textproduct: Salt Lake City

KEY MESSAGES

- Persistent monsoon moisture will bring a daily threat of showers and thunderstorms, primarily focused over the higher terrain, through Thursday.

- Coverage of showers and thunderstorms may become more widespread, particularly for northern portions of the area, Friday through the weekend due to the passage of a grazing trough.

- Highs averaging up to 5F above seasonal normals are expected to drop to values near or below normal by the weekend.

DISCUSSION

Utah and southwest Wyoming remain under the influence of high pressure this morning, with the ridge axis centered roughly over Utah. This is bringing mostly clear skies with generally light flow aloft. Lingering monsoon moisture remains in place, with satellite derived PWs primarily in the 0.7 to 0.9 inch range, in the 75th to 90th percentile for this time of year. This should be more than enough moisture for convective initiation over the higher terrain this afternoon, but the lack of flow and lack of additional instability will result in a more limited valley threat than the past few days. Highs today will average about 5F above seasonal normals.

Little change in the weather pattern is anticipated through Thursday, with the ridge axis creeping ever so slightly east each day, eventually returning to the Four Corners by Friday. Thus, convective threat will remain mostly unchanged with a subtle warming trend. By Wednesday into Thursday, portions of far southern Utah will see isolated pockets of HeatRisk values in the red (major) range, but at this time the elevated risk of heat related illness does not look widespread enough to warrant heat related headlines. Additionally, will see enough drying during this time for RH values in western and southern valley locations to approach critical levels, though winds will remain generally light.

Rather than parking near the Four Corners for the weekend, guidance is increasingly suggesting that the ridge will continue east, potentially opening up the West to a more active pattern for the weekend and into early next week. The ridge should initially limit the influence of a Pacific Northwest storm system over the weekend, keeping it as primarily a grazing feature for northern portions of the area. Main impact will be on temperatures as the associated front moves through Saturday, with maxes up to 5F below seasonal normals anticipated by early next week. The resultant increase in instability will also bring the potential for more widespread convective activity, particularly for northern Utah and southwest Wyoming. With the ridge then most likely out of the picture, at least for the time, troughs will have the potential to bring more significant impacts for the forecast area. However, any details on the potential timing, track, and strength of any of these systems remains low at this time.

AVIATION, Issued 448 AM MDT Tue Aug 25 2026

KSLC...VFR conditions will persist for the KSLC terminal through the period. Variable winds associated with nearby showers will continue through 12Z before conditions dry and a light southerly flow returns. Isolated thunderstorms redevelop this afternoon, but there is <30% chance of impacts to the terminal. Winds will primarily be light and northerly during the afternoon.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist for the entire airspace through the period. A few showers across the northern airspace continue to decrease in coverage. Isolated storms develop this afternoon with <30% chance of impacting most terminals. Winds will be light and diurnally driven aside from gusty and erratic winds near storms that develop.

FIRE WEATHER

High pressure will remain over the area through at least Thursday. Lingering monsoon moisture will allow for the daily development of showers and thunderstorms each afternoon and evening, with limited drift off of the terrain. Any storms that develop will be capable of producing gusty and erratic winds. Relative humidity values for the valleys of western and southern Utah are expected to move closer to critical values for Wednesday and Thursday, though winds will remain generally light. The ridge will track east of the area Friday through early next week, with a grazing Pacific Northwest system providing increasing southerly winds Friday into Saturday. However, the southerly flow will be drawing additional moisture northward during this time. A cold front on Saturday will bring less warm temperatures and an increased potential for convection, particularly for northern Utah. The absence of the persistent ridge will bring a more active pattern beginning early next week, though confidence is low on the details at this time.

SLC WATCHES/WARNINGS/ADVISORIES

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