FOUS11 KWBC 090716
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
316 AM EDT Thu Apr 9 2026

Valid 12Z Thu Apr 09 2026 - 12Z Sun Apr 12 2026

...Sierra Nevada... Days 2-3...

A robust closed low will drop SSEward from the Gulf of Alaska
tomorrow and move into NorCal Saturday night into Sunday. Ahead of
that system a lead upper low will weaken into an open wave tonight
over NorCal but will bring in some moisture to the region. But it
will be the second system that will be the primary driver for
snowfall over the Sierra from late Friday/early Saturday through
Sunday (beyond this forecast period). Though moisture/IVT anomalies
will be modestly high (90th-95th percentile), the slow-moving
upper low will allow for a longer sustained fetch into the Sierra.
Moderate to heavy snow is expected over the High Sierra at first,
then lowering through many passes as colder air filters in. Snow
levels at precip onset tonight will be above 9000ft but fall to
7500-8000ft Friday morning, 6000ft Saturday morning, and
4000-4500ft Sunday morning. The heaviest snow is expected Saturday
afternoon through the overnight hours with rates of 1-3"/hr.

WPC probabilities for >6" of snow are >50% above 5000ft or so and
for >12" are >50% above 6000-7000ft or so. Total snowfall could
exceed 2-3ft for the event in the higher peaks (>50% chance).
Travel across the higher mountain passes (including I-80) will
increasingly become a concern through the weekend as snow levels
lower. Minor to moderate impacts can be expected over the Sierra
per the WSSI, with isolated major impacts in the High Sierra.

The probability of significant icing for days 1-3 across the CONUS
is less than 10 percent.

Fracasso


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