textproduct: Salt Lake City

KEY MESSAGES

- An influx of smoke originating from numerous fires across the Pacific Northwest will continue through at least Thursday.

- A combination of gusty winds and low relative humidity will result in critical fire weather conditions across the western Uinta Basin and San Rafael Swell today.

- A gradual warming trend through the latter half of the week brings potential for widespread dangerous heat to develop Friday into Saturday.

- Chances for afternoon showers and thunderstorms with microburst potential begin as early as Thursday across southwest Utah, with the threat continuing into the weekend.

DISCUSSION

Relatively benign conditions are expected areawide today on the backside of an upper-level trough currently centered over the Northern Plains. Enhanced west to northwest flow across portions of eastern Utah, however, will result in gusty winds developing across the San Rafael Swell and western Uinta Basin particularly in areas favored by downsloping. This will result in another period of critical fire weather conditions this afternoon and evening for these locations. Otherwise, conditions remain dry with near to slightly above normal temperatures areawide today.

The aforementioned west to northwest flow across the region today will also continue to transport both near surface and vertically integrated smoke from numerous fires across the Pacific Northwest. Specifically, high resolution guidance is showing a notable surge this evening into Wednesday morning across northern Utah as near- surface smoke currently pooled across the Snake River Plain gets pulled along the Wasatch Front as winds switch more northerly overnight. Across central and southern Utah, the Widemouth 2 Fire will continue to push smoke into southeast and south-central Utah through Wednesday. While concentrations will fluctuate through the period, smoke is expected to linger through at least Thursday morning as fires around the region remain active under hot and dry conditions. As such, expect hazy skies to continue especially across central and northern Utah and southwest Wyoming, in addition to deteriorated air quality.

High pressure developing across the western US mid-to-late week will result in a warming trend into the weekend, with temperatures peaking on Saturday around 10 degrees above average. Widespread Major to locally Extreme HeatRisk emerges Friday and Saturday for valley locations, indicating heightened concerns for heat-related illness. HeatRisk remains elevated into Sunday for northern and central Utah valleys as overnight lows remain warm due to increasing cloud cover.

While moisture availability remains limited this week, chances for afternoon showers and thunderstorms emerge as early as Thursday given increased instability from intense heating under the ridge. Daily chances will continue through the weekend, with best chances for development across the southern mountains. Given dry low levels, the main threat for storms late week will be dry lightning and gusty and erratic outflow winds. There is potential for increasing PWATs from a modest monsoonal surge into southwest Utah as early as Sunday, which would bring an increasing risk for isolated flash flooding into early next week. However, confidence is low at this time on the coverage and magnitude of flash flooding potential.

AVIATION, Issued 737 AM MDT Tue Aug 4 2026

KSLC...Minimal operational concerns are forecast for the KSLC terminal through the valid TAF period, with clear skies prevailing. Lingering valley smoke will drop visibility into the MVFR category during the early morning hours at times. This smoke is expected to clear mid-tolate-morning, though is likely (60% chance) to return late tonight. Light south to westerly winds will turn northwesterly between 15 and 17Z.

REST OF UTAH AND SOUTHWEST WYOMING...Most areas of Utah and southwest Wyoming are expected to follow light diurnally driven flows with VFR conditions prevailing. That said, area smoke settling into valley areas may bring a reduction in VIS to MVFR thresholds. Visibility is expected to improve by mid- to late-morning with breezy west to northwest winds prevailing areawide. Additional smoke is likely to move in from the northwest tonight, impacting northern Utah terminals.

FIRE WEATHER

Enhanced west to northwest flow behind an upper- level system will bring gusty winds this afternoon and evening mainly across the Uinta Basin and San Rafael Swell. Existing critically dry conditions will allow a period of critical fire weather conditions to develop today across these areas as a result. Upper- level flow becomes lighter on Wednesday through the remainder of the week as high pressure begins amplifying across the western US. This pattern will bring a warming trend in addition to a continuation of critically dry conditions and poor overnight humidity recoveries through Saturday. Chances for afternoon showers and thunderstorms return mainly to far southwest Utah as early as Thursday, but limited moisture will yield a dry lightning and microburst threat with any storms that develop. High temperatures are expected to peak around 10 degrees above average across the region on Saturday, before a more modest monsoon surge brings increasing cloud cover Sunday into early next week that will moderate daytime highs, but keep overnight lows quite warm with improving overnight recoveries.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Red Flag Warning until 9 PM MDT this evening for UTZ482-489.

WY...None.