Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
257 PM EST Mon Dec 03 2018

Valid 00Z Tue Dec 04 2018 - 00Z Fri Dec 07 2018

...Sierra...

With the primary exception of the Sierra, daytime model runs
continued to show little threat for heavy snow accumulations
across the CONUS through the period.  Models continue to show an
upper low dropping south along the California coast
Tuesday-Wednesday.  Moisture transport and upper jet forcing may
be sufficient for some locally heavy snow accumulations across
portions of the Sierra, with WPC probabilities showing a Slight
Risk for accumulations of 8-inches or more for elevations mainly
above 7000 ft on Day 2 (ending 00Z Thu).  By Day 3 (ending 00z
Fri), with the low continuing to slide south, any heavy snow
threat will become more confined to the southern Sierra, with WPC
probabilities showing a Slight Risk for 8-inches mainly across the
highest elevations.

The probability of significant icing (0.25 inches or more) is less
than 10 percent days 1-3.

Pereira