textproduct: Western and Central Wyoming

KEY MESSAGES

- Monsoon moisture will be slightly decreased today, but still in abundance for showers and isolated thunderstorms this afternoon. Lack of upper level support will keep chances limited to the higher elevations and foothills today, primarily along and east of the continental divide. Localized flooding is somewhat possible along the eastern portions of the Absarokas and Wind Rivers if storms produce heavy rain on top of saturated soils.

- High pressure builds across the Rockies for this weekend, bringing another round of heat to the state. Areas of northern and central Wyoming could again reach the upper 90s and low 100s from Friday through Monday.

- Lingering monsoon moisture and weak disturbances from the Great Basin will continue to bring isolated showers and thunderstorms over western and northwest WY as well as other higher elevations this weekend into early next week.

UPDATE

Issued at 206 PM MDT Thu Jul 23 2026

Convection is well under way this early to mid afternoon across western and central WY, with most of the storms across southern and central WY. Still expecting more development over the eastern portions of the Absarokas, Bighorns, and Wind Rivers, moving to the southeast, as a shortwave trough rides over the ridge axis just to our west. The 18Z KRIW sounding not only shows a very moist lower atmosphere, but a significant cap around 500 mb which would limit the vertical extent of any convection. A new-ish flood watch remains in effect through 8 PM for some areas due to the possibility of heavy rain failing on now- saturated soils. However, the ground seems to be taking in quite a bit of precipitation giving the lack of localized flooding the past two days. Otherwise, welcome showers and thunderstorms are expected through sunset this evening, moving toward southeast WY.

The upper-level ridge axis will slide eastward over western WY on Friday, keeping relatively light winds over the area. A weak shortwave trough is expected to move from the northern Great Basin toward NW WY during the afternoon, bringing isolated showers and thunderstorms to west-central WY, then into northern WY during the evening hours. Locally moderate rain and gusty winds up to 30 mph are possible from 4 to 8 PM Friday due to possible thunderstorms. With the ridge axis moving into WY Friday, temperatures are expected to climb about 7 to 10 degrees Friday afternoon, ranging from the upper 80s to upper 90s. Even warmer temperatures are expected on Saturday, with the expectation that another shortwave trough will bring increasing afternoon cloudiness and scattered showers and thunderstorms late in the day.

DISCUSSION

Issued at 247 AM MDT Thu Jul 23 2026

After a day of scattered to numerous showers and thunderstorms yesterday, the overall threat for precipitation decreases some for Thursday. The shortwave trough that swept across the state yesterday is moving into eastern WY, taking most of the thunderstorm activity with it. WV imagery shows the main moisture pool shifting east with it, while a push of drier air moves in from the west. The lack of midlevel energy and the decrease in moisture will keep thunderstorm activity much more isolated today, mainly along the higher elevations of the Absarokas and Winds. With PW values holding near 1.00 late this afternoon, will likely continue the Flash Flood Watch through this evening, but only for those mountain ranges, after yesterday's saturating rainfall keeps some watershed prone for more runoff.

The H5 ridge builds across the Rockies for the weekend, centered still on the Four Corners region. Temperatures jump nearly 10 degrees from Thursday to Friday, with highs in the upper 80s to the mid 90s. Saturday will see continued warming, with highs from the mid 90s for western valleys and south WY, to upper 90s and low 100s for northern and central WY. Monsoon moisture will still be able to draw into the state, but will be decreased enough to limit shower activity to higher elevations. The flooding risk will these will also be much lower. This warmer pattern with more isolated daytime showers on higher elevations look to remain the trend well into the upcoming week.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1145 AM MDT Thu Jul 23 2026

VFR conditions prevail today, with brief MVFR conditions possible east of the Continental Divide. Today will feature abundant mid-level clouds, with isolated thunderstorms this afternoon, mainly east of the Continental Divide affecting TAF sites such as COD, LND, and CPR. It's less likely that locations in the middle of basins (such as WRL and RIW) receive any rain today, but there is a small chance (around 10%). Unlike Wednesday evening, any isolated storms should quickly end around their typical time this evening, shortly after sunset. The air mass dries slightly on Friday, with notably warmer temperatures but continued isolated showers and thunderstorms.

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

Flood Watch until 8 PM MDT this evening for WYZ002-003-005-007- 015.