FXUS65 KRIW 121036

AFDRIW



Area Forecast Discussion

National Weather Service Riverton WY

336 AM MST Fri Dec 12 2025



.KEY MESSAGES...



- Period of snow and gusty wind will bring slick roads to the

  Bighorns and Johnson County this morning.



- Above normal temperatures continue for most locations into

  next week.



- The next weather system moves in Tuesday or Wednesday with the

  next chance of snow and wind.



&&



.DISCUSSION...

Issued at 1117 PM MST Thu Dec 11 2025



The main concern in the short term will be the expected snow and 

travel impacts across northern Wyoming, especially from the Bighorn

Range and eastward where the Winter Weather Advisory is in 

effect. Snow is now spreading into the area and will continue 

through the night before tapering off later in the morning. As 

was noted by the day shift, the main concern will not be 

snowfall amounts, as they should remain below advisory 

criteria. The main concern is icy roads from the rapidly falling

temperatures following the warm temperatures today, (it was in 

the 50s and 60s) and a possible flash freeze. We will continue 

the Advisory as is for now. The only other location with a

greater than a 1 in 3 chance of 3 inches or more is the northern

Absarokas, and there are few impacts in that location. 

Otherwise, the challenge today will be temperatures and how far

south the front can reach. Johnson County and the northern 

Bighorn Basin will be much cooler, with the high in Buffalo 

possibly 40 degrees colder than yesterday. It will remain 

milder further south though as the front would likely not make 

it. It should be a bit cooler than yesterday, but still well 

above normal for mid-December. We will continue to have some 

gusty breezes at times as well with the jet close to the area, 

but nothing like the wind we have seen the past few days.



Zonal to flat ridging then controls the weather through the 

weekend and into Monday. This means a continuation of above 

normal temperatures and breezy conditions. It is possible we 

could see more high temperature records fall, especially on 

Sunday and Monday following the brief cooldown on Friday and 

Saturday. There will be a gusty wind continuing in the favored 

areas, but high wind is not expected through that time period. 

The only fly in the ointment through this period will be one 

last piece of energy that could bring some snow showers to 

Johnson County on Saturday, but any amounts would be light and 

impacts minimal to none.



The next likely weather maker will be in the form of a Pacific 

trough and cold front that approaches Tuesday and Wednesday. 

Given the zonal flow across the area, impacts look similar to 

this weeks situation with most of the precipitation across 

western Wyoming with the orographic enhancement. Models are 

split on if any precipitation makes it east of the Divide 

though. There is higher confidence in strong to potentially high

wind, with most guidance having an 140 to 160 knot jet over 

Wyoming from later Tuesday through Thursday. Details are 

obviously impossible to nail down this far out though. We are 

highly confident on above normal temperatures continuing across 

most of the area through most of the next seven days.



&&



.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...

Issued at 330 AM MST Fri Dec 12 2025



Ceilings will hover near LIFR conditions at KCOD, KWRL and KCPR

through 18Z. Confidence is greater for these conditions at KWRL

for now, as these conditions have been bouncing back and forth

at KCOD and KCPR since 06Z. Additionally, winds will turn to 

the southwest by 15Z at KCPR. This will help lift these ceilings

to VFR and scatter out the clouds. 



KRIW continues to have wind gusts around 25kt. These winds are

expected to subside by 15Z as well. Wind gusts of 25 to 30kt

will return to KRKS and KCPR by 17Z and 20Z,respectively.

Otherwise, winds will be light (10kt or less) at the other 

terminals. Wind gusts of 25 to 30kt will return to KLND, KRIW 

and KCPR between 00Z and 07Z and last through the rest of the 

TAF 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...

Winter Weather Advisory until 7 AM MST this morning for 

WYZ008>010.



&&



$$



DISCUSSION...Hattings

AVIATION...LaVoie