textproduct: Western and Central Wyoming

KEY MESSAGES

- Patchy areas of low clouds and fog should dissipate through this morning.

- Above normal temperatures continue for most locations into next week.

- The next weather system moves in Tuesday or Wednesday, with the potential for western mountain snow and widespread gusty winds.

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

None.