878
FXUS65 KRIW 091021
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
321 AM MST Sun Nov 9 2025

.KEY MESSAGES...

- Minimal chances (<10% chance) for fog near rivers and valley
  bottoms overnight giving way to seasonable temperatures and a
  pleasant Sunday.

- Warming and dry trend Monday through Thursday with
  temperatures 10 to 15 degrees above average and breezy winds
  winds expected in the afternoon hours.

- Increasing precipitation chances come Friday and into the
  weekend.

&&

.DISCUSSION...
Issued at 1205 AM MST Sun Nov 9 2025

WV/IR imagery shows mainly cloudless skies across the CWA with
ridging evident to the west. This upper level ridge will
continue to build in Sunday and into the early part of the work
week with increased convergence aloft. With surface high
pressure and light winds to go along with the clear skies, there
is a low (<10%) chance for patchy fog across some of the areas
in Jackson Hole and northern Bighorn Basin/Johnson County. With
such a dry airmass, confidence low at this point but there is a
hint with the short term model data to occur by sunrise Sunday
morning.

Otherwise, expect a pleasant Sunday to be had with seasonable
temperatures and relatively light winds. Warming and dry trend
continues into the new work week with the aforementioned upper
level ridge/surface high pressure set in place through mid
week. Temperatures 10 to 15 degrees above average expected with
breezy winds as well due to the stronger daytime heating and
mixing element. This ridge will start to breakdown into Thursday
and push east Friday. This will give way to an upper level low
currently in the GOA to push near the Pacific northwest coast
opening back up the westerly, moisture rich flow for points west
of the Divide. Precipitation chances increase as a result for
Friday and especially into the weekend. Details not concrete at
this time with timing and amounts, but western mountain snow and
valley rain probable not expecting it to push east of the
Divide at this point in time. Stay tuned for updated forecasts
in the coming days.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 319 AM MST Sun Nov 9 2025

VFR conditions should continue through 12Z Monday. Patchy fog
can`t ruled out in the western valleys, mainly in vicinity of
KJAC, but the chance is less than 1 out of 10. Wind should
remain less 12 knots or less through the period, with some
increase in vicinity of KCPR after 09Z Monday.
&&

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

&&

$$

DISCUSSION...Lowe
AVIATION...Hattings