Where is NOAA indicating a heavy snow risk for November 15–18, 2026? In its November 7, 2026 Week-2 Hazards Outlook, the National Oceanic and Atmospheric Administration’s Climate Prediction Center (CPC) identified a moderate risk of heavy snow at higher elevations of the Klamath and Sierra Nevada mountains on Sunday, November 15. The outlook also identified broader slight risks from November 15 through November 18 across western mountain areas, including the Cascades and parts of the Rockies.
This is an advance risk outlook, not a confirmed snowfall report or a local winter storm warning. Weather forecasts can change; check the current NOAA CPC hazards map for updated areas and dates. The outlook described here was issued November 7 and has a stated valid period of November 15–21, 2026.
Which western U.S. regions are included in NOAA’s November 15–18 snow outlook?
The official outlook separates different hazards, elevations and valid dates:
| Region | Snow risk category | Dates in Nov. 2026 |
|---|---|---|
| High elevations of Klamath and Sierra Nevada mountains | Moderate | Nov. 15 |
| High elevations of Cascades, Klamath and Sierra Nevada mountains | Slight | Nov. 15–18 |
| Parts of Northern Intermountain region, Great Basin, Central and Northern Rockies | Slight | Nov. 15–18 |
These categories are from CPC’s November 7 hazards discussion. They do not mean every city in these broad geographic regions is forecast to receive heavy snow. The text specifically identifies higher elevations; lower-elevation communities may experience very different conditions.
What is the difference between a slight risk and a moderate risk of heavy snow?
NOAA uses probability-based hazard categories to signal the chance that conditions will meet the agency’s risk criteria over a forecast period. A slight risk represents a lower probability than a moderate risk. The CPC’s November 6 key messages identify the agency’s general probability ranges as 20–40% for slight and 40–60% for moderate in the discussed outlook context.
These percentage categories are not inches of snow and are not promises of a particular road closure, damage level or storm track. Examine the map’s legend, the exact shaded location, the forecast issue time and the dates printed beside the risk before making any travel decision.
Why are California’s Sierra Nevada and Klamath mountains highlighted?
The CPC discussion describes a large-scale pattern that may carry enhanced Pacific moisture toward the West Coast around the beginning of the 8–14-day window. The combination of moisture and terrain can support heavy precipitation and, at sufficiently high elevations, heavy snow. The outlook indicates a moderate risk of heavy precipitation in southwestern Oregon and northern/central California on November 15, alongside the high-elevation snow risk.
The agency emphasizes forecast uncertainty concerning the timing and strength of the moisture surge. Snow levels, mountain-pass exposure and road effects depend on the evolving weather pattern. It would be misleading to interpret a mountain snow-risk area as a prediction that downtown San Francisco, Sacramento, Portland or Seattle will be buried by snow.
What are the high-wind and rain risks in the same NOAA outlook?
CPC also indicates a moderate risk of high winds near coastal Washington, Oregon and much of California on November 15 and broader slight wind risks in the West extending into November 18. It flags heavy precipitation across portions of the West and Southwest, with potential additional concerns for areas recently affected by heavy rainfall. Rainfall, wind and mountain snow are separate map layers and should not be conflated.
If severe weather affects electrical service, see our generator and carbon monoxide safety guide. That resource explains the 20-foot outdoor generator-clearance recommendation and safe power-outage practices.
How do I open and read the NOAA heavy snow risk map?
- Go to the Climate Prediction Center Week-2 Hazards Outlook directly on a .noaa.gov federal website.
- Check the issue date and valid period first. The November 7 outlook covers November 15–21; later updates can shift shaded regions.
- Choose the Snow hazard category and consult its composite and probabilistic map options.
- Use the map legend to distinguish slight, moderate and other categories, and read the associated discussion for elevation limits and date ranges.
- For your exact location and near-term forecast, enter your ZIP code or city at Weather.gov.
Is the NOAA 8–14-day heavy snow outlook the same as a winter storm warning?
No. CPC’s Week-2 outlook highlights potential weather hazards with longer lead time. The Weather Prediction Center (WPC) provides more detailed nearer-term products, including winter storm severity and probabilistic snow forecasts. Local National Weather Service offices issue location-specific watches, warnings and advisories when appropriate.
A shaded risk area does not mean a warning has already been issued. Our winter storm warning vs. watch vs. advisory explainer explains how those shorter-term alerts differ and what readers should do if issued for their area.
Does the 2026–27 NOAA winter outlook predict these snowfall totals?
No. NOAA’s 2026–27 winter outlook announcement emphasizes that seasonal climate outlooks describe the probabilities of above-, near- or below-average temperature and precipitation, not specific seasonal snowfall accumulations. CPC’s November 15–21 hazard guidance is a shorter-range assessment and still does not specify a guaranteed snowfall total for an individual address.
What should mountain travelers do between now and November 15?
Before heading toward the Sierra Nevada, Cascades or Rockies, check updated NWS forecasts, the local NWS winter travel alerts and the relevant state transportation department’s road conditions. Mountain-pass roads can be affected at elevations where nearby valleys remain above freezing. Carry appropriate cold-weather supplies, allow itinerary flexibility, and avoid assuming an 8–14-day outlook is precise enough to finalize an exposed pass crossing.
For motorists, review our winter car preparation and emergency kit checklist, which covers tires, batteries, visibility and emergency gear for U.S. road trips. For broader alerts, browse Weather & Emergency Preparedness.
When will the next snow-risk map be available?
CPC updates its hazard outlooks as conditions and forecasting models evolve. Do not treat the November 7 map as permanent. The official live CPC page displays the current issue and valid dates. As the period approaches, compare it with WPC maps and Weather.gov’s local short-range forecasts before acting.
Official sources and additional reading
- NOAA CPC: U.S. Week-2 Hazards Outlook, November 7 issuance and current updates
- NOAA CPC: U.S. Hazards Assessment and how to use it
- NOAA CPC: November 6 key messages on Western U.S. hazard risk
- NOAA Weather Prediction Center: Winter forecasts and severity products
- NOAA: 2026–27 winter outlook and limitations of seasonal snowfall projections
- National Weather Service: Location-specific current alerts
Photo note: Featured photograph shows Desolation Wilderness near Lake Tahoe in California’s Sierra Nevada, taken February 7, 2026. It is a public-domain U.S. Forest Service archival image illustrating the relevant mountain geography, not evidence of a November 2026 snowfall event. Photo: Paul Wade / USFS via DVIDS.
Sık Sorulan Sorular
Where does NOAA show the highest heavy snow risk for November 15, 2026?
The November 7 CPC outlook indicates a moderate heavy high-elevation snow risk in the Klamath and Sierra Nevada mountains on November 15.
Are the Cascades and Rockies included in the snow outlook?
Yes. The November 7 outlook indicates slight risks of heavy high-elevation snow in parts of the Cascades and in portions of the Northern Intermountain, Great Basin, Central and Northern Rockies November 15–18.
Does a moderate risk mean heavy snow is guaranteed?
No. It is a probability-based hazard category; it does not guarantee heavy snow at every location or specify an exact accumulation.
Where can I see updated NOAA snow maps?
Use the NOAA Climate Prediction Center Week-2 Hazards Outlook for the 8–14-day view; check the Weather Prediction Center and local Weather.gov office for nearer-term forecasts and alerts.
