textproduct: Salt Lake City

KEY MESSAGES, Issued 121 PM MDT Wed Sep 9 2026

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

- Isolated showers and thunderstorms are possible Friday and Saturday ahead of a cold front.

DISCUSSION, Issued 121 PM MDT Wed Sep 9 2026

Visible satellite over the Great Basin shows mostly clear skies areawide aside from a few high clouds across the Uintas. This is due to our synoptic setup of a ridge to our south and an active northern stream that is keeping us in an area of zonal flow resulting in warm dry days and cool nights with light and diurnally driven winds. The one exception to this is across the western Uinta Basin and portions of the Swell that tend to get enhanced winds in westerly flow. This pattern will continue on Thursday before our pattern begins to transition ahead of a cold front.

By Friday a trough will start digging into the PNW with westerly flow aloft transitioning to southwesterly flow. This will allow some mid and upper level moisture to stream back into the Great Basin. As upper level diffluence starts to overspread the region there will be some isolated showers and thunderstorms Friday and Saturday, primarily across eastern portions of the CWA, however some CAMs are suggesting some convection developing across northern Utah on Friday afternoon as a subtle shortwave precedes the parent trough.

Saturday will have the strongest winds as southwesterly winds enhance. Ensemble guidance gives ~50% chance of advisory levels winds across areas along and west of the I-15 corridor. These winds will decrease after the cold front moves through Saturday night with some enhanced post frontal winds across valleys of eastern Utah. Temperatures will fall 10-20 degrees behind the front with our coldest air of the season likely by Monday morning with many valley locations dipping down into the 30s and 40s.

Deterministic EC and GFS both depict a rex block setting up off the west coast next week that would likely keep southwesterly winds in place along with warm and dry conditions.

AVIATION

KSLC...VFR conditions will prevail over the KSLC terminal with little to no operational concerns. Largely clear skies persist through the evening hours, with light northerly winds becoming southerly after 04Z. South winds prevail through the night before returning to a northerly flow tomorrow afternoon.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will prevail across all terminals through the valid TAF period. Diurnally driven flows will persist through the next 24 hours, with most locations seeing a transition to downsloping flows around 03-04Z this evening.

FIRE WEATHER, Issued 315 PM MDT Wed Sep 9 2026

High pressure to our south and low pressure to our north will keep winds aloft out of the west and keep the dry warm air in place along with light diurnally driven winds. The exception to this will be across the western Uinta Basin where winds will be gusty up to 25 mph with low relative humidity creating locally critical fire weather conditions.

The pattern starts to change on Friday as winds start to transition to the southwest ahead of an approaching cold front. This will help to bring a little bit of mid and upper level moisture back to the area, but precipitation will likely remain isolated and across southeastern portions of Utah. There won't be much low level moisture that moves into the area so relative humidity will remain in the teens and 20s for most low elevation areas. This paired with gusty winds 30-45 mph on Saturday will result in locally critical fire weather conditions.

This mostly dry cold front will move through overnight Saturday through Sunday morning with a transition to weaker northerly winds and increasing relative humidity along with temperatures dropping 10-20 degrees.

SLC WATCHES/WARNINGS/ADVISORIES

UT...None. WY...Red Flag Warning until 9 PM MDT Thursday for WYZ277.