textproduct: Salt Lake City

KEY MESSAGES

- Increasing winds this afternoon brings the threat for elevated to locally critical fire weather conditions to Southern UT where fuels are critically dry.

- As temperatures climb through Saturday, the threat for heat- related illness increases for those who are sensitive to heat, without adequate cooling or hydration, or have chronic health conditions.

- More widespread critical fire weather conditions develop across central and southern UT Saturday, lasting through at least Wednesday as widespread wind gusts look to develop statewide.

DISCUSSION

Today, modest zonal flow will persist across the Great Basin resulting in generally diurnal winds across much of UT. A weak mid-level shortwave will slowly traverse across southern UT bringing localized gusts to 30kts across the area. With single digit humidities in place, near-critical fire weather conditions may develop locally across southern UT this afternoon.

Through the remainder of the week into the weekend, gradual height rises amidst dry westerly flow is forecast to occur which will serve to raise temperatures markedly. Heating is moderated somewhat across northern UT tomorrow due to the aforementioned shortwave brushing by slowly this evening. regardless, the warming trend is forecast to continue through Saturday with temperatures ranging 10-15F above average across just about the entirety of the forecast area. Temperatures will continue to climb Friday and Saturday as a deepening trough progresses toward the Great Basin bringing prolonged southwesterly flow into the region. While these temperatures continue to fall short of HeatRisk related headline issuance across most valleys, please take precautions to keep yourself and others safe such as staying hydrated, wearing light colored and loose clothing, and limiting time in the direct sunlight.

As we draw closer to the weekend, confidence regarding the fire weather threat across central and southern UT continues to increase as a deepening midlevel trough progresses toward the Great Basin. A strengthening pressure gradient amidst strong mixing to around 5km from the surface favors strong winds translating to the surface out of the southwest. Chances for gusts greater than 30mph range from 50- 80% across most central and southern UT valleys on Saturday and 90%+ across southwest UT. Additionally, chances greater than 40mph are generally 20-40% across most of southern and central UT with 60%+ across southwest UT. With poor overnight recoveries and widespread single digit humidities Saturday afternoon, critical fire weather conditions will exist across central and southern UT Saturday.

Regarding Sunday, there is at least some potential for isolated scattered dry thunderstorms with attendant strong to severe microbursts. Widespread PVA amidst height falls and inverted-V soundings across northern UT may favor the development of these storms across northern UT Sunday afternoon. Lightning is also possible with this storms in the presence of some instability aloft, potentially yielding a more localized fire weather threat across northern UT Sunday afternoon.

On Sunday across southern and central UT, a frontal boundary will slowly move east with time keeping the gusty wind threat more confined to southeast UT. Critical fire weather conditions will remain in place across central and southern UT, though winds are expected to taper off with a midlevel trough lifting north of the area displacing synoptic wind support from the region somewhat. Despite this, confidence continues to exist regarding critical fire weather conditions due to ample coverage of expected wind gusts greater than 30mph and humidities in the single digits to low teens.

Monday and Tuesday, however, bring another interesting round of critical fire weather conditions to the area as models hone in on some stronger winds moving into the area. Additionally, the fire weather threat looks to persist through at least Wednesday given enhanced midlevel flow via persistent troughs across the western U.S..

REST OF UTAH AND SOUTHWEST WYOMING

No impactful weather expected across the airspace through the TAF period. Enhanced westerly winds with gusts 20-25 kts are expected for southern and eastern Utah terminals this afternoon; otherwise, winds generally follow diurnal trends for all other regional terminals.

FIRE WEATHER

A notably dry period remains in place with near- critical fire weather conditions this afternoon locally across southern UT given low humidities and pockets of gusts greater than 30mph.

A prolonged period of critical fire weather conditions looks to develop this Saturday, lasting through at least Wednesday next week as multiple systems move through the area. These systems are expected to be dry and serve to bring multiple days with gusts greater than 30mph in the afternoon hours amidst humidities in the single digits to low teens. On Saturday, winds will see a notable increase out of the southeast with high confidence in widespread gusts greater than 30mph, and medium confidence in scattered gusts greater than 40mph (~40% across central and southern UT). A cold front will shift this threat more towards southeast UT on Sunday, though gusty and dry conditions will remain in place across much of central and southern UT. Monday and Tuesday stand out given high confidence in widespread wind gusts in excess of 40mph across central and southern UT with humidities in the single digits to low teens.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Fire Weather Watch from Saturday morning through Tuesday evening for UTZ484-489-492>498.

WY...None.