What Is a Winter Storm Warning?

A Winter Storm Warning is the National Weather Service telling you that hazardous winter weather — heavy snow, sleet, or ice, often with wind — is happening now or is about to in your area. It is the "take action" level of winter alert, and it usually means travel will be difficult or dangerous.

Warning vs Watch vs Advisory

Winter weather comes in the same three tiers as every other NWS hazard (see watch vs warning vs advisory):

• Winter Weather Advisory — expect a nuisance amount of snow, sleet or freezing rain. Roads may be slick; allow extra time and drive carefully.
• Winter Storm Watch — a significant storm is possible in the next 12–48 hours. Conditions are coming together; prepare now while it is easy.
• Winter Storm Warning — that significant storm is now expected or underway. Finish preparing and avoid unnecessary travel.

What counts as "significant"?

There is no single nationwide snowfall number. Each local NWS office sets thresholds for what genuinely disrupts its region: a couple of inches can warrant a warning across the South, while northern snow-belt areas may need a foot or more. Warnings also account for ice (which can bring down trees and power lines at a fraction of an inch) and blowing snow that destroys visibility.

The more severe cousin: a Blizzard Warning

A Blizzard Warning is not just "a lot of snow." It specifically requires winds of 35 mph or higher combined with snow that drops visibility to a quarter mile or less for three hours or more. The killer in a blizzard is the whiteout, not the depth — which is why it gets its own, more urgent alert.

What to do during a Winter Storm Warning

• Avoid travel if you can. If you must drive, keep a blanket, water, a charged phone and a full tank.
• Prepare for power loss — ice and wind bring down lines. Have flashlights, warm layers and a way to charge devices.
• Protect pipes and people — let faucets drip in extreme cold, and check on elderly neighbors.
• Keep checking — warnings are updated as the storm evolves, and a separate heat or wind hazard may follow.

Check your area

See whether a Winter Storm Warning, Watch or Advisory is active where you are with the free Weather Alerts tool, and pair it with the Weather Forecast tool to see the snow and temperatures behind the alert.