textproduct: Salt Lake City

KEY MESSAGES

- Somewhat drier air will move into the area over the weekend, decreasing the threat of showers and thunderstorms. However, moisture is expected to increase again starting Tuesday. - Hot temperatures as high as the lower 100s can be expected for the valleys of northwest Utah as well as the Uinta Basin through Monday, with highs in the upper 100s for portions of southeast Utah, including Zion National Park. Overnight lows will remain in the 70s to around 80, limiting the potential for overnight relief from the heat.

DISCUSSION

High pressure is centered east of the area this morning, over Colorado and Wyoming. A Pacific Northwest trough is making its way over the top of the ridge, flattening that feature as it does so. For us, the primary impact is to add more of a westerly component to the flow over Utah and southwest Wyoming, which is allowing some drier air to filter in. Satellite derived PWs are in the 0.8 to 1.0 inch range across the area. While this is still in the 75th to 90th percentile, this is a notable change from the near 99th percentile values observed over southern Utah yesterday, and this gradual drying trend will continue through the remainder of the weekend. Thus, while afternoon and evening convection is still anticipated, primarily focused over the higher terrain, coverage will be a bit less, and there is a bit more steering flow, which slightly decreases the potential for flooding.

Despite the drying, enough moisture will be around to keep low temperatures elevated. In the valleys, this means that many valley locations will stay in the 70s to around 80 overnight with high temperatures rising above 100F, with the lack of relief contributing to an increased risk for heat related illness. Main change with this forecast package was to add Heat Advisories for Zion National Park, south central Utah, and western Canyonlands, as well as to add an Extreme Heat Warning for Lake Powell, all in effect through Monday like the existing heat headlines for northwest Utah.

By Tuesday, shifting of the ridge is expected to return Utah and southwest Wyoming to a more southerly flow aloft, which would draw monsoon moisture back northward into the area, with increasing confidence that this moisture would then remain in place for most of the remainder of the upcoming week. It looks like that the increasing moisture may moderate high temperatures somewhat for Tuesday into Wednesday, though low temperatures will most likely remain elevated. This should decrease the HeatRisk a bit, but there are some indications temperatures will be on the rise again late in the upcoming week, something to monitor.

AVIATION, Issued 527 AM MDT Sat Jul 25 2026

KSLC...Southeasterly winds will prevail through the morning, likely transitioning to northwesterly after 19-20z. Confidence in shower and thunderstorm development is low this afternoon, resulting in low confidence in wind direction given a gusty wind threat with these storms. An initial few storms will likely develop off the higher terrain between 19-23z, potentially followed by a (even lower confidence) second push of showers and gusty outflow between 03-07z. VFR conditions will prevail.

REST OF UTAH AND SOUTHWEST WYOMING...Showers and thunderstorms will begin to form over higher terrain after 17-18z, becoming more scattered across all but far southwest Utah after 20z. These storms will be capable of producing gusty and erratic outflow winds, with the highest winds possible across northwest Utah, potentially exceeding 50kts. Outside of outflow, winds will slightly favor a westerly to southwesterly direction during the afternoon, and will be light and terrain-driven otherwise. VFR conditions will likely prevail, though a heavier shower could produce a temporary VIS reduction.

FIRE WEATHER, Issued 455 AM MDT Sat Jul 25 2026

Drier air moving into the area over the weekend will cause a gradual decrease in coverage of showers and thunderstorms through Monday. On Sunday, these storms will likely be limited to southern and eastern Utah as a weak wave passes through. In general, storms this weekend will be capable of producing gusty and erratic outflow winds up to 45 mph, the exception being today across northwest Utah where gusts could exceed 60 mph.

With this drier air moving in, portions of western and southern Utah are expected to see minimum relative humidity values approach critical levels on Saturday, potentially becoming more widespread Sunday into Monday. While forecast confidence is still fairly low across northern and western Utah, moisture is likely to increase again across the rest of the state beginning Tuesday.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Heat Advisory until midnight MDT Monday night for UTZ101>107-114.

Heat Advisory until midnight MDT Monday night for UTZ124-128-130.

Extreme Heat Warning until midnight MDT Monday night for UTZ131.

WY...None.