Winter Storm Watch or Warning: when to prepare, delay travel, and stay put

Read the complete product name

Outlooks, forecasts, advisories, watches, and warnings answer different questions

A seasonal outlook can help with broad planning, while a local forecast describes expected weather for a particular place and time. Advisories, watches, and warnings identify a hazard and the level of action it requires. Local NWS offices set winter criteria for their own areas, so the snow amount that triggers a warning can differ between the Northern Plains and the Southeast.

Climate outlook

A CPC monthly or seasonal outlook shows whether temperature or precipitation is more likely to be above, near, or below normal across a broad period. It is not a local snow-total forecast and does not predict a specific winter storm.

Local forecast

A forecast describes expected precipitation type, timing, temperature, wind, and accumulation for a location. Use it to plan, then check again because the storm track and the rain-snow-ice line can change.

Winter Weather Advisory

Snow, blowing snow, ice, sleet, or a combination is expected, but conditions should remain below local warning criteria. Travel may still be difficult. Allow extra time, use caution, and be ready to change plans.

Winter Storm Watch

Conditions are favorable for a significant winter storm, which may include heavy snow, heavy sleet, an ice storm, or heavy snow with blowing snow. Prepare supplies and make a travel alternative before conditions arrive.

Winter Storm Warning

A significant event involving snow, ice, sleet, blowing snow, or a combination is expected or occurring. Travel can become difficult or impossible. Delay travel until conditions improve.

Blizzard Warning

Frequent gusts of at least 35 mph with falling or blowing snow are expected to reduce visibility below one-quarter mile for three hours or longer. Whiteout conditions can make travel extremely difficult. Do not travel.

Ice Storm Warning

Significant ice accumulation—usually around one-quarter inch or more—is expected. Roads may become dangerous or impossible, and the weight of ice can bring down branches and power lines. Travel is strongly discouraged.

When a watch is issued

Use the preparation window before roads, power, or deliveries are affected

A watch is the time to finish preparations, not proof that every forecast detail is settled. Check the expected start and end times, the hazards named in the watch, and whether your route crosses higher terrain or a different alert area.

• Charge phones, backup batteries, and medical equipment that can be charged safely.
• Make sure flashlights, smoke alarms, and carbon-monoxide detectors work.
• Have food, water, essential medicine, and pet supplies for more than a day if travel could stop.
• Refuel before the storm and keep heating fuel from running too low.
• Decide which trips can be moved, canceled, or completed before conditions begin.
• Keep more than one path to official warnings, including NOAA Weather Radio where available.

Never run a portable generator in a home, garage, basement, or other enclosed space. Keep exhaust outside and away from doors, windows, and vents, and follow the manufacturer's instructions.

Before winter travel

Check the full route and carry enough to wait safely

Conditions can vary sharply over a route. Snow may be light at home while ice, lake-effect snow, mountain weather, or blowing snow makes another part of the trip dangerous. Check forecasts, alerts, and official road information before leaving.

• Clear every window, mirror, light, and the vehicle roof before driving.
• Check tires, wipers, washer fluid, battery, heater, lights, and the exhaust system.
• Carry warm clothing, blankets, a flashlight, food, water, a first-aid kit, a phone charger, a shovel, and traction material.
• Tell someone the route and expected arrival time, especially for longer or rural trips.
• Leave additional following distance and avoid sudden braking, acceleration, and steering.
• Treat a road that only looks wet as potentially icy when temperatures are near freezing.

A Winter Weather Advisory is not permission to drive normally. It means hazardous wintry conditions are expected even though local warning criteria may not be met. A Warning is a stronger reason to delay travel, but official road closures and emergency instructions always take priority over a general weather product.

A fast, localized warning

A Snow Squall Warning is not the same as a long-duration winter storm alert

Snow squalls often last less than an hour, but they can produce a sudden whiteout and rapidly icing roads. They may occur when no large winter storm is underway and may leave only a small amount of snow. Their short duration does not make the highway risk small.

• If a Snow Squall Warning covers your route, avoid or delay driving until it passes.
• If already traveling and you can exit safely, leave the highway before the squall arrives.
• If you cannot exit, reduce speed, turn on headlights and hazard lights, and greatly increase following distance.
• Do not slam on the brakes; slick pavement and poor visibility can trigger chain-reaction crashes.
• Do not use snowfall totals alone to judge the danger. Visibility, wind, and rapidly falling temperatures matter.

During the storm

Stay inside when possible and use heat without creating a second emergency

The safest trip is often the one postponed. At home, protect heat, watch for carbon monoxide, and keep vents clear only when it is safe to go outside. Wear loose, warm layers and avoid overheating or sweating if the heat goes out.

• Close off rooms you do not need and use curtains or blinds to reduce heat loss.
• Use fireplaces, wood stoves, and space heaters with proper ventilation and fire safeguards.
• Never use a grill, camp stove, or generator indoors for heat or cooking.
• Keep exterior furnace and dryer vents from becoming blocked by snow when they can be reached safely.
• Avoid overexertion while shoveling, pushing a vehicle, or walking through deep snow.
• Check on relatives or neighbors who may need help without putting yourself in unsafe travel conditions.

If stranded in a vehicle

Stay with the vehicle, make yourself visible, and protect against carbon monoxide

Leaving a stranded vehicle in wind-driven snow can make a person disoriented quickly. The vehicle provides shelter and is easier for rescuers to find. Call 911 for an emergency and share your location when service is available.

1. Stay in the vehicle unless a safe occupied building is immediately reachable.
2. Clear snow from the exhaust pipe before running the engine.
3. Run the engine for about 10 minutes each hour for heat and open a window slightly for fresh air.
4. Use the dome light while the engine runs at night and tie a bright cloth to the antenna or door.
5. Move arms and legs periodically, add dry layers, and avoid exhausting yourself.
6. Conserve phone power while keeping an official alert path available.

After snow or ice stops

The warning may end before every road and neighborhood is safe

Partly cleared roads can refreeze, melting snow can cause flooding, and fallen branches may hide power lines. Check official road and utility information before leaving, and give crews room to work.

• Clear the tailpipe and remove snow from the entire vehicle before starting it.
• Expect black ice, blocked lanes, snowbanks that hide traffic, and changing road closures.
• Never approach a downed power line; report it to emergency services or the utility.
• Keep portable generators outdoors and away from openings during an extended outage.
• Do not drive through water from snowmelt; the road may be damaged beneath it.
• Continue checking the local forecast because another round of snow, wind, or cold may follow.

Cold alerts use current names

Extreme cold can accompany snow, arrive later, or occur without snow

Cold is a separate hazard from winter precipitation. NWS now uses Extreme Cold Watch, Extreme Cold Warning, and Cold Weather Advisory instead of the former Wind Chill Watch, Warning, and Advisory names. The change makes clear that dangerous cold can occur with or without strong wind. Read every active product and do not assume the end of a snow warning means the cold risk has ended.