A fast-moving but potent low pressure system is approaching from the northwest this afternoon, along with a cold front at the leading edge, which will result in a good burst of snowfall across the Salt Lake City area this evening along with snowpacked roads expected for the Monday morning commute.
Conditions are mild and windy ahead of this system this afternoon with temperatures near 40 in Salt Lake City and winds from the south at 20-30mph with gusts to 40mph. We are also seeing some sunshine this afternoon, but take a look at the latest satellite image, and we can see the system quickly approaching from the northwest, with the band of moisture located over NE Nevada and SE Idaho (image source: College of DuPage).
Snow is expected to reach Salt Lake late this afternoon as the cold front arrives and will continue through the evening hours with 1-2″/hour rates possible at times. The prime time for snow will be from about 5pm through midnight, so this will be a short-duration but fairly intense snowfall event.
Snowfall amounts this evening are likely to range from 3-6″ across the SLC area, with higher amounts possible along the eastern benches. Temperatures will fall to near freezing by the time snowfall begins as the cold front arrives, and will drop further into the low 20s by midnight, and into the upper teens by daybreak Monday.
There could be some brief melting on road surfaces at the onset of snowfall, but then snow will quickly accumulate all surfaces with areas of icing also possible overnight. Fortunately, winds will quickly decrease behind the cold front this evening from the NW at 5-15mph, so while there could be some isolated pockets of blowing snow, the overall threat for blowing snow should be minor.
Partial clearing is expected during the day Monday after early cloud cover with highs reaching the low 30s in Salt Lake City. This should allow for good recovery on pavement aside from heavily shaded areas.