321
FXUS65 KRIW 042303
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
403 PM MST Wed Dec 4 2024

.KEY MESSAGES...

- Dry and warmer than normal conditions will persist into the
  weekend.

- Precipitation potential increases beginning Saturday night,
  with snow likely across the mountains Sunday and Monday. Less
  certainty regarding lower elevation snow with best chances
  across western valleys.

&&

.DISCUSSION...
Issued at 1234 PM MST Wed Dec 4 2024

Not much has changed in the forecast today. The ridge to our west
will remain in place through the next several days, keeping a fairly
dry and uneventful northwest mid level flow over the area. This will
keep the unusually warm start to December going for at least a
little longer, with temperatures generally peaking near 10 degrees
normal east of the Continental Divide. This is in large part due to
a lack of a snowpack. There is some snow on the ground west of the
Divide which will help keep temperatures cooler, though still at
least a few degrees above normal.

The ridge will finally begin to break down Saturday night as a
Canadian trough pushes south. This will bring a shot of moisture and
cooler temperatures to the area Sunday through Monday. As mentioned
in previous discussions, guidance is not hinting at this being a
very impressive event; the system will likely pass as a fairly
unorganized positively tilted trough. This would keep snow
favored across the west or northwest facing slopes, with less
east of the Divide owing to a lack of a stronger upslope
component there. Still, there is time for this scenario to
evolve differently in the coming days. The more guaranteed
variable will be increased winds starting Saturday night, with
most of the area seeing a gusty Sunday regardless of
precipitation potential as a cold front sweeps through. This
will make for a colder start to next week behind the system.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 401 PM MST Wed Dec 4 2024

Prevailing VFR Conditions expected at all terminals through the
forecast period. There is a 30% chance of fog returning to KJAC
after 08Z Thursday. If fog does redevelop, it is likely (80% chance)
that it will linger through at least 16Z to 17Z Thursday morning.
All other terminals will see mostly clear skies with no weather
elements during the forecast period.

A southwesterly wind at 14 to 16 kts will redevelop at KCPR by
15 to 16Z Thursday. All other terminals will see wind less than
8 kts through the period.

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

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Myers
AVIATION...Hensley