756
FXUS65 KRIW 061953
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
153 PM MDT Mon Oct 6 2025

.KEY MESSAGES...

- Clearing skies expected through the rest of the day behind the weekend
  system. This will lead to cold temperatures tonight with many
  locations seeing their first sub-freezing lows of the season.

- Warming and drying conditions are expected through most of the
  upcoming week.

- The next system is favored to arrive by the weekend, returning the
  potential for precipitation and cooler temperatures.

&&

.UPDATE...
Issued at 146 PM MDT Mon Oct 6 2025

Precipitation has ended across the area as the previous system fully
departs. Some lower cloud cover remains early this afternoon, but
this is expected to clear in the coming hours as drier air moves in
aloft. This clearing will make for a cold night, bringing sub-
freezing temperatures to many locations that have not yet seen them
this season. Accordingly, a Freeze Warning is now in effect across
southern Wyoming and lower elevations east of the Divide. Fog is
also possible tonight with the best chances (60-70%) across Jackson
Hole, Star Valley, and the Wind River Basin.

&&

.DISCUSSION...
Issued at 212 AM MDT Mon Oct 6 2025

The remaining trough axis continues to drift southward today,
but will still be producing some light precip across central WY
through around noon today. As the trough axis moves south, it
will allow northerly flow aloft to begin to carve out the low
clouds across the state. Most areas should be nearly clear by
late this afternoon. With the core of the coldest temps with
this system still in the vicinity, temperatures will struggle
to reach back into the 50s this afternoon. With clear skies
tonight, another round of freezing temperatures is expected
across all of western and central WY.

Behind this trough, a large ridge builds across the
Intermountain West, paired against a large cutoff low settling
just off the PacNW Coast. This should keep the weather more
tranquil for the latter half of the week, allowing temps to
recover back to near to just above normal in the 60s to near 70.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1108 AM MDT Mon Oct 6 2025

The main consideration through the period is fog and low clouds. To
start the period, low clouds (MVFR and IFR) are dissipating and
should either be gone to start the period, or will dissipate in the
first few hours. A clear sky and light winds are expected through
the remainder of the period. There is the chance for fog development
again tonight. Confidence is low at this time, but have included
some VCFG and FEW008 groups to indicate the potential. Models
struggled with the fog this morning, so they are probably not
capturing the potential tonight well either.

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...
Freeze Warning from 1 AM to 9 AM MDT Tuesday for WYZ003>006-
010-011-017>020-028>030.

&&

$$

UPDATE...Myers
DISCUSSION...Straub
AVIATION...Wittmann