A Vigorous Cold Front & Snow Expected Monday Night into Tuesday.

The current El Nino winter has brought plenty of precipitation to Utah. Most areas are above average on liquid water since October 1st, including the Wasatch Front Valleys. Mountain snowpack is well above 100% of average across the state. 

Mild temperatures have kept much of the valley precipitation in the liquid form, unlike last year. Snow has been hard to come by in the valleys with an active mild southern stream jet. Only 2.2" of snow has fallen at the SLC airport this month (10.7" avg month of February). As you can see, snowfall since start of the October 1st water year is running less than half of normal: 

I fully expect to end the valley snow season well below average even with above average rainfall. But, we can certainly add to our meager seasonal snow amounts at SLC! Here's a look at the jet stream forecast Monday 5pm:

You can see a cold polar jet driving a low-pressure system from the Pacific Northwest into Utah. A sub-tropical jet will be pumping moisture into Utah ahead of the cold front. This will add juice to our storm! You can see Precipitable Water will reach near 200% of average as the front approaches Monday evening:

Models remain very consistent in showing a vigorous surface front with sharp temperature gradient. Any brief rain will quickly change over to snow sometime after midnight Monday night. There is a bit of uncertainty with timing. But good agreement on a strong front as seen using the 850-700 mb thickness values-

With the milder moist air in place as the front pushes through, strong lift should produce 2-3 hours of moderate to heavy snow. We could also get some thunder as the front moves through, maybe thundersnow!! As for amounts, 2-4" of snow seems like a good early estimate for most valley locations. Slightly higher along the benches. This is a fast mover which will limit larger accumulations. 

There is some question regarding possible lake effect and if that will add to amounts through Tuesday evening. It's just too soon to know yet but watch the forecast! Be prepared for slippery road conditions for the Tuesday morning commute.