textproduct: Western and Central Wyoming

KEY MESSAGES

- A weak disturbance will bring increased winds (gusts of 40 to 50 mph) and light snow chances (less than an inch) to lower elevations of northern Johnson County tonight through Sunday.

- Mild and mostly dry elsewhere through the weekend.

- Above average temperatures, breezy winds, and mostly dry conditions will persist through much of the upcoming week.

UPDATE

Issued at 114 PM MST Sat Jan 17 2026

Not much change in the forecast today, with a mild and mostly dry weekend now in place across the state. As noted below, an incoming disturbance will elevate wind again across the Bighorns and Johnson County tonight. This will also bring the weekend's only shot at a little moisture, with low snow chances (20-30%) across the same wind impacted areas through the daylight hours Sunday. The Owl Creek/Bridger Range, eastern Absarokas, and Casper Mountain will see similar chances during this time. The best chance for light snow accumulations across lower elevations will be along the I-90 corridor, including the Buffalo area which may see a half inch Sunday (only 10% chance of exceeding an inch).

DISCUSSION

Issued at 145 AM MST Sat Jan 17 2026

This winter's dominant H5 ridge remains steady along the west coast, which will continue to provide the unusually warm winter across the state. Not much to knock this area out of place, so the tranquil winter continues for the upcoming week. For today, a return of westerly winds across the state, with gusty winds expected in the usual locations across Natrona County and across South Pass. For the most part, gusts will be limited today, with peak gusts around 30 knots this afternoon. The westerly flow will again bring back some warming to the state, with highs recovering into the 30s and 40s this afternoon. The difficult piece in this forecast will be across Johnson County. Models are not picking up on any downsloping westerly flow there today, so temperatures are holding back in the lower 30s. If any downsloping does form up, this could easily push their temperatures well into the 40s. For western valleys, shallow cold pools will be sheltered from west winds for today, so highs will max out around 30.

Overnight tonight, another weak clipper-style wave will sweep across the Northern Plains, with the tail edge brushing against central WY. This will bring reinforcing cold air back to mainly along the I-25 corridor, along with a rush of cold northwest winds. Winds could again gust 45 to 50 mph across Johnson County on Sunday. While a few light snow showers are possible as the system passes through, winds generally aren't in a favorable direction for any significant accumulations in the Bighorns. Western valleys will be generally unimpacted by this system, so the status quo with the shallow cold air keeping temps around 30 again for Sunday.

And so this pattern continues the upcoming week, with quick- moving systems expected Tuesday night and Friday, bringing reinforcing cold air each time, along with some gusty winds to central WY. Wind return flow on Tuesday ahead of that system looks to be a bit stronger, bringing temperatures east of the Divide back into the 40s for the day. Western valleys hold steady in the 30s closer under the western ridge. The system late this week looks to be better placed to bring back some modest snowfall to the western mountains.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 359 PM MST Sat Jan 17 2026

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

High pressure keeps a mainly clear sky and relatively light winds through the period. Some gusty winds at KBPI, KPNA, and KRKS should decrease this evening. Otherwise, winds are diurnally driven, with slight increases into Sunday afternoon. Increasing high clouds towards the end of the period.

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

Lighter winds into tonight, with the exception of KRIW where downvalley winds are likely. A cold front moves in from the north Sunday, bringing a northerly wind shift and brief gusty winds with its passage and for a few hours after. Precipitation chances with this front are very limited, with 20 percent chances for favored terrain locations like KCOD, KCPR, and KLND. Clouds do increase with this, with the latest HRRR indicating low-end VFR to MVFR ceilings, which may be too pessimistic.

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.