textproduct: Salt Lake City

KEY MESSAGES, Issued 1151 AM MDT Sat Aug 29 2026

- Multiple rounds of scattered showers and thunderstorms are expected to occur this afternoon across UT, primarily northern and central UT where strong to severe storms are expected.

- Flash flooding concerns exist across UT today through at least Monday. Of the days within this stretch, Monday looks to be the most concerning. - Weather areawide may calm down somewhat by midweek, though some uncertainties remain regarding this solution.

DISCUSSION, Issued 1151 AM MDT Sat Aug 29 2026

Currently, a deepening upper trough is pushing inland with its axis centered over WA/OR with a shortwave to its southeast progressing NE through the Great Basin. Ample mid-level mass response has developed an enhanced belt of southwesterlies atop strong mid-level frontogenesis, serving as a focal point for thunderstorm development across northern UT this morning. A few severe wind gusts have been observed primarily across the Great Salt Lake Desert with sub-severe hail closer to the Wasatch Front, though northeasterly winds and surface temperatures in the 60s have largely limited the severe threat keeping storms elevated instead of surface based due to a stable boundary layer. A few stronger gusts can't be ruled out with this complex as it moves further east into the Uinta basin where surface temperatures have continually warmed this morning in the absence of cloud cover, though gusts are not expected to be widespread.

Through the remainder of the afternoon, multiple shortwave perturbations embedded within the flow will traverse northwest UT serving as a focal point for thunderstorm development. Continual moistening of the boundary layer with daytime heating increasing with the erosion of a persistent cloud deck should result in increasing instability generally south of a line extending from Wendover to Salt Lake City yielding MLCAPE values from 1000-1500J/kg, perhaps higher if cloud cover clears faster. Additionally, enhanced southwest flow aloft will result in Eff. Shear values exceeding 40kts across a large portion of northern UT to central UT, supporting the development of supercells capable of wind gusts potentially in excess of 70mph and hail to around 1".

Flooding remains a concern today as well, particularly if more supercellular convection develops given the moist environment characterized by PWATs from 1-1.3" of water. However, this threat may be limited by fast ENE storm motions today, though would still pose a problem if storms are to track over problematic terrain and burn scars.

Tomorrow, the upper trough progresses through ID serving as a focal point for widespread thunderstorm development tomorrow afternoon across UT. Moisture, instability, and shear leave much to be desired, though portions of southern UT may see some flash flood threat develop with slower moving storms associated with a trailing wave. Come Monday, the threat for flash flooding across southern UT increases substantially as a stronger moisture surge races north. High PWATs, potentially as high as 1.3-1.5" of water are expected to advect north amidst an environment favorable for slow moving (and potentially backbuilding) storms. Some uncertainties exist regarding this, though Monday is shaping up to be quite wet across southern UT in particular.

AVIATION

KSLC...Southerly winds are expected to prevail through the evening and into the morning, with passing showers and thunderstorms causing periodic gusty and erratic winds. The strongest storms will be capable of producing heavy rainfall that may result in periods of MVFR to IFR conditions.

REST OF UTAH AND SOUTHWEST WYOMING...For northern terminals, widespread showers and thunderstorms are expected to persist through the evening and into early morning before dissipating. The strongest storms will be capable of producing gusty and erratic outflow winds and heavy rainfall that may result in periods of MVFR to IFR conditions. Southern terminals will remain gusty into early evening.

FIRE WEATHER, Issued 1226 PM MDT Sat Aug 29 2026

Active weather continues today with strong to severe thunderstorms developing this afternoon across northern and central Utah with a flash flooding threat also developing this afternoon across central and southern Utah. Regarding the severe threat further north, wind gusts in excess of 58-70mph and hail to around 1" are expected this afternoon with any of the stronger storms that form. Across southern Utah, monsoonal moisture continues to surge north bringing an attendant flash flooding threat to the area through at least Monday. While storm development across southern Utah may be somewhat muted Sunday afternoon, Monday appears somewhat concerning regarding rainfall high rainfall rates and amounts. Regardless, a wetting rain is expected across the entirety of Utah through early next week.

Following this active patter, a drying and cooling trend will take place as most showers and thunderstorms appear to remain confined to the higher terrain at this time. Temperatures will run roughly 5F below seasonal normals with RH approaching normals around mid- week.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Flood Watch through Monday evening for UTZ116>121-123>131.

WY...None.