textproduct: Salt Lake City

KEY MESSAGES

- Critical fire weather conditions will again develop in portions of south central to southeast Utah through the day Thursday due to gusty winds and low humidity values.

- Cooler and more unsettled conditions return Friday on through the weekend as a broad area of low pressure moves through the area.

- High pressure is favored to return early next week, bringing drier weather and warming temperatures.

DISCUSSION

A broad low continues to spin over the Great Basin this evening, with the center currently over southern California. The position of the low is resulting in enhanced southerly flow across the area, which produced some strong winds again today, particularly for southwest Utah. With drier air having advected into the area, convection was once again suppressed, with rather mild conditions prevailing.

With the low moving little tomorrow, little change in conditions is expected. The pressure gradient will decrease somewhat, making the threat of 40+ mph gusts much more isolated, but the breezy and dry conditions will combine to produce another day of critical fire weather conditions where fuels are dry over southeastern Utah.

Being nudged by a Pacific ridge, it looks like the Great Basin low will finally be on the move Friday, crossing Utah and southwest Wyoming through Saturday morning. This evening's guidance is now initially showing a more southern track for the center of the low during the day Friday, putting the best instability for scattered showers and thunderstorms over southern Utah.

For Friday night into Saturday, the low will move roughly northeast, putting the best instability during that time over northern Utah and southwest Wyoming. Available moisture at this point in the guidance is trending upward, so it looks like associated showers will be fairly widespread, though associated accumulations look to be on the low side. Though the center of the low is expected to exit the area Saturday morning, some showers could linger into the afternoon hours. A weak wave following on the system's heels may bring a few additional showers to northern Utah during the day Sunday. Behind the trough, temperatures will drop to at least seasonal normals across the area, and likely several degrees below for northern portions of the area.

Drier and warmer air looks to advect back into the area by early next week, though the Pacific ridge may not formally build back into the area until the middle of next week. Still, confidence is high in continued dry and mild conditions during this period.

REST OF UTAH AND SOUTHWEST WYOMING

Winds will lighten up overnight in most locations, with a preference for a southerly/southeasterly direction overall. One exception is KCDC, though forecast confidence is low. Although southerlies have largely decreased, gusts could ramp back up as early as 09z or as late as 14z. Gusts may be intermittent overnight at KCDC before becoming more steady around 30-35kts during the day. Breezy southerly winds will prevail once again after 15-16z across Utah and southwest Wyoming.

FIRE WEATHER

An expansive area of low pressure remains across much of the west. Locally, this is resulting in deep southerly flow which is driving dry and gusty conditions across Utah. With widespread gusts in the 25-40 mph range or so and daytime minimum humidity values in the teens to single digits, elevated to critical fire weather conditions will develop where fuels are sufficiently dry for Thursday. Unsettled conditions will return Friday into the weekend as the low finally crosses the area. It will bring cooler temperatures in addition to showers and thunderstorms. Initially precipitation coverage will be favored across the high terrain of southern Utah Friday, shifting to northern Utah overnight on through Saturday as the low lifts out. As such, areas of northern Utah have better chances to see wetting rains. High pressure is then favored to return early next week, resulting in drier conditions along with a warming trend.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Red Flag Warning until 9 PM MDT Thursday for UTZ494-498.

WY...None.