What Does an Orange Winter Storm Warning Mean?
An orange winter storm warning means that multiple types of severe winter weather are occurring or expected, with conditions likely to cause significant travel disruptions, power outages and property damage.
Environment and Climate Change Canada issues winter storm warnings when a combination of winter weather hazards is expected to affect an area. These may include heavy snowfall, freezing rain, strong winds and blowing snow.
The orange designation indicates that forecasters expect high impacts with high or very high confidence, or extreme impacts with moderate or high confidence.
Unlike a snowfall warning, which focuses on significant snow accumulation, a winter storm warning covers multiple winter weather hazards occurring together.
The warning colour is not determined by a specific snowfall amount, wind speed or ice accumulation. Forecasters consider the expected impacts, forecast confidence and conditions in the affected area.
Winter Storm Warning Colours in Canada
Canada uses three warning colours to communicate the expected severity of weather events.
| Warning Colour | Meaning |
|---|---|
| Yellow | Hazardous weather that may cause moderate, localized or short-term disruptions. |
| Orange | Severe weather likely to cause major, widespread or longer-lasting disruptions. |
| Red | Extremely dangerous weather expected to cause extensive and prolonged disruptions. |
Orange winter storm warnings are uncommon and indicate that severe winter weather may significantly affect transportation, electrical services, property and everyday activities.
What Causes an Orange Winter Storm Warning?
Winter storms develop when weather systems bring together cold air, moisture and atmospheric conditions capable of producing several winter hazards.
Large low-pressure systems are a common cause of winter storms in Canada. These systems can draw moisture into colder regions, producing widespread snowfall, freezing rain and strong winds.
Several weather conditions can contribute to a significant winter storm:
- Heavy snowfall: Large amounts of snow can accumulate over several hours or days, making roads difficult to clear and travel hazardous.
- Freezing rain: Rain that freezes on contact with cold surfaces can coat roads, sidewalks, trees and power lines in ice.
- Strong winds: Powerful winds can create blowing snow, reduce visibility and cause damage to trees and electrical infrastructure.
- Rapid temperature changes: Changing temperatures can cause precipitation to switch between snow, freezing rain and rain, creating difficult road conditions.
- Blowing snow: Strong winds can lift existing snow from the ground, reducing visibility and creating snowdrifts across roads.
The combination of these hazards can make a winter storm more disruptive than a weather event involving only one type of precipitation.
What Should You Expect During an Orange Winter Storm Warning?
An orange winter storm warning indicates that severe winter conditions may affect transportation, homes, businesses and essential services.
Possible impacts include:
- Dangerous road conditions: Heavy snow, freezing rain and blowing snow can make roads slippery and difficult to navigate.
- Widespread travel disruptions: Highway closures, vehicle collisions and poor visibility may cause lengthy delays.
- Stranded motorists: Heavy snow accumulation, drifting snow and road closures may leave drivers unable to continue travelling.
- Power outages: Ice accumulation, strong winds and falling branches can damage electrical lines and interrupt power.
- Structural damage: Heavy snow or ice may damage roofs, buildings and other structures.
- Significant tree damage: Ice and heavy snow can cause large branches to break or entire trees to fall.
- Emergency response delays: Dangerous roads and severe weather may delay ambulances, fire services and other emergency responders.
The severity of these impacts depends on the combination of weather hazards affecting each community.
Some areas may experience primarily heavy snowfall, while nearby communities encounter freezing rain, strong winds or a mixture of precipitation.
How Severe Is an Orange Winter Storm Warning?
An orange winter storm warning indicates a greater expected impact than a yellow warning, but the severity can vary depending on the weather system and affected region.
Environment and Climate Change Canada uses its Winter Storm Impact Guide to assess potential consequences.
High-impact winter storms may cause:
- Dangerous travel conditions and widespread road closures.
- Numerous vehicle collisions and stranded motorists.
- Power outages affecting homes and businesses.
- Significant damage to trees and buildings.
- Major delays for emergency responders.
- Disruptions to essential services.
The same storm can produce different levels of disruption across Canada.
For example, a large snowfall may be less disruptive in a community accustomed to frequent winter storms than in an area where major snowfall is uncommon.
The timing of a storm, existing snow cover and local infrastructure can also influence the warning level.
What Should You Do During an Orange Winter Storm Warning?
During an orange winter storm warning, residents should avoid unnecessary travel and prepare for potential disruptions to electricity, transportation and essential services.
Recommended precautions include:
- Postpone unnecessary travel. Heavy snow, freezing rain and blowing snow can make roads dangerous or impassable.
- Check highway conditions. Consult your provincial road information service for current closures, collisions and travel advisories.
- Monitor weather warnings. Follow Environment and Climate Change Canada for updates on expected snowfall, freezing rain, wind conditions and storm timing.
- Prepare for power outages. Keep flashlights, charged devices, drinking water, medications and other essential supplies available.
- Keep important exits accessible. Clear snow from necessary walkways and entrances when conditions are safe.
- Avoid damaged trees and power lines. Heavy ice, snow and strong winds can cause branches and electrical wires to fall.
- Follow local instructions. Pay attention to road closures, emergency notices and recommendations from local authorities.
If you must travel, keep a winter emergency kit in your vehicle containing warm clothing, blankets, drinking water, a flashlight and a charged phone.
What If You Lose Power During a Winter Storm?
Power outages can become particularly dangerous during winter storms when outdoor temperatures are below freezing.
If your home loses electricity, close unnecessary doors and windows to help retain heat. Wear additional layers of clothing and use blankets to stay warm.
Never operate portable generators, barbecues, camping stoves or other fuel-burning equipment indoors or inside an attached garage. These devices can produce carbon monoxide, a dangerous gas that cannot be seen or smelled.
If your home becomes too cold to remain safely, consider relocating to a designated warming centre or another heated location when travel conditions allow.
How Long Does an Orange Winter Storm Warning Last?
An orange winter storm warning does not have a fixed duration.
Some winter storms produce severe conditions for several hours, while larger weather systems can affect communities for a day or longer.
The duration depends on the size and movement of the weather system, precipitation intensity, wind conditions and changing temperatures.
Environment and Climate Change Canada may update, change or end a warning as conditions develop.
Even after a warning ends, significant snow accumulation, icy roads, power outages and fallen trees may continue to affect communities.
Road clearing and restoration of electrical services can take additional time, particularly following storms that cause extensive damage.
Frequently Asked Questions
A yellow winter storm warning indicates hazardous conditions that may cause moderate or localized disruptions. An orange winter storm warning indicates a greater risk of major impacts, including widespread road closures, stranded vehicles, power outages and significant property damage.
There is no fixed snowfall amount that automatically triggers an orange winter storm warning across Canada. Environment and Climate Change Canada considers the combined impacts of snow, ice, wind and other winter hazards, along with forecast confidence.
A snowfall warning focuses on significant snow accumulation. A winter storm warning is issued when multiple types of severe winter weather are expected together, such as heavy snowfall combined with freezing rain or strong winds.
You can check current winter storm warnings through Environment and Climate Change Canada’s weather website or the WeatherCAN mobile app. Both provide official warnings, affected regions, expected weather conditions and updates as storms develop. For current highway conditions and road closures, consult your provincial road information service.