Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
438 PM EDT Sat Apr 04 2020

Valid 00Z Sun Apr 05 2020 - 00Z Wed Apr 08 2020


...Western U.S....

Days 1-3...
A weakening system will continue to produce mountains snows as it
lifts across northern California and Oregon Saturday evening. 
This will quickly be followed by a deepening closed low dropping
south along the Oregon to the northern California coasts
overnight.  This system is forecast to bring widespread heavy
mountain snows across northern California on Sunday.  Areas
impacted are expected to include the northwest California coastal
ranges, the southern Cascades and the northern Sierra.  As the low
continues its southern track, the heaviest snows are forecast to
shift south along the Sierra into the southern Sierra and into the
higher elevations of the Transverse Ranges on Monday.  Moisture
spilling east of the Sierra may interact with favorable upper jet
forcing to produce some locally heavy amounts across portions of
the central Nevada mountains as well.  Heavy snows are expected to
wane late Monday into Tuesday, however additional locally heavy
amounts are possible across portions of the Transverse Ranges,
southern Sierra and the central to southern Nevada mountains.  WPC
PWPF continues to show high probabilities for widespread storm
total amounts exceeding two feet along the Sierra, with local
amounts of 4 feet or more possible.   

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

Pereira