGERY SHOWS FLAT RIDGING WITH BROAD TROFFING TO BOTH THE WEST AND
EAST. VERY STRONG JET OFF TO THE N AND ACROSS THE BORDER REGION OF
THE NW CONUS AND CA. AT THE SFC...WEAK TROF ACROSS NRN ROCKIES AND
ACROSS THE NRN PLAINS W/ A WEAK FRONT SPLITTING MT THEN SWD THRU ERN
ID AND EVENTUALLY INTO NV.

STRONG WINDS AND SOME MOUNTAIN WAVE ACTION PINNED AND BREAKING JUST
EAST OF THE HIGH MOUNTAINS OF THE NRN ABSAROKAS TONIGHT. THESE WILL
BEGIN TO DECREASE LATER THIS MORNING. OTHERWISE...STRONG FLOW
ALOFT...WARM LL TEMPS WITH GOOD LAPSE RATES UP THRU 600 MB WILL
CONTINUE TO ALLOW FOR VARIOUS WIND SCENARIOS OVER THE NEXT COUPLE OF
DAYS. AFTERNOON WINDS WILL COME UP ACROSS THE SRN/SERN WIND
CORRIDOR...WHILE NOCTURNAL WINDS INCREASE OVER/NEAR THE LEE PORTIONS
OF THE MAJOR MOUNTAIN RANGES...WITH PERHAPS SOME OCCASIONAL SPILL
INTO THE LOWER ELEVATIONS...PARTICULARLY SATURDAY NIGHT AS
CONDITIONS BECOME MUCH MORE FAVORABLE FOR MOUNTAIN WAVE PRODUCTION.
THE UPR LVLS TRANSITION INTO A MORE SOUTHWEST UPR FLOW PATTERN BY
SATURDAY WITH THE APPROACHING TROF AXIS...AND MOISTURE WILL START
TO FEED INTO THE WRN FA ALONG WITH INCREASING VORTICITY AND LIFT.
THIS WILL PUSH A COLD FRONT THRU AND ALLOW BOTH RAIN AND SNOW
SHOWERS TO DEVELOP SAT NIGHT AND SPREAD ACROSS MUCH OF THE WRN FA
THRU THE REST OF THE DAY ON SUNDAY. ATTM...DEEP RELATIVELY WARM
TEMPS WILL KEEP THE SNOW ON THE WET AND ON THE LOWER END OF THE
ACCUMULATION SCALE...MAXING OUT AT 6 INCHES OVER THE HIGHEST
PEAKS.

.LONG TERM...MONDAY THROUGH FRIDAY

MONDAY WILL SEE THE WEATHER SYSTEM PASS THROUGH WY PRODUCING
SCATTERED RAIN SHOWERS WITH SNOW FOR MOST MOUNTAINS. BRISK WIND IN
PLACES AND COOL HIGH TEMPS. THE SHOWERS END MONDAY EVENING. TUESDAY
LOOKS DRY FOR MOST AREAS...ISOLATED SHOWERS MAY DEVELOP OVER THE NW
WY MOUNTAINS LATE TUE PM WITH INCREASING SHOWERS IN THE NW WY
MOUNTAINS TUE NIGHT. THE NEXT WEATHER SYSTEM PASSES THROUGH THE
REGION ON WEDNESDAY. A CHANCE OF RAIN SHOWERS IN THE WEST WITH SNOW
IN THE HIGHER MOUNTAINS. EAST OF THE DIVIDE...ISOLATED SHOWERS AT
BEST WITH SOME RAIN AND SNOW SHOWERS IN THE BIGHORN MOUNTAINS. THE
PRECIP ENDS WED NIGHT. AS FOR NEXT THURSDAY AND FRIDAY...THE ECMWF
MODEL IS DRY WITH UPPER RIDGE OVER THE REGION. THE GFS HAS THURSDAY
DRY BUT THEN HAS SOME PRECIP IN THE WEST ON FRIDAY AHEAD OF THE NEXT
WEATHER SYSTEM. THIS MAY BE TOO FAST AND WILL NOT ADD ANY PRECIP TO
THE WEST AT THIS TIME. HIGH TEMPS TO BE ON THE COOL SIDE TUESDAY
WITH ONLY SLIGHT WARMING ON WED. NEXT THURSDAY AND FRIDAY WILL BE
MILDER.

&&

.AVIATION.../12Z ISSUANCE/

CONCERN TODAY AGAIN WILL BE CONSIDERABLE MOUNTAIN TURBULENCE WITH
STRONG MOUNTAIN TOP WINDS...ESPECIALLY THIS MORNING. LLWS ON THE LEE
SIDE OF MOUNTAIN RANGES IS EXPECTED THIS MORNING AT COD AND
LND...BUT IT IS EXPECTED TO IMPROVE THROUGH THE MORNING HOURS.
CONSIDERABLE HIGH AND MID LEVEL CLOUDINESS THIS MORNING ARE EXPECTED
TO WILL BECOME MAINLY SKC BETWEEN 20Z AND 00Z. THERE COULD BE
ISOLATED SHOWER ACTIVITY OVER EXTREME NW WYOMING THIS MORNING...BUT
SHOULD NOT IMPACT COD OR JAC. THUS VFR AND DRY CONDITIONS WILL OCCUR
AT AREA TERMINALS THROUGH TAF VALID PERIOD...WITH BREEZY TO WINDY
CONDITIONS BEING THE MAIN CONCERN TODAY.

PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON
TURBULENCE FORECASTS.

&&

.FIRE WEATHER...

FIRE DANGER WILL BECOME SOMEWHAT ENHANCED TODAY THROUGH
SATURDAY...PRIMARILY ACROSS THE NATRONA COUNTY TODAY...THEN OVER
MOST BASINS AND VALLEYS EAST OF THE DIVIDE ON SATURDAY. MINIMUM RH
VALUES ACROSS THESE AREAS WILL FALL INTO THE MID AND UPPER TEENS
WHILE WINDS INCREASE OUT OF THE SOUTHWEST TO 15 TO 25 MPH WITH
HIGHER GUSTS AT TIMES. SUNDAY...MOISTURE WILL INCREASE ACROSS THE
ENTIRE REGION WITH A BETTER CHANCE FOR SHOWERS ACROSS THE NORTH AND
WEST...LOWERING FIRE DANGER ONCE AGAIN.

&&

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

&&

$$

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







000
FXUS65 KRIW 240550
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1150 PM MDT THU OCT 23 2014

.SHORT TERM...TONIGHT AND FRIDAY

THE RIGHT FRONT QUAD OF A STRONG 160KT UPPER JET WILL CONTINUE TO
IMPACT THE FORECAST AREA INTO FRIDAY MORNING KEEPING VERY STRONG
WESTERLY WINDS ON THE LEE SIDE OF MOUNTAIN RANGES. CHIEF JOSEPH
MEASURED A 71 MPH AT 9 PM THIS EVENING. THE STRONGEST WINDS ARE
EXPECTED TO OCCUR THROUGH 12Z OVER THE ABSAROKA MTS...WITH THE
BULK OF THE STRONGEST WINDS REMAINING ABOVE THE CODY FOOTHILLS.
SPS STILL LOOKS GOOD IN THOSE AREAS. THERE REMAINS A SLIGHT CHANCE
OF A FEW SHOWERS OVER NORTHWEST WYOMING...MAINLY YELLOWSTONE
THROUGH FRIDAY MORNING. UPPER RIDGE BEGINS TO BUILD INTO THE AREA
FRIDAY...WITH DECREASING CLOUDINESS IN THE AFTERNOON...AND WINDS
NOT BEING AS STRONG IN MANY AREAS...ESPECIALLY IN THE MOUNTAINS.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY

WARM RIDGE BUILDS OVER THE SRN ROCKIES AND HIGH PLAINS LEADING TO A
VERY MILD SATURDAY WITH H7 TEMPERATURES BETWEEN +6C AND +9C. A FEW
TEMPERATURES RECORDS ARE STILL POSSIBLE...ESPECIALLY IN CENTRAL WYO
WHERE READINGS WILL BE IN THE 70S FOR MOST AREAS. THEN WE START A
SIGNIFICANT CHANGE AS THE ERN PACIFIC UPPER LOW MOVES IN. THE SRN
PART OF THIS TROUGH MOVES IN FIRST ON SUNDAY INTO SUNDAY NIGHT WITH
THE NRN PIECE FOLLOWING QUICKLY BEHIND SUNDAY NIGHT AND MONDAY.
STILL A LOT OF DIFFERENCES IN THE DETAILS BUT ENOUGH COLD AIR WITH
THIS SYSTEM FOR SNOW OUT WEST SUNDAY WITH POTENTIAL FOR SNOW LINE
LOWERING TO THE VALLEY FLOOR. EAST OF THE DIVIDE...THE COLD AIR
FILTERS IN SUNDAY NIGHT WITH POTENTIAL FOR RAIN CHANGING TO SNOW
ACROSS THE NORTH AND THEN SPREADING INTO PARTS OF CENTRAL WYO LATER
SUNDAY NIGHT OR MONDAY MORNING. NOT A REAL ORGANIZED OR CLOSED OFF
SYSTEM BUT ENOUGH FORCING...OROGRAPHICS OUT WEST AND SOME
FORCING...UPSLOPE EAST TO GENERATE SOME LIGHT TO MODERATE SNOWFALL IN
THE MOUNTAINS AND POTENTIAL FOR SOME ACCUMULATION IN THE LOWER
ELEVATIONS EAST OF THE DIVIDE ALSO. WILL CONTINUE TREND OF
INCREASING POPS IN THE WEST SUNDAY AND THEN KEEP HIGH POPS IN THE
WEST INTO SUNDAY NIGHT WHILE INCREASING THEM IN THE NORTH AND THEN
WORKING SOUTH INTO MONDAY BEFORE THE SYSTEM MOVES OFF TO THE EAST
AND SOUTH. BRIEF RIDGING TUESDAY BEFORE THE NEXT SHORTWAVE IN THE NW
FLOW MOVES IN TUESDAY NIGHT AND WEDNESDAY. GFS HAS ANOTHER SYSTEM
MOVING INTO THE NRN PLAINS THURSDAY WITH A FRONT DROPPING SOUTH
ACROSS OUR NRN AND ERN ZONES. THE ECMWF HAS A RIDGE AHEAD OF A
POTENTIAL SYSTEM BEYOND THE MEDIUM RANGE. STILL A LOT OF AT THE END
OF THE PERIOD AS TO THE EVOLUTION/MOVEMENT OF OUR SYSTEMS OVER
SIBERIA AND MOVING EWD. OP ECMWF AND GFS SHOW MORE SPLITTING WITH
THIS SYSTEM AND THUS MUCH MORE ENERGY/UPPER LOW FORMING OVER THE ERN
PACIFIC LATE NEXT WEEK. THE GFS HAS A LITTLE MORE ENERGY RIDING OVER
THE AK RIDGE EARLY NEXT WEEK AND THUS A STRONGER SYSTEM DIVING INTO
THE NRN HIGH PLAINS ON THURSDAY WITH MAINLY DRY FRONTAL SYSTEM
IMPACTING OUR AREAS EAST OF THE DIVIDE. CONFIDENCE STILL LOW ON THE
LAST COUPLE DAYS OF THIS PERIOD AND BEYOND WITH MORE ACTIVE
HEMISPHERIC 5 WAVE DEVELOPING.

&&

.AVIATION.../06Z ISSUANCE/

CONCERN FOR THE REST OF TONIGHT AND FRIDAY WILL BE CONSIDERABLE
MOUNTAIN TURBULENCE WITH STRONG MOUNTAIN TOP WINDS...ESPECIALLY
THROUGH FRIDAY MORNING. LLWS ON THE LEE SIDE OF MOUNTAIN RANGES IS
EXPECTED FRIDAY MORNING AT COD AND LND...BUT IT IS EXPECTED TO
IMPROVE THROUGH THE MORNING HOURS. CONSIDERABLE HIGH AND MID LEVEL
CLOUDINESS THIS MORNING ARE EXPECTED TO WILL BECOME MAINLY SKC
BETWEEN 20Z AND 00Z. THERE COULD BE ISOLATED SHOWER ACTIVITY OVER
EXTREME NW WYOMING THIS MORNING...BUT SHOULD NOT IMPACT COD OR
JAC. THUS VFR AND DRY CONDITIONS WILL OCCUR AT AREA TERMINALS
THROUGH TAF VALID PERIOD...WITH BREEZY TO WINDY CONDITIONS BEING
THE MAIN CONCERN TODAY.

PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON
TURBULENCE FORECASTS.

&&

.FIRE WEATHER...

THE MAIN CONCERN FOR THE REMAINDER OF TONIGHT INTO FRIDAY WILL BE
THE STRONG WINDS OCCURRING THE MOUNTAINS AND IN THE TYPICAL WIND
CORRIDORS. OVER THE LOWER ELEVATIONS OF NATRONA COUNTY /FIRE
WEATHER ZONE 280/ THERE BE A COMBINATION OF LOW RH BETWEEN 15 AND
20 PERCENT AND BREEZY WINDS TO CREATE ELEVATED FIRE BEHAVIOR.
THERE COULD BE ISOLATED SHOWERS OVER EXTREME NORTHWEST WYOMING
THROUGH FRIDAY MORNING...BUT THEY WILL BE VERY LIGHT AND NO
WETTING RAIN WILL OCCUR.

&&

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

&&

$$

SHORT TERM...TEAM RIVERTON
LONG TERM...SKRBAC
AVIATION...WM
FIRE WEATHER...TEAM RIVERTON







000
FXUS65 KRIW 231720
AFDRIW

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1120 AM MDT THU OCT 23 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

OVERNIGHT SATELLITE IMAGERY IS SHOWING THE CLOUD COVER ASSOCIATED
WITH A DISTURBANCE TO OUR WEST CLIPPING OUR WESTERN BORDER WITH
IDAHO. IT WILL RESULT IN LITTLE MORE THAN SOME ENHANCED CLOUD COVER
BEFORE IT SHOOTS OFF TO THE NORTH THIS AFTERNOON. HOWEVER...THE
DYNAMIC SYSTEM TO OUR NORTH AND WEST POWERED BY A STRONG 160KT JET
CORE WILL IMPACT OUR WEATHER THROUGH AT LEAST FRIDAY MORNING BEFORE
THE RIDGE FIGHTING FOR POSITION TO OUR SOUTH FINALLY WINS OUT.

ANOTHER WINDY DAY IS IN STORE FOR THE FORECAST AREA AS THIS SYSTEM
TO OUR NORTHWEST BUTS UP AGAINST THE RIDGE TO OUR SOUTH...LEAVING
OUR AREA RIGHT IN BETWEEN THE TWO. A PERIOD OF 20 TO 40 KNOT
WESTERLY FLOW WILL EVENTUALLY MIX DOWN THIS AFTERNOON...AND WILL
LATER BE FORCED DOWN TONIGHT BY THE SUBSIDENT RIGHT EXIT REGION OF
THE JET TO OUR NORTH. THE AREAS THAT WILL BE IMPACTED THE MOST BY
THIS JET INTERACTION WILL BE THE CODY FOOTHILLS AND THE ABSAROKAS
WHERE A HIGH WIND WATCH REMAINS. STEADY 40 KNOT WESTERLIES ACROSS
THE ABSAROKAS WILL PROVIDE THE PERFECT FLOW FOR BREAKING MOUNTAIN
WAVE ACTION LATER THIS EVENING...THAT COMBINED WITH A LITTLE HELP
FROM THE JET WILL INCREASE THE LIKELIHOOD OF THIS MOUNTAIN WAVE
SURFACING AROUND CLARK AND WEST CODY BETWEEN SUNSET TONIGHT AND
SUNRISE FRIDAY MORNING.

SWIFT WESTERLIES HANG AROUND ON FRIDAY BUT THERE WILL NOT BE MUCH
AROUND TO FORCE THESE WINDS TO THE SURFACE...THE GRADIENT AT THE
SURFACE WILL BE MUCH LOOSER AND THE JET STREAK TO OUR NORTH WILL BE
MORE ZONAL AND THE STRONGEST FORCING WILL BE WELL TO OUR NORTH.
OTHERWISE...WE WILL START TO FEEL MORE INFLUENCE FORM THE RIDGE TO
OUR SOUTH WITH MILD TEMPERATURES AND LOW HUMIDITY.

FLOW TURNS MORE SOUTHWESTERLY ON SATURDAY AS THE RIDGE AXIS SHIFTS
EAST AND THE TROUGH DIGGING TO OUR WEST BEGINS TO ADVANCE. IT WILL
BE ON THE BREEZY SIDE ON SATURDAY AS THE GRADIENT TIGHTENS WITH A
LEE TROUGH DIGGING TO OUR EAST. THE LEADING EDGE OF THIS TROUGH
COULD BEGIN TO IMPACT OUR WEST AS EARLY AS LATE SATURDAY NIGHT...SO
KEPT AT LEAST A SLIGHT CHANCE OF RAIN IN THE FORECAST FOR NOW BUT
TIMING THE PRECIPITATION WITH THIS NEXT SYSTEM IS STILL DIFFICULT TO
PIN DOWN THIS FAR OUT.

.LONG TERM...SUNDAY THROUGH THURSDAY

A WEATHER SYSTEM AND ASSOCIATED COLD FRONT PUSHES INTO THE WEST
SUNDAY MORNING AND THEN MOVES EAST OF THE DIVIDE SUNDAY AFTERNOON
AND NIGHT. BREEZY TO WINDY AREAS AND A CHANCE OF RAIN SHOWERS AND
MOUNTAIN SNOW. MONDAY LOOKS COOL WITH SCATTERED SHOWERS AT THE LOWER
ELEVATIONS WITH SNOW SHOWERS IN THE MOUNTAINS. DECREASING CLOUDS AND
SHOWERS MONDAY NIGHT. DRY ON TUESDAY MOST AREAS AND A LITTLE MILDER.
ISOLATED RAIN OR SNOW SHOWERS MAY DEVELOP LATER TUE AFTERNOON IN NW
WY. THE NEXT WEATHER SYSTEM BRINGS SOME LIGHT PRECIP TO THE
MOUNTAINS OF WY TUE NIGHT INTO WED WITH ISOLATED SHOWERS FOR THE
LOWER ELEVATIONS ON WED. THE GFS AND ECMWF MODELS ARE CLOSE WITH THE
TIMING AND STRENGTH OF THIS SYSTEM. HIGHS WED LOOKS A TAD WARMER.
NEXT THURSDAY LOOKS MOSTLY DRY PER THE MODELS WITH ISOLATED MOUNTAIN
SHOWERS...AND THAT MAY BE OVERDONE AT THIS POINT...BUT WILL LEAVE
THEM IN AND SEE HOW THINGS LOOK TONIGHT. SEASONAL HIGH TEMPS NEXT
THURSDAY.

&&

.AVIATION.../18Z ISSUANCE/

THE MAIN CONCERN THROUGH THE TAF VALID PERIOD WILL BE CONSIDERABLE
MOUNTAIN TURBULENCE...AS WELL AS LLWS ESPECIALLY ON THE LEE SIDE OF
THE ABSAROKA AND WIND RIVER MOUNTAINS INCLUDING COD AND LND
TERMINALS. VFR AND DRY CONDITIONS WILL OCCUR AT AREA TERMINALS WITH
ONLY MID/HIGH LEVEL CLOUDINESS EXPECTED TODAY. THERE COULD BE SOME
CONVECTION TONIGHT NW OF A KJAC-KCOD LINE...BUT THIS ACTIVITY IS
EXPECTED TO BE LIGHT AND REMAIN AWAY FROM THE TERMINALS.

PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON
TURBULENCE FORECASTS.

&&

.FIRE WEATHER...

WARMER AND DRY TODAY BUT IT WILL BE ANOTHER BREEZY DAY IN SPOTS WITH
SOUTHWEST WINDS OF 15 TO 25 MPH COMMON BETWEEN ROCK SPRINGS AND
CASPER AND OVER THE HIGHER ELEVATIONS. STRONG WINDS POSSIBLE ALONG
THE NORTH ZONE OF THE SHOSHONE AND IN THE CODY FOOTHILLS THIS
EVENING WITH SUDDEN 50 TO 60MPH WIND GUSTS POSSIBLE. SOUTHWEST FLOW
RETURNS ON FRIDAY WITH DRIER AND WARMER CONDITIONS REMAINING. THERE
COULD BE A FEW GUSTS OVER 25 MPH IN THE AFTERNOON BETWEEN RAWLINS
AND SOUTHERN CASPER DISPATCH BUT MOST AREAS WILL HAVE RELATIVELY
LIGHT WINDS.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...

HIGH WIND WATCH FROM THIS EVENING THROUGH FRIDAY MORNING WYZ003.

&&

$$

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










000
FXUS65 KRIW 230922
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
322 AM MDT THU OCT 23 2014

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT

OVERNIGHT SATELLITE IMAGERY IS SHOWING THE CLOUD COVER ASSOCIATED
WITH A DISTURBANCE TO OUR WEST CLIPPING OUR WESTERN BORDER WITH
IDAHO. IT WILL RESULT IN LITTLE MORE THAN SOME ENHANCED CLOUD COVER
BEFORE IT SHOOTS OFF TO THE NORTH THIS AFTERNOON. HOWEVER...THE
DYNAMIC SYSTEM TO OUR NORTH AND WEST POWERED BY A STRONG 160KT JET
CORE WILL IMPACT OUR WEATHER THROUGH AT LEAST FRIDAY MORNING BEFORE
THE RIDGE FIGHTING FOR POSITION TO OUR SOUTH FINALLY WINS OUT.

ANOTHER WINDY DAY IS IN STORE FOR THE FORECAST AREA AS THIS SYSTEM
TO OUR NORTHWEST BUTS UP AGAINST THE RIDGE TO OUR SOUTH...LEAVING
OUR AREA RIGHT IN BETWEEN THE TWO. A PERIOD OF 20 TO 40 KNOT
WESTERLY FLOW WILL EVENTUALLY MIX DOWN THIS AFTERNOON...AND WILL
LATER BE FORCED DOWN TONIGHT BY THE SUBSIDENT RIGHT EXIT REGION OF
THE JET TO OUR NORTH. THE AREAS THAT WILL BE IMPACTED THE MOST BY
THIS JET INTERACTION WILL BE THE CODY FOOTHILLS AND THE ABSAROKAS
WHERE A HIGH WIND WATCH REMAINS. STEADY 40 KNOT WESTERLIES ACROSS
THE ABSAROKAS WILL PROVIDE THE PERFECT FLOW FOR BREAKING MOUNTAIN
WAVE ACTION LATER THIS EVENING...THAT COMBINED WITH A LITTLE HELP
FROM THE JET WILL INCREASE THE LIKELIHOOD OF THIS MOUNTAIN WAVE
SURFACING AROUND CLARK AND WEST CODY BETWEEN SUNSET TONIGHT AND
SUNRISE FRIDAY MORNING.

SWIFT WESTERLIES HANG AROUND ON FRIDAY BUT THERE WILL NOT BE MUCH
AROUND TO FORCE THESE WINDS TO THE SURFACE...THE GRADIENT AT THE
SURFACE WILL BE MUCH LOOSER AND THE JET STREAK TO OUR NORTH WILL BE
MORE ZONAL AND THE STRONGEST FORCING WILL BE WELL TO OUR NORTH.
OTHERWISE...WE WILL START TO FEEL MORE INFLUENCE FORM THE RIDGE TO
OUR SOUTH WITH MILD TEMPERATURES AND LOW HUMIDITY.

FLOW TURNS MORE SOUTHWESTERLY ON SATURDAY AS THE RIDGE AXIS SHIFTS
EAST AND THE TROUGH DIGGING TO OUR WEST BEGINS TO ADVANCE. IT WILL
BE ON THE BREEZY SIDE ON SATURDAY AS THE GRADIENT TIGHTENS WITH A
LEE TROUGH DIGGING TO OUR EAST. THE LEADING EDGE OF THIS TROUGH
COULD BEGIN TO IMPACT OUR WEST AS EARLY AS LATE SATURDAY NIGHT...SO
KEPT AT LEAST A SLIGHT CHANCE OF RAIN IN THE FORECAST FOR NOW BUT
TIMING THE PRECIPITATION WITH THIS NEXT SYSTEM IS STILL DIFFICULT TO
PIN DOWN THIS FAR OUT.

.LONG TERM...SUNDAY THROUGH THURSDAY

A WEATHER SYSTEM AND ASSOCIATED COLD FRONT PUSHES INTO THE WEST
SUNDAY MORNING AND THEN MOVES EAST OF THE DIVIDE SUNDAY AFTERNOON
AND NIGHT. BREEZY TO WINDY AREAS AND A CHANCE OF RAIN SHOWERS AND
MOUNTAIN SNOW. MONDAY LOOKS COOL WITH SCATTERED SHOWERS AT THE LOWER
ELEVATIONS WITH SNOW SHOWERS IN THE MOUNTAINS. DECREASING CLOUDS AND
SHOWERS MONDAY NIGHT. DRY ON TUESDAY MOST AREAS AND A LITTLE MILDER.
ISOLATED RAIN OR SNOW SHOWERS MAY DEVELOP LATER TUE AFTERNOON IN NW
WY. THE NEXT WEATHER SYSTEM BRINGS SOME LIGHT PRECIP TO THE
MOUNTAINS OF WY TUE NIGHT INTO WED WITH ISOLATED SHOWERS FOR THE
LOWER ELEVATIONS ON WED. THE GFS AND ECMWF MODELS ARE CLOSE WITH THE
TIMING AND STRENGTH OF THIS SYSTEM. HIGHS WED LOOKS A TAD WARMER.
NEXT THURSDAY LOOKS MOSTLY DRY PER THE MODELS WITH ISOLATED MOUNTAIN
SHOWERS...AND THAT MAY BE OVERDONE AT THIS POINT...BUT WILL LEAVE
THEM IN AND SEE HOW THINGS LOOK TONIGHT. SEASONAL HIGH TEMPS NEXT
THURSDAY.

&&

.AVIATION.../12Z ISSUANCE/

THE MAIN CONCERN THROUGH THE TAF VALID PERIOD WILL BE CONSIDERABLE
MOUNTAIN TURBULENCE...AS WELL AS LLWS ESPECIALLY ON THE LEE SIDE OF
THE ABSAROKA AND WIND RIVER MOUNTAINS INCLUDING COD AND LND
TERMINALS. VFR AND DRY CONDITIONS WILL OCCUR AT AREA TERMINALS WITH
ONLY MID/HIGH LEVEL CLOUDINESS EXPECTED TODAY. THERE COULD BE SOME
CONVECTION TONIGHT NW OF A KJAC-KCOD LINE...BUT THIS ACTIVITY IS
EXPECTED TO BE LIGHT AND REMAIN AWAY FROM THE TERMINALS.

PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON
TURBULENCE FORECASTS.

&&

.FIRE WEATHER...

WARMER AND DRY TODAY BUT IT WILL BE ANOTHER BREEZY DAY IN SPOTS WITH
SOUTHWEST WINDS OF 15 TO 25 MPH COMMON BETWEEN ROCK SPRINGS AND
CASPER AND OVER THE HIGHER ELEVATIONS. STRONG WINDS POSSIBLE ALONG
THE NORTH ZONE OF THE SHOSHONE AND IN THE CODY FOOTHILLS THIS
EVENING WITH SUDDEN 50 TO 60MPH WIND GUSTS POSSIBLE. SOUTHWEST FLOW
RETURNS ON FRIDAY WITH DRIER AND WARMER CONDITIONS REMAINING. THERE
COULD BE A FEW GUSTS OVER 25 MPH IN THE AFTERNOON BETWEEN RAWLINS
AND SOUTHERN CASPER DISPATCH BUT MOST AREAS WILL HAVE RELATIVELY
LIGHT WINDS.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...

HIGH WIND WATCH FROM THIS EVENING THROUGH FRIDAY MORNING WYZ003.

&&

$$

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







000
FXUS65 KRIW 230528
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1128 PM MDT WED OCT 22 2014

.SHORT TERM...TONIGHT THROUGH THURSDAY

A DRY STABLE CONFLUENT FLOW HAS ENSUED OVER THE AREA AS TUESDAYS
TROUGH EXITS THE AREA AND A FLATTENING RIDGE MOVES IN FROM THE
WEST. THE TREND THROUGH THU WILL BE FOR INCREASING WESTERLY FLOW
AS THE GRADIENT TIGHTENS WITH THE FLATTENING RIDGE AND THE CLOSED
LOW OVER THE GULF OF ALASKA CHURNS OUT ANOTHER CLOSED LOW EAST
ACROSS CANADA AND SLINGS A VIGOROUS SHORTWAVE TOWARD THE NORTHERN
ROCKIES...AND AT THE SAME TIME A RIDGE BUILDS INTO THE SOUTHERN
ROCKIES FROM THE SOUTHWEST. INCREASING WEST WINDS WILL RESPOND TO
THIS SET UP... ESPECIALLY ALONG THE EAST SLOPE OF THE CONTINENTAL
DIVIDE AND ALONG THE SOUTHERN WIND CORRIDOR. IN ADDITION...WEST
WINDS WILL LIKELY INCREASE SIGNIFICANTLY IN THE AREA NORTH OF CODY
BY LATE THU AFTERNOON...PRIMARILY AROUND CLARK AS A POTENTIAL MTN
WAVE...ALBEIT RELATIVELY WEAK...DEVELOPS. A FROUDE NUMBER OF 1 BY
00Z FRI IN THAT AREA AS WELL AS A PROGGED CRITICAL LAYER ABOVE THE
ABSAROKA MTNS REFLECTS THIS NOTION. IN ADDITION...THE WEST
SOUTHWEST DIFLUENT FLOW WILL RESULT IN ISOLD RAIN/SNOW SHOWERS IN
THE FAR NW MTNS LATE THU. SOUTHWEST WEST WINDS HAVE ALREADY KICKED
IN ALONG THE SOUTHERN WIND CORRIDOR FROM THE GREEN MTNS TO KCPR.
OTHERWISE...EXPECT DRY WEATHER THROUGH THU. TEMPERATURES WILL BE
AROUND 10 DEGREES WARMER EVERYWHERE THU AS THE COOL AIR BEHIND
WEDNESDAYS TROUGH EXITS TO THE EAST.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

POTENTIAL MOUNTAIN WAVE EVENT TO START THIS PERIOD IN THE CODY
FOOTHILLS AS POTENTIALLY FAVORABLE MOUNTAIN TOP CONDITIONS COMBINE
WITH APPROACHING RIGHT FRONT QUAD OF 150KT+ UPPER JET AND MODERATE
GAP FLOW SIGNATURE. NAM12 IS PICKING UP A PERIOD OF UPSTREAM
MOUNTAIN TOP INVERSION AFTER MIDNIGHT THURSDAY NIGHT WHILE THE WRF
CROSS SECTION IS SHOWING A PERIOD IN THE EVENING THURSDAY OF
POTENTIAL FLOW REVERSAL OR AT LEAST POTENTIAL FOR WAVE INDUCED
CRITICAL LAYER. FROUDE CALCULATIONS FOR THURSDAY NIGHT ARE PRETTY
CONSISTENT IN THE 1 RANGE. WRF BOUNDARY LEVEL WINDS ARE NOT OVERLY
IMPRESSIVE ON THE FLATS BUT GET OVER 50KTS NEAR THE STEEP TERRAIN.
POTENTIAL IS GREAT ENOUGH TO AT LEAST GET THE WATCH OUT AS THERE ARE
ENOUGH FEATURES THAT COULD CAUSE THIS TO BE A DECENT EVENT. THE LOW
END WOULD PROBABLY PRODUCE NEAR OR AT HIGH WINDS FOR THE GAPS AND
WEST SIDE OF CLARK WHILE THE HIGH END WOULD RESULT IN A WAVE
BREAKING MOUNTAIN WAVE EVENT WITH WINDS WELL OVER 60 MPH WITH
POTENTIAL FOR 80 MPH PLUS. MOIST PLUME APPROACHES ABOUT THE SAME
TIME WITH OUR APPROACHING FRONTAL BOUNDARY WHICH WILL PROBABLY CLIP
THE NWRN CORNER WITH A LITTLE LIGHT PCPN THURSDAY NIGHT INTO FRIDAY
MORNING BEFORE RIDGING PUSHES IT NORTH INTO MT. SHALLOW FRONTAL
BOUNDARY STILL EXPECTED TO SIT ACROSS THE NORTH FRIDAY FOR A SLIGHT
TEMPERING OF TEMPERATURES COMPARED TO AREAS JUST TO THE SOUTH.
SATURDAY LOOKS WARM AND DRY WITH INCREASING SW WIND.

ERN PACIFIC TROUGH THEN OPENS UP AND MOVES INLAND ACROSS US SUNDAY
INTO MONDAY WITH MODELS VARYING ON TIMING AND STRENGTH OF SECONDARY
BACK SIDE SYSTEM SUNDAY NIGHT/MON MRNG. AIRMASS STILL LOOKS COLD
ENOUGH FOR POTENTIAL LIGHT SNOW IN CENTRAL WYO LATER SUNDAY NIGHT
INTO MONDAY MORNING WHERE PCPN FALLS. DECENT SHOT OF RAIN CHANGING
TO SNOW IN THE MOUNTAINS WITH THIS SYSTEM WITH A COUPLE TO SEVERAL
INCHES QUITE POSSIBLE IN THE MOUNTAINS. BRIEF RIDGING WITH
TEMPERATURES RECOVERING SOME TUESDAY BEFORE POTENTIAL SEWD MOVING
SHORTWAVE MOVES ACROSS LATER TUESDAY NIGHT INTO WEDNESDAY. MODELS
STRUGGLING WITH THE PATTERN CHANGE AND MOVEMENT OF SEVERAL KEY UPPER
LOWS OVER ASIA BUT IT DOES APPEAR THAT SIGNIFICANT CHANGES COULD BE
IN THE OFFING JUST BEYOND THE MEDIUM RANGE PERIOD. HOW IT ALL
EVOLVES AND THE EXACT TIMING IS STILL UNCERTAIN...MOST LIKELY
BETWEEN HALLOWEEN AND THE FIRST COUPLE DAYS OF NOVEMBER. NOTHING
CERTAIN YET.

&&

.AVIATION.../06Z ISSUANCE/

THE MAIN CONCERN THROUGH THE TAF VALID PERIOD WILL BE CONSIDERABLE
MOUNTAIN TURBULENCE...AS WELL AS LLWS ESPECIALLY ON THE LEE SIDE OF
THE ABSAROKA AND WIND RIVER MOUNTAINS INCLUDING COD AND LND
TERMINALS AT TIMES. VFR AND DRY CONDITIONS WILL OCCUR AT AREA
TERMINALS WITH ONLY MID/HIGH LEVEL CLOUDINESS OVERSPREADING THE AREA
THROUGH 12Z AND THEN REMAINING OVER THE AREA THROUGH THURSDAY NIGHT.
THERE COULD BE SOME CONVECTION THURSDAY NIGHT NW OF A KJAC-KCOD
LINE...BUT THIS ACTIVITY IS EXPECTED TO BE LIGHT AND REMAIN AWAY
FROM THE TERMINALS.

PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON
TURBULENCE FORECASTS.

&&

.FIRE WEATHER...

TEMPERATURES REBOUND A BIT ON THURSDAY AS HIGH PRESSURE BUILDS IN
FROM THE SOUTH BUT IT WILL BE ANOTHER BREEZY DAY IN SPOTS WITH
SOUTHWEST WINDS OF 15 TO 25 MPH COMMON BETWEEN ROCK SPRINGS AND
CASPER AND OVER THE HIGHER ELEVATIONS. ON THURSDAY NIGHT WEST WINDS
WILL INCREASE SIGNIFICANTLY IN THE AREA AROUND CLARK NORTH OF
CODY.SOUTHWEST FLOW RETURNS ON FRIDAY WITH DRIER AND WARMER
CONDITIONS REMAINING. THERE COULD BE A FEW GUSTS OVER 25 MPH IN THE
AFTERNOON BETWEEN RAWLINS AND SOUTHERN CASPER DISPATCH BUT MOST
AREAS WILL HAVE RELATIVELY LIGHT WINDS.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING
WYZ003.

&&

$$

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












000
FXUS65 KRIW 222058
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
258 PM MDT WED OCT 22 2014

.SHORT TERM...TONIGHT THROUGH THURSDAY

A DRY STABLE CONFLUENT FLOW HAS ENSUED OVER THE AREA AS TUESDAYS
TROUGH EXITS THE AREA AND A FLATTENING RIDGE MOVES IN FROM THE
WEST. THE TREND THROUGH THU WILL BE FOR INCREASING WESTERLY FLOW
AS THE GRADIENT TIGHTENS WITH THE FLATTENING RIDGE AND THE CLOSED
LOW OVER THE GULF OF ALASKA CHURNS OUT ANOTHER CLOSED LOW EAST
ACROSS CANADA AND SLINGS A VIGOROUS SHORTWAVE TOWARD THE NORTHERN
ROCKIES...AND AT THE SAME TIME A RIDGE BUILDS INTO THE SOUTHERN
ROCKIES FROM THE SOUTHWEST. INCREASING WEST WINDS WILL RESPOND TO
THIS SET UP... ESPECIALLY ALONG THE EAST SLOPE OF THE CONTINENTAL
DIVIDE AND ALONG THE SOUTHERN WIND CORRIDOR. IN ADDITION...WEST
WINDS WILL LIKELY INCREASE SIGNIFICANTLY IN THE AREA NORTH OF CODY
BY LATE THU AFTERNOON...PRIMARILY AROUND CLARK AS A POTENTIAL MTN
WAVE...ALBEIT RELATIVELY WEAK...DEVELOPS. A FROUDE NUMBER OF 1 BY
00Z FRI IN THAT AREA AS WELL AS A PROGGED CRITICAL LAYER ABOVE THE
ABSAROKA MTNS REFLECTS THIS NOTION. IN ADDITION...THE WEST
SOUTHWEST DIFLUENT FLOW WILL RESULT IN ISOLD RAIN/SNOW SHOWERS IN
THE FAR NW MTNS LATE THU. SOUTHWEST WEST WINDS HAVE ALREADY KICKED
IN ALONG THE SOUTHERN WIND CORRIDOR FROM THE GREEN MTNS TO KCPR.
OTHERWISE...EXPECT DRY WEATHER THROUGH THU. TEMPERATURES WILL BE
AROUND 10 DEGREES WARMER EVERYWHERE THU AS THE COOL AIR BEHIND
WEDNESDAYS TROUGH EXITS TO THE EAST.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY

POTENTIAL MOUNTAIN WAVE EVENT TO START THIS PERIOD IN THE CODY
FOOTHILLS AS POTENTIALLY FAVORABLE MOUNTAIN TOP CONDITIONS COMBINE
WITH APPROACHING RIGHT FRONT QUAD OF 150KT+ UPPER JET AND MODERATE
GAP FLOW SIGNATURE. NAM12 IS PICKING UP A PERIOD OF UPSTREAM
MOUNTAIN TOP INVERSION AFTER MIDNIGHT THURSDAY NIGHT WHILE THE WRF
CROSS SECTION IS SHOWING A PERIOD IN THE EVENING THURSDAY OF
POTENTIAL FLOW REVERSAL OR AT LEAST POTENTIAL FOR WAVE INDUCED
CRITICAL LAYER. FROUDE CALCULATIONS FOR THURSDAY NIGHT ARE PRETTY
CONSISTENT IN THE 1 RANGE. WRF BOUNDARY LEVEL WINDS ARE NOT OVERLY
IMPRESSIVE ON THE FLATS BUT GET OVER 50KTS NEAR THE STEEP TERRAIN.
POTENTIAL IS GREAT ENOUGH TO AT LEAST GET THE WATCH OUT AS THERE ARE
ENOUGH FEATURES THAT COULD CAUSE THIS TO BE A DECENT EVENT. THE LOW
END WOULD PROBABLY PRODUCE NEAR OR AT HIGH WINDS FOR THE GAPS AND
WEST SIDE OF CLARK WHILE THE HIGH END WOULD RESULT IN A WAVE
BREAKING MOUNTAIN WAVE EVENT WITH WINDS WELL OVER 60 MPH WITH
POTENTIAL FOR 80 MPH PLUS. MOIST PLUME APPROACHES ABOUT THE SAME
TIME WITH OUR APPROACHING FRONTAL BOUNDARY WHICH WILL PROBABLY CLIP
THE NWRN CORNER WITH A LITTLE LIGHT PCPN THURSDAY NIGHT INTO FRIDAY
MORNING BEFORE RIDGING PUSHES IT NORTH INTO MT. SHALLOW FRONTAL
BOUNDARY STILL EXPECTED TO SIT ACROSS THE NORTH FRIDAY FOR A SLIGHT
TEMPERING OF TEMPERATURES COMPARED TO AREAS JUST TO THE SOUTH.
SATURDAY LOOKS WARM AND DRY WITH INCREASING SW WIND.

ERN PACIFIC TROUGH THEN OPENS UP AND MOVES INLAND ACROSS US SUNDAY
INTO MONDAY WITH MODELS VARYING ON TIMING AND STRENGTH OF SECONDARY
BACK SIDE SYSTEM SUNDAY NIGHT/MON MRNG. AIRMASS STILL LOOKS COLD
ENOUGH FOR POTENTIAL LIGHT SNOW IN CENTRAL WYO LATER SUNDAY NIGHT
INTO MONDAY MORNING WHERE PCPN FALLS. DECENT SHOT OF RAIN CHANGING
TO SNOW IN THE MOUNTAINS WITH THIS SYSTEM WITH A COUPLE TO SEVERAL
INCHES QUITE POSSIBLE IN THE MOUNTAINS. BRIEF RIDGING WITH
TEMPERATURES RECOVERING SOME TUESDAY BEFORE POTENTIAL SEWD MOVING
SHORTWAVE MOVES ACROSS LATER TUESDAY NIGHT INTO WEDNESDAY. MODELS
STRUGGLING WITH THE PATTERN CHANGE AND MOVEMENT OF SEVERAL KEY UPPER
LOWS OVER ASIA BUT IT DOES APPEAR THAT SIGNIFICANT CHANGES COULD BE
IN THE OFFING JUST BEYOND THE MEDIUM RANGE PERIOD. HOW IT ALL
EVOLVES AND THE EXACT TIMING IS STILL UNCERTAIN...MOST LIKELY
BETWEEN HALLOWEEN AND THE FIRST COUPLE DAYS OF NOVEMBER. NOTHING
CERTAIN YET.

&&

.AVIATION.../00Z ISSUANCE/
VFR CONDITIONS WILL OCCUR TONIGHT WITH MAINLY SKC SKIES. EXPECT
INCREASING MID/HIGH LEVEL CLOUDINESS AND STRENGTHENING MOUNTAIN
TOP WINDS WITH POSSIBLY SOME LLWS ON THE LEE SIDE OF MOUNTAIN
RANGES ALONG THE CONTINENTAL DIVIDE DEVELOPING AFTER 06Z TONIGHT. HOWEVER
NOT ENOUGH CONFIDENCE OR MAGNITUDE TO INCLUDE AT KCOD OR KLND AT
THIS TIME. WEST SOUTHWEST WINDS WILL INCREASE FROM KRKS TO KCPR BY
18Z THURSDAY. WEST WINDS WILL INCREASE FROM KCOD NORTH TO CLARK BY
00Z FRIDAY.

&&

.FIRE WEATHER...
TEMPERATURES REBOUND A BIT ON THURSDAY AS HIGH PRESSURE BUILDS IN FROM
THE SOUTH BUT IT WILL BE ANOTHER BREEZY DAY IN SPOTS WITH
SOUTHWEST WINDS OF 15 TO 25 MPH COMMON BETWEEN ROCK SPRINGS AND
CASPER AND OVER THE HIGHER ELEVATIONS. ON THURSDAY NIGHT WEST
WINDS WILL INCREASE SIGNIFICANTLY IN THE AREA AROUND CLARK NORTH
OF CODY.SOUTHWEST FLOW RETURNS ON FRIDAY WITH DRIER AND WARMER
CONDITIONS REMAINING. THERE COULD BE A FEW GUSTS OVER 25 MPH IN
THE AFTERNOON BETWEEN RAWLINS AND SOUTHERN CASPER DISPATCH BUT
MOST AREAS WILL HAVE RELATIVELY LIGHT WINDS.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING
WYZ003.

&&

$$

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









000
FXUS65 KRIW 221830
AFDRIW

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE RIVERTON WY
1230 PM MDT WED OCT 22 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

A COOLER AIRMASS HANGING AROUND TODAY BEHIND THE COLD FRONT THAT
PASSED THROUGH OVERNIGHT WITH SOME MODERATION ON THURSDAY AND
FRIDAY. AFTER A RELATIVELY CALM DAY TODAY...THURSDAY IS EXPECTED TO
BE ANOTHER WINDY DAY AS A TUG OF WAR ENSUES BETWEEN THE COLD BUT
DYNAMIC TROUGH TO OUR NORTHWEST AND THE RIDGE POKING IN FROM THE
SOUTH. MODELS HAVE BEEN TRENDING FURTHER SOUTH WITH THE
STRENGTHENING JET TO OUR NORTHWEST ON THURSDAY...WHICH COULD
INTRODUCE STRONGER WINDS ACROSS THE NORTHERN MOUNTAINS AND A SLIGHT
CHANCE FOR PRECIPITATION. AS THE INFLUENCE OF THE RIGHT EXIT REGION
OF THE JET INTRUDES THURSDAY AFTERNOON THROUGH FRIDAY...THIS WILL
KICK UP THE MOUNTAIN WAVE POTENTIAL OVER THE ABSAROKAS...MAINTAINING
CONSISTENCY WITH THE DAY SHIFT FORECAST FOR SOME WIND GUSTS IN THE
WESTERN CODY FOOTHILLS AT 50 MPH FOR LATE THURSDAY OR THURSDAY NIGHT
INTO FRIDAY MORNING. ALSO BUMPED UP POPS A LITTLE FOR THE NORTHWEST
ON THURSDAY NIGHT AND FRIDAY AS A WAVE MOVES THROUGH. MOST OF THE
ACTION WILL REMAIN TO OUR WEST BUT THERE COULD BE A FEW SHOWERS
AROUND YELLOWSTONE AND THE TETONS. OTHERWISE WESTERN AND CENTRAL
WYOMING WILL BE DRY AND BREEZY THROUGH THE PERIOD WITH ABOVE NORMAL
TEMPERATURES.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
SYNOPSIS...UNSEASONABLY WARM AND BREEZY TO WINDY CONDITIONS WILL
PREVAIL ON SATURDAY WITH RECORD OR NEAR RECORD HIGHS POSSIBLE. A
COLD FRONT WILL PUSH ACROSS THE AREA SUNDAY AND SUNDAY NIGHT
SPREADING RAIN AND SNOW SHOWERS AND COLDER TEMPERATURES ACROSS THE
AREA INTO MONDAY. A WESTERLY FLOW WILL BRING MAINLY DRY AND
SEASONABLE MILD CONDITIONS ON TUESDAY AND WEDNESDAY.

DISCUSSION...COMPLEX VORTEX OVER THE GULF OF ALASKA THIS MORNING
WILL WOBBLE SE TO THE WEST COAST SATURDAY MORNING. MEDIUM RANGE
MODELS CONTINUE TO HANDLE THE INDIVIDUAL VORTICES WITHIN THIS
COMPLEX DIFFERENTLY...BUT AGREE THAT A VERY WARM SW FLOW WILL
PREVAIL OVER THE AREA SATURDAY BETWEEN THIS SYSTEM AND STRONG
DOWNSTREAM RIDGE OVER THE PLAINS. RECORD HIGH TERRITORY FOR THE
25TH IS GENERALLY 72-74F RANGE ACROSS CENTRAL WY FOR THE 25TH...A
BIT WARMER AT WRL AT 79F. FORECAST HIGHS ARE CURRENTLY NEAR OR
EXCEEDING THESE RECORDS.

ON THE 22/00Z GFS AND ECMWF RUNS...GFS CONTINUES TO EJECT LEAD
SHORTWAVE OUT OF BASE OF THE TROUGH NE INTO WESTERN MONTANA
SATURDAY NIGHT WHILE THE ECMWF SHOWS A MORE SPLIT
SYSTEM...SWINGING THIS SHORTWAVE FURTHER SOUTH ACROSS THE GREAT
BASIN SATURDAY NIGHT. GFS VERSION WOULD KEEP MOST OF THE
PRECIPITATION CONFINED TO THE WEST DURING THE DAY SUNDAY WITH
WINDY AND MILD CONDITIONS ACROSS THE CENTRAL AND SOUTH. ECMWF
DEPICTION WOULD RESULT IN MUCH COOLER AND WETTER CONDITIONS ACROSS
THE AREA SUNDAY. EC AND GFS ENSEMBLE MEANS FAVOR SLOWER
PROGRESSION...MORE RESPECT FOR STRONG PLAINS RIDGE.
HOWEVER...EITHER WAY MUCH COLDER AIR WILL SPILL INTO THE AREA
SUNDAY NIGHT BEHIND THE FRONT WITH SNOW LEVELS EXPECTED TO BE
BETWEEN 5-6KFT BY MONDAY MORNING. THE NORTHERN THIRD OF THE AREA
STANDS THE BEST CHANCE FOR SOME ACCUMULATION MONDAY
MORNING...MAINLY ON VEGETATION WITH WET ROADS BELOW 6KFT. COOL AND
UNSETTLED NW FLOW WILL PREVAIL ON THE BACK SIDE OF THE TROUGH
LATTER IN THE DAY MONDAY WITH THE BETTER MOISTURE AND INSTABILITY
EXPECTED OVER THE NE HALF OF THE CWA. ZONAL FLOW WILL DEVELOP
BEHIND THIS TROUGH TUESDAY AND WEDNESDAY...BRINGING IN MILDER
PACIFIC AIRMASS ALONG WITH SOME OROGRAPHIC PRECIPITATION IN THE
WEST.

&&

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS WILL OCCUR TODAY WITH MAINLY SKC SKIES AND LIGHT
WINDS. AFTER 00Z...EXPECT INCREASING MID/HIGH LEVEL CLOUDINESS AND
STRENGTHENING MOUNTAIN TOP WINDS WITH POSSIBLY SOME LLWS ON THE LEE
SIDE OF MOUNTAIN RANGES ALONG THE CONTINENTAL DIVIDE DEVELOPING
AFTER 06Z. HOWEVER NOT ENOUGH CONFIDENCE OR MAGNITUDE TO INCLUDE AT
KCOD OR KLND AT THIS TIME. WEST SOUTHWEST WINDS WILL INCREASE FROM
KRKS TO KCPR BY 18Z THURSDAY.

&&

.FIRE WEATHER...

THE WIND AND THE RAIN WILL CLEAR OUT TODAY WITH COOL TEMPERATURES
REMAINING BEHIND THE FRONT THAT PASSED THROUGH YESTERDAY.
TEMPERATURES REBOUND A BIT ON THURSDAY AS HIGH PRESSURE BUILDS IN
FROM THE SOUTH BUT IT WILL BE ANOTHER BREEZY DAY IN SPOTS WITH
SOUTHWEST WINDS OF 15 TO 25 MPH COMMON BETWEEN ROCK SPRINGS AND
CASPER AND OVER THE HIGHER ELEVATIONS. SOUTHWEST FLOW RETURNS ON
FRIDAY WITH DRIER AND WARMER CONDITIONS REMAINING. THERE COULD BE A
FEW GUSTS OVER 25 MPH IN THE AFTERNOON BETWEEN RAWLINS AND SOUTHERN
CASPER DISPATCH BUT MOST AREAS WILL HAVE RELATIVELY LIGHT WINDS.

&&

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

$$

SHORT TERM...ALLEN
LONG TERM...AEM
AVIATION...WM/LIPSON
FIRE WEATHER...ALLEN














000
FXUS65 KRIW 220937
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
337 AM MDT WED OCT 22 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

A COOLER AIRMASS HANGING AROUND TODAY BEHIND THE COLD FRONT THAT
PASSED THROUGH OVERNIGHT WITH SOME MODERATION ON THURSDAY AND
FRIDAY. AFTER A RELATIVELY CALM DAY TODAY...THURSDAY IS EXPECTED TO
BE ANOTHER WINDY DAY AS A TUG OF WAR ENSUES BETWEEN THE COLD BUT
DYNAMIC TROUGH TO OUR NORTHWEST AND THE RIDGE POKING IN FROM THE
SOUTH. MODELS HAVE BEEN TRENDING FURTHER SOUTH WITH THE
STRENGTHENING JET TO OUR NORTHWEST ON THURSDAY...WHICH COULD
INTRODUCE STRONGER WINDS ACROSS THE NORTHERN MOUNTAINS AND A SLIGHT
CHANCE FOR PRECIPITATION. AS THE INFLUENCE OF THE RIGHT EXIT REGION
OF THE JET INTRUDES THURSDAY AFTERNOON THROUGH FRIDAY...THIS WILL
KICK UP THE MOUNTAIN WAVE POTENTIAL OVER THE ABSAROKAS...MAINTAINING
CONSISTENCY WITH THE DAY SHIFT FORECAST FOR SOME WIND GUSTS IN THE
WESTERN CODY FOOTHILLS AT 50 MPH FOR LATE THURSDAY OR THURSDAY NIGHT
INTO FRIDAY MORNING. ALSO BUMPED UP POPS A LITTLE FOR THE NORTHWEST
ON THURSDAY NIGHT AND FRIDAY AS A WAVE MOVES THROUGH. MOST OF THE
ACTION WILL REMAIN TO OUR WEST BUT THERE COULD BE A FEW SHOWERS
AROUND YELLOWSTONE AND THE TETONS. OTHERWISE WESTERN AND CENTRAL
WYOMING WILL BE DRY AND BREEZY THROUGH THE PERIOD WITH ABOVE NORMAL
TEMPERATURES.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
SYNOPSIS...UNSEASONABLY WARM AND BREEZY TO WINDY CONDITIONS WILL
PREVAIL ON SATURDAY WITH RECORD OR NEAR RECORD HIGHS POSSIBLE. A
COLD FRONT WILL PUSH ACROSS THE AREA SUNDAY AND SUNDAY NIGHT
SPREADING RAIN AND SNOW SHOWERS AND COLDER TEMPERATURES ACROSS THE
AREA INTO MONDAY. A WESTERLY FLOW WILL BRING MAINLY DRY AND
SEASONABLE MILD CONDITIONS ON TUESDAY AND WEDNESDAY.

DISCUSSION...COMPLEX VORTEX OVER THE GULF OF ALASKA THIS MORNING
WILL WOBBLE SE TO THE WEST COAST SATURDAY MORNING. MEDIUM RANGE
MODELS CONTINUE TO HANDLE THE INDIVIDUAL VORTICES WITHIN THIS
COMPLEX DIFFERENTLY...BUT AGREE THAT A VERY WARM SW FLOW WILL
PREVAIL OVER THE AREA SATURDAY BETWEEN THIS SYSTEM AND STRONG
DOWNSTREAM RIDGE OVER THE PLAINS. RECORD HIGH TERRITORY FOR THE
25TH IS GENERALLY 72-74F RANGE ACROSS CENTRAL WY FOR THE 25TH...A
BIT WARMER AT WRL AT 79F. FORECAST HIGHS ARE CURRENTLY NEAR OR
EXCEEDING THESE RECORDS.

ON THE 22/00Z GFS AND ECMWF RUNS...GFS CONTINUES TO EJECT LEAD
SHORTWAVE OUT OF BASE OF THE TROUGH NE INTO WESTERN MONTANA
SATURDAY NIGHT WHILE THE ECMWF SHOWS A MORE SPLIT
SYSTEM...SWINGING THIS SHORTWAVE FURTHER SOUTH ACROSS THE GREAT
BASIN SATURDAY NIGHT. GFS VERSION WOULD KEEP MOST OF THE
PRECIPITATION CONFINED TO THE WEST DURING THE DAY SUNDAY WITH
WINDY AND MILD CONDITIONS ACROSS THE CENTRAL AND SOUTH. ECMWF
DEPICTION WOULD RESULT IN MUCH COOLER AND WETTER CONDITIONS ACROSS
THE AREA SUNDAY. EC AND GFS ENSEMBLE MEANS FAVOR SLOWER
PROGRESSION...MORE RESPECT FOR STRONG PLAINS RIDGE.
HOWEVER...EITHER WAY MUCH COLDER AIR WILL SPILL INTO THE AREA
SUNDAY NIGHT BEHIND THE FRONT WITH SNOW LEVELS EXPECTED TO BE
BETWEEN 5-6KFT BY MONDAY MORNING. THE NORTHERN THIRD OF THE AREA
STANDS THE BEST CHANCE FOR SOME ACCUMULATION MONDAY
MORNING...MAINLY ON VEGETATION WITH WET ROADS BELOW 6KFT. COOL AND
UNSETTLED NW FLOW WILL PREVAIL ON THE BACK SIDE OF THE TROUGH
LATTER IN THE DAY MONDAY WITH THE BETTER MOISTURE AND INSTABILITY
EXPECTED OVER THE NE HALF OF THE CWA. ZONAL FLOW WILL DEVELOP
BEHIND THIS TROUGH TUESDAY AND WEDNESDAY...BRINGING IN MILDER
PACIFIC AIRMASS ALONG WITH SOME OROGRAPHIC PRECIPITATION IN THE
WEST.

&&

.AVIATION.../12Z ISSUANCE/

LOW CLOUDS /020-050 KFT AGL/ AND POSSIBLY SOME PATCHY FOG ACROSS
NORTHWEST WYOMING /NW OF A KAFO-KPNA-30W KCOD LINE/ THIS MORNING
WILL BE THE MAIN AVIATION HAZARD FOR THIS SET OF TAFS. THIS WOULD
PRIMARILY IMPACT THE KJAC TERMINAL...WITH CEILINGS AT KJAC PROBABLY
HIGH MVFR TO LOW VFR. FOG CHANCES AT KJAC WILL BE SLIM DUE TO THE
AFOREMENTIONED STRATCU DECK. THIS FOG/LOW CLOUDS ACROSS THE
NORTHWEST ARE EXPECTED TO ERODE BY AROUND 18Z. OTHERWISE...VFR
CONDITIONS WILL OCCUR TODAY WITH MAINLY SKC SKIES AND LIGHT WINDS.
AFTER 00Z...EXPECT INCREASING MID/HIGH LEVEL CLOUDINESS AND
STRENGTHENING MOUNTAIN TOP WINDS WITH POSSIBLY SOME LLWS ON THE LEE
SIDE OF MOUNTAIN RANGES ALONG THE CONTINENTAL DIVIDE DEVELOPING
AFTER 06Z. HOWEVER NOT ENOUGH CONFIDENCE OR MAGNITUDE TO INCLUDE AT
KCOD OR KLND AT THIS TIME.

&&

.FIRE WEATHER...

THE WIND AND THE RAIN WILL CLEAR OUT TODAY WITH COOL TEMPERATURES
REMAINING BEHIND THE FRONT THAT PASSED THROUGH YESTERDAY.
TEMPERATURES REBOUND A BIT ON THURSDAY AS HIGH PRESSURE BUILDS IN
FROM THE SOUTH BUT IT WILL BE ANOTHER BREEZY DAY IN SPOTS WITH
SOUTHWEST WINDS OF 15 TO 25 MPH COMMON BETWEEN ROCK SPRINGS AND
CASPER AND OVER THE HIGHER ELEVATIONS. SOUTHWEST FLOW RETURNS ON
FRIDAY WITH DRIER AND WARMER CONDITIONS REMAINING. THERE COULD BE A
FEW GUSTS OVER 25 MPH IN THE AFTERNOON BETWEEN RAWLINS AND SOUTHERN
CASPER DISPATCH BUT MOST AREAS WILL HAVE RELATIVELY LIGHT WINDS.

&&

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

$$

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











000
FXUS65 KRIW 220937
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
337 AM MDT WED OCT 22 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT

A COOLER AIRMASS HANGING AROUND TODAY BEHIND THE COLD FRONT THAT
PASSED THROUGH OVERNIGHT WITH SOME MODERATION ON THURSDAY AND
FRIDAY. AFTER A RELATIVELY CALM DAY TODAY...THURSDAY IS EXPECTED TO
BE ANOTHER WINDY DAY AS A TUG OF WAR ENSUES BETWEEN THE COLD BUT
DYNAMIC TROUGH TO OUR NORTHWEST AND THE RIDGE POKING IN FROM THE
SOUTH. MODELS HAVE BEEN TRENDING FURTHER SOUTH WITH THE
STRENGTHENING JET TO OUR NORTHWEST ON THURSDAY...WHICH COULD
INTRODUCE STRONGER WINDS ACROSS THE NORTHERN MOUNTAINS AND A SLIGHT
CHANCE FOR PRECIPITATION. AS THE INFLUENCE OF THE RIGHT EXIT REGION
OF THE JET INTRUDES THURSDAY AFTERNOON THROUGH FRIDAY...THIS WILL
KICK UP THE MOUNTAIN WAVE POTENTIAL OVER THE ABSAROKAS...MAINTAINING
CONSISTENCY WITH THE DAY SHIFT FORECAST FOR SOME WIND GUSTS IN THE
WESTERN CODY FOOTHILLS AT 50 MPH FOR LATE THURSDAY OR THURSDAY NIGHT
INTO FRIDAY MORNING. ALSO BUMPED UP POPS A LITTLE FOR THE NORTHWEST
ON THURSDAY NIGHT AND FRIDAY AS A WAVE MOVES THROUGH. MOST OF THE
ACTION WILL REMAIN TO OUR WEST BUT THERE COULD BE A FEW SHOWERS
AROUND YELLOWSTONE AND THE TETONS. OTHERWISE WESTERN AND CENTRAL
WYOMING WILL BE DRY AND BREEZY THROUGH THE PERIOD WITH ABOVE NORMAL
TEMPERATURES.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
SYNOPSIS...UNSEASONABLY WARM AND BREEZY TO WINDY CONDITIONS WILL
PREVAIL ON SATURDAY WITH RECORD OR NEAR RECORD HIGHS POSSIBLE. A
COLD FRONT WILL PUSH ACROSS THE AREA SUNDAY AND SUNDAY NIGHT
SPREADING RAIN AND SNOW SHOWERS AND COLDER TEMPERATURES ACROSS THE
AREA INTO MONDAY. A WESTERLY FLOW WILL BRING MAINLY DRY AND
SEASONABLE MILD CONDITIONS ON TUESDAY AND WEDNESDAY.

DISCUSSION...COMPLEX VORTEX OVER THE GULF OF ALASKA THIS MORNING
WILL WOBBLE SE TO THE WEST COAST SATURDAY MORNING. MEDIUM RANGE
MODELS CONTINUE TO HANDLE THE INDIVIDUAL VORTICES WITHIN THIS
COMPLEX DIFFERENTLY...BUT AGREE THAT A VERY WARM SW FLOW WILL
PREVAIL OVER THE AREA SATURDAY BETWEEN THIS SYSTEM AND STRONG
DOWNSTREAM RIDGE OVER THE PLAINS. RECORD HIGH TERRITORY FOR THE
25TH IS GENERALLY 72-74F RANGE ACROSS CENTRAL WY FOR THE 25TH...A
BIT WARMER AT WRL AT 79F. FORECAST HIGHS ARE CURRENTLY NEAR OR
EXCEEDING THESE RECORDS.

ON THE 22/00Z GFS AND ECMWF RUNS...GFS CONTINUES TO EJECT LEAD
SHORTWAVE OUT OF BASE OF THE TROUGH NE INTO WESTERN MONTANA
SATURDAY NIGHT WHILE THE ECMWF SHOWS A MORE SPLIT
SYSTEM...SWINGING THIS SHORTWAVE FURTHER SOUTH ACROSS THE GREAT
BASIN SATURDAY NIGHT. GFS VERSION WOULD KEEP MOST OF THE
PRECIPITATION CONFINED TO THE WEST DURING THE DAY SUNDAY WITH
WINDY AND MILD CONDITIONS ACROSS THE CENTRAL AND SOUTH. ECMWF
DEPICTION WOULD RESULT IN MUCH COOLER AND WETTER CONDITIONS ACROSS
THE AREA SUNDAY. EC AND GFS ENSEMBLE MEANS FAVOR SLOWER
PROGRESSION...MORE RESPECT FOR STRONG PLAINS RIDGE.
HOWEVER...EITHER WAY MUCH COLDER AIR WILL SPILL INTO THE AREA
SUNDAY NIGHT BEHIND THE FRONT WITH SNOW LEVELS EXPECTED TO BE
BETWEEN 5-6KFT BY MONDAY MORNING. THE NORTHERN THIRD OF THE AREA
STANDS THE BEST CHANCE FOR SOME ACCUMULATION MONDAY
MORNING...MAINLY ON VEGETATION WITH WET ROADS BELOW 6KFT. COOL AND
UNSETTLED NW FLOW WILL PREVAIL ON THE BACK SIDE OF THE TROUGH
LATTER IN THE DAY MONDAY WITH THE BETTER MOISTURE AND INSTABILITY
EXPECTED OVER THE NE HALF OF THE CWA. ZONAL FLOW WILL DEVELOP
BEHIND THIS TROUGH TUESDAY AND WEDNESDAY...BRINGING IN MILDER
PACIFIC AIRMASS ALONG WITH SOME OROGRAPHIC PRECIPITATION IN THE
WEST.

&&

.AVIATION.../12Z ISSUANCE/

LOW CLOUDS /020-050 KFT AGL/ AND POSSIBLY SOME PATCHY FOG ACROSS
NORTHWEST WYOMING /NW OF A KAFO-KPNA-30W KCOD LINE/ THIS MORNING
WILL BE THE MAIN AVIATION HAZARD FOR THIS SET OF TAFS. THIS WOULD
PRIMARILY IMPACT THE KJAC TERMINAL...WITH CEILINGS AT KJAC PROBABLY
HIGH MVFR TO LOW VFR. FOG CHANCES AT KJAC WILL BE SLIM DUE TO THE
AFOREMENTIONED STRATCU DECK. THIS FOG/LOW CLOUDS ACROSS THE
NORTHWEST ARE EXPECTED TO ERODE BY AROUND 18Z. OTHERWISE...VFR
CONDITIONS WILL OCCUR TODAY WITH MAINLY SKC SKIES AND LIGHT WINDS.
AFTER 00Z...EXPECT INCREASING MID/HIGH LEVEL CLOUDINESS AND
STRENGTHENING MOUNTAIN TOP WINDS WITH POSSIBLY SOME LLWS ON THE LEE
SIDE OF MOUNTAIN RANGES ALONG THE CONTINENTAL DIVIDE DEVELOPING
AFTER 06Z. HOWEVER NOT ENOUGH CONFIDENCE OR MAGNITUDE TO INCLUDE AT
KCOD OR KLND AT THIS TIME.

&&

.FIRE WEATHER...

THE WIND AND THE RAIN WILL CLEAR OUT TODAY WITH COOL TEMPERATURES
REMAINING BEHIND THE FRONT THAT PASSED THROUGH YESTERDAY.
TEMPERATURES REBOUND A BIT ON THURSDAY AS HIGH PRESSURE BUILDS IN
FROM THE SOUTH BUT IT WILL BE ANOTHER BREEZY DAY IN SPOTS WITH
SOUTHWEST WINDS OF 15 TO 25 MPH COMMON BETWEEN ROCK SPRINGS AND
CASPER AND OVER THE HIGHER ELEVATIONS. SOUTHWEST FLOW RETURNS ON
FRIDAY WITH DRIER AND WARMER CONDITIONS REMAINING. THERE COULD BE A
FEW GUSTS OVER 25 MPH IN THE AFTERNOON BETWEEN RAWLINS AND SOUTHERN
CASPER DISPATCH BUT MOST AREAS WILL HAVE RELATIVELY LIGHT WINDS.

&&

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

$$

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











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