647
FXUS65 KRIW 172200
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
300 PM MST SUN NOV 17 2024
KEY MESSAGES
- GUSTY WINDS CONTINUE ACROSS CENTRAL WY TODAY AHEAD OF THE NEXT
SYSTEM. GUSTS ACROSS NATRONA WILL CONTINUE TO REACH 40 MPH
THROUGH THE REST OF THE AFTERNOON.
- THE NEXT BROAD WEATHER SYSTEM SWEEPS ACROSS THE STATE ON
MONDAY, BRINGING ANOTHER ROUND OF SNOW MAINLY TO THE HIGHER
ELEVATIONS OF WESTERN AND NORTHERN WY.
- ANOTHER COLD DAY TUESDAY BEHIND THE SYSTEM, BUT THE COLDEST
AIR WILL BE LIMITED TO AREAS WEST OF THE DIVIDE.
DISCUSSION
ISSUED AT 115 PM MST SUN NOV 17 2024
WINDS CONTINUE TO RACE ACROSS PARTS OF THE STATE AGAIN TODAY
AHEAD OF THE APPROACHING WINTER SYSTEM. WINDS AT KCPR CONTINUE
TO GUST 40 TO 50, WHILE AREAS JUST OFF THE WESTERN MOUNTAINS
(KCOD/KDUB) CONTINUE TO GUST 30 TO 35. WINDS WILL DECOUPLE SOME
THIS EVENING, BUT SOME BREEZY SOUTHWEST FLOW WILL CONTINUE
OVERNIGHT, MAINLY ACROSS THE KCPR REGION.
THE NEXT TROUGH IS MOVING ACROSS IDAHO RIGHT NOW, AND WILL START
TO IMPACT THE WESTERN MOUNTAINS AROUND SUNSET. MIDLEVEL FLOW IS
IN GOOD ALIGNMENT FOR UPSLOPE SNOW PRODUCTION FOR THE WESTERN
MOUNTAINS TONIGHT AND MONDAY. MOISTURE IS NOT ABUNDANT WITH THIS
SYSTEM, AND THE SPEED IS FAIRLY QUICK, SO SNOWFALL AMOUNTS WILL
BE LIMITED AND FOCUSED ON THE HIGHER ELEVATIONS. OVERALL SNOW
FORECAST FOR THE WESTERN MOUNTAINS HAS REMAINED CONSISTENT WITH
THE PREVIOUS FORECAST, WITH 10 TO 14 INCHES FOR THE TETONS AND
WESTERN YNP, WITH THE REST OF THE PARK, THE GROS VENTRES, SALTS
AND WYOMINGS STILL AT 4 TO 8 INCHES. HIGHLIGHTS REMAIN FOCUSED
ON THE WESTERN MOUNTAINS, WITH WARNING FOR THE TETONS AND
ADVISORIES FOR YNP/SALTS/WYOMINGS. AS THE TROUGH PIVOTS TO THE
NORTHEAST MONDAY NIGHT, STEERING FLOW TURNS MORE FROM THE
NORTHWEST. THIS WILL PUSH A COLDER AIRMASS BACK ACROSS THE
STATE BY TUESDAY MORNING, WITH MOST AREAS BACK TO NEAR NORMAL
TEMPERATURES IN THE 20S AND 30S. THIS FLOW ALSO PUTS THE
SOUTHER BIGHORN RANGE IN A BETTER ALIGNMENT FOR OROGRAPHIC SNOW
PRODUCTION. BUT AGAIN, THE MOISTURE REMAINS LIMITED, SO
ACCUMULATIONS REMAIN IN THE 3 TO 6 INCH RANGE BY MIDDAY
TUESDAY.
THIS COLDER AIRMASS WILL ALSO BE A BRIEF PUSH, AS H5 RIDGING
BUILDS BACK ACROSS THE ROCKIES FOR THE LATTER HALF OF THE WEEK.
THIS WILL BRING TEMPERATURES BACK ABOVE NORMAL AGAIN, WITH MOST
AREAS SEEING HIGHS IN THE 40S AND LOW 50S THROUGH SATURDAY.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 300 PM MST SUN NOV 17 2024
WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS TERMINALS
LIGHT SNOW STEADILY INCREASES OVER THE WESTERN MOUNTAINS SUNDAY
EVENING AND EVENTUALLY SPREAD INTO THE VALLEYS BEFORE 06Z/MONDAY.
KJAC SEES MVFR SNOW DEVELOP BETWEEN 05Z-07Z/MONDAY. MOISTURE
DEEPENS BY EARLY MONDAY MORNING ACROSS WESTERN WYOMING AS A
SHORTWAVE TROUGH APPROACHES THE REGION. CAMS STILL INDICATING AN
ENHANCED BAND OF SNOW MOVING FIRST ACROSS KJAC 08Z-12Z/MONDAY
BEFORE PUSHING SOUTHEAST THROUGH KBPI/KPNA, AND ON TO KRKS
BETWEEN 13Z-16Z/MONDAY. THE BEST CHANCE FOR IFR IS AT KJAC WITH
THIS BAND, BUT KPNA AND POTENTIALLY KRKS COULD EACH SEE A ONE-
TO TWO-HOUR PERIOD OF IFR. TEMPO GROUP HAS BEEN ADDED AT KPNA
FOR THIS ENHANCED BAND. OROGRAPHIC MVFR SNOW CONTINUES THROUGH
AT LEAST MIDDAY AT KJAC, WHILE OTHER WESTERN TERMINALS SEE
CONDITIONS GRADUALLY RETURN TO VFR BY EARLY AFTERNOON. GUSTY
SOUTHWEST SURFACE WIND BEGINS LATE MONDAY MORNING AT KJAC, WHILE
OTHER TERMINALS FIND WESTERLY WIND INCREASE TO 20-30KTS EARLY
MONDAY AFTERNOON BEHIND PASSAGE OF THE SHORTWAVE. MOUNTAIN TOPS
OBSCURED AFTER 03Z/MONDAY.
EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL TERMINALS
TERMINALS TO REMAIN VFR THROUGH MIDDAY MONDAY AHEAD OF AN
APPROACHING SHORTWAVE TROUGH. THE PRIMARY HAZARD UNTIL THAT TIME
WILL BE SOUTHWEST SURFACE WIND 15-30KTS THROUGH SUNDAY EVENING AT
KCPR AND KCOD. THE WIND SUBSIDES BETWEEN 03Z-06Z/MONDAY AT KCOD, BUT
A FAVORABLE PRESSURE GRADIENT ALLOWS FOR GUSTY WIND TO CONTINUE
OVERNIGHT AT KCPR ALONG WITH A LAYER OF WIND SHEAR IN THE LOWEST
1,500 FT AGL. A COLD FRONT SLIPS THROUGH KCOD AND KWRL BETWEEN 16Z-
20Z/MONDAY WITH NORTHERLY WIND AND SCATTERED SNOW SHOWERS
DEVELOPING DURING THAT TIME. KCOD AND KWRL EACH HAVE A 40-60
PERCENT CHANCE OF MVFR CONDITIONS AFTER 21Z/MONDAY, AND HAVE
TRENDED TOWARD PREVAILING LOW-END VFR OR PROB30 IN LIGHT SNOW AT
BOTH TERMINALS. AHEAD OF THE FRONT, GUSTY WESTERLY WIND
INCREASES FIRST AT KCPR BY MID-MORNING AND EVENTUALLY AT KRIW
AND KLND AROUND 20Z/MONDAY BEHIND PASSAGE OF THE SHORTWAVE.
INSTABILITY FAVORS WIDELY SCATTERED LATE DAY SNOW SHOWERS OVER
CENTRAL WYOMING, BUT IMPACTS AT SPECIFIC TERMINALS WOULD BE
SHORT-LIVED. MOUNTAIN TOPS FREQUENTLY OBSCURED AFTER 20Z/MONDAY.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND ZLC FOR
THE LATEST INFORMATION ON SMOKE, ICING, AND TURBULENCE FORECASTS.
RIW WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 PM MST
MONDAY FOR WYZ001-024.
WINTER STORM WARNING FROM 10 PM THIS EVENING TO 10 PM MST
MONDAY FOR WYZ012.
DISCUSSION...STRAUB
AVIATION...CNJ
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