textproduct: Salt Lake City

KEY MESSAGES

- Scattered showers and thunderstorms will develop across Utah and southwest Wyoming again late Friday morning through Friday night, with gusty winds and isolated flash flooding being the main threats.

- An approaching trough on Saturday will bring noticeably cooler temperatures, gusty winds, and more widespread precipitation. Strong to severe storms will be a possibility.

- An active pattern will continue through at least the first half of next week.

DISCUSSION

High pressure is centered south of the Four Corners this evening, with southwest flow in place over Utah. Moisture continues to spread into western Utah along the periphery of this high. Latest PWAT analysis has between 0.9-1.1 inches across western Utah decreasing to around 0.7 inches across eastern Utah. Weak ripples embedded in the southwesterlies are also aiding more focused rounds of convection, with one such round moving through northern Utah at this time.

Models continue to show isolated weak shower activity tonight, increasing again by mid-morning Friday as another weak disturbance ripples through. As moisture further increases through the day Friday, convection will become stronger and increase in coverage and become stronger towards the middle part of the afternoon and into Friday evening. Scattered nocturnal shower activity looks like a strong possibility Friday night.

On Saturday, a storm system crossing the PacNW will bring increased southwesterly flow to the area. The upper jet shifting into Utah ahead of this storm, combined with moisture and instability in place, will bring more widespread convection to the area, with increased potential for strong to severe storms. A Marginal Risk of severe thunderstorms is already in place for northern Utah on Saturday. Given the more widespread coverage and potential training nature of the storms, the flash flood threat will increase as well, with a Marginal Risk of excessive rainfall in place for the entirety of the forecast area for Saturday.

The trough will cross Idaho Saturday night, resulting in continued showers and thunderstorms through the night. By Sunday afternoon, subsidence behind the trough should bring a marked decrease in convection across at least western Utah, while eastern Utah will see convection gradually decrease in coverage through the day, depending on how quickly said trough progresses eastward.

The trough axis will settle well east of the area through the early to middle part of next week. Although PWATs will trend lower, additional weak disturbances will continue which will maintain daily shower and thunderstorm activity, although chances decrease by midweek.

Temperatures will trend cooler Friday into Saturday, with high temperatures falling below climatological normals by Saturday. These cooler temperatures are expected to more or less persist through much of next week.

AVIATION

KSLC...Winds are expected to shift southeast and remain overall light through the overnight hours. Showers developing after 15z across northern Utah may result in more variable winds through the morning before shifting northwesterly after 18z. Chances for thunderstorms increases to a 30% chance between 21-01z, with a brief lull in activity before a more well-defined line of storms moves in later in the evening. Storms tomorrow will be capable of producing gusty and erratic outflow winds with gusts 35 to 40 kts possible.

REST OF UTAH AND SOUTHWEST WYOMING...Shower activity will dwindle across the airspace through the remainder of the evening and overnight. Isolated showers developing after 15z across portions of northern Utah may result in variable winds for some terminals through the morning. Otherwise, winds remain generally light and diurnally driven across the rest of the airspace through the morning. Widespread convection is expected to develop after 19-21z across much of Utah and southwest Wyoming, moving northeast through the remainder of the evening. A lull in activity is expected across northern Utah in the evening before a more developed area of thunderstorms moves through late in the evening into early Sunday morning. Storms tomorrow will be capable of producing gusty and erratic outflow winds, with isolated gusts to 50 kts possible.

FIRE WEATHER, Issued 1249 PM MDT Thu Aug 27 2026

High pressure has moved over the Four Corners today, and the southerly flow developing is allowing moisture to increase once again. Expect another round of scattered showers this afternoon, primarily focused over the higher terrain, but the increasing southerly flow will provide a bit more valley drift. Increasing instability from the approach of a Pacific Northwest system will also bring the threat of isolated strong to severe thunderstorms capable of producing wind gusts to 60 mph for northern Utah. The trough will bring a cold front through the area late Friday into Saturday. Ahead of the front, southerly winds will become breezy for Friday, particularly for the valleys of western Utah, but increasing moisture should keep relative humidities above critical values. As the cold front passes through, it will bring more widespread coverage of showers and thunderstorms to northern Utah, with at least a few strong to severe gusts. It will also bring cooler temperatures, a higher potential for wetting rains, and increasing relative humidity values. The cooler and more active pattern will continue next week.

SLC WATCHES/WARNINGS/ADVISORIES

UT...None. WY...None.