textproduct: Western and Central Wyoming

KEY MESSAGES

- Temperatures again stay near to just above normal for January, with highs today in the 30s and 40s east of the Divide and around 30 for the western valleys.

- A series of weak waves will move across the Northern Plains this week, keeping temperatures closer to normal most days.

- As each system passes, gusty northwest winds will return across areas east of the Divide, especially across Johnson County.

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 /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1004 AM MST Sat Jan 17 2026

A greater influence from the high pressure to the west keeps a mostly clear sky today, with winds on the lighter side, though some places do remain gusty. Locations with gusty winds should see them decrease this evening. At KCOD, models have the southwest-north boundary around the airport, so they may fluctuate between these two directions this afternoon. Towards the end of the period, an incoming front brings increasing clouds and northerly winds.

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.