textproduct: Salt Lake City

KEY MESSAGES, Issued 1220 PM MDT Sat Jun 20 2026

- Gusty west to southwest winds with gusts in excess of 30 mph will combine with very low relative humidity values to bring critical fire weather conditions to areas of central and southern Utah east of I-15 on Saturday.

- Widely scattered showers and thunderstorms, mostly dry, will develop over northern Utah this afternoon and evening, with the best chances near the Idaho border. Strong outflow winds in excess of 50 mph can be expected with these storms, along with dry lightning.

- High pressure will rebuild for early next week, keeping conditions very dry with a steady warming trend in temperatures. The potential for heat related illness could increase for some valleys by the middle of the upcoming week.

DISCUSSION, Issued 1220 PM MDT Sat Jun 20 2026

An upper trough slowly making its way through the northern Rockies has pushed a cold front through much of northern Utah. Ahead of this feature gusty west to southwest winds and very low relative humidity will continue to bring critical fire weather conditions across much of central and southern Utah east of I-15 through this evening. A Red Flag Warning remains in effect for these areas. Further north, closer to the upper forcing and cold air aloft associated with the upper trough, a band of showers and thunderstorms is gradually weakening as it lifts along the Idaho border region and will continue to do so into the early afternoon hours.

Hi-res guidance is in good agreement developing scattered convection by mid afternoon across northern Utah, with the threat shifting east of the Wasatch Crest into the Bear River Valley and southwest Wyoming late this afternoon into the early evening. Strong outflow winds will be possible with this convection, with the greatest threat east of the Wasatch Crest extending into Uinta County WY. Further west, a slightly more stable post-frontal environment may mute the microburst threat a bit, which seems to be indicated in hi-res guidance. Regardless, this activity should largely exit the forecast area by mid-evening.

A more stable airmass will settle across the forecast area Sunday cooling daytime temperatures to near climo. This reprieve will be short lived, as mid level ridging amplifying across the region early next week will bring a warming trend, and a return to hot and very dry conditions. By Thursday this ridge looks to break down as an upper trough approaches the Pacific Coast. Spread in the guidance lends to a considerable amount of uncertainty regarding how this trough evolves as it moves inland, but there is some potential for moisture to be pulled northward into the forecast area by Thursday...something to keep an eye on.

AVIATION, Issued 942 PM MDT Sat Jun 20 2026

KSLC...Vertically integrated smoke from various wildfires across northern Utah will continue to impact slantwise visibility through the period. The nearby Bonneville Fire east of the terminal may produce visibility reductions overnight as winds lighten and smoke settles to the valley floor, dependent on continued fire activity. Otherwise, northwest winds become lighter overnight and continue through Sunday, though may become more variable at times between 10- 14z.

REST OF UTAH AND SOUTHWEST WYOMING...Vertically integrated smoke from various wildfires will continue to impact slantwise visibility across the airspace through the period. Moderate to heavy surface smoke is possible across portions of central Utah overnight near active wildfires. Winds are expected to taper areawide overnight, with more terrain-driven winds developing for southern Utah terminals Sunday afternoon. Enhanced northwesterly breezes develop Sunday afternoon across the remainder of the airspace.

FIRE WEATHER

A more seasonal day is expected today across UT as high pressure begins to settle in behind the exiting system moving east. Temperatures will see a decrease closer to climatological normals and winds are forecast to taper off somewhat. Very dry conditions remain in place statewide with southern UT forecast to experience elevated fire weather conditions this afternoon given single digit humidities and gusts from 20-30mph.

Come Monday, high pressure begins to establish itself over the region serving to raise daytime high temperatures markedly into the mid to upper 90s each day across most UT valleys, with lower Washington county seeing temperatures break into the 100s. Humidities will also see a steady drop across the entire state through at least Tuesday with widespread humidities in the low teens to single digits.

Humidities begin to see an increase, potentially as early as Wednesday starting with southern and central UT as southwest flow begins to settle in ahead of an approaching system. Wednesday appears to potentially usher in a return to a period of critical fire weather conditions as winds see an increase areawide, as well as the potential for high-based dry thunderstorms. A similar environment exists Thursday, though coverage of thunderstorms increases across southern and central UT with some development of thunderstorms expected across northern UT. Winds appear to strengthen markedly Friday and potentially Saturday with the highest confidence surrounding the development of critical fire weather conditions occurring through this stretch.

SLC WATCHES/WARNINGS/ADVISORIES

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