textproduct: Salt Lake City

KEY MESSAGES, Issued 1002 PM MDT Wed Aug 19 2026

- Building high pressure will bring a steady warming trend in temperatures through Thursday across the south and through Friday across the north.

- Monsoon moisture will move back into Utah and southwest Wyoming late in the week, persisting through at least early next week. This will bring an increased threat of showers and thunderstorms capable of producing flash flooding.

DISCUSSION, Issued 1002 PM MDT Wed Aug 19 2026

High pressure centered over AZ this evening will shift east on Thursday before ending up over NM/west TX over the weekend where it is expected to remain in place into early next week. This shift will initially aid in a continued warming trend before bringing increased moisture into the area beginning during the Thursday/Friday timeframe. Current PWATs of around 0.8 inches is expected to increase to 1-1.1 inches across the area by Saturday afternoon.

Expect afternoon highs of near to above 100 degrees in many valleys on Thursday even as midlevel moisture starts to creep into southern Utah. On Friday, as the moisture starts to surge into southern and central Utah, temperatures there may begin to cool but continue to trend slightly warmer or at least remaining near persistence across northern Utah. This moisture, the initial surge being associated with a vort max lifting through the area, will then spread into northern Utah by Saturday, allowing for a cooling trend thereafter. HeatRisk is in the Red (Major) category across many valley areas on Thursday, then will become more confined to northern Utah for Friday. Heat Advisories are in effect for west- central through northwest Utah valleys as a result. The need for any Warnings is diminished due to acclimation to hot temperatures throughout the summer.

With the arrival of the moisture, expect increasing coverage of showers and thunderstorms along with increasing heavy rain potential into early next week. There is currently a Marginal Risk of Excessive Rainfall across southern Utah Thursday and Friday. This Marginal Risk will spread through the rest of the forecast area for Saturday and Sunday.

The high pressure looks to slowly start building westward again by the middle of next week. Depending on how for west the high center ends up (as there is still some model spread in this regard), the airmass may start to gradually dry for the second half of next week.

AVIATION... KSLC

VFR conditions will persist for the KSLC terminal through the period. Dry and stable conditions with mostly clear skies will continue with light diurnally driven winds.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist for the entire airspace through the period. Dry and stable conditions will continue across most of the airspace with some isolated convection across the eastern airspace this afternoon. Winds will be relatively light and diurnally driven.

FIRE WEATHER, Issued 256 AM MDT Thu Aug 20 2026

High pressure continues to strengthen across the area with high temperatures today and Friday ~10 degrees above normal for this time of year. While moisture is starting to increase across the region there still remains quite a bit of dry air at the surface. This will keep minimum RH in the upper single digits to 20s across the entire area today. These will improve over the next several days as moisture continues to surge into the area.

As for storms, isolated afternoon thunderstorms will develop across the terrain and portions of eastern Utah. Given the dry surface these storms will struggle to produce wetting precipitation across the lower terrain with strong gusty outflow winds and frequent lightning being the more likely outcome. By Friday afternoon storms will become more widespread across the state with wetting rain chances increasing. Temperatures will trend down to near normal this weekend as increased cloud cover and diurnal storms keep temperatures tapered. This moisture will stick around through the weekend and into early next week with southwesterly winds increasing late weekend.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Heat Advisory from noon today to 7 AM MDT Saturday for UTZ101>106.

Heat Advisory from noon today to 7 AM MDT Friday for UTZ115-116.

WY...None.