154
FXUS65 KRIW 101756
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1056 AM MST Wed Dec 10 2025

.KEY MESSAGES...

- Snowfall across the western mountains begins to taper off by
  this afternoon, adding a final 3 to 6 inches accumulation to
  the higher elevations.

- Strong and gusty winds will continue across southern WY
  through this afternoon, with some gusts near 60 mph still
  possible. High Wind Warnings remain in effect through tonight.

- Near record highs continue east of the Divide the rest of the
  week into the upcoming weekend, with highs holding in the 40s
  and 50s.

&&

.DISCUSSION...
Issued at 218 AM MST Wed Dec 10 2025

The broad ridge across the western US continues to impact the
overall lack of any semblance of a winter season so far across
Wyoming, and does not look to improve this outlook for at least
the next week. The current tap of moisture off the Pacific has
been able to produce snowfall for the western mountains, but the
warm lower valley temps keeps any precip as rainfall. A passing
wave to the north will continue produce another 3 to 6 inches
of snowfall for the western mountains, but the western ridge
will build slightly this afternoon, pushing the moisture tap
farther north, ending precip by this evening. The passing wave
and cold front will keep the local gradient tight, resulting in
strong and gusty winds across southern WY. A High Wind Warning
remains in effect as gusts could still reach 60mph, but the
frequency could be lower this afternoon. Temperatures remain
particularly warm, with highs in the 40s and 50s for lower
elevations, running about 5 degrees under record levels.

Another cold front passes by to the north in Montana Thursday
through Saturday. The moisture and energy will just clip far
northern WY Thursday night into Friday morning, bringing another
quick round of snowfall to the YNP, the Absarokas and the
Bighorns, with minimal to no snowfall expected from the Tetons
southward. The only other area of concern would be northern
Johnson County, which could get a brief push of colder
temperatures Friday, and some brief snowfall and gusty northwest
winds could bring brief travel hazards Friday night along I-90.

For the remainder of the region, the ridge will keep the warm
temperatures in place through the weekend, with highs stuck in
the 40s and 50s. This is troublesome for anyone that actually
wants winter to arrive, especially local outdoor hockey teams
that still don`t have hockey rinks for practice!

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1055 AM MST Wed Dec 10 2025

MVFR flight conditions and light rain/snow at KJAC should begin to
improve to VFR around 20Z as winds begin to pick up. Confidence in
MVFR ceilings this afternoon is 20%-30% at KJAC, KRKS, KBPI, and
KPNA so a SCT030 or SCT035 has been added to reflect this potential.
Any low cloud/MVFR ceiling potential is forecast to end between 23Z-
02Z, with high confidence (90%+) in VFR flight conditions persisting
the remainder of the TAF period.

Gusty winds are expected at all West of the Divide terminals (KJAC,
KRKS, KBPI, KPNA), KCPR, and KCOD this TAF period. Gusty winds at
KBPI and KPNA begin to diminish between 00Z-01Z, with winds at all
other aforementioned terminals remaining gusty the entire TAF
period. However, there is a 20% chance in gusts diminishing
after 08Z at KCOD, but given confidence is low in this occurring,
opted to keep persistent gusts in TAF at this time. Winds
remain around or less than 12 kts at KRIW, KLND, and KWRL but
an occasional gust around 20kts is not out of question (30%
chance).

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for
the latest information on icing and turbulence forecasts.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 5 PM MST this afternoon for WYZ001-
002-012.

Winter Weather Advisory until 5 PM MST this afternoon for
WYZ008-014-015-024.

High Wind Warning until 5 AM MST Thursday for WYZ019-020-022-
027>030.

&&

$$

DISCUSSION...Straub
AVIATION...Gerhardt