Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
302 AM EST Tue Feb 20 2024

Valid 12Z Tue Feb 20 2024 - 12Z Fri Feb 23 2024

...The West...
Days 1-2...

A slowly filling/weakening upper low off Oregon will continue to
drift north through tonight as a shortwave trough rounding the
base pushes across southern CA late tonight. Until that shortwave
trough passage early Wednesday, expect continued onshore flow and
showery conditions with snow levels around 5000ft on the Sierra
Nevada and the Shasta/Siskiyou where Day 1 PWPF for >8" are
40-80%. Snow levels for the SoCal ranges remain around 7000ft
today, dipping to around 6000ft tonight on approach of the trough
axis. The stream of moisture shifts across the Great Basin to the
Utah ranges with snow levels of 6000-7000ft and moderate rates
continuing until the shortwave trough passage late Wednesday. Day
1.5 PWPF for >8" is 40-80% for the central NV ranges and all Utah
ranges. Additional moisture reaches the central WY/CO border
ranges with Day 2 PWPF 40-70% for >8" for that area.

East of the upper low off the PacNW coast, moderate precip rates
and snow levels around 5000ft, generally above pass level, can be
expected through Wednesday.

As of now, the next low looks to remain completely off the West
Coast through at least this weekend.


The probability of receiving at least 0.1" of ice is less than 10
percent Day 1-3.


Jackson