Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
427 AM EDT Fri Apr 12 2024

Valid 12Z Fri Apr 12 2024 - 12Z Mon Apr 15 2024

...California...
Day 2...

A potent upper low currently west of OR at around 135W will shift
southwest through tonight, reaching the SF Bay Area by early
Saturday where it will be 3 sigma below normal for heights in the
mid/low levels. This impressive low for mid-April will bring heavy
snow Saturday morning along the coastal range and in the Klamath/
Shasta-Siskiyou Mountains with snow levels generally around 4500ft.
The heavy snow focus then shifts to the Sierra Nevada that
afternoon with similar snow levels. The heavy snow is in a fairly
short window with rates of 1" to up to 2" per hour. Day 2 PWPF for
>6" are 40-80% through these CA ranges.

The filling low then drifts east over the Great Basin through
Sunday night with less than 20% Day 3 probs for >4" over the
southern Sierra Nevada and more like 40-60% over the Warner Mtns in
the far northeast corner of CA.


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


Jackson