textproduct: Salt Lake City

KEY MESSAGES, Issued 1213 PM MDT Sat Jul 18 2026

- Scattered showers and thunderstorms are expected to develop across portions of central, southern, northeast UT, and southwest WY each afternoon within this forecast as monsoonal moisture continues making its way north.

- The risk for flash flooding continues across the majority of the forecast area, highlighted by WPC with a Marginal Risk (1/4) of exceeding flash flood guidance each day encompassing nearly all of UT. A Slight Risk (2/4) of exceeding flash flood guidance exists across southern UT this afternoon, Sunday afternoon across southwest UT, and Tuesday afternoon across southwest UT.

- A Flash Flood Watch remains in effect for southern UT and portions of Central UT this afternoon, ending around midnight. Additionally, another Flash Flood Watch has been issued for southern UT and portions of central UT tomorrow afternoon.

DISCUSSION, Issued 1213 PM MDT Sat Jul 18 2026

The monsoonal pattern persists across the southwest as broad ridging remains overhead. Beneath this ridge, PWATs in excess of 1" continue to overspread most valley locations with southwest UT potentially exceeding 1.6" PWATs once again this afternoon. Daily chances for showers, thunderstorms, and potentially flash flooding continue for the foreseeable future across southern and central UT with this pattern in place. Modest moisture return continues to push across northern UT, though most storms have remained anchored to the terrain further east each afternoon due to drier PBL conditions across northwest UT valleys and considerably weaker steering flow. This brings great uncertainty to the forecast each day, keeping PoPs generally 10% or less across most of the Wasatch Front and northwest UT. Some deeper boundary layer moisture may build into the area Monday afternoon, though considerable uncertainty remains.

With PWAT anomalies statewide once again ranging from 0.5" to nearly 1" this afternoon, the threat for flash flooding is expected to continue across southern and central UT. Tall, skinny CAPE profiles (potentially in excess of 1000J/kg) with a deeper warm cloud layer supports yet another round of efficient rainmakers with heavy rain expected from well established storms. The stronger instability axis with CAPE values >= 1000J/kg once again resides across southwestern UT, supported by both SPC Mesoanalysis and current CAM guidance, with storms expected to initiate along higher terrain and propagate down terrain toward the instability gradients. A similar failure mode to yesterday exists across southeast UT where cold pool development and eastward propagation leads to strong CIN as storms propagate southwest, resulting in shallower convection with eastern extent favoring weaker storms. A few wetter storms are still possible, though not nearly as widespread as coverage is forecast across southwest UT.

Forecast guidance continues to hone in on the monsoonal pattern persisting with weak steering flow aloft continuing as ridging remains overhead through the remainder of the forecast period. Sunday and Tuesday stand out in particular as robust mid-level moisture rides along the southern periphery of the ridge into southern UT, reflected by the WPC Slight Risk (2/4) for excessive rainfall for each respective day. Monday has some potential for more isolated flash flooding, though drier mid-levels may hinder vertical extent of these storms and moisture quality overall.

AVIATION, Issued 1213 PM MDT Sat Jul 18 2026

KSLC, Issued 1213 PM MDT Sat Jul 18 2026... VFR conditions are expected over the KSLC terminal through the TAF period alongside showers and isolated thunderstorm development over the nearby high terrain. Northwesterly winds will dominate through at least 01z, with a 20% chance for erratic outflow winds to impact the airfield between 00-03Z. Easterly winds are possible for a brief period between 01-03z, with a 40% chance these don't materialize and the typical shift to diurnal southeasterlies appears around 03-04z.

REST OF UTAH AND SOUTHWEST WYOMING...Scattered showers and thunderstorms will continue across the southern half of the area today, with more isolated coverage across the northern area. Storms producing heavy rainfall may drop VIS to MVFR thresholds. Across the northern portion of the airspace, storms will be capable of producing gusty and erratic outflow winds to 30 kts throughout the afternoon, primarily at HCR and EVW. Coverage of showers and thunderstorms will become more isolated through the evening. Outside of any outflow winds, anticipate diurnally driven flows across all terminals.

FIRE WEATHER

Monsoonal moisture continues to surge north into UT increasing humidities while raising chances for showers and thunderstorms across the state, both serving to moderate fire weather conditions. Chances for showers and thunderstorms remain highest across central and southern UT, high terrain across northern UT, and the Uintas ranging from 60-90%. A wetting rain remains favored this afternoon across each mentioned location. Expect showers and thunderstorms to develop along higher terrain parallel to I-15 each afternoon over the next several days around 1200-1300 with gusty outflow winds, heavy rainfall, and lightning. Winds will generally remain light terrain driven / diurnal over the next several days.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Flood Watch until midnight MDT tonight for UTZ122>128.

Flood Watch from Sunday afternoon through Sunday evening for UTZ122>128.

WY...None.