647
FXUS65 KRIW 150448
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
948 PM MST Fri Nov 14 2025

.KEY MESSAGES...

- Winds will remain strong with gusts of 50 to 70 mph over the
  east side of the Absaroka, Wind River and Bighorn Mountains
  through the overnight hours tonight.

- Light convective snow showers continue across the northwestern
  mountains this evening with snow levels generally at or above
  9,000 feet. This activity is expected to end before midnight.

- It remains warm Saturday, with high temperatures 10 to 15
  degrees above normal.

- There will be a transition into a cooler and more active
  pattern starting Sunday and continuing into next week.

&&

.UPDATE...
Issued at 1036 AM MST Fri Nov 14 2025

Light rain and mountain snow showers will persist across the
northwest through the evening. Snow levels generally remain above
9000 feet, with rain showers across the valleys. Precipitation will
be convective in nature, and there have even been a lightning strike
or two observed earlier this morning near the Beartooths. Brief
heavier snow showers across the higher peaks and mountain passes are
the main concern today and tonight. Snow accumulations above
9,000 feet will generally be minimal, only 1 to 3 inches.

Wind is the other concern over the next 12 hours, as this shortwave
pushes through. Gusts 35 to 45 mph will continue through much of the
day and into the evening along the Absarokas and from South Pass to
Casper. Isolated stronger gusts 50 to 60 mph are possible across
favored locations including Chief Joseph Hwy and the Clark area
(north of Cody) as well as Fales Rock and Casper Outer Drive (Hwy
258). Winds will gradually decrease after around 9-10PM this
evening, and will continue to decrease through the night.

The forecast remains on track for the next weather system moving in
for Sunday night. This will kick off a cooler and more active
weather pattern that looks to continue through much of next week.

&&

.DISCUSSION...
Issued at 251 AM MST Fri Nov 14 2025

More active weather has finally returned to the area after a long
lull. And, we have two concerns today, nothing earth shattering, but
something to talk about. That is why we write these discussions of
course. An approaching Pacific trough is the cause of this.

The first concern is snow. Radar shows some echoes over Idaho and
these will spread into western Wyoming this morning, although the
steadiest precipitation would be during the afternoon and early
evening. The best forcing looks to remain to the north, and as a
result so will the best snow. This will only be a concern for the
northwestern mountains. And, the chance of 3 inches or greater is at
most 1 out of 3 and this is in the Absarokas where impacts would be
slim to none. There is little no cold air with this system as well,
with 700 millibar temperatures only falling to minus 1C, which
would keep snow levels to 8000 feet or higher. So, no highlights
will be needed. Downsloping flow should keep areas east of the
Divide largely dry though. But this leads into the second and
possibly greater concern.

And this concern is strong wind. We did give some thought to a
High Wind Warning for Natrona County today. The 700 millibar
winds have increased to around 50 knots at times. There will
also be an 110 knot jet moving across northern Wyoming, with
that region in the favored right front quadrant of it. It is a
bit too far north though for ideal forcing. As for the
ensembles, the National Blend of Models only gives around a 1 in
4 chance of wind gusts past 55 mph along the south side of
Casper, which is the main region of concern in regards to
impacts. Criteria is also higher here, needing gusts to 65 mph.
With this, we have decided to not issue. There could be an
isolated gust of 60 or 65 mph, but at this point this seems to
be the exception. The time of greatest concern may be this
morning, with gradually improving conditions later this
afternoon. The downsloping flow will also bring another
unusually warm day, with temperatures 20 degrees above normal.
Some locations, like Casper, could make a run at 70 with most
lower elevations east of the Divide having at least a 3 out of
4 chance of high temperatures over 60.

Ridging then builds back over the area for Saturday, bringing a
dry day. Temperatures will be somewhat cooler, but still well
above normal for this time of year. The next weather maker in
the form of an upper level low moving northeastward from
California will bring the next chance of showers, this one more
widespread than the system today. There is somewhat better
agreement today with the highest amounts of precipitation across
northern Wyoming, with wrap around moisture from a low
developing in the Lee of the Rockies. Amounts don`t look
excessive at this time though. Temperatures will be cooler with
this system, but 700 millibar temperatures generally remain
above minus 4C through the period, so again it looks like
mainly rain for the lower elevations. There are still
differences in timing of the heaviest precipitation though,
spanning anywhere from later Sunday night through Monday
evening. We will likely then see more typical November weather,
with near normal temperatures and a few chances of rain and
snow, although details are still fuzzy this far out.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 945 PM MST Fri Nov 14 2025

Partial mountain obscurations will continue over the
western mountains through 12Z and continue over portions of
Yellowstone and the north end of the Tetons through 18Z.
Otherwise, VFR flight conditions, FEW-BKN FL200-250, will be
common across the forecast area through the TAF period. Winds
will remain strong with gusts of 45 to 55 kt over the
Absaroka, Wind River and Bighorn Mountains through 18Z before
finally decreasing through the rest of the afternoon. LLWS is
not expected at any nearby terminal.

Precipitation over northwestern portions will continue to wane
and is expected to end by the start of the forecast. Winds will
remain light (10 kt or less) for most terminals through 18Z.
KCPR and KJAC will have sustained winds up to 13 kt through much
of this time frame. The light winds will also continue for most
terminals through the period, with a mainly west-southwest
direction. KCPR will be the exception to the light winds, with
gusts up to 30 kt returning by 18Z and continuing through 00Z.

High clouds will increase from the south toward the end of the
TAF period, with skies becoming BKN-OVC. Chances for
precipitation become possible for terminals west of the Divide
toward 06Z Sunday.

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...
None.

&&

$$

UPDATE...Hensley
DISCUSSION...Hattings
AVIATION...LaVoie