textproduct: Salt Lake City

KEY MESSAGES

- Valley rain and mountain snow will become widespread over northern Utah and southwest Wyoming during the day Monday with the passage of a cold front, bringing some high elevation accumulations.

- A colder system impacts the region late Wednesday through Thursday, bringing better chances for more substantial mountain snow and potential for light valley snow.

DISCUSSION

A low remains parked over the northern California coast this evening, with the associated cold front draper over northeast Nevada and far northwest Utah. As the front approaches, seeing precipitation (valley rain, snow levels at or above 9,000 feet) start to spread into the area. The front should move slowly over northwest Utah overnight, its speed increasing as the low opens up and catches up with its frontal boundary by late Monday morning. The arrival of the trough will also bring frontogenesis along the boundary, bringing heavier and more widespread precipitation with it (snow levels lowering to as low as 7,000 feet by late afternoon) as it moves across the area through the evening. An unstable northwest flow will keep some showers going, primarily over the higher terrain, into Tuesday morning before the trough pulls out of the area.

Guidance continues to show high confidence in another relative lull late Tuesday into early Wednesday as weak ridging develops in between storm systems. The next system in this train is on track to arrive late Wednesday into Thursday. This system will be colder in origin, coming from the Pacific Northwest, but a bit less organized. The majority of solutions are now showing more moisture associated with this system than they were at this time yesterday, and also are favoring somewhat slower movement of the trough, increasing the period of precipitation over the area. Thus, expected mountain accumulations have increase somewhat and the chance for northern valley snow goes from minuscule to simply low (10-20%).

Behind that system, maxes across the area should be running near normal for this time of year (for once), with some indications of an at least somewhat unsettled pattern continuing into the upcoming weekend, though model spread in the details remains quite high.

REST OF UTAH AND SOUTHWEST WYOMING

At northern terminals, shower chances increase overnight, with a brief decrease in activity ~11- 16Z Mon or so. A cold front will then push through late morning into the afternoon, enhancing precipitation, and generally W to NW winds. There is roughly a 10-30% chance of some embedded -TSRA around time of frontal passage. Some shower activity will then linger on into the evening. VFR conds largely prevail, with ~20-30% chance of MVFR conds during periods of heavier precip, and ~5-10% chance of IFR in any -TSRA. At southern terminals, gusts W to SW winds develop through the day, with frontal passage ~01-04Z Tue. Lower precip chances are noted further south.

SLC WATCHES/WARNINGS/ADVISORIES

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