textproduct: Salt Lake City

KEY MESSAGES

- High-based showers capable of producing gusty and erratic outflow winds to 50 mph will develop across southern Utah Sunday afternoon and evening.

- The threat for thunderstorms and gusty outflow winds shifts into northern Utah Monday afternoon and evening, with additional precipitation anticipated on Tuesday.

- Temperatures dip to near seasonal normals Tuesday, but building high pressure beginning Wednesday will allow temperatures to rebound through the weekend.

DISCUSSION

Recent satellite imagery shows cumulus buildups across southern Utah early this afternoon, resulting from increased mid- level moisture advection courtesy of a cutoff low nudging into southern California. Mesoanalysis indicates instability will begin to steadily increase through the afternoon across southern Utah, which will support the development of more robust updrafts resulting in scattered thunderstorm activity through the evening. Model soundings continue to show inverted-V profiles across southern Utah, given very dry antecedent conditions. Models indicate widespread DCAPE values between 800-1000 J/kg this afternoon across southern Utah, with more isolated pockets approaching 1200 J/kg across lower Washington County. These environmental conditions are prime for microbursts producing gusty and erratic outflow winds up to 50 mph, though can't rule out an isolated gust in excess of 55 mph.

Showers will continue moving northward and taper in intensity late Sunday, with shower activity dwindling across southern Utah by early Monday morning as a dry slot moves in overhead. The cutoff low becomes elongated as it begins to phase with a deepening northern stream trough Monday afternoon, which will increase instability across northern Utah and southwest Wyoming and result in scattered convection developing across the area, including the Wasatch Front. Microbursts producing gusty and erratic winds to 50 mph will once again be the main concern through the evening.

The low is expected to phase with the northern stream longwave trough on Tuesday as it sweeps through the Desert Southwest. Moisture advection from the northern stream trough is expected, which will support more widespread showers and thunderstorms on Tuesday afternoon. especially across northern Utah. Increased moisture throughout the atmospheric column will minimize the wind threat with these storms. Cooler air will also usher into the region courtesy of this system, with temperatures moderating to near-seasonal normals on Tuesday.

Other than some lingering showers over the high terrain Wednesday, much drier conditions will settle in across the region as high pressure quickly builds back in across the western US. A gradual warming trend is expected through at least the end of the work week, with highs climbing back around 10 degrees above average by Friday.

REST OF UTAH AND SOUTHWEST WYOMING

A system will gradually lift northward through the TAF period. This will impact southern terminals late afternoon into the the early overnight with scattered showers and thunderstorms, bringing potential for gusty erratic outflow winds and periodically reduced VIS/CIGS. While shower chances decrease in the south moving into Monday, this activity then brings similar impacts to northern terminals late Monday morning on through the day. Outside of the influence of showers and thunderstorms, winds at area terminals generally follow a normal diurnal pattern.

SLC WATCHES/WARNINGS/ADVISORIES

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