textproduct: Salt Lake City

KEY MESSAGES, Issued 159 PM MDT Wed Jul 29 2026

- Scattered showers and thunderstorms moving across the forecast area through the remainder of the day will bring an increased threat of heavy rainfall and flash flooding before conditions dry out substantially by Thursday. - There is a high chance that temperatures will become extremely hot by the weekend as the ridge continues to build, bring the potential for an increase in heat related illness.

- An active northern storm track is expected to bring an increase in southwest winds late this weekend. There is a low to moderate (30-50%) chance of critical fire weather conditions developing Sunday and Monday afternoon.

DISCUSSION, Issued 159 PM MDT Wed Jul 29 2026

Two waves of energy can be noted on satellite analysis this afternoon; one across northeast Utah/ southwest Wyoming and one across southwestern Utah. For the northern area, this shortwave is fairly worked over, with stratiform rain and isolated thunderstorms translating through the Uinta Mountains and Uinta County, WY. The southern shortwave, however, continues to produce a concentrated area of strong showers and thunderstorms as it continues to march northward. A moisture rich near-surface environment and stout synoptic support for lift will continue to support a threat of flash flooding under this area of showers and thunderstorms. This area of storms is expected to track northeast through the remainder of the evening, with the eastern side of the disturbance looking like the primary focus area for stronger convection. As the northeastern Utah wave continues its track northeast as well, northern Utah will then move out of the subsident wake which will assist with development of showers and thunderstorms across Utah's West Desert. Isolated storms are expected to progress into the Wasatch Front through the evening, mainly the northern portions, and bring potential for strong outflow winds in excess of 40 mph.

By Thursday, a much drier air mass will build into the area and cut off nearly all chances for showers and thunderstorms across the forecast area. Locations which may continue to see isolated shower and thunderstorm activity will be the Uinta Mountains, where high elevation surface heating may tap into high-based instability associated with the departing mid-level moisture. Otherwise, anticipate a cumulus field to develop over the high terrain through the afternoon hours. There's generally a low chance (10% or less) that these clouds develop into showers, but if it's going to happen, it'll happen over the central Utah mountains. That said, there will be a much lower chance for heavy rainfall and flash flooding. By Friday, moisture will be hard to find over the area as surface relative humidity falls into the single digits to low-teens across the entire area alongside a near zero chance for showers.

In addition to the drier air mass, a significant warming trend is expected across the entirety of the forecast area. Each day from Thursday through Saturday, daytime highs are expected to increase by 3-5 degrees with overnight low temperatures following suit. By Friday, temperatures along the Wasatch Front will climb back to the triple digit mark with overnight lows only falling into the low- to mid-70s. For the lower elevations of southern Utah (lower Washington County/ Glen Canyon area), high temperatures will bump into the low-110s with overnight lows only dropping into the upper-70s to low-80s. As such, a litany of heat headlines (extreme heat watches, warnings, and heat advisories) have been issued and will go into effect starting at noon on Friday.

An active northern jet stream over the PacNW and northern Rockies region late in the weekend is expected to help bring an increase in southwest winds across a portion of Utah. Pairing with the very hot and very dry conditions, these increasingly breezy southwest winds will bring elevated to near-critical fire weather conditions across southwest, west-central, and northeast Utah on Sunday and Monday afternoon. A dry cold front is anticipated to move into northern Utah and southwest Wyoming Sunday night into Monday, bringing at least some relief from heat. If enough northwest flow develops in the wake of this potential cold front, we may begin to see impacts from wildfire smoke originating the Columbia Basin as we head into the first half of next week.

AVIATION

KSLC...A line of thunderstorms is expected to impact the terminal within the next hour bringing frequent lightning and gusts in excess of 50kts out of the west. Following these gusts, variable winds are possible behind the storms for an hour before southerly winds resume. Following this convection, VFR conditions will resume with light terrain driven winds at the terminal.

REST OF UTAH AND SOUTHWEST WYOMING...A line of thunderstorms will continue to impact all northern UT sites over the next 1-2hrs bringing gusts in excess of 40kts and frequent lightning with heavy rainfall. This threat will extend to KEVW later on within the next 2- 3hrs. Following this, conditions will improve making way for VFR conditions with light and terrain driven winds across all TAF sites.

FIRE WEATHER, Issued 159 PM MDT Wed Jul 29 2026

One final moisture surge moves across Utah through the remainder of today, allowing for scattered shower and thunderstorm development across a majority of Utah. Under stronger storms, heavy rainfall and frequent lightning are expected. With drier air in place over far northern Utah, any storms developing in this region will be capable of outflow wind gusts in excess of 40 mph.

As we move into Thursday, a significant drying of the air mass is expected as high pressure repositions nearly overhead. Afternoon relative humidity is expected to fall by upwards of 10 percent in the western area and by as much as 30 percent in the eastern area. A less significant day of drying is expected, however, relative humidity is expected to drop into the single digits to low-teens across a majority of Utah (including the high terrain features) by Friday. Alongside this significant drying trend, a significant warming trend is also expected. High temperatures in the lower elevation areas across western and eastern Utah will be reaching into the low- to mid-100s, with temperatures as high as 112-114 in the lowest elevations of southern Utah. Adding to the very hot and very dry conditions, an active storm track to our north is anticipated to dip far enough south by late this weekend to bring an increase in southwest winds. There is currently a low to medium chance (30-50% probability) for critical fire weather conditions to develop over a portion of west-central, southwest, and northeast Utah on Sunday and Monday. Thereafter, hot and dry conditions will remain in place through at least the middle of next week.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Heat Advisory from noon Saturday to 9 PM MDT Sunday for UTZ101- 115-116-120>122.

Extreme Heat Watch from Saturday afternoon through Sunday evening for UTZ102-104>106-114.

Extreme Heat Warning from noon Friday to 9 PM MDT Sunday for UTZ123-124-128>131.

WY...None.