FXUS65 KRIW 270851

AFDRIW



Area Forecast Discussion

National Weather Service Riverton WY

251 AM MDT Mon Oct 27 2025



.KEY MESSAGES...



- Valley rain and mountain snow will continue across the region

  today, with snow accumulations continuing above 8000 feet.

  Winter conditions will continue for most mountain passes

  through the day.



- Gusty northwest winds return today, with widespread gusts

  above 30 mph expected.



- Cold temperatures continue Tuesday before moderating through

  the rest of the week.



&&



.DISCUSSION...

Issued at 221 AM MDT Mon Oct 27 2025



The broad trough continues to sweep across the northern Rockies

this morning. This is keeping the moisture feed off the Pacific

well placed for lift along local mountain ranges. Models

continue to show elevated lift aloft through the rest of the

day, which will continue to aid in snow production. Peak times

for the northwest mountains should be between now and around

noon, with the focus shifting briefly east to the Bighorns this

afternoon. Additional snowfall accumulations of 3 to 6 inches is

expected before the system moves out tonight. Current warnings

and advisories mesh well with the current timings, so will not

need any adjustments here. As the system moves east this 

evening, a brief period of rain/snow mix will develop for 

Natrona and Johnson Counties, with snow accumulations up to a 

half inch possible.



Winds will also come up across the state today, as the northwest

flow aloft mixes down to the sfc. Widespread wind gusts above 

30 mph are expected, except for the more shaded places across NW

WY. The southern half of the state will see even higher gusts

this afternoon, with frequent gusts 40 to 50 mph likely (>60%).



High pressure builds in for Tuesday, with much colder

temperatures. Highs will struggle to reach 40 degrees, before

falling into the teens and low 20s Tuesday night. H5 ridging

builds across the Rockies midweek, deflecting the next system

into Montana. Right now it would only provide some high clouds

during the day. Models differ on the next system which may pass

through Friday night, with a wide range of strength and moisture

available. Current trend is for a drier passage, with milder

temperatures in the 50s and 60s remaining through the weekend.



&&



.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...

Issued at 1010 PM MDT Sun Oct 26 2025



West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals



IFR/MVFR conditions will remain in place at KJAC/KBPI/KPNA, 

with on and off snow showers through 09Z. Similar conditions 

will be in place at KRKS, with a rain/snow mix expected through 

08Z. Winds will begin to increase here by this time as well. As 

the trough axis shifts through Monday morning, expect west- 

northwest winds to increase at the other terminals. Expect gusts

of 30 to 40 kt to occur through much of the day. Scattered 

showers will remain possible through 12Z, with decreasing 

chances through the rest of the day. No direct impacts to any of

the terminals are expected. Winds will begin to decrease after 

sunset, possibly lingering a bit longer at KRKS. 



East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals



Mountain obscurations will remain prevalent over the Absaroka, Wind

River and Bighorn Mountains as well as Casper Mountain through

18Z, with most of the cloud cover continuing over the Absaroka

and Bighorn Mountains through about 03Z. There is a 30% chance

for rain showers (mainly in the Bighorn Basin) through 12Z.

Confidence remain too low to include in any of the forecasts.  

By sunrise Monday, winds become a greater concern once again, 

with a potent cold front pushing through. West winds gusting 20 

to 30 kt are possible at many locations ahead of this front, 

with a wind shift to the northwest and gusty winds also 

occurring behind the front, especially after 18Z Monday. These

winds will begin to subside by 01Z. Johnson County will have the

highest confidence for rain showers this afternoon. There is

still a 30% chance for showers over the Bighorn Basin in the

afternoon. There is a small window that KCOD could be impacted

between 18Z and 20Z, but this could be added in future

forecasts.  



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...

Winter Storm Warning until 6 PM MDT this evening for WYZ001-

012.



Winter Weather Advisory until noon MDT today for WYZ002-014-

015-024.



Winter Weather Advisory until 6 PM MDT this evening for WYZ008.



&&



$$



DISCUSSION...Straub

AVIATION...LaVoie