Area Forecast Discussion

KEY MESSAGES, Issued 1054 AM MDT Sat Sep 19 2026

- Cool and dry conditions prevail areawide through the weekend.

- Chances for showers and thunderstorms return late Monday into Tuesday as moist, southerly flow develops over the region.

- The pattern remains progressive through the remainder of the week, with periods of unsettled weather continuing into next weekend.

DISCUSSION, Issued 1054 AM MDT Sat Sep 19 2026

An upper-level low that brought severe weather to northern Utah yesterday will continue to shift eastward and out of our region today. Northwesterly flow behind the associated cold front will keep conditions cool and dry across most of the region today. However, isolated showers and thunderstorms are possible this afternoon across northeast Utah, including the Uinta Basin, as some modest instability lingers in this area. Chances for severe storms are unlikely, with the main threat being heavy rain and small hail from any storms that develop. Continued dry and mild conditions prevail areawide on Sunday under a transient ridge. High temperatures this weekend will run around 5-10 degrees below seasonal normals across northern Utah and southwest Wyoming, whilst highs across southern Utah remain near- normal.

Dry conditions will be short lived as a closed low drops down the coast of California on Monday, introducing moist, southerly flow over the region. A shortwave ejects off this parent low late Monday into Tuesday, lifting northeastward across the forecast area. As such, chances for showers and thunderstorms return to mainly southwest Utah on Monday, with coverage expanding northward across the remainder of the region Tuesday. PWAT values appear to be quite meager through this period, so the heavy rainfall threat will be more limited. A microburst threat appears more favorable from these environmental conditions, especially on Tuesday afternoon and evening, as instability peaks with the passage of the shortwave.

Ridging develops mid-week through the end of the work week, favoring dry and mild conditions through this period. The overall pattern remains progressive, however, with ensembles hinting at the potential for deeper trough to impact the western US with more unsettled weather by the weekend.

AVIATION

KSLC...VFR conditions are forecast to prevail at the KSLC terminal through the TAF period, with a 30% chance of brief periods of MVFR to IFR BKN cigs through the afternoon. Northwesterly winds will persist into early evening, with a late diurnal shift around 04-05z, though winds may remain light and variable through 09z before becoming predominantly light southeast.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected across all airspace terminals, though KEVW and KLGU may briefly see MVFR CIGs and/or vsbys with isolated to scattered thunderstorms this afternoon. Otherwise, mostly clear skies with northwest winds will prevail across most sites.

FIRE WEATHER, Issued 1150 AM MDT Sat Sep 19 2026

Lingering instability as a low pressure system continues to move eastward across northern Utah today will result in the development of isolated showers and thunderstorms across northeastern portions of the state this afternoon. Main threats will include frequent lightning, heavy rain, and small hail. Cooler conditions with elevated RH values continue across the remainder of northern Utah through the weekend, while near-normal temperatures and decreasing RH will exist across southwest Utah. Improvements in both daytime RH and overnight recoveries are expected late Monday into Tuesday as moist southerly flow develops over the region. Chances for showers and thunderstorms increase across southwest Utah late Monday, before spreading northward across the remainder of the state into Tuesday. The main threat from storms that develop through this period will be gusty and erratic outflow winds, especially Tuesday afternoon.

SLC WATCHES / WARNINGS / ADVISORIES

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