textproduct: Salt Lake City

KEY MESSAGES, Issued 1159 AM MDT Sat Sep 12 2026

- An isolated flash flood threat will persist as moisture remains in place across primarily southeastern Utah.

- Breezy southwesterly winds will develop Saturday and Sunday afternoons, with gusts up to 35 mph on Saturday and up to 40 mph on Sunday ahead of a cold front. The highest wind gusts are expected across western valleys and in Uinta Co., WY.

DISCUSSION, Issued 1159 AM MDT Sat Sep 12 2026

Southwesterly flow will continue to strengthen across the region ahead of a trough currently pushing into the PacNW. Gusts this afternoon are expected to reach up to 35 mph across typically prone areas such as western valleys south of I-80 and across Uinta Co., WY. Tomorrow, as this trough approaches, southwest flow will further increase though still remain under advisory criteria around 40 mph in these same areas. High-res guidance suggests an initial boundary will develop across northern Utah as a distant shortwave trough rotates through the mid-level low, which will result in somewhat lighter, westerly flow around the Salt Lake Valley northward. As a stronger shortwave passes through the main low Sunday evening and overnight, this will bring the main cold front through northern and central Utah, resulting in colder temperatures and a switch to gusty northwesterly winds. Monday highs will reach 5-10 degrees below normal across northern areas (near normal across central/southern Utah).

Lingering moisture across southeastern Utah will result in isolated thunderstorms developing this afternoon between mainly Lake Powell up into the Uinta Basin. Given that this moisture is relatively shallow in the mid-levels, the main threat will be gusty outflow winds, with just an isolated flash flood threat given any training storms over a sensitive area. Southwest flow will potentially draw a bit more moisture over the state on Sunday, however model guidance shows higher uncertainty in the magnitude of this moisture. Similar to today, the flash flood threat will still remain fairly isolated despite slightly higher spatial coverage of storms, particularly considering quicker storm motions.

The cold front will struggle to scour the moisture out of southeastern Utah as it dissipates partway through the state, thus expect isolated to scattered showers and thunderstorms to develop each afternoon this week. Across the rest of the area, expect dry conditions and gradually warming temperatures.

Uncertainty increases greatly by mid-week, with potential for another shortwave trough drawing moisture northward across Utah late Wednesday into Thursday. Around 30% of ensemble members suggest this shortwave does not develop, which would likely yield quieter conditions.

AVIATION, Issued 1159 AM MDT Sat Sep 12 2026

KSLC...Light and variable winds currently across the terminal are expected to transition to a prevailing northwest around 19z. A normal diurnal wind switch is once again expected between 02-03z, with increasingly gusty southerly winds developing late night/Sunday morning in advance of a cold front. Frontal passage is expected to switch winds back to northwest between 19-21z. VFR conditions will continue to hold.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected to prevail across the airspace throughout the valid TAF period. Gusty southerly winds are expected today, largely focused across southern and eastern portions. Isolated showers and thunderstorms are expected this afternoon and evening across southern and southeastern Utah, but will dissipate with loss of solar input this evening.

FIRE WEATHER

Lingering moisture across southern and eastern Utah will result in isolated to scattered showers and thunderstorms Sunday afternoon, with gusty outflow winds and moderate-heavy rain being the main threats. Large-scale southwesterly winds will continue to strengthen ahead of a cold front, with gusts up to 40 mph possible across western valleys. A dry cold front will then move through northern and central Utah before dissipating late Sunday into early Monday morning. This front will bring a quick transition to briefly gusty northwesterly winds alongside cooler temperatures, particularly further north.

Through at least Wednesday, expect a gradual warming trend with most areas seeing little to no precipitation. Given moisture hanging on across southeastern Utah, these areas still could see isolated showers and thunderstorms each afternoon. Additionally, minimum RH will remain elevated across much of southern and eastern Utah, exceeding 30 percent in most areas. Western valleys, especially further north, may continue to see minimum RH in the upper teens with good overnight recoveries.

SLC WATCHES/WARNINGS/ADVISORIES

UT...None. WY...None.