textproduct: Western and Central Wyoming

KEY MESSAGES

- Warmer today, with most areas reaching highs in the 60s. Johnson County is especially warm, with highs in the mid to upper 70s.

- Mostly clear and warm conditions continue into early next week, with highs again in the 60s.

- A low chance for showers returns to far western Wyoming on Tuesday, but any rain accumulations are minimal.

UPDATE

Issued at 1231 PM MDT Sat Oct 17 2026

High pressure continues over the area, with warm and dry conditions remaining. Current water vapor imagery shows the dry air over the state, with a little moisture bringing high clouds across far northern Wyoming. No notable changes made to the forecast with this update, as a subtle trough is still expected to bring cooler (but seasonal) temperatures for Sunday, as well as lighter winds.

DISCUSSION

Issued at 207 AM MDT Sat Oct 17 2026

H5 ridging dominates the weather today, bringing much warmer temperatures across western and central Wyoming. This will bring a beautiful autumn afternoon across Wyoming, with highs reaching the 60s for most areas. A weak trough sweeping by well to the north along the Canadian border will tighten the local gradient enough to ramp up winds this afternoon, generally from South Pass east across Natrona and Johnson Counties. Gusts in these areas will reach 30 to 40 mph. This gusty wind will also tap some drier air across Johnson County, pushing temperatures there even higher, reaching the mid to upper 70s.

The system to the north will bring a weak cold front down along the I-25 corridor after sunset, bringing lighter north winds, and drawing temperatures back down closer to normal into the day Sunday. Highs will draw back down to the low 60s, similar to the remainder of western and central Wyoming.

Models are getting more consistent on the larger trough that will be dropping southward along the West Coast this week. This will put Wyoming in southwesterly flow between the trough and the amplifying ridge across the Great Plains. A decaying cutoff trough will wrap ahead of the diving coastal trough and zip northward Tuesday across western WY. Moisture with this decreasing system is limited, so a few showers are possible Tuesday afternoon, but any accumulations will be minimal at best. The trough holds in place for a couple days across central California before ejecting to the northeast late in the week. Where this trough moves northeast will have bearing on precipitation chances and amounts when it moves through Thursday and Friday.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1152 AM MDT Sat Oct 17 2026

VFR conditions are expected through the period with mostly clear skies. Southwesterly gusts to around 30 knots are expected at KCPR through most of the afternoon. KJAC will also see breezy winds, gusting out of the south-southwest to around 20 knots. Otherwise, wind remains lighter with gusts under 20 knots. Wind decreases at sunset, though KCPR will stay breezy through most of Sunday morning.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on smoke, icing, and turbulence forecasts.

RIW WATCHES/WARNINGS/ADVISORIES

None.