Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
233 AM EDT Thu Apr 11 2024

Valid 12Z Thu Apr 11 2024 - 12Z Sun Apr 14 2024

...California...
Day 3...

An upper low west of British Columbia will drop south-southeastward
over the next couple of days, paralleling the West Coast and
spreading some light snow into the Olympics/Cascades. By Saturday
evening into early Sunday, the closed low will turn east into
NorCal where it may start to stretch/deform along a NE-SW axis.
Southwest flow ahead of it will draw in moisture from the Pacific
into NorCal and the Sierra, with modest PW anomalies (+1 to +2
sigma) and IVT around the 97-98th percentile (200-300 kg/m/s) on
day 3. Without a tap to the subtropics, QPF/snow amounts will be
modest, but still appreciable. Snow levels will start high -- above
6000ft -- then drop to about 4500ft over the Sierra by early Sunday
(perhaps 4000ft over the NorCal ranges around Redding). WPC
probabilities for at least 6 inches of snow are highest in the
central Sierra, generally >50% above 6000ft or so.

For days 1-3, the probability of significant icing is less than 10
percent.

Fracasso