textproduct: Salt Lake City

KEY MESSAGES

- High pressure will continue to bring dry and increasingly mild conditions to Utah and southwest Wyoming through early Tuesday.

- A warm Pacific storm system will move through the area late Tuesday through Wednesday, bringing valley rain and mountain snow primarily to the northern half of the forecast area.

DISCUSSION

High pressure is centered over Utah and southwest Wyoming this evening, keeping conditions dry, with just some high clouds observed over northern portions of the area. The ridge will remain in place over the next several days, with its center drifting slowly to the south. As a result, dry conditions will persist through Monday and into Tuesday as temperatures steadily warm. By Monday, maxes will tend to average around 10F above seasonal normals.

As the center of the high slides south, the ridge is expected to gradually flatten over the area, resulting in an increasingly zonal flow aloft. Confidence is high that this flow will tap into moisture from a decaying atmospheric river during the day Tuesday, bringing the initial development of valley rain and mountain snow across primarily far northern Utah. A relatively weak storm system is then expected to move over the top of the ridge late Tuesday into Wednesday, providing additional instability for northern Utah in an already moist airmass, and bringing a cold front through.

Though this is a relatively high confidence forecast given the timeframe, there remains a good amount of uncertainty as to how far south the wave and its associated cold front will track, which impacts temperature and snow level forecasts. Regardless of the amount of cold air, however, it looks nearly certain that valley precipitation will fall as rain given the very mild nature of the airmass. Mountain snow total have, if anything, gone down slightly with this evening's forecast package as guidance is trending somewhat weaker with the system as a whole.

Behind that wave, the broad ridge looks to reamplify along the California coast, bringing a return to mild and generally dry weather beginning late Thursday. A minority of guidance, however, indicates some moisture being drawn back into northern portions of the forecast area during the upcoming weekend, bringing some potential for additional valley rain and mountain snow during that time.

REST OF UTAH AND SOUTHWEST WYOMING

The vast majority of the airspace will see VFR conditions through the night with some high clouds over northern Utah. The exception to this will be in the vicinity of KLGU, where MVFR to IFR conditions will prevail through the overnight hours in fog. The fog is expected to diminish between 15Z and 17Z.

SLC WATCHES/WARNINGS/ADVISORIES

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