textproduct: Salt Lake City

KEY MESSAGES

- Near record to record breaking heat builds in through Tuesday.

- Anomalous heat, single-digit daytime RH, poor overnight humidity recoveries, and modestly gusty winds may bring periods of elevated fire weather conditions to southern Utah through mid-week.

- A more unsettled pattern develops mid-to-late week, introducing chances for thunderstorms across the region.

DISCUSSION

A ridge currently situated along the west coast will gradually shift eastward beginning Sunday, with the ridge axis moving overhead by Tuesday. This pattern favors intense warming through this period, with high temperatures climbing to around 15-25 degrees above average across Utah and southwest Wyoming Monday and Tuesday. The Wasatch Front and other valley locations are likely (70+% chance) to climb over 90 degrees on Monday, the first of this benchmark for the year. Lower Washington County is likely see their first triple digit day of the year through this period, with a 50-60% chance on Monday increasing to a 70+% chance on Tuesday. Given it is only early May and we will be nearing or potentially even exceeding daily records with temperatures more reminiscent of those typically observed in early-to-mid July, take the time now to ensure cooling devices are in working order. If you have outdoor activities planned early this upcoming week, consider shifting them to cooler parts of the day.

Ensembles are beginning to converge on a pattern shift for the mid-to-late week period. Members are now on board for a trough developing along the west coast that will shunt the ridge further east late Tuesday into Wednesday. This will place our area under more moist, southerly flow on the backside of the exiting ridge, with model soundings indicating increasing mid- level moisture areawide through Wednesday evening. These conditions are supportive for the development of afternoon convection Wednesday, mainly across the higher terrain given the lack of outside forcing. Still to be determined is the magnitude of this moisture advection, which will dictate the threat of dry microbursts.

Plenty of uncertainty still remains for the remainder of next week. However, troughing looks to remain the dominant feature across the western US through the end of next week, which will keep temperatures moderated through this period.

REST OF UTAH AND SOUTHWEST WYOMING

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

FIRE WEATHER

An anomalous ridge of high pressure builds in across the region through Tuesday, with high temperatures nearing to potentially exceeding daily records through this period. A very dry airmass will also build into the region through mid-week, with widespread daytime RH values in the single digits to low teens across the state. Overnight humidity recoveries will also be poor (or essentially non-existent, mainly across southern Utah) through Wednesday morning. Winds will remain below critical levels through Tuesday, with strongest gusts generally 20-25 mph mainly across southern Utah. However, periods of elevated fire weather conditions may exist mainly for fire weather zones 495/496/497 where fuels are approaching critical.

An approaching weather system yields gusty southwesterly winds Wednesday afternoon and evening, with widespread gusts 20-35 mph. While daytime RH is expected to increase slightly, values will remain in the low teens, resulting in locally critical fire weather conditions for same zones listed above. Increasing mid- level moisture will also bring about chances for afternoon high- based convection, around a 10-20% chance. Any storms that develop could be capable of producing gusty and erratic outflow winds given dry antecedent conditions.

SLC WATCHES/WARNINGS/ADVISORIES

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