066
FXUS65 KRIW 150216
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
716 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
  and the Wind Corridor 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 /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 424 PM MST Fri Nov 14 2025

VFR flight conditions are forecast throughout the TAF period. Winds
are forecast to remain elevated with gusts between 20-25kts through
02Z at KCOD and through 06Z at KCPR. Winds at both terminals
decrease to around 10kts before increasing again after 13Z at KCOD
and after 18Z at KCPR. With strong winds aloft over the western
mountains, LLWS remains possible at KCOD through 05Z. Winds at all
other terminals are forecast to be around or less than 10kts the
entire TAF period.

Light rain chances (30%) remain possible at KJAC between 01Z-05Z and
these chances are reflected in a PROB30 group. There is a 20%
chance in light rain through 02Z at KCOD, but given the low chances there is
no mention in the TAF at this time. Chances in MVFR ceilings is
around 10% at KJAC with any light rain and around 20% at KPNA
after 08Z. Given these low chances, the potential for MVFR
ceilings is reflected as a SCT030 group. Occasional mountain
obscuration is possible for the western mountains through the
overnight hours.

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...Gerhardt