Weather
Light to moderate early season snow returns to the Sierra and Southern California mountains from Wednesday night through Saturday, with a modest refresh in the Tahoe and Eastern Sierra region and a more substantial hit for the higher peaks near Mount Baldy. Most high elevation terrain will see a few fresh inches with this midweek system, focused from late tonight through Friday morning in the Sierra and from Thursday into Saturday in Southern California. Snow levels generally hover around 5,500 to 6,500 feet, keeping precipitation all snow for the resorts, although the lowest base areas may flirt with a rain or mix at times in Southern California. Snow quality looks generally decent for building early season coverage in the Sierra thanks to snow to liquid ratios running in the low to mid teens, while Southern California leans toward denser, wetter snow as the storm winds down. After this stretch, a drier and somewhat milder pattern dominates into the Thanksgiving week, with only low confidence hints at another system toward the end of the extended period.
A compact Wednesday night through Friday morning system will be the primary snow producer for the Sierra, spreading from far northern zones into Tahoe and down to Mono County by Thursday morning. Precipitation arrives in northeastern California late tonight, then quickly drops south along the crest, reaching the Tahoe resorts and central Sierra areas like Dodge Ridge and Bear Valley around Thursday morning and continuing into Thursday night. Snow levels start roughly in the 5,500 to 6,500 feet band and dip a bit lower Thursday night as cooler air filters in, so all of the resort elevations remain cold enough for snow, with overnight temperatures generally in the 20s to near 30 degrees. This is not a major storm, but it is a useful early season refresher that lays a couple of new inches on most upper mountain slopes, especially along and just west of the crest where orographic lift is strongest. Ridgetop winds increase into the 20 to 30 mph range at times with gusts in the mid 30s to mid 40s, which will be noticeable along the highest ridgelines while the resorts remain closed and prepping for upcoming openings.
Across the northern and central Sierra from Tahoe south to the Highway 4 corridor, snowfall with this system is fairly uniform, with subtle differences tied to elevation and exposure to the southwest flow. Around Lake Tahoe, resorts such as Palisades Tahoe, Sugar Bowl, Northstar, Diamond Peak, and Mt Rose pick up on the order of a couple to several inches between Wednesday night and Thursday night, with the higher elevation ski areas like Mt Rose and the upper reaches of Palisades and Sugar Bowl favored for slightly higher totals. Snow to liquid ratios here generally sit in the 10 to 13 to 1 range, which points to moderately dense but still reasonably dry snow that will bond well as initial base material ahead of planned openings later this month. Further south, Dodge Ridge, Bear Valley, and Kirkwood ride the colder side of the system as it slides by, with Kirkwood in particular benefiting from its lofty 7,800 to 9,800 feet elevation to squeeze out a bit more snow from the same moisture plume. Heavenly joins the party slightly later, from Thursday into Friday, with snow levels creeping up toward 6,400 to 6,600 feet by Friday so the very lowest terrain could see some mixing while the mid and upper mountain stays locked in snow.
The Eastern Sierra around Mammoth sees the best combination of intensity and snow quality in this pattern, thanks to colder mid level temperatures and favorable northwest to north flow as the storm exits. Light snow develops at Mammoth on Thursday, with the main burst focused Thursday night when temperatures in the low 20s and snow to liquid ratios in the low to mid teens support relatively dry, chalky snow at the 7,900 to 11,000 feet elevations of the resort. Totals by Friday morning look to be in the mid single digits in inches, enough to freshen upper elevation coverage and improve early season snow surfaces once the area opens. Winds here are moderate compared to farther north, mostly 5 to 15 mph with gusts around 20 mph, so this system is more about steady snowfall than significant wind impacts. By Friday midday lingering showers in southern Mono County taper off, and a broad ridge builds in for the weekend into early next week, bringing drier weather, lighter winds, and a gradual warming trend with daytime highs climbing back toward seasonal norms in the mountains.
In Southern California, a separate cutoff low dropping down the coast drives a more prolonged Thursday through Saturday event for the San Bernardino and eastern Los Angeles County mountains, with Mount Baldy seeing the largest snowfall in the region. Light showers are possible over the higher terrain early Thursday, but the more significant precipitation arrives late Thursday night into Friday as the low parks just offshore and feeds moisture inland. Snow levels hover around 6,500 feet at the onset, dipping toward roughly 5,900 feet Thursday night and Friday before rising again toward 7,000 feet by Saturday, which means Baldy’s upper elevations near 8,600 feet remain solidly in snow while the base area near 6,400 feet may flip between wet snow and rain at times later in the event. Snow to liquid ratios start near about 8 to 1 then trend lower toward 6 to 1 and even 4 to 1 by Saturday, a clear signal that the snow becomes increasingly dense and heavy as temperatures edge upward and snow levels rise. Winds are stronger here than in the Sierra, with sustained speeds often in the upper teens to mid 20s mph and gusts topping 50 mph on exposed ridges Friday night, so upper elevation conditions will be quite turbulent even as the resort remains closed and accumulating a solid early season base.
Looking beyond the weekend, the overall pattern favors a quieter stretch for California mountains through the Thanksgiving week, with only low confidence hints at another system late in the extended period. Large scale guidance points to higher than normal heights and temperatures over much of California from roughly November 25 through November 29, which lines up with a warmer and generally drier than average signal for both the Sierra and Southern California mountains. Into the November 27 to December 3 window, temperatures in California still lean a bit above normal, while precipitation probabilities trend closer to climatology, suggesting that any storms that do try to undercut the ridge would be more transient rather than a locked in stormy pattern. Shorter range guidance also hints at a possible weakening of the ridge and the introduction of another low pressure system off the coast by mid to late next week, but details on timing, strength, and snow levels are highly uncertain at this lead time. For now, the takeaway is that after this week’s snow, the mountains probably enter a milder, mostly dry regime for several days, with the next meaningful chance of new snow more likely to arrive sometime near or after the end of the outlook window rather than immediately following this storm cycle.
Resort Forecast Totals
- Mount Baldy – 10″–13″ Thu (11/20) – Sat (11/22)
- Mammoth – 5″–6″ Thu (11/20) – Fri night (11/21)
- Kirkwood – 3″–4″ Wed night (11/19) – Fri (11/21)
- Heavenly – 3″–4″ Thu (11/20) – Fri night (11/21)
- Mt Rose – 3″–4″ Wed night (11/19) – Fri (11/21)
- Dodge Ridge – 2″–3″ Wed night (11/19) – Thu night (11/20)
- Palisades Tahoe – 2″–3″ Wed night (11/19) – Thu night (11/20)
- Sugar Bowl – 2″–3″ Wed night (11/19) – Thu night (11/20)
- Bear Valley – 2″–3″ Wed night (11/19) – Thu night (11/20)
- Diamond Peak – 2″–2″ Wed night (11/19) – Fri (11/21)
- Northstar – 2″–2″ Wed night (11/19) – Thu night (11/20)
