textproduct: Salt Lake City

KEY MESSAGES, Issued 1033 AM MDT Wed Aug 26 2026

- Scattered showers and thunderstorms will develop Thursday afternoon, bringing potential for gusty winds as well as isolated heavy rainfall.

- Coverage of showers and thunderstorms will increase further Friday evening, with a grazing trough bringing additional instability for the weekend, along with noticeably cooler temperatures. A more active pattern will continue for much of the upcoming week.

DISCUSSION, Issued 1038 PM MDT Wed Aug 26 2026

Evening satellite and radar analysis continues to show areas of showers and thunderstorms across western Utah from southern Tooele County southward through Beaver County as subtle shortwave energy continues to progress through the forecast area. Showers and isolated thunderstorms are expected to continue eastward through the late evening and early morning hours (around 3AM), primarily in northern Utah and southwest Wyoming as this wave continues its track through the ridge in place.

The next 3 days of weather in the eastern Great Basin region will become quite interesting as moisture from former tropical cyclone Iselle becomes entrained into the mid-latitude flow. While we'll maintain an area of high pressure over the forecast area on Thursday, an upstream trough over the PacNW region will help to bring an influx of mid-level moisture into the entirety of the forecast area, helping to kick off another round of diurnally drive showers and thunderstorms. With a lack of sufficient moisture in the lower levels of the atmosphere, would anticipate an isolated heavy rainfall threat and a more pronounced threat of strong outflow winds in excess of 40 mph. Temperature-wise, we'll see very little in the way of change (+/-1 degree as compared to Wednesday), with similar changes expected in surface humidity.

The trough over the PacNW region is anticipated to remain quasi- stationary through at least Friday afternoon, however, remnant energy from the former eastern Pacific tropical cyclone will phase into the flow across the Great Basin region which will help to provide broad-scale lift across the region. This lift, paired with the influx of lower level moisture, is expected to kick off widespread precipitation across the northern area Friday evening and through Saturday. Model guidance is supportive of the PacNW trough dipping farther south and east from Saturday into Sunday, which will help to shunt moisture and large scale lift into the remainder of the forecast area. As such, would anticipate coverage of precipitation to shift into the remainder of central and southern Utah through the day on Saturday. It's likely that the large scale lift will help to generate abundant cloud cover which may act to limit the amount of thunderstorm activity across the area. In general, anticipating widespread coverage of showers with embedded isolated to widely scattered thunderstorms across Utah and southwest Wyoming, with any thunderstorms carrying high potential for heavy rainfall.

The shortwave associated with the previous TC will shift eastward through Sunday morning, cutting off the broad-scale lift. That said, there is high confidence that the PacNW trough will remain steadfast, placing the forecast area in a favorable position for subsequent ejecting shortwave troughs. Moisture is expected to remain in place over the eastern Great Basin through the day on Sunday, with conditions not showing much potential for stabilization in the wake of the shortwave trough. Therefore, another day of showers and thunderstorms is anticipated on Sunday with the high terrain and adjacent valley areas east of high terrain features expected to see the higher probability of precipitation.

Models show higher amounts of uncertainty revolving around how deep this PacNW trough will become and how far east it shifts through the first half of next week. While temperatures across the forecast area are heavily favored to be below average from Saturday through the middle of next week, there is a fairly high amount of uncertainty (up to 8-10 degrees) with high temperature forecasts due to the aforementioned uncertainty in the upstream trough.

AVIATION

SLC...The SLC terminal will see VFR conditions throughout the TAF period. Outflow may bring southwesterly to westerly winds through 07Z. Otherwise, southerly winds will continue through the overnight hours.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist for the entire airspace through the period with generally light and terrain driven winds. Another round of showers and thunderstorms will develop after 18Z across much of the airspace.

FIRE WEATHER, Issued 1038 PM MDT Wed Aug 26 2026

High pressure will remain over Utah through Thursday. Though the area will see a subtle drying and warming trend, scattered showers and thunderstorms will develop each day, primarily focused over the higher terrain. Any storms that develop will bring the potential for gusty and erratic winds as well as lightning. Coverage of showers will become more widespread as moisture increases. With the ridge shifting east over the weekend, a Pacific Northwest trough will graze northern Utah, bringing a cold front through. Southwesterly winds ahead of the front will become gusty, but relative humidity values are likely to stay above critical values. This will also bring cooler temperatures and more widespread showers and thunderstorms, particularly for northern Utah, with an increasing chance of wetting rainfall. The more active pattern will persist next week, bringing less warm temperatures, occasionally breezy winds, and the potential for convection.

SLC WATCHES/WARNINGS/ADVISORIES

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