textproduct: Western and Central Wyoming

KEY MESSAGES

- Isolated (15-40%) showers and thunderstorms are expected through his evening, spreading from southwest to northeast across the area. The main threat with this activity will be strong outflow wind gusts to around 50 mph.

- Showers and thunderstorms will be more widespread on Saturday, with the best chances west of the Continental Divide.

- Elevated fire weather conditions are expected Saturday afternoon, especially across central Wyoming. Sunday brings a similar concern.

- The unsettled pattern will persist through next week, with mild temperatures and several chances for moisture.

UPDATE

Issued at 129 PM MDT Fri Apr 10 2026

The forecast remains on track this afternoon, with convection expected to increase as the leading shortwave from the approaching trough arrives. Mesoanalysis currently shows 100-300 J/kg of surface based CAPE west of the Divide, with most of the area farther east capped under a layer of cooler, more stable air. Heating over the next couple of hours will help destabilize, especially west of the Divide (SBCAPE >500 J/kg), and should lead to scattered coverage of showers and thunderstorms. These will move northeastward through the rest of the afternoon and evening, spreading east of the Divide after 22Z. As noted below, the main concern will be strong outflow wind gusts up to 50 mph or so. Most of this activity will wane by midnight. The next wave will follow quickly Saturday morning, bringing more widespread and robust coverage of showers and thunderstorms to the area through Saturday evening.

DISCUSSION

Issued at 147 AM MDT Fri Apr 10 2026

Today sees the transition from a ridge over the area to the incoming trough. With the ridge still over the state, temperatures warm once again, with highs generally around 70 degrees for most of the area. The tightening pressure gradient will bring a breezy afternoon, with gusts 15 to 25 mph. Stronger gusts to 35 mph occur across Sweetwater County and northern Johnson County. A subtle shortwave passes through ahead of the advancing trough today. Moisture will be limited, but the lift should be just enough to produce some virga or light rain showers, as well as a very slight (10-15%) chance for a thunderstorm. Given the overall dryness of the atmosphere, most of these showers should be virga. If a shower does produce rain, amounts would be about 0.02 inches or less. The Wind River Mountains may aid in some additional lift, increasing the chances for better moisture amounts there, mainly at the higher elevations. In terms of chances of a seeing a virga shower or light rain today, it's very difficult to pinpoint. It's going to be one of those days where its effectively random where a shower decides to pop-up. Overall, would give any location at least a 10 percent chance today. Western Wyoming will be more favored, as the better moisture is there, with chances more in the 10 to 40 percent range. One last note about any showers (virga or light rain) is outflow gusts, which could be up to 55 mph at the high end, though would more likely be more likely in the 20 to 40 mph range.

Saturday shares similarities to today. However, a more potent shortwave passes through ahead of the main system. This brings better precipitation chances to the area, in additional to better moisture availability. Snow levels will be around 9000 feet, so expect rain in the lower elevations. Everywhere has at least a 20 percent chance for rain, again favored higher chances over the west. Western locations could see up to 0.2 inches of rain if a shower moves right overhead. Overall, amounts should be under 0.1 inches (and mainly under 0.05 inches) unless a stronger showers moves directly over.

The advancing low is slow moving, so although each day this weekend sees increasing precipitation chances, the main system won't pass through until Monday/Tuesday. As it's so slow moving, it will drop most of its moisture to our west and southwest. So, moisture availability will be limited here through early next week. As a result, models have, rightfully so, lowered precipitation amounts each day compared to previous runs.

Taking a peek further ahead, late next week (maybe Thursday or Friday) could see another system from the north. This has the chance to bring below freezing nighttime temperatures. Though confidence is low on the details, heads-up to anyone with sprinkler systems or early season vulnerable vegetation.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 512 PM MDT Fri Apr 10 2026

VFR flight conditions are forecast to continue through 00Z Sunday. Scattered rain shower chances (15 to 30 percent chance) exist through 02Z/03Z, at the latest, at most terminals. An isolated thunderstorm cannot be ruled out during this timeframe, mainly near KBPI and KPNA. Showers will move from southwest to northeast and be mostly dry/virga, so it is uncertain if any given terminal will see any actual rain. PROB30 groups are maintained where confidence is around 30 percent in direct impacts to a terminal. Largely dry conditions are expected overnight, except near KJAC and KRKS where light rain showers in the vicinity could develop. Shower and/or thunderstorm chances (up to 30 percent) increase after 18Z Saturday. For any showers/thunderstorms near terminals, sporadic and gusty 25 to 45kt outflows are possible.

Any elevated or gusty winds are expected to diminish by 03Z Saturday at the latest and remain relatively light overnight. Winds begin to increase and become gusty first at KCPR, KRKS, and KBPI after 16Z/17Z Saturday with all other terminals becoming gusty between 18Z and 21Z. Expect wind gusts of between 20kts and 30kts on Saturday afternoon.

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.