703
FXUS65 KRIW 011123
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
523 AM MDT Sat Nov 1 2025

.KEY MESSAGES...

- Warm temperatures 8 to 15 degrees above normal today.

- Increasing winds across the mountains starting this afternoon. Strongest
  winds occur late this evening through Sunday morning, with
  gusts 30 to 40 mph.

- Increasing winds from South Pass to Casper this afternoon,
  with gusts 30 to 40 mph through Sunday. Strongest winds occur
  tonight into Sunday morning. Isolated stronger gusts possible
  for wind prone locations.

- Another quick weather system moves through Tuesday, with precipitation
  chances (15%-35%) for northern Wyoming and gusty winds.

&&

.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 /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 522 AM MDT Sat Nov 1 2025

Mostly cloudy skies this morning will quickly scatter out to mostly
clear skies by mid afternoon. With the clouds to start the period
and through much of the morning, expect occasional mountain
obscurations above 9000ft AGL. A few very light isolated snow
showers are also possible through the early part of the morning,
mainly over the northern WY mountains. However, there is a
slight chance that those showers could spread into KCOD, KLND,
and/or KRIW terminals (10% chance), but confidence remains too
low to include mentions in the TAFs. A few sites will see winds
increasing by early afternoon today, most notably KCPR and KRKS.
The remaining sites will see winds begin to increase late in
the period as a strong jet drops slightly southward through the
day. The strongest winds will remain over Montana, but stronger
westerly winds will be likely at KCOD and KCPR with gusts around
30+ kts by the end of the period.

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...Wittmann
AVIATION...Hensley