textproduct: Salt Lake City

KEY MESSAGES

- Inversion conditions will persist across the northern valleys through at least Tuesday, though with weaker inversions than those that occurred earlier in the week.

- Approximately 40% of ensemble members suggest sufficient mid- level cooling will improve inversion conditions by Wednesday afternoon into Thursday morning.

DISCUSSION

An elongated upper level ridge remains in place across the Pacific coastal states into the western Great Basin this morning. Northerly flow on the west side of a digging upper level trough across the Plains is present across Utah.

Looking at MDCRS (Aircraft) soundings over the last 6 hours, a shallow surface inversion continues...with limited mixing above the surface inversion. Model soundings show inversions gradually strengthening over the next few days, though keeping inversions relatively weak compared to the last few days. This may allow particulates to spread through a deeper layer...and thus improving visibility in haze. Continued to indicate haze in the forecast, but trends will need to be monitored today into Sunday.

Looking at reported visibility across northern Utah overnight, visibility reduction in fog is far less pervasive than the last few nights, with a fog bank developing near the SLC Airport and perhaps the Provo Airport, but no significant reductions being reported near the remainder of the Great Salt Lake. Depending on how the inversion evolves over the next 24 hours, dense fog may increase in likelihood in areas near bodies of water Saturday night into Sunday morning.

As far as when the inversion conditions may end, approximately 40% of the ensemble members show marked cooling Wednesday as a backdoor cold front associated with another Plains trough crosses the region. The remainder hold off until a stronger shortwave trough drops into the Interior West Friday into Saturday.

Now...not trying to be pessimistic...but about this system Friday into Saturday...

To be optimistic, ~60% of ensemble members depict at least 0.01" of precipitation across northern Utah. Or to be pessimistic, ~40% of ensemble members indicate no measurable precipitation will occur with this system across northern Utah. Something to continue to monitor moving forward.

REST OF UTAH AND SOUTHWEST WYOMING

Urban haze along the Wasatch Front will remain in place through the TAF period, though reductions to VIS are expected to be less than what has been seen in days past. That said, conditions will still fluctuate between MVFR and VFR. Otherwise, anticipate VFR conditions across the remainder of Utah and southwest Wyoming with flow remaining light and terrain driven.

SLC WATCHES/WARNINGS/ADVISORIES

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