The Sierra’s First Big Snow Is Here — and NOAA Has Flagged a Heavy-Snow Risk
NOAA’s Climate Prediction Center has put the Sierra Nevada and Klamath Mountains under a “moderate risk” of heavy snow on November 14–15, 2026 — the season’s first significant mountain storm, landing just days after the earliest polar-vortex collapse on record.
Snow is piling into the high Sierra. NOAA’s Climate Prediction Center has drawn a “moderate risk” of heavy snow across the high elevations of the Sierra Nevada and the Klamath Mountains for November 14 and 15, with a slight risk running through November 17 into the Cascades, the Great Basin and the Central and Northern Rockies. In NOAA’s terms, “heavy snow” means at least four inches in 12 hours or six in 24 — enough to shut passes and lay down the first real base of the ski season.
The storm is targeting eastern and northern California, southern Oregon and western Nevada. It is the Pacific half of an unusually early turn to winter: the stratospheric polar vortex collapsed a record three weeks early on November 10, and the same early-season cold is also driving the Northeast’s first snow on the other side of the country. The useful question isn’t whether this is strange — it’s how it stacks up against a normal Sierra November. Our NOAA records answer that cleanly.
Where the Heavy Snow Lands
The sharpest totals ride the crest. NOAA’s moderate-risk zone is drawn tightly around the high elevations of the Sierra Nevada and the Klamath Mountains straddling the California–Oregon line — the places that wring the most snow out of a landfalling Pacific system. Lower down, the same storm falls mostly as rain, which is why a pass can see chain controls while the foothills a few thousand feet below stay merely wet.
The slight-risk area is far broader, stretching north into the Oregon and Washington Cascades and east across the Great Basin and the Central and Northern Rockies through November 17. For the mountain West as a whole, this is the storm that flips the season — the first one that builds snowpack rather than melting off by afternoon.
What a Normal November Drops Up Here
Here is the grounding the forecast maps don’t give you: how much snow the Sierra actually banks in a typical November, and the biggest single November days on record, straight from our NOAA station archive. Note how steeply it climbs with elevation.
| Station (elevation) | Normal November snow | Biggest November day on record |
|---|---|---|
| Blue Canyon, CA5,285 ft | 25.6″ | 19″ · Nov 29, 1982 |
| Tahoe City, CA6,230 ft | 13.7″ | 23″ · Nov 21, 2010 |
| Truckee / Donner, CA5,938 ft | 12.8″ | 23″ · Nov 10, 1985 |
| Mammoth Lakes, CA7,805 ft | 13″ | 18″ · Nov 26, 1994 |
Averages and records computed November 14, 2026 from our Neon copy of NOAA GHCN-Daily (SNOW in millimeters ÷ 25.4 = inches). Normal November = total November snowfall averaged over each station’s period of record (Blue Canyon 22 Novembers, Tahoe City 56, Truckee/Donner 42, Mammoth Lakes 27). Higher crest sites and snow-sensor networks routinely record far more than these valley-and-town co-op gauges.
The takeaway: a heavy-snow November storm in the Sierra is normal. Blue Canyon, perched at about 5,300 feet on the I-80 corridor, averages roughly two feet of snow across a full November all by itself. What makes this week notable is the timing against the rest of the country — a coast-to-coast early-winter pattern — not the amount of Sierra snow, which is right on schedule.
Mid-November Has Buried the Sierra Before
If this week’s storm overperforms, it won’t be unprecedented. Two of the biggest November snow days in our records landed in the same mid-November window the current storm is aiming at: Truckee and nearby Donner picked up 23 inches in a single day on November 10, 1985, and Tahoe City matched that 23 inches on November 21, 2010. Blue Canyon’s biggest November day, 19 inches, came at the tail end of the month in 1982. Early-season Sierra blizzards are a feature of the range, not a surprise — the crest can bank multiple feet from a single atmospheric river before Thanksgiving.
The Passes to Watch
For anyone driving the Sierra this weekend, the forecast matters most at the crossings. Expect chain controls at higher elevations on Donner Pass (I-80), Echo Summit (US-50) and Carson Pass (SR-88) between November 13 and 15, even where the road surface is wet rather than snow-covered lower down. The National Weather Service warned of hazardous travel across the Sierra through the weekend. Check Caltrans QuickMap before you commit to a pass, carry chains, and give the plows room — the first big storm of the year is also the one drivers are least prepared for.
Why Winter Showed Up This Early
A single mountain storm doesn’t need an exotic explanation — November snow is routine in the Sierra. But the fact that it’s happening at the same time as the Northeast’s first snow and a historic stratospheric event is the real story. The record-early polar-vortex collapse has loosened the Arctic’s grip on cold air weeks ahead of schedule, and that cold is helping steer active, snow-bearing storms into the mountain West.
Pulling the other way is a strong El Niño, which historically tilts the odds toward a wetter southern storm track — good news for Sierra snowpack, and part of why forecasters are watching this winter so closely. We dug into whether that actually delivers more snow in does El Niño mean more snow, and tracked when each US city normally sees its first snow of the year. For the longer view of how much the Sierra and the rest of the country bank each winter, see the snowiest cities in America.
Getting snow this week? Look up any past storm at your elevation with our weather-history tool, and tell us what your gauge or your deck railing actually measured — the on-the-ground totals are the record we care about most.
Frequently Asked Questions
Is the Sierra Nevada getting snow November 14–15, 2026?
Yes. NOAA's Climate Prediction Center flagged a 'moderate risk' of heavy snow at high elevations across the Sierra Nevada and Klamath Mountains on November 14 and 15, 2026, with a slight risk extending through November 17 into the Cascades, Great Basin and Central and Northern Rockies. NOAA defines heavy snow as four or more inches in 12 hours, or six or more inches in 24 hours. The hardest-hit areas are high elevations in eastern and northern California, southern Oregon and western Nevada.
How much snow does the Sierra normally get in November?
It varies sharply with elevation. In our NOAA records, Blue Canyon (about 5,300 feet) averages roughly 26 inches of snow across a full November, while Tahoe City, Truckee and Mammoth Lakes average around 13 inches each. The biggest single November snow days on record at these sites run 18 to 23 inches — Tahoe City picked up 23 inches on November 21, 2010, and Truckee logged 23 inches on November 10, 1985. A storm that drops heavy snow this week would be a normal-to-above-normal November event, not an anomaly.
Will the mountain passes close or require chains?
Expect chain controls at higher elevations on the main Sierra crossings — Donner Pass (I-80), Echo Summit (US-50) and Carson Pass (SR-88) — between November 13 and 15, even where valley roads stay wet rather than snow-covered. The National Weather Service warned of hazardous driving across the Sierra through the weekend. Always check Caltrans QuickMap before crossing.
Is this storm connected to the record-early polar vortex collapse?
It is part of the same unusually early turn to winter, but it is a separate system. A record-early sudden stratospheric warming — the polar vortex's winds reversed on November 10, the earliest major event since records began in 1958 — has helped open the door to cold, early-season storms across the country. This Western storm is the Pacific side of that early-winter pattern; the nor'easter that brought the Northeast its first snow November 12–14 was the Eastern side.
Sources & Method
The November 14–15, 2026 forecast — NOAA’s Climate Prediction Center “moderate risk” of heavy snow for the Sierra Nevada and Klamath Mountains, the slight-risk area through November 17, the heavy-snow definition and the affected states — is from NOAA CPC and NWS reporting carried by Yahoo News and NOAA CPC, fetched November 14, 2026. Average November snowfall and the biggest single November snow day on record at Blue Canyon, Tahoe City, Truckee/Donner and Mammoth Lakes were computed November 14, 2026 from our Neon copy of NOAA’s Global Historical Climatology Network–Daily dataset (SNOW in millimeters ÷ 25.4 = inches). The live storm post-dates our station data’s current cutoff; its forecast figures are NOAA’s, and the quantities we report are historical climatology. For road conditions, check Caltrans QuickMap.