A major California storm Sunday night through early Friday looks set to drop 25″-100+” across the Sierra, with Mount Baldy in the 20″-35″ range. Two waves drive the bulk of the snow, with a relatively higher snow level and denser snow early, followed by a colder surge that improves powder quality and brings the strongest winds. Expect long stretches of snowfall for the Sierra with only brief lulls, plus periods of wind-driven, low-visibility skiing on upper mountain. Southern California gets meaningful mountain snow as well, but snow levels are a bigger deal there and the best accumulation favors higher terrain. After the main storm, the pattern stays colder than normal statewide and northern California keeps the better signal for additional snow later in the period.
Sunday night through Monday evening kicks off the first wave, with snow levels starting relatively high and winds ramping quickly. All models are all locked onto a widespread start overnight Sunday, with the snow turning heavy on Monday even though the exact start time varies by several hours. In the Sierra, snow levels generally run about 4,500 to 6,000 feet early, which keeps most bases cold enough for snow but can make the first round denser near the lowest elevations. Snow ratios are mostly in the 9 to 12:1 range through Monday, so expect a heavier, more consolidated feel underfoot before the colder air arrives. In Southern California, snow levels start around 6,500 to 7,000 feet Monday, and snow ratios often sit closer to 5 to 10:1 early, so the upper mountain is the clear winner while lower elevations can lean wetter and heavier.
Tuesday afternoon through early Wednesday brings the colder Sierra surge, and Wednesday into Thursday looks like the best all-snow window for Southern California. For the Sierra, guidance converges on snow levels dropping hard as the colder wave arrives, commonly falling into the 1,500 to 2,500 foot range by Wednesday, which locks in snow from base to summit and keeps coverage expanding downhill. Snow ratios respond fast, with many hours in the 12 to 18:1 range and the lightest periods generally Tuesday night into Wednesday, so the quality trend is up even as totals keep piling. Winds stay a major story, and several models show ridge gusts in the 70 to 90 mph ballpark at the most exposed resorts, which can lead to lift holds and blowing-snow whiteouts near the top. Down south, the colder wave can pull snow levels toward about 3,500 to 4,000 feet, and Mount Baldy is temporarily closed, so treat this storm as a rebuild opportunity once operations resume…