textproduct: Salt Lake City

KEY MESSAGES, Issued 1032 PM MDT Thu Sep 10 2026

- A marginal risk (level 1/4) for excessive rainfall is in place across portions of southern Utah Friday through Sunday.

- There is a ~50% chance the northern valleys will see wind gusts in excess of 45 mph for 3 or more hours Saturday evening into late Saturday night ahead of a strong cold front.

DISCUSSION, Issued 1032 PM MDT Thu Sep 10 2026

A weak shortwave crossing the region embedded in quasi-zonal flow continues to shift across northern Nevada into northern Utah through the overnight hours. Mainly high-based showers are noted on radar moving into far western Utah. A few locations may see a period of light rain overnight, but widespread rain is not expected. Given decoupling, don't expect much of a gusty, microburst wind threat with this high-based convection.

As broad troughing engulfs the Pacific Northwest, the upper level ridge will continue to flatten, allowing for modest moisture advection to shift into southern Utah Friday. The bulk of the CAMS indicate that the highest threat of isolated to widely scattered thunderstorms will be across southern and eastern Utah Friday afternoon into Friday evening. Given the net moisture increase, WPC has outlooked this area in a marginal risk for excessive rainfall. This correlates well with conceptual models and guidance. The flash flood potential product for the southern Utah national park and rec areas has every location in a "possible" for Friday.

By Saturday, weak subsidence will likely suppress convection in most locations, though isolated thunderstorms across far eastern portions of the CWA including the Swell and Capitol Reef area will represent a low end flash flood threat.

As early as Saturday evening, another period of moisture advection will shift into southern Utah ahead of a strong cold front. This front continues to slow down in each iteration of guidance...now looking to reach northwestern Utah after sunrise Sunday, reaching southern Utah by Monday morning. This may provide another window with enhanced moisture for another round of at least isolated to widely scattered thunderstorms across southern and eastern Utah ahead of the cold front.

As far as gusty winds ahead of the cold front, it will be a battle between decoupling and a strong gradient whether northern valleys will see advisory level winds Saturday evening/night into early Monday. NBM probs still suggest around a 50% chance wind advisory criteria will be met, but the later this cold front shifts, the less likely wind advisory criteria will be met.

Much cooler temperatures will build into the region by Monday. Given the slower cold front timing, the cooldown Sunday isn't as aggressive, around 10-15 degrees across northern Utah, with around another 5 degrees of cooling by Monday.

Longer range, southern and eastern Utah is outlooked in a moderate risk for heavy precipitation between the 18th and 20th. Something to keep an eye on...and an indication that an extended period of dry conditions is the less likely outcome through the next few weeks.

AVIATION

KSLC...Increased cloud cover, isolated shower chances, and associated potential for gusty erratic outflow winds will persist into late Friday morning. Winds otherwise follow a normal diurnal pattern, most likely shifting NW ~17-19Z. Cloud cover will then decrease through the day, with diurnally typical winds and VFR conditions favored.

REST OF UTAH AND SOUTHWEST WYOMING...A weak grazing system will bring isolated shower chances to northern terminals through roughly late Friday morning, and isolated convection to southern terminals through Friday afternoon. Aside from the influence of precipitation, winds are expected to follow a diurnally typical pattern. VFR conditions are also anticipated to continue, with cloud cover trending downward as moisture with the system decreases.

FIRE WEATHER, Issued 228 AM MDT Fri Sep 11 2026

A weak grazing system will continue to push a correspondingly weak boundary into northern Utah into Friday morning, bringing increased moisture, cloud cover, and isolated shower chances. Isolated convective redevelopment is then expected across portions of southern Utah Friday afternoon.

Moving into the weekend, the next approaching system will bring increasing deep southwesterly flow. Winds will tend to increase, especially in unsheltered valley locations across western Utah, with daytime gusts around 25-40 mph. Models continue to fluctuate on timing of a cold frontal boundary with this system. In general, and especially if during the day, southwest winds will increase and become maximized ahead of this frontal passage, with a briefer period of gusty northwest winds likely following the front. Largely, this front is expected to by dry in nature with the best chance of precipitation noted across portions of eastern Utah where moisture is favored to be higher. An unsettled pattern will yield continued isolated to at times scattered convective chances along and east of Utah's high terrain through midweek. There is considerable uncertainty in if, and to what extent, tropical moisture may then combine with another system later in work week.

SLC WATCHES/WARNINGS/ADVISORIES

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