textproduct: Salt Lake City

KEY MESSAGES

- Locally critical fire weather conditions will occur across portions of southern and eastern Utah Monday afternoon and evening.

- Critical fire weather conditions are increasing in likelihood Thursday afternoon and evening across much of the southern half of Utah.

- The probability of reaching moderate HeatRisk increases over 40% across the northern and central valleys of Utah as early as Wednesday...with probabilities steadily increasing through Saturday.

DISCUSSION

The upper level low responsible for widespread rain across northern Utah continues to shift away from the region this evening. Weak showers continue in association with weak lift embedded in westerly flow across mainly northern Utah. Looking at the HREF members, the majority of solutions suggest these showers will diminish near to after midnight...though impact will be quite limited regardless.

Another shortwave trough rotating on the western flank of the long wave trough will shift into the Pacific Northwest by early Monday. This shortwave trough will shift along the Utah/Idaho border Monday bringing isolated showers and thunderstorms to mainly northern Utah and perhaps the higher terrain of central Utah Monday afternoon and evening. A few microbursts up to 45 mph or so are the most likely impact from any thunderstorms.

Further south, wind gusts in the 25-30 mph range will combine with lowering humidities to bring at least locally critical fire weather conditions to portions of southern and eastern Utah Monday afternoon and evening.

As yet another shortwave trough passes to the north Thursday afternoon and evening, more widespread critical fire weather conditions are increasing in likelihood.

High pressure will build into the region for much of the next week, as the northern stream remains quite active well north of Utah for the most part. HeatRisk will creep up, with probabilities exceeding 40 percent by Wednesday for many northern and central valleys. Temperatures will continue to climb with cumulative heat stress building. By Saturday, the probability of a moderate HeatRisk increases to 65-75% for much of the lower elevations of northern Utah as temperatures increase to the low to even mid 90s. Moderate HeatRisk means that the heat will impact those who are sensitive to the heat, especially those without cooling/hydration, chronic illness, or advanced age.

The main point is that there is little threat of measurable rain for southern and eastern through the next 7 days, and only a few hundredths at best for much of the remainder of the state. With a much drier airmass building in to the region and single digit humidities during the day with poor overnight recoveries by early to mid-week...it will become even more important for Utahns use good best practices (Fire Sense) and avoid any human-related wildfire starts. This includes avoiding parking on high grass, dragging chains, throwing cigarettes out windows and making sure you drown out completely any campfires. See more information at utahfiresense.org.

REST OF UTAH AND SOUTHWEST WYOMING

Winds will be largely light and terrain-driven overnight, with lingering showers ending by 08z. After 17-18z, expect westerly to northwesterly winds across northern UT/southwest WY, gusting up to 20-25kts across southwest WY. VFR conditions will likely prevail with clearing skies, however there is a low chance of fog development overnight at KEVW (15% chance) and KLGU (10% chance) between 10-14z.

FIRE WEATHER

The storm system that brought wetting rain to northeast Utah will continue to exit to the northeast this afternoon into early this evening. As it does so, precipitation will gradually wind down. However, a few additional isolated and generally weak showers and thunderstorms may develop across northern and central Utah this afternoon behind the retreating swath of precipitation.

From Sunday through the rest of the coming week, expect drier conditions along with a warming trend as the storm track remains north of Utah. By the end of week, afternoon max temperatures will trend 5-15 degrees above normal. Meanwhile, afternoon min relative humidities will fall below 15% in most valleys from Tuesday onward, with increasingly poor overnight recoveries. Winds will likely remain on the light side through the period, but if any of the storms to the north end up amplifying more, then the potential for stronger southerly winds will exist, which could then bring critical fire weather conditions.

SLC WATCHES/WARNINGS/ADVISORIES

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