textproduct: Salt Lake City

KEY MESSAGES, Issued 1038 PM MDT Fri Sep 4 2026

- 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, Issued 1038 PM MDT Fri Sep 4 2026

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...Gusty south winds will prevail over the KSLC terminal throughout the day under clear skies. Gusts are expected to increase over the terminal after around 15Z, with peak speeds expected to be around 25kts through the afternoon. Gusts diminish after sunset, with south flow remaining in place throughout the overnight hours.

REST OF UTAH AND SOUTHWEST WYOMING...Breezy southwest winds remain in place across a majority of Utah and southwest Wyoming today, with many areas seeing gusts pick up after around 15-16Z. The strongest winds are expected across the western and northern half of the area, while the southeast portions of Utah see speeds about 5-8kts slower. VFR conditions are expected to prevail throughout the day, with localized reduced visibility possible over the West Desert due to blowing dust.

FIRE WEATHER, Issued 326 AM MDT Sat Sep 5 2026

Dry and windy conditions will remain in place primarily across western Utah today as low pressure to the west maintains a dry air mass over the region. As compared to yesterday, western Utah will see very little in the way of change from previous days as afternoon minimum humidity at, or below, 15% combines with strong south to southwest winds. Drier conditions are anticipated in eastern Utah, with afternoon minimums falling by upwards of 5% alongside a decrease in afternoon wind speeds.

Moisture will rapidly spread across Utah from Saturday evening through Sunday afternoon. Showers and thunderstorms are expected to build into southern Utah during the early morning hours on Sunday, expanding into central and northern Utah through the remainder of the day. The areas with the highest likelihood of receiving a wetting rain will be the mountainous terrain running parallel with I-15, where the lower lying terrain of western and eastern Utah will see overall lower chances of precipitation. Though areas in western and eastern Utah may not see rainfall, the increase in moisture will bring increased humidity, with good to excellent humidity recovery expected across the state. The moisture quickly exists the region on Monday, though continued chances for precipitation will remain across the northern area mountains. Additionally, a cold front will sweep across the northern and central area on Monday, bringing shifting winds (west to northwesterly) as well as cooler temperatures. Drier conditions should be anticipated by Tuesday and Wednesday as the cooler and drier air mass remains in place, however, another moisture surge is poised to push into Utah during the second half of next week.

SLC WATCHES/WARNINGS/ADVISORIES

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