929
FXUS65 KRIW 022257
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
357 PM MST Sun Nov 2 2025

.KEY MESSAGES...

- Gusty winds continue this afternoon up to 40-50 mph through
  the wind corridor ahead of a frontal boundary from South Pass
  to Casper. Gusty winds over 50 mph possible for Casper
  Mountain and right behind the front through Johnson County as
  well.

- Above average temperatures continue this afternoon and for
  much of the work week (5 to 15 degrees).

- Precipitation chances skirt across northern parts of the state
  (30-40%) Monday night into Tuesday.

- Mainly dry for most but next chance for a more widespread
  system will come by week`s end and into next weekend.

&&

.UPDATE...
Issued at 1200 PM MST Sun Nov 2 2025

Midday WV imagery shows the broadening upper level trough and
associated finger of the PFJ pushing across northern parts of
the CWA and into Montana. As such, IR shows increasing mid to
upper level cloud cover for these areas with some isolated
shower activity across the northern Bighorn Basin. This will
subside further behind the frontal boundary now making its way
further south into the Basin and into Natrona County. However,
the tricky part will be when and where it stalls and retreats
northeastward overnight into Monday. Winds have increased ahead
of the frontal push seeing gusts up to 40 to 50 mph from South
Pass to Casper, and even some isolated gusts over 50 to 55 mph
as well to include post-frontal around the Buffalo and Powell
areas.

Otherwise, expect winds to diminish as the afternoon progresses
and especially towards sunset and overnight. Breezy winds but
not near as strong Monday and Tuesday with the next subtle
shortwave that will skirt across northern parts of the CWA once
again. Most of the energy will be in Montana more along and
north of the main finger of the PFJ. Behind this Tuesday,
ridging continues with above average temperatures for much of
this next work week. The next bigger system is expected to push
through by week`s end but much uncertainty on how this unfolds
at this point in time. Stay tuned for updated forecasts in the
coming days.

&&

.DISCUSSION...
Issued at 1241 AM MDT Sun Nov 2 2025

Wind is the main forecast element today. Gusty winds 30 to 55
mph are ongoing across the Absaroka and eastern Wind River
Ranges, with some isolated gusts above 50 mph in the Absarokas,
around the Clark area. These winds continue into Sunday morning,
but should decrease some after sunrise from north to south.
Gusts 20 to 40 mph then occur through the rest of the day,
finally coming to an end Sunday night.

The other windy location is the Wind Corridor from around South Pass
to Casper. Generally wind gusts are 30 to 40 mph, though wind prone
locations (like Red Canyon of South Pass and Outer Drive in Casper)
are seeing stronger winds to around 50 or 55 mph. These winds
continue longer than over the mountains, through mid-afternoon. The
gusty winds end Sunday night. Elsewhere, gusty winds will occur
today, with many lower elevations seeing gusts 15 to 30 mph this
morning and afternoon.

A little moisture, aided by some shortwave energy, could bring a few
light snow/rain showers over northwest Wyoming (and the Bighorn
Mountains) today, primarily between 9am and 11pm MST, though some
could linger in the Yellowstone area a few hours longer.

Monday brings increasing gusty winds again, though will be less than
today. Dry air will also limit any chances for precipitation.
Another embedded shortwave moves through for Tuesday, continuing the
breezy conditions and bringing rain/snow chances (20%-45%) across
northwest Wyoming. This system is quick and relatively unimpactful.
Wednesday is a transition day as a quick moving ridge passes over,
keeping the mild temperatures over the area. A more potent system
arrives as early as late Wednesday, though could slow down more into
Thursday. This system looks to mainly bring snow to the western
mountains Thursday and Friday, though also brings low rain chances
across the area for Friday.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 357 PM MST Sun Nov 2 2025

The surface cold front moving south through areas east of the
Continental Divide has swept through KCPR and is nearing KRIW late
Sunday afternoon. A period of northerly wind 12-22kts occurs in
the wake of the cold front into early Sunday evening before
slowing by 03Z/Monday. Earlier mid-cloud deck across northwest
Wyoming has been slowly fading, leaving a clearing VFR sky
overnight for all terminals except KBPI. Hi-res ensembles
continue to favor IFR/MVFR fog (50 percent or more) at KBPI late
tonight and early Monday morning (10Z-16Z/Monday). The best
chance for fog at KBPI arises between 12Z-15Z/Monday, and may
bleed northeast toward KPNA. Occasional mountain top
obscurations until 03Z/Monday, then localized foothill
obscurations in the vicinity of KBPI and KPNA 10Z-17Z/Monday.
Surface wind is less Monday, with KCPR and KJAC the most likely
terminals to see 12-22kt southwest wind in the afternoon.

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

&&

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

&&

$$

UPDATE...Lowe
DISCUSSION...Wittmann
AVIATION...CNJ