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 1220 PM MDT Sat Jun 20 2026

KSLC...Scattered showers and TS will develop this afternoon, potentially impacting the terminal between 22-02z with lightning and gusty outflow winds. There is a 10% chance that VRB wind gusts briefly exceed 50kts, and a 30% chance of lightning within 5 miles. VFR conditions will prevail, though could briefly go MVFR with blowing dust with any outflow. Elevated smoke will likely remain far to the south.

REST OF UTAH AND SOUTHWEST WYOMING...Scattered showers and TS will develop this afternoon across N-UT/SW-WY between ~21-03z. Any showers will be capable of producing gusty and erratic outflow winds, with a 10 percent chance of gusts briefly exceeding 45kts. VFR conditions will prevail across most areas, though wildfire smoke may produce locally MVFR VIS near wildfires. Elevated smoke may be seen across southern UT in particular.

FIRE WEATHER

A weather system crossing the northern Rockies is pushing a cold front through northern Utah early this afternoon. Ahead of this front, very low RH combined with gusty winds is resulting in another day of critical fire weather conditions across central and southern Utah mainly east of I-15. To the west of I-15, although wind speeds are a little weaker fire weather conditions remain elevated, and a few localized pockets of critical fire weather conditions may develop this afternoon where terrain influences locally enhance wind gusts.

Along and behind this front, daytime heating will allow for widely scattered high based showers and dry thunderstorms across northern Utah this afternoon. These storms will be most numerous near the Idaho border region and will be accompanied by strong outflow winds in excess of 40 mph, with a few gusts exceeding 60 mph possible. As the cold front sags into west central Utah, isolated dry thunderstorms will be possible late this afternoon and early evening across northern portions of zone 492 and potentially impact the Iron fire.

A slightly cooler airmass will spread across the area Sunday dropping daytime temperatures to near normal across the state. Despite this, very low RH daytime RH across central and southern Utah will continue to result in elevated fire weather conditions. High pressure will bring a warming trend through the first half of next week, with a return to hot and very dry conditions by Tuesday. This high will break down later in the week, however confidence is low regarding how this plays out. Solutions Thursday into Friday range from a drier southwest flow potentially resulting in critical fire weather conditions, to a influx of moisture bringing a decent chance for showers and thunderstorms.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Red Flag Warning until 10 PM MDT this evening for UTZ478.

Red Flag Warning until 10 PM MDT this evening for UTZ482-484-488- 489-493-494-496-498.

WY...None.