904
FXUS65 KRIW 161730
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1030 AM MST SAT NOV 16 2024
KEY MESSAGES
- SNOW CHANCE COMING TO AN END TODAY FOR MOST PLACES.
- THERE IS A CHANCE (30%) FOR SOUTH PASS TO SEE HEAVY SNOW THIS AFTERNOON
IN THE FORM OF A SNOW SHOWER OR SNOW BAND.
- NEXT WEATHER SYSTEM ARRIVES LATE SUNDAY, WITH SNOW CHANCES AND WIND
THROUGH MONDAY.
- THE LATTER HALF OF NEXT WEEK FAVORS DRY CONDITIONS AND WARM TEMPERATURES.
DISCUSSION
ISSUED AT 124 AM MST SAT NOV 16 2024
WE ARE AT THE TAIL END OF A WEAK WINTER WEATHER SYSTEM THAT HAS
BROUGHT SNOW TO WESTERN AND NORTHERN WYOMING, AS WELL AS SOME GUSTY
WINDS. SNOW WILL BE ON A DECREASING TREND THROUGH THE MORNING. A
MAJORITY OF THE SNOW SHOULD HAVE FALLEN BY ABOUT SUNRISE THIS
MORNING. MOST PEOPLE IN THE LOWER ELEVATIONS SEE ONLY A DUSTING OR
SO OF ADDITIONAL SNOW THROUGH THIS MORNING, MAINLY THOSE IN WESTERN
OR NORTHERN WYOMING LOCATIONS. MOUNTAINS MAY PICK UP A BIT MORE, BUT
OVERALL NOT MORE THAN FEW INCHES MOST PLACES. SNOW LINGERS LONGEST
OVER THE WESTERN MOUNTAINS, WITH LIGHT SNOW SHOWERS CONTINUING INTO
THIS EVENING. WINDS ARE NOT MUCH OF A CONCERN TODAY. BREEZY 20 TO 25
MPH WINDS OCCUR OVER NATRONA AND JOHNSON COUNTIES AS THE SYSTEM
TRACKS EAST. NEAR ROCK SPRINGS MAY ALSO SEE AROUND 20 MPH WINDS FROM
THE WEST. THESE WINDS DECREASE THIS EVENING.
SOUTH PASS WILL BE A PLACE TO WATCH THIS AFTERNOON. HIGH-RESOLUTION
MODELS (ESPECIALLY THE HRRR) ARE HINTING AT AT THE POTENTIAL FOR
SOME STRONGER SNOW SHOWERS, OR POSSIBLE SNOW BANDING, THIS
AFTERNOON, ROUGHLY BETWEEN 19Z AND 23Z (12PM-4PM MST). MODEL
SOUNDING DATA OVER THE SOUTH PASS AREA WOULD SUPPORT THE POTENTIAL
FOR MODERATE TO HEAVY SNOW, WITH NON-ZERO VALUES OF INSTABILITY, AS
WELL AS A NORTHWEST FLOW ALOFT (A FAVORED DIRECTION FOR SNOW BANDING
OFF THE SOUTHERN END OF THE WIND RIVER RANGE). SHOULD A HEAVY SNOW
SHOWER OR SNOW BAND FORM, A QUICK 1 TO 6 INCHES IS POSSIBLE OVER A
PORTION OF THE PASS. DETERMINING EXACTLY WHERE A SHOWER MAY OCCUR IS
VERY DIFFICULT, BUT ANYTHING OFF THE MOUNTAINS WOULD IMPACT SOUTH
PASS. GIVEN MODEL DISAGREEMENT AND MARGINAL CRITERIA IN THE MODELS,
WOULD GIVE A WORST CASE SCENARIO (4 OR MORE INCHES IN A SHORT TIME)
ABOUT A 30% CHANCE.
THE OVERALL PATTERN REMAINS ACTIVE INTO TOMORROW (SUNDAY). A BROAD
TROUGH TO THE WEST KEEPS MOISTURE ADVECTION INTO THE WESTERN
MOUNTAINS AND YELLOWSTONE. AS A RESULT, SNOW CHANCES OF 15% TO 40%
CONTINUE TONIGHT AND THROUGH THE DAY SUNDAY. OVERALL ACCUMULATIONS
THROUGH SUNDAY ARE MINIMAL, WITH MAYBE AN INCH OR SO AT THE HIGHER
PEAKS. A STRONGER PIECE OF THE JET ALSO PASSES OVER. THIS WILL BRING
GUSTY WINDS TO THE MOUNTAINS. GUSTS UP TO 50 MPH SEEM LIKELY FOR THE
CENTRAL MOUNTAINS (WIND RIVER AND ABSAROKA RANGES). WILL HAVE TO
WATCH MODEL TRENDS FOR THE AREA BETWEEN CODY AND CLARK FOR STRONGER
WINDS MAKING IT TO THE LOWER ELEVATIONS FROM THE ABSAROKAS. THE WIND
CORRIDOR FROM SOUTH PASS TO CASPER ALSO SEE GUSTY SOUTHWEST WINDS.
THE TROUGH MOVES INTO THE AREA LATE SUNDAY INTO MONDAY.
PRECIPITATION CHANCES WILL BE ON AN INCREASING TREND FROM THE WEST
AS A RESULT. CHANCES SPILL EAST OF THE CONTINENTAL DIVIDE DURING THE
DAY MONDAY. OVERALL, THIS SYSTEM LOOKS TO MOVE THROUGH RELATIVELY
QUICK AND DOESN'T PRODUCE AN ABUNDANCE OF SNOW FOR MOST OF THE
POPULATED AREAS. THE WESTERN MOUNTAINS (MAINLY TETONS AND SOUTHWEST
YELLOWSTONE) ARE MOST FAVORED FOR SNOW. CURRENT MODEL RUNS SHOW
ADVISORY-WORTHY AMOUNTS, BUT CONFIDENCE IS TOO LOW AT THIS RANGE OUT
FOR ANY HIGHLIGHTS. MONDAY ALSO LOOKS TO BE A BREEZY TO WINDY DAY
ACROSS THE AREA.
AFTER PRECIPITATION ENDS THROUGH THE DAY TUESDAY, LONG RANGE MODELS
ARE SHOWING A BRIEF PERIOD OF RIDGING OVER THE AREA FOR THE LATTER
HALF OF NEXT WEEK. THIS WOULD FAVOR LOW, TO NO, PRECIPITATION
CHANCES, AS WELL AS WARMER TEMPERATURES. THERE IS POTENTIAL FOR
ANOTHER SYSTEM NEXT WEEKEND, THOUGH CONFIDENCE IS VERY LOW AT THIS
TIME.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1026 AM MST SAT NOV 16 2024
STILL HAVE SOME -SN MEANDERING AROUND KCOD/KWRL/KLND/KRIW/KJAC
CURRENTLY, BUT MOST OF THESE SHOULD BE ENDING WITHING THE NEXT
COUPLE HOURS. MIDLEVEL CLOUDS WILL CONTINUE THROUGH THE REST OF
THE DAY, BUT SHOULD BE ABOVE VFR RULES THROUGH TOMORROW. CLOUD
COVER WILL BE MORE DENSE AROUND MOUNTAINS, SO CONSIDERABLE
MOUNTAIN OBSCURATION WILL CONTINUE THROUGH THE NIGHT TONIGHT.
LIGHTER NORTHWEST WINDS CONTINUE FOR ALL EXCEPT KCPR, WITH SEES
SOME GUSTS NEAR 20KTS THIS AFTERNOON. WINDS WILL AGAIN RAMP UP
TOMORROW FROM THE SOUTHWEST FOR THE KCPR/KCOD/KRKS, AND MAY
EDGE INTO KLND BRIEFLY IN THE AFTERNOON.
RIW WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...WITTMANN
AVIATION...STRAUB
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