textproduct: Salt Lake City

KEY MESSAGES

- Gusty winds out of the southwest persist through at least Sunday across much of Utah and southwest Wyoming, with an emphasis on areas west of I-15.

- Tropical moisture advects north into Utah Sunday increasing chances for precipitation, but uncertainty remains regarding QPF totals.

- There is a slight risk for flash flooding along with the potential for some strong thunderstorms.

- There is ~45% chance that tropical moisture returns towards the end of next week.

DISCUSSION

An impressive early season trough is currently positioned across the Pacific Northwest and is producing a notable thermal gradient with high temperatures across Utah in the upper 80s to low 90s while areas to our northwest in southwestern Idaho struggled to get out of the 50s. This thermal gradient is also coinciding with a pressure gradient that has kept winds gusty out of the southwest across much of the area with max wind gusts between 30-40 mph with a few isolated locations between 45-55 mph (briefly). This trough will continue to linger over the next couple of days just to our northwest which will keep winds elevated and similar in magnitude to what we have experienced the past couple of days.

The base of this trough will rotate through the Great Basin on Sunday while pulling in tropical moisture from Hurricane Marie. This moisture is slated to arrive Sunday morning in tandem with a 110+ kt jet. The majority of the guidance has Utah positioned in the right entrance region of this jet leading to upper-level diffluence and a narrow swatch of relatively heavy precipitation. There are some differences in the solution, however with much drier solutions. The 10th-90th percentile QPF totals range from almost nothing to upwards of 1.00"+ of precipitation from a band that sets up from southwest Utah up through southwestern Wyoming. Additionally, the arrival of a cold front late Sunday into Monday morning will provide another area of focused convection with the majority of guidance pinpointing northwestern Utah as the favored location of this convection. A high shear/low cape environment is denoted amongst most guidance which could lead to some quasi- linear convection with the potential for strong gusty winds.

The post-frontal airmass will bring cooler and drier weather into the region through the first half of the week. Beyond that, ensemble members become divergent with a 45/55 split of a wet/dry pattern. The 45% of members phase the remaining moisture of Hurricane Marie into a trough across the PNW with a trajectory into the Great Basin. The other 55% of members phase this moisture into a low off the PNW coast which would lead to a drier solution for the Great Basin.

AVIATION

KSLC...Ongoing pattern expected to persist with dry southwesterly flow. At times when winds relax overnight, modest low level shear around 30-35 kts is anticipated through 2 km AGL or so. Gusts will redevelop following sunrise and persist through the day, once again relaxing by later in the evening. VFR conditions prevail with some high clouds beginning to filter in Saturday night.

REST OF UTAH AND SOUTHWEST WYOMING...A pattern dominated by dry southwesterly flow will persist. At area terminals where winds relax overnight, modest low level shear of around 30-35 kts through the first 2 km AGL or so is anticipated. Occasional high clouds will filter in, especially beginning Saturday night, but VFR conditions prevail.

FIRE WEATHER, Issued 123 PM MDT Fri Sep 4 2026

Moisture will continue to gradually increase into the weekend as southwesterly flow pushes moisture further north. Today and tomorrow, expect locally critical fire weather conditions primarily across the West Desert and Great Salt Lake Desert where humidities may drop below 15%. Additionally, strong wind gusts across areas primarily west of I-15 will range from 30-45mph each afternoon into Sunday.

On Sunday, a stronger push of moisture arrives to Utah with widespread showers and thunderstorms across the state, though primarily across central and southern Utah. Temporary drying is expected Monday and Tuesday, though the pattern developing midweek supports another round of moisture pushing north subsequently increasing chances for showers and thunderstorms across Utah once again.

SLC WATCHES/WARNINGS/ADVISORIES

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