textproduct: Western and Central Wyoming

KEY MESSAGES

- High pressure builds into western and central Wyoming today, bringing much warmer temperatures, with highs in the lower elevations ranging from the high 80s to near 100 this afternoon.

- Monsoon moisture continues to draw into western WY this afternoon as well, with isolated showers and thunderstorms expected main over west-central WY, but also extending from SW to NW WY, and possibly filtering into the western Wind River Basin.

- This pattern continues through the weekend, with hot temperatures approaching 98 to 102 degrees, and chances for showers and thunderstorms for the western mountains each afternoon, with Saturday having the highest chances.

- Very warm temperatures with afternoon showers and thunderstorms continues through Thursday, with even warmer yet drier conditions expected for next Friday and Saturday.

UPDATE

Issued at 1230 PM MDT Fri Jul 24 2026

As the upper-level ridge axis slowly slides west to east across Wyoming today, temperatures are climbing compared to Thursday, with afternoon high temperatures ranging from the upper 80s to near 100 in the lower elevations. A weak shortwave trough is moving from NE Nevada into SE Idaho, across NW WY and into south-central MT. This feature will bring isolated showers and thunderstorms to western WY (from SW to NW) this afternoon and evening, mainly focusing on west-central WY. Some very isolated showers and thunderstorms may push past the crests of the Wind Rivers and Absarokas into the eastern slides of the Wind River and Bighorn River Basins. Late this morning, the Storm Prediction Center included an marginal risk of severe thunderstorms from NW NV into SE ID, indicating the threat of 60-70 mph wind gusts. The edge of the marginal is right along the ID/WY border, so west-central WY (Star Valley, etc.) may see wind gusts of 50+ mph with storms this afternoon. Elsewhere, the storms should bring brief heavy rain and gusty outflow winds of 30-50 mph. A few showers should linger until midnight or so before dissipating.

The ridge axis centers over the eastern WY border on Saturday, bringing in slightly warmer mid-level air along with increasing southwest flow. A stronger shortwave trough from the Great Basin will again move through western WY into southern MT. More widespread isolated to scattered showers and thunderstorms are expected Saturday, even though afternoon high temperatures in the lower elevations will range from the low 90s to over 100 degrees. West-southwest winds will increase to 10-15 mph in the afternoon, with gusty outflow winds of 30-50 mph possible as well. A higher chance of 40-60 mph thunderstorm outflow winds will be over the northern Bighorn Basin with the thunderstorms in the late afternoon. Showers and isolated thunderstorms will linger into the late evening as winds decrease.

Sunday looks to be a repeat of Friday, with only isolated showers and thunderstorms, expect that the afternoon high temperatures will be similar to Saturday. As a result, a Heat Advisory is in effect for the lower elevations east of the continental divide addressing/highlighting the very warm to hot temperatures (with elevated humidity leading to abnormally warm minimum temperatures).

DISCUSSION

Issued at 300 AM MDT Fri Jul 24 2026

H5 ridging begins to build across the southern Rockies today, reintroducing heat to the region. Temperatures today will reach the 90s for the lower elevations, with warmest readings in the usual lower elevations of the Bighorn Basin and along the I-25 corridor. The ridge axis remains to the east, allowing the monsoon moisture to continue to draw northward into western WY. Daytime heating will allow another round of showers and thunderstorms to build along the western mountain ranges. A lack of a considerable shortwave sweeping through will keep any significant organization of storms from occurring, with showers remaining more isolated in nature. The lighter steering flow around the ridge will allow showers to move off to the northeast from mountain ranges, but once they detach from the range, they will generally decrease and dissipate. With slightly lower moisture levels and enough steering flow to move any storms, will not need to continue any Flash Flood Watches for the day today. Once daytime heating decreases, showers will quickly dissipate, with mostly clear skies overnight.

Saturday will see the heat ridge strengthen slightly, bringing highs well into the 90s, with readings above 100 for the Bighorn Basin and Johnson County. There is a very weak shortwave noted in models, which may be enough to bring a little more organization to western showers and thunderstorms, but will they be able to overcome capping from the increased ridging is the question. Right now, shower activity looks to be more widespread, but showers would be smaller in nature, and would have better motion to keep from sitting in one place.

Longer range models don't have much change in this pattern for the upcoming week. High temperatures hover in the 90s each afternoon, while the chance for monsoon showers continues for the western mountains. Shower activity would be more dependent on any passing shortwaves enhancing any lift.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 345 PM MDT Fri Jul 24 2026

VFR conditions will be the normal over the next 24 hours. Scattered showers and thunderstorms have developed west of the Continental Divide as expected, and these will last until shortly after sunset. Only about a 30% chance of receiving precipitation at any given basin location; however, rain will be heavy under storm cells, and one can expect lowered visibility where storms do form. Wind gusts in the vicinity of storms will likely be in 30 to 40 kt range. Apart from storm vicinities, afternoon winds will be fairly light, only gusting 15 to 20 kt.

Most storms will not make it East of the Divide, with only around a 10% chance of LND or RIW being affected by storms. Winds decrease quickly after sunset, with another chance for scattered storms tomorrow, this time on both sides of the Divide.

RIW WATCHES/WARNINGS/ADVISORIES

Heat Advisory from noon Saturday to 9 PM MDT Sunday for WYZ003>006-010-011-017-018-020.