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...KSLC

The SLC terminal will see VFR conditions through the day with some scattered clouds. Southerly winds are likely to persist through the night and into Monday morning. However, there is a 40 percent chance that outflow from nearby thunderstorms will bring periods of gusty and erratic winds to the terminal, primarily between 02-05z this evening, and a 30 percent chance of these thunderstorms crossing within 5SM of the terminal. Northerly winds are expected to develop around 19-20z Monday, but may become gusty and erratic due to the potential (30% chance) for another round of thunderstorms to impact the terminal between 19-23z.

REST OF UTAH AND SOUTHWEST WYOMING...Generally VFR conditions will prevail across the airspace tonight into Monday. Scattered showers and thunderstorms will taper off after 06z, then redevelop Monday afternoon. Pockets of heavy rain and gusty winds may bring brief MVFR conditions and ceilings that could result in temporary mountain obscurations. Outside of showers and thunderstorms, generally light diurnal winds can be expected. Locally reduced visibility in smoke will occur near several large wildfires including near Richfield, near Cedar City, near Morgan, and between Ephraim and Huntington.

FIRE WEATHER, Issued 1256 PM MDT Sun Aug 9 2026

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.