Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Wed Nov 19 2025

Valid 12Z Wed Nov 19 2025 - 12Z Sat Nov 22 2025

...California through the Southern Rockies...
Days 1-3...

An upper low centered over Southern California this morning will
slowly translate eastward over the next 24 hours before the next in
a series of developing lows approaches the coast and begins to
eject it eastward. As the leading low moves east, it will continue
to direct deeper moisture and associated mid level energy farther
inland. With high snow levels in place at the onset, there will be
little threat for widespread heavy snow accumulations through early
Thursday. WPC's Day 1 probabilities shows the threat for
accumulations above 6 inches to be isolated and mostly confined to
the higher peaks of the southern Utah Mountains, the San Francisco
Peaks and White Mountains in Arizona, and the San Juans in
southwestern Colorado.

As the leading system moves east, the extent of light snow
accumulations is forecast to increase across the Colorado and
northern New Mexico ranges. However, accumulations greater than 6
inches will likely be limited to areas in the San Juans and Sangre
de Cristos above 10,000 ft.

Meanwhile, mountain snow will spread quickly south across
California from the southern Cascades to the northern Transverse
Ranges on Thursday. Given the progressive nature of this second
system and more modest moisture, widespread heavy snow
accumulations are unlikely. WPC probabilities for 24 hour amounts
exceeding 6 inches are limited mostly to the higher peaks of the
Sierra Nevada.

Similar to its predecessor, this second low is expected to settle
and linger over Southern California Friday into Saturday. The
footprint for heavy snow is expected to become even more
confined, limited to the higher peaks of the Transverse Ranges and
perhaps the southern Nevada mountains.

Pereira