455
FXUS65 KRIW 120700
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1200 AM MST Wed Nov 12 2025

.KEY MESSAGES...

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

- Increasing precipitation chances west of the Divide Friday
  and into the weekend, although a decreasing trend to
  accumulating snow for the western mountains.

- Active pattern continues into next week as well with more
  seasonable temperatures and wetter conditions to be had going
  forward.

&&

.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 THURSDAY/...
Issued at 927 PM MST Tue Nov 11 2025

Conditions will remain VFR through the TAF period. Some mid-level
moisture will begin streaming in from the southwest Wednesday
afternoon, which will lead to increased mid to high clouds. These
clouds will generally be from FL100-FL200, but may drop as low as
FL080 Wednesday evening. No precipitation is expected with these
clouds, although an isolated virga shower is possible near KJAC
Wednesday evening into Wednesday night.

Wind will be light (< 8 knots) for most terminals through the TAF
period. The exceptions are KCPR and KCOD where wind will increase to
10-15 knots, with gusts of 20-25 knots Wednesday afternoon. Wind
will subside by 23Z, Wednesday. There may be an hour or two of gusty
northwest wind at KRIW to start the period, but that should end
shortly.

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.

&&

$$

DISCUSSION...Lowe
AVIATION...Rowe