textproduct: Salt Lake City

KEY MESSAGES

- Dry and mild conditions persist through the weekend.

- Near record to potentially record breaking heat develops by Monday, persisting through mid-week.

- Widespread anomalous heat, single-digit daytime RH, and poor overnight humidity recoveries bring elevated fire weather conditions Sunday onward.

DISCUSSION

Dry conditions with temperatures running 5-10 degrees above average are expected through Saturday as ridging across the western US is moderated by a weak shortwave trough passing to our north. The ridge amplifies along the west coast on Sunday, then gradually shifts eastward through Tuesday. Gradual warming is expected through this period, with the warmest day being Tuesday as the ridge axis shifts overhead. Ensembles suggest H7 temperatures warming to around 12-14C across northern Utah and 14-16C across southern Utah on Tuesday, which translates to high temperatures around 20-25 degrees above average...more reminiscent of highs typically observed in early-to-mid July.

In addition to potentially record-breaking heat, very dry conditions across the region may yield elevated fire weather conditions early next week where fuels are critical. See the fire weather discussion below for more information.

Details become more murky mid-week as ensembles are more split on the placement of a trough across the west. Regardless, the ridge axis shifts eastward over the Rockies on Wednesday, introducing more moist, southerly flow over the region. Meager mid-level moisture advection under this flow pattern yields low-end (10-15%) chances for high-based thunderstorms across the region Wednesday afternoon.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions will persist for the entire airspace through the period. Dry conditions and clear skies will continue with light and diurnally driven winds.

FIRE WEATHER

High pressure remains the dominant feature over the Intermountain West through roughly the next 7 days. Warming will be limited this weekend, however, as a shortwave trough brushing by to the north on Saturday keeps temperatures somewhat moderated. Enhanced north to northwest winds are expected to accompany the passage of this system on Saturday afternoon, mainly across northern Utah.

Behind this trough, an anomalous ridge of high pressure begins to amplify across the west coast on Sunday, bringing much warmer and drier conditions to the region. The ridge axis will gradually shift eastward before moving overhead on Tuesday. High temperatures climb to around 20-25 degrees above average between this period, challenging records across the state. This ridge will also usher in a much drier airmass, with daytime RH values in the single digits to low teens across the state Sunday onward. Overnight recoveries will be virtually non-existent across southern Utah through at least Wednesday. Winds remain below critical levels through this period, but given fuels across portions of southern Utah already reaching critical levels, could see some elevated fire weather conditions across this area. Increasing mid-level moisture on the backside of this ridge on Wednesday may yield some high-based thunderstorms mainly across the higher terrain, though chances remain low, around a 10-15% chance.

SLC WATCHES/WARNINGS/ADVISORIES

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