textproduct: Salt Lake City

KEY MESSAGES, Issued 1044 PM MDT Sun Aug 9 2026

- 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.

- Temperatures will decrease 10-15 degrees by the end of the week with slightly drier air pushing into the area by the weekend.

DISCUSSION

High pressure is centered over the four corners today. This is drawing up moisture into the region with PWATs around 1.1" across southwestern Utah and west central Utah and upwards of 0.9" extending into eastern and northern Utah. This will result in diurnal convection developing each day and persisting through the early evening before weakening and dissipating overnight. Potential for nocturnal convection will be present with any convection that develops into an MCS-ish features, but guidance usually struggles with representing the details of this activity until the day of. WPC ERO shows a marginal risk for flash flooding across the southern 2/3rds of Utah through Wednesday before spreading into all of Utah Thursday and Friday thanks to an approaching trough.

This trough will be moving into the western CONUS during the second half of the week. This will help to develop more widespread convection across northern Utah and SW Wyoming as well as cool temperatures 10-15 degrees compared to where they have been. Highs on Thursday and Friday are forecast to be in the low 80s across most valley locations with low 90s across lower Washington county. As this trough approaches southwesterly winds will increase, but the pressure gradient remains weak which will limit the magnitude of these southwesterly winds to 20-30 mph across the southwester portions of the state.

As this trough continues to push through Great Basin it will push the ridge to the south/southeastern CONUS. Drier air will advect into the area and decrease the flash flood risk as storms become more isolated and high based in nature.

AVIATION

KSLC...Southerly winds shift out of the northwest after 19z, remaining generally breezy except for periods of outflow winds from showers and thunderstorms in the vicinity of the terminal between 21- 04z. Wind gusts in excess of 35 kts are possible through this period. Otherwise, VFR conditions generally prevail through the period, though a brief reduction to MVFR VIS could be achieved under a cell producing heavy rainfall. Dry conditions prevail through the remainder of the night with light southeasterly winds persisting.

REST OF UTAH AND SOUTHWEST WYOMING...Across northern Utah, environmental conditions are favorable for pyrocumulonimbus development on the Rocky Canyon Fire near East Canyon Reservoir late this afternoon, but is heavily dependent on fire activity remaining high. Otherwise, widely scattered showers and thunderstorms developing this afternoon will move northeast through the evening, capable of producing gusty and erratic outflow winds to 40 kts for nearly all regional terminals. VFR conditions generally prevail for most terminals, though MVFR VIS may develop briefly under heavy rainfall. Outside of outflows, winds remain generally light and diurnally driven through the TAF period.

FIRE WEATHER

The monsoon pattern remains in place for the remainder of the week. This moisture will primarily be focused across the southern 2/3rds of the area through midweek before a trough moving in from the west helps to develop more convection across the north Thursday and Friday. Temperatures will also decrease by 10-15 degrees by the end of the week. Nocturnal convection will be possible through the week, but details will likely remain uncertain on where and when until the day of any nocturnal activity as these features are usually based on how the convection evolves during the day.

This trough will bring slightly drier air to the region for this weekend which will reduce the flash flooding probabilities. It will also slightly increase southwesterly winds Thursday and Friday, but the magnitude of these winds currently look to remain below 30 mph.

SLC WATCHES/WARNINGS/ADVISORIES

UT...None. WY...Red Flag Warning until 9 PM MDT this evening for WYZ277.