362
FXUS65 KRIW 070452
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1052 PM MDT Mon Oct 6 2025

.KEY MESSAGES...

- Cold, near to below freezing, temperatures tonight. Thus, a
  Freeze Warning is in effect for southern Wyoming and lower
  elevations east of the Divide Tuesday morning.

- There is a 40-70% chance of fog development tonight across
  portions of the Wind River Basin, Star Valley, Jackson Hole,
  and eastern Sweetwater County.

- Dry weather with near to above normal temperatures Tuesday
  through Thursday.

- Precipitation chances (30-60%) return Friday and continue
  into next weekend, especially west of the Divide, along with
  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 /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1051 PM MDT Mon Oct 6 2025

Clear skies and light winds overnight will create favorable
conditions for fog/low cloud development between 09Z-17Z at most
terminals. Confidence ranges from 10-40% in fog development. At
KRIW, KCPR, and KJAC there is slightly higher confidence (30-40%) in
fog/low ceiling development so included VCFG and SCT004/FEW006
groups. Confidence is lower (10-20%) at KBPI, KPNA, KLND, and KRKS so
only included a FEW008 group. Any fog development should diminish by
17Z with clear skies and winds around or less than 10 kts the
remainder of the TAF period.

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

&&

$$

UPDATE...Myers
DISCUSSION...Straub
AVIATION...Gerhardt