textproduct: Salt Lake City

KEY MESSAGES

- Dangerous heat will persist across portions of northern Utah and the low desert of southern Utah into Sunday.

- A marginal risk of excessive rainfall will continue across portions of Utah through the next five days.

- The threat of flash flooding will be most significant across slot canyons, normally dry washes, slick rock areas and recent burn scars.

DISCUSSION

High pressure over the Four-Corners region will continue to support a monsoon surge into Utah over the next 5-7 (or more) days. Evening analysis indicates that a potential MCV is developing over central Arizona. This may rotating around the ridge into Utah Sunday...potentially increasing the threat of flash flooding. This will be something to watch Sunday.

Looking at CAMS this evening, fairly widespread convection is forecast across much of the region. HREF suggest peak rainfall rates Sunday will be between 0.25 to 0.50 inches per hour, however, looking at ground truth today, stronger storms were capable of rates a bit higher than 0.50 inches per hour given slow storm motions.

Adjusted heat headlines based on latest trends. With lows struggling to fall below 80 degrees for the lower deserts of southern Utah, extended the Excessive Heat Warnings for lower Washington County, Zion National Park and Glen Canyon National Recreation Area. Even though highs will be slightly cooler Sunday, the lack of any meaningful relief overnight will continue to create cumulative heat stress...especially for those without adequate cooling and/or hydration.

With cooler temperatures forecast across central Utah, cancelled going heat products for these areas.

Expect convection to continue each afternoon and evening with an attendant flash flooding threat through at least the next 5 to 7 days.

AVIATION...KSLC

Southeasterly winds will continue overnight, likely shifting to northwesterly between 19-20z. However, isolated thunderstorms developing first over higher terrain between 20-00z may result in gusty and erratic outflow winds. A second round of a few showers and thunderstorms may linger into the evening between 01-06z, though confidence is low on timing. VFR conditions will prevail with hazy skies from wildfire smoke.

REST OF UTAH AND SOUTHWEST WYOMING...Winds will continue to subside as lingering showers across mainly southwestern Utah diminish over the next couple of hours. By 10z or so, winds will be largely light and terrain-driven. Scattered showers and thunderstorms are expected to develop after 18-19z across much of the state; any storms will be capable of gusty and erratic outflow winds. VFR conditions will largely prevail outside of areas near local wildfires and outside any blowing dust from outflow winds.

FIRE WEATHER, Issued 152 PM MDT Sat Aug 8 2026

With high pressure centered near the Four Corners area, monsoonal moisture will continue to increase over the area, spreading north and east tonight before lingering in place through the coming week. This will lead to diurnal showers and thunderstorms across the area. Showers and thunderstorms will become more widespread across the area tomorrow. Storms across southern Utah will continue to become increasingly wet tomorrow, while across the north, some storms near the northern/eastern edge of the moisture surge may initially begin on the drier side tomorrow. As humidities increase, wetting rain potential will increase areawide through the coming week. Gusty outflow winds in excess of 45 mph will remain possible with showers and thunderstorms through at least tomorrow. Outside of showers and thunderstorms, winds are expected to remain relatively light and terrain-driven.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Extreme Heat Warning until midnight MDT Sunday night for UTZ101- 102-104-105.

Heat Advisory until midnight MDT Sunday night for UTZ103-106-107- 116.

Extreme Heat Warning until 9 PM MDT Sunday for UTZ123-124-131.

WY...Red Flag Warning until 9 PM MDT Sunday for WYZ277.