945
FXUS65 KRIW 130436
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
936 PM MST Wed Nov 12 2025

.KEY MESSAGES...

- Warmer than average temperatures (5 to 15 degrees) and dry
  conditions Thursday.

- Increasing precipitation chances west of the Divide Friday and
  into the weekend.

- Seasonable temperatures and wetter conditions next week with
  multiple weather systems.

&&

.UPDATE...
Issued at 1130 AM MST Wed Nov 12 2025

No major changes with this update, with mild temperatures and dry
conditions today. Clouds continue to increase through the day, and
then slowly clear overnight and into Thursday morning.

Snow over the western mountains continues to trend down for the
Friday/Saturday weather system. Wind ahead of the system (on Friday)
picks up, with widespread gusts over 20 mph, with many of the more
wind-prone areas (like South Pass to Casper) in the 30 to 45
mph range.

&&

.DISCUSSION...
Issued at 1200 AM MST Wed Nov 12 2025

WV imagery continues to show the strong upper level ridging
across the western portions of the country with just some high
clouds spilling over it across the CWA on IR. This will continue
to be the case Wednesday and Thursday with the strong
convergence aloft as the main finger of the PFJ remains well
north. As such, expect the warming and dry trend to continue
both of these days ahead of the next system come Friday and into
the weekend. Regardless, expect warmer than average temperatures
(5 to 15 degrees), and some breezy winds once again each
afternoon.

Models indicate a trending down of accumulating snowfall west of
the Divide for the western mountains. HREF shows the best
chance to be over 2 to 4 inches at this point in time (70-80%),
with much less chances for anything over that (20-30%). As such,
confidence has continued to drop for any significant weather to
occur at this time with any hazards less likely for Friday into
Saturday. Mountain passes will still be affected, just not to
the extent as once thought earlier in the week. Timing will
continue to be the key as well with early Friday morning start
times to precipitation to push in from Idaho with much of it
being during the daytime. Anything in the lower valleys west of
the Divide is more likely to be just rainfall at this point in
time as temperatures do not become more seasonable until
overnight Friday and into the weekend behind cold frontal
passage.

The Euro continues to handle the system a bit better longer term
as the GFS has, with now indications of the PFJ cutting the main
Pacific northwest trough off into a closed low near southern
California. The main energy looks to hold off until late Sunday
night and into early next week. Even with that said, the system
overall itself looks to be more progressive. As such, expect
amounts even beyond this to be less than previously forecasted.
The overall pattern continues to be active into much of next
week as well with the main finger of the PFJ continuing to pump
in the Pacific moisture west of the Divide with a series of
trough-ridge couplets to propagate through the upper Rockies.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 936 PM MST Wed Nov 12 2025

Thanks to persistent ridging, conditions will continue to be VFR and
dry through the TAF period. A little bit of jet stream energy will
move over the region during the period, which will allow for breezy
conditions to develop at several terminals Thursday afternoon. At
KCOD, KCPR, KJAC, and KRKS wind will be 10-20 knots, with gusts of
20-30 knots. Otherwise, mid to high clouds (FL100-250) will continue
to stream overhead for the next 24 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...Wittmann
DISCUSSION...Lowe
AVIATION...Rowe