textproduct: Salt Lake City

KEY MESSAGES, Issued 1211 PM MDT Sun Aug 9 2026

- Dangerous heat will persist across portions of northern Utah and the low desert of southern Utah on Sunday before high temperatures trend lower.

- A marginal risk of excessive rainfall will continue across much of Utah through the next five days. Expect an increased threat of flash flooding, primarily across slot canyons, normally dry washes, slick rock areas, and recent burn scars.

DISCUSSION, Issued 1211 PM MDT Sun Aug 9 2026

High pressure residing over the Four Corners continues to allow monsoonal moisture to move into the region from the south. This moisture is primarily limited to the mid- levels currently, with dry low levels supporting the threat of strong outflow winds as thunderstorms develop again this afternoon. Convection will be fairly widespread today, with model soundings suggesting MUCAPE around 200-500 J/kg coupled with minimal shear and steep low-level lapse rates...a favorable dry microburst environment. The HREF maximum suggests upper-end wind gusts around 50-60 mph, particularly across western and southern Utah where instability is the greatest.

Similar to yesterday, flash flooding remains a threat across the area despite these dry low levels and slightly faster storm motions today. The highest rainfall rates yesterday were up to 0.50"/hour, with high-res guidance suggesting similar rates today. Although storm motions are faster, convective coverage is a bit higher today, resulting in this increased threat of flash flooding over sensitive areas.

Monsoonal moisture will continue to gradually increase through at least Wednesday, with storms trending wetter alongside a higher flash flood threat. Even after Wednesday, although confidence is a bit lower, moisture is likely to remain elevated heading into next weekend. A developing trough over the west coast is the reason for this lower forecast confidence, which may nudge the ridge and main moisture plume eastward.

As for heat across the region, although high temperatures have decreased by a couple degrees today, nighttime cloud cover left minimum temperatures this morning only dipping into the upper-70s along the Wasatch Front and low- to mid-80s down in St. George. Heat effects are cumulative, therefore have continued the going Extreme Heat Warnings and Heat Advisories for these areas, which are set to expire later this evening as high temperatures continue to trend lower through the week. In fact, forecast highs are currently down to the low-80s along the Wasatch Front by Friday as that trough develops; this is 10-15 degrees below normal.

AVIATION, Issued 1211 PM MDT Sun Aug 9 2026

KSLC...Mostly VFR conditions will persist through the remainder of the period for the KSLC terminal. Afternoon convection will develop across the Oquirrh Mountains with most of the convection staying in the southern half of the valley as it moves to the east. Pyrocumulus will develop this afternoon across the terrain east of the terminal. Decaying storms moving in from the west desert this evening between 02-06Z will bring a threat for gusty outflow winds and rain showers with limited embedded lightning. Conditions dry overnight with light southerly drainage flow developing. Convection redevelops tomorrow afternoon with a 30% chance of convection impacting the terminal.

REST OF UTAH AND SOUTHWEST WYOMING...Mostly VFR conditions across the airspace throughout the period. Convection develops this afternoon and persists through the early evening with ~30% chance of terminal impacts. Additionally, pyrocumulus across the northern airspace will develop this afternoon associated with the Rocky Canyon Fire. Convection will weaken across the central and northern portion of the airspace this evening with gusty outflow winds develop along with rain showers. Conditions overnight will be mostly dry with light diurnally driven winds developing.

FIRE WEATHER

Monsoonal moisture will continue to gradually increase statewide through at least Wednesday, resulting in increasing coverage of showers and thunderstorms, particularly across higher terrain. Today, storms will feature a mix of strong outflow winds statewide and some wetting rains primarily across southern Utah. Wind gusts could reach 50-60 mph with collapsing storms. As moisture continues to increase this week, relative humidities and wetting rain chances will increase alongside decreasing temperatures. Daily afternoon showers and thunderstorms will persist likely through the week, with fairly light winds expected outside of any outflow.

SLC WATCHES/WARNINGS/ADVISORIES

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

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

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

WY...Red Flag Warning until 9 PM MDT this evening for WYZ277.