Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
423 AM EDT Mon Apr 06 2020

Valid 12Z Mon Apr 06 2020 - 12Z Thu Apr 09 2020


...Southwest U.S....
Days 1-3...

A closed low drifting south of the coast of Northern California
will become cutoff from northern stream flow today and stall off
southern California into the midweek before shifting onshore.
Continued enhanced Pacific moisture flowing around the system and
snow levels generally 5000 to 6000ft will make for heavy snow over
the southern Sierra Nevada and southern CA ranges (particularly
the San Gabriel and San Bernardino Mtns), as well as the higher
mountains of Clark Co, NV today into Wednesday/Day 3. For the
three day period ending 12Z Thursday, WPC PWPF has moderate to
high probabilities for accumulations of 18 or more inches for
these mountain ranges.

As the system shifts inland Wednesday night into Thursday it
pushes into a ridge and weakens. Moderate precipitation/mountain
snows are still expected though in northern Arizona (snow levels
also about 5000 to 6000ft) into southern Utah where there are low
to moderate Day 3 risks for 8 or more inches.

For Days 1-3, the probability of significant icing (0.25-inch or
greater) is less than 10 percent.

Jackson