068 

FXUS65 KRIW 301046

AFDRIW



Area Forecast Discussion

National Weather Service Riverton WY

346 AM MST Tue Dec 30 2025



.KEY MESSAGES...



- Warming temperatures through this week, with above normal 

  temperatures for New Year's Eve and New Year's Day.



- Dry weather today and tomorrow, with a weak system bringing

  light snow (or rain) to western Wyoming Thursday into Friday.

  Little to no impacts expected.



&&



.DISCUSSION...

Issued at 151 AM MST Tue Dec 30 2025



Quiet weather is expected through the end of the year. A ridge 

situated over the southwestern US brings mild temperatures and 

relatively light winds to the area the next couple days. Highs today 

are in the mid-30s to low 40s for much of the area, which are 5 to 

10 degrees above normal for the end of December. Have dropped the 

western valley temperatures slightly, as has been the trend over the 

last couple days. 



The next weather system of any note arrives as early as Thursday 

morning, with increasing clouds and precipitation from the west-

southwest. This is in response to an upper-level low entering into 

southern California. However, this system gets absorbed into the 

flow and does not have any indications of anything potent. Light 

snow will be possible over the western and southwestern mountains as 

early as Thursday morning, but more likely later Thursday into 

Friday morning. Snow levels of 6500 to 7000 feet means light rain is 

possible for lower elevations. High pressure returns after this 

quick system, so temperatures won't fluctuate much with this 

disturbance. 



Looking into next weekend, a trough to the west could bring some 

gusty winds as the pressure gradient tightens, but there is weak, if 

any, evidence of strong winds (55+ mph) at this time. With the ridge 

still in place, and some winds to mix the air, temperatures continue 

to warm, with currently forecasted highs (mid-40s to mid-

50s) hovering near daily records to start January.



&&



.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...

Issued at 330 AM MST Tue Dec 30 2025



VFR conditions prevail across the region over the next 24 hours

with minimal aviation weather impacts expected. A band of SCT-

BKN FL180-250 clouds will drop southward from MT after 12Z and

will dissipate by 20Z, as it progresses southward. Low

clouds/fog can be noticed over Jenny Lake this morning and have

added a FEW002 to KJAC for now. Generally light winds are 

forecast for all areas, with KCPR seeing gusts around 30kt for 

several hours in the morning and early afternoon. No 

precipitation is expected in the forecast.



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.



&&



$$



DISCUSSION...Wittmann

AVIATION...LaVoie/VandenBoogart