187
FXUS65 KRIW 011800
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1200 PM MDT Sat Nov 1 2025

.KEY MESSAGES...

- 10 degrees or more warmer than average temperatures this
  afternoon, even warmer another 5 to 10 degrees Sunday.

- Increasing winds late this afternoon and through the overnight
  hours over 30 to 40 mph, strongest in wind prone areas from
  South Pass to Casper and along with over the Cody Foothills up
  to 50 mph possible (50-60%).

- Next quick moving system across northern parts of the state
  Tuesday with increasing precipitation chances (30-40%) and a
  bit stronger winds.

- Warmer than average temperatures continue throughout the work
  week.

&&

.UPDATE...
Issued at 1200 PM MDT Sat Nov 1 2025

Mainly quiet weather conditions still expected for the short
term forecast. IR continues to show ample cloud cover in the
upper levels spilling over the sharp upper level ridge centered
across much of the wester CONUS. Precipitation has diminished
pushing off to the east. Warmer than average temperatures
continue to be the story this afternoon and beyond. Over 10
degrees above for today, over 15 degrees possible Sunday, with
10 to 15 degrees above average likely into much of the work
week.

Winds increase this afternoon after 3-4PM seeing widespread 30
to 40 mph gusts for much of the area, especially east of the
Divide. As the aforementioned upper level ridge broadens at its
apex, expect the strongest winds towards sunset and overnight
with gusts up to 50 mph possible for the wind prone areas from
South Pass and eastern Sweetwater County to Casper and Natrona
County (80-90%). Also, areas off the leeside of the Absarokas
and Cody Foothills could see the stronger gusts as well
(~50-60%). Winds will subside towards sunrise through the
morning hours with only breezy conditions expected the rest of
Sunday.

A bit less precipitation chances (30-40%) for Tuesday across
northern portions of the viewing area as a minor shortwave
pushes across the ridge through MOntana. Otherwise, the next
bigger system possible later in the work week but warmer than
average temperatures still on track in the longer term forecast.

&&

.DISCUSSION...
Issued at 1249 AM MDT Sat Nov 1 2025

Mild temperatures bring in the start of November. High pressure
moves into the area from the west today, with high temperatures
in the mid-50s to low-60s across the area; these values are 8
to 15 degrees above normal for November 1st. The leading edge of
the ridge does bring a little moisture, so expect a partly to
mostly cloudy sky for the morning, though clearer for the
afternoon. There is enough moisture to spark a light snow/rain
shower (10%-15% chances) over the Absaroka and Wind River ranges
from about 3am to 11am MDT. The Bighorn Basin, Wind River
Basin, Natrona County, and Yellowstone could also see a light
shower (10%). Overall, no impacts expected.

The ridge does not last long, with a broad trough sweeping through,
flattening the ridge starting mid-Saturday afternoon. The main
impact from this is increasing westerly winds aloft. Yellowstone,
the Absaroka Range, and the eastern Wind River Range will see
increasing winds Saturday afternoon and into Saturday night. Gusts
over 30 mph will be common, with frequent gusts 40 to 50 mph. There
are indications of some eastern downsloping winds over 50 mph being
possible, which would be most favored around the Clark area. Other
mountain locations will also see gusts 20 to 35 mph. For lower
elevations, the main area of focus is the Wind Corridor (South Pass
to Casper) where southwest winds gust 30 to 40 mph. Some wind prone
locations, like Outer Drive in Casper, could see gusts over 40 mph.
Strongest winds occur after sunset Saturday, continuing through
Sunday morning. Winds look to decrease a little for the afternoon,
but not by much. Winds should finally lessen Sunday night.

For fire weather concerns, the winds are the main hazard, with the
focus on Sunday. Minimum RHs will be 20 to 30 percent across most of
the lower elevations.

Following this quick system, Monday looks fairly unremarkable.
Temperatures will be a bit cooler than Sunday, mainly a result of
the lack of wind mixing the air. Still, highs are near to above
normal. Another quick system passes through for Tuesday, bringing
gusty winds and precipitation chances (15%-35%) to northern Wyoming,
mainly the mountains. A more potent system looks to arrive for the
end of the week, as early as Thursday. At this time details are
lacking, though currently looks to mainly impact the western
mountains.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1114 AM MDT Sat Nov 1 2025

Extensive mid and high cloud cover within northwest flow aloft
dissipates Saturday afternoon. The upper flow gradually backs to the
west late today and overnight as an active jet stream lays just to
our north. Another batch of mid-level moisture arrives in northwest
Wyoming Sunday morning, but all terminals remain VFR throughout the
entire forecast period. Wind will be the primary aviation hazard
through Sunday. Gusty west to southwest surface wind 12-25kts
persists at KCPR, KRKS, and KCOD Saturday afternoon, with KCPR and
KCOD seeing the gusty wind continue through the period. Proximity to
the Absaroka Range leads to intermittent LLWS at KCOD overnight.
KRKS, along with KJAC, see west to southwest surface wind
increase to 12-24kts late Sunday morning.

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.

&&

$$

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