textproduct: Salt Lake City

KEY MESSAGES

- An inversion will remain in place across Utah valleys into next week, resulting in stagnant air with decreasing air quality and visibility, particularly along the Wasatch Front.

DISCUSSION

Broad high pressure is centered over the Great Basin this afternoon. A trough on the front side of the ridge moving into the central United States brought an increase in high clouds overnight, and these clouds are finally starting to erode. The trough also brought a modest increase in northerly flow aloft that will relax overnight into tomorrow.

Temperatures are on the mild side for much of the area, with the major exception being the inversion prone valleys, including the Wasatch Front, where temperatures are near normal for this time of year. In the stagnant airmass, particulates continue to accumulate, resulting in decreasing visibility and air quality, currently most evident in the Salt Lake valley.

Another trough will move over the front side of the ridge late Thursday into Friday, and the cold air from this system is expected to move a bit farther west than with the previous system. This will act to cool the airmass aloft somewhat, bringing less mild temperatures for the high elevations. The vast majority of ensemble guidance, however, continues to indicate that though this could weaken valley inversions, it will not be strong enough to mix them out.

Behind that system, the Great Basin ridge is expected to recenter itself a bit farther west. This will act to limit warming aloft, but in light flow the valley inversions will continue to persist. The next chance of seeing mixing occurs late next week with guidance continuing to indicate the potential for a storm system to impact the area. This far out, though, confidence in any scenario remains low.

REST OF UTAH AND SOUTHWEST WYOMING

MVFR vsbys for haze and perhaps fog will persist through the duration of the TAF period at KSVR. Additionally, there is a chance that fog develops in the morning at KLGU. Otherwise, VFR conditions will persist across all other sites not mentioned.

SLC WATCHES/WARNINGS/ADVISORIES

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