textproduct: Western and Central Wyoming

KEY MESSAGES

- Lingering snow over the western mountains and Bighorn Mountains today, with an additional 1 to 5 inches possible.

- Light rain possible for the lower elevations through this evening, mainly for northern Wyoming, like the western valleys, Bighorn Basin, and Johnson County.

- Widespread gusty winds today, with gusts 30 to 45 mph, strongest for wind prone areas, like South Pass to Casper, and higher elevations.

- Temperatures are cooler for the rest of the week, but remain above normal for mid-February. Additional precipitation chances occur through the week, favoring western and southern Wyoming.

UPDATE

Issued at 921 AM MST Mon Feb 9 2026

Overall, snow accumulations seem to be underperforming so far. This is likely a result of a few factors: a slightly weaker system than previously projected, the system is a bit more north than anticipated, and snow levels are a little higher. This has meant continuing rain for lower elevations, like in Jackson Hole and Dubois. For higher elevations, snow has been wetter, resulting in lower accumulations (in addition to just an overall lower snow amount than forecasted). Going forward today, snow becomes more isolated and showery, likely resulting in locally higher amounts of snow where it does occur. As the system moves eastwards, the associated shortwave could bring lower elevation rain to the Bighorn Basin and Johnson County through about midnight. There could be some snow mixed in as well.

DISCUSSION

Issued at 259 AM MST Mon Feb 9 2026

Strong westerly flow aloft over Wyoming and a shortwave trough over western Idaho are both evident on 10Z satellite water vapor imagery. The shortwave trough will traverse eastwards through the morning, and aid in bringing either snow and/or wind to the entire area. As the shortwave approaches, upper-level winds will increase to around 110kts to 120kts over the entire state and Pacific moisture will be funneled into northwestern Wyoming. In addition to the stronger upper-level winds, the surface pressure gradient will tighten ahead of the shortwave's surface reflection, a cold front. This shortwave is forecast to quickly traverse the state in a 6 to 8 hour period beginning this morning. The specifics of snow, including the Winter Weather Advisories, and wind will be discussed further below.

Northwest Wyoming, specifically the Tetons and Gros Ventre Mountains, Yellowstone National Park, and the Absarokas, will see moderate snowfall through 5PM. Both deterministic and ensemble model guidances have increased QPF across these areas, which in turn increased the overall snow amounts through 5PM this evening. Thus, the Absaroka Mountains have been added to the Winter Weather Advisory. Given this is a quicker system and overall available moisture gets quickly cut off behind the front, we opted to leverage the lower end of QPF to reflect snow accumulations in the 6 to 12 inch range (80% chance). Enhanced frontogenesis and orographic lift will still allow for moderate snowfall to occur with widespread rates up to 1 inch/hour through the afternoon. Teton and Togwotee Mountain Passes fall into this 6 to 12 inch range so anticipate winter travel conditions today. Anything above 12 inches (up to 16 inches) will be confined to the higher terrain and peaks of the aforementioned locations. As mentioned previously, overall available moisture will be cut off behind the front this evening with only light snow lingering into the overnight hours.

Snow amounts are expected to be rather minimal, if any, across low elevations of western and northern Wyoming today. Snow amounts across Jackson Hole Valley and Star Valley are expected (80%-90%) to be in the trace to 2 inch range. This is largely due to warm, above freezing temperatures when a bulk of the precipitation falls. As the front progresses eastward across the area, there is a 30% to 50% chance of rain or snow across the Bighorn Basin, Johnson County, and the Bighorn Mountains. If temperatures drop fast enough across the Bighorn Basin, a light dusting of snow is possible this evening. The Bighorn Mountains are forecast to see 1 to 5 inches of snow with the front. All other locations will be lucky to see any precipitation, and if they do it will likely fall as rain due to warm, above normal temperatures.

Widespread wind gusts of 25 mph to 40 mph (70% to 90%+ chance) are forecast across the entire area ahead and along the cold front. Wind gusts above 50 mph are not out of the realm of possibilities for wind prone locations and high elevations due to 40kt to 50kt 700mb winds. Gusty winds will persist longer across southern Wyoming and east of the Continental Divide. Elevated fire weather conditions are possible today, especially across Natrona and Fremont Counties and southern Wyoming due to above normal temperatures, gusty winds, and overall dry conditions. The currently forecasted minimum relative humidity could be a bit too high given gusty winds and deep mixing could future dry out the low levels.

Cooler, although still above normal, temperatures are forecast behind the cold front Tuesday with largely dry weather. The next chance (50%-90%) for precipitation is on track for Wednesday as an upper-level trough over the western CONUS puts the Intermountain West southwest flow aloft. This flow opens the region up to some Pacific moisture as an embedded shortwave and an associated front traverse the state. Temperatures are currently forecast to be well above freezing (40s and low 50s), so this is setting up to be a low elevation rain and mountain snow show. There is relatively decent consensus that the trough will pass through the region sometime in the Thursday/Friday timeframe and cut off moisture. This means that precipitation chances will drop considerably by the end of the week, so be sure to enjoy the rain or snow the first half of the week!

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1134 AM MST Mon Feb 9 2026

A system will continue to bring precipitation chances to the area, mainly across western Wyoming through this evening. One challenge with this system continues to be the lack of colder temperatures. This has been keeping KJAC with rain instead of snow, with visibility remaining IFR. A cold front currently moving through will fight with diurnal heating to drop temperatures slightly at KJAC, which will likely see a transition to snow by mid-afternoon. However, the bulk of the moisture was expected ahead of this front, so confidence on persistent impacts is lower. Still, high-res guidance continues to indicate a period of MVFR conditions this afternoon at KJAC, most likely from 20Z through 00Z Tuesday.

Confidence for impacts at other terminals is much lower, with KCOD most favored to see occasional MVFR to IFR impacts this afternoon. Otherwise, the more widespread impact continues to be wind, with gusts of 25 to 40 knots in the forecast for most terminals this afternoon. Wind will decrease from 00Z to 06Z, with conditions improving to IFR at all terminals through Tuesday morning.

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 5 PM MST this afternoon for WYZ001-002-012.