textproduct: Salt Lake City

KEY MESSAGES

- Increasing winds Thursday brings the threat for elevated to locally critical fire weather conditions 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.

- Gusty southwesterly winds develop areawide Saturday and Sunday, resulting in more widespread critical fire weather conditions.

DISCUSSION

Generally benign weather is expected through Wednesday as our region remains under the influence of a broad ridge along the west coast. Temperatures warm further tomorrow, with highs approaching or breaking into the 90s for most valleys and the 100s for lower Washington County.

This gradual heating is moderated across northern Utah on Thursday as a weak shortwave brushes by to the north. Models have trended this wave a bit farther north with more west-to-northwest flow aloft, which has resulted in winds trending down a bit over southern Utah and up across portions of eastern Utah, including the Uinta Basin. Specifically for the western Uinta Basin, there is a 40-60% chance for winds in excess of 25 mph through the evening.

Heat maximizes across Utah and southwest Wyoming Friday and Saturday as southwesterly flow increases across the region in response to a trough deepening into the Pacific Northwest. Highs during this period will top out around 10-12 degrees above seasonal averages. Widespread Moderate to locally Major HeatRisk is expected for most valley locations during this period, meaning those sensitive to heat should take extra care to avoid heat illness.

As the trough digs further south Saturday into Sunday, strong southwesterly winds are expected to develop areawide by Saturday afternoon. Current guidance suggests a 20-30% chance for portions of western Utah to see gusts exceeding 45 mph late Saturday as flow aloft maximizes over the area. Gusty winds continue into the first half of Sunday, then gradually taper off as the system lifts northward through the remainder of the day. Cooler temperatures will remain behind this system on Sunday, with highs trending around 5-10 degrees cooler.

REST OF UTAH AND SOUTHWEST WYOMING

No significant weather expected at area terminals. VFR conditions are expected to prevail with some clouds filtering through above 10 kft or so. Winds at most terminals will be fairly light (less than 15 kts), with some modest gusts expected at typically gusty or exposed locations (e.g. EVW/CDC). Directions anticipated to follow a diurnally normal pattern.

FIRE WEATHER

Very dry conditions will remain in place across the state through at least this weekend, especially across southern Utah where overnight recoveries will be extremely poor. Concerns for elevated to potentially locally critical fire weather conditions arise on Thursday as a weak system brushes by to our north, bringing increasing winds on Thursday afternoon. Recent guidance has backed off on the magnitude of winds across southern Utah, however, with only a 20-30% chance for localized gusts in excess of 25 mph. The westerly to northwesterly winds on Thursday will instead favor strongest gusts to 30 mph across eastern Utah. Southwesterly flow increases aloft beginning late Friday as a stronger system digs into the western US. Gusty surface winds will develop by Saturday afternoon, with widespread gusts 30-40 mph across the state, persisting into Sunday. More confidence exists for critical fire weather conditions to develop this weekend, especially where fuels are critically dry across southern Utah.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Fire Weather Watch from Thursday morning through Thursday evening for UTZ496-498.

WY...None.