Do you know the difference between weather advisories, watches and warnings? While all these terms cover exceptional weather events, they differ in meaning and severity. It is the responsibility of Environment and Climate Change Canada to issue Advisories, Watches and Warnings.
Advisories
Advisories and weather statements can be used to cover a wide array of deteriorating weather conditions and are frequently used to describe weather events that can be cause for public concern. Advisories and weather statements can be issued before watches and warnings or they can be issued to indicate severe weather in a long-term forecast.
Watches
Watches are issued when there is the potential for severe weather. When conditions indicate severe weather is forming, a watch will be released to make the public aware of what could happen.
Warnings
A warning is the next step in the process. Warnings are issued when that severe weather is actually occurring or is imminent.
For example, a tornado watch would mean there is a good chance that a tornado will form in the affected area, whereas a tornado warning would mean a tornado is occurring or about to occur and those in the region should take cover immediately.
Identifying watches and warnings
Tornado watches occur when conditions favorable for a severe thunderstorm with a tornado are imminent.
Tornado warnings occur when a tornado has been reported or there is evidence a tornado is imminent.
Severe Thunderstorm Watch is issued if there is the potential for the development of a thunderstorm with either wind gusts of 90 kilometres an hour or greater, hail with a diameter of two centimetres or greater, or heavy rainfall (with 50 millimetres or more within one hour).
Severe Thunderstorm Warning would be issued if a cell was spotted on radar with one or more of the weather conditions listed above occurring.
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Tornados
Tornadoes are unmistakable rotating columns of high-velocity wind that bring devastation to anything in their path. Ontario averages 13 tornadoes per year. Most tornadoes occur in June, July and August, although the season extends from April to September. They frequently develop in mid-afternoon to early evening.
Environment and Climate Change Canada warns the public about tornadoes but because they are hard to predict and can move at up to 70 km/hr, a tornado can strike without warning. Typically, a tornado is preceded by a severe thunderstorm and is associated with black skies, strong wind and heavy rain or hail. Sometimes the sky will turn an unusual green colour and the wind will sound like a freight train.
Funnel clouds normally appear just after heavy rain or hail, at the rear base of a thunderstorm. Often a cloud of swirling debris or flash of electrical power lines can be seen along its path.
When a tornado threatens
When a tornado threatens, take the following steps:
- Take shelter immediately, if available, preferably in the basement or lowest level of a sturdy building
- Stay away from windows, doors and exterior walls. Flying glass is extremely dangerous
- Don’t waste time opening windows to keep pressure from building up in the house. It’s unlikely to help anyway
- Outdoors, with no shelter available, lie flat in a ditch, ravine or another low-lying area, and shield your head with your arms
- Don’t get caught in a vehicle or mobile home, which the tornado can lift. Take shelter elsewhere or, if none is available, even a ditch offers better protection
- Choose a location where your vehicle won’t be hurled or rolled on top of you. More than half of tornado deaths occur in mobile homes. If you live in a mobile home, it is wise to identify a nearby sturdy shelter well in advance, and go to that shelter when a severe storm is approaching
- Beware of flying debris. Even small objects such as sticks and straw can become lethal missiles
Shelter
In the event of a tornado, these are your best shelter options:
- In a house, go to the basement and take shelter under a stairway or a sturdy work table in the centre of the house
- In a house with no basement, the safest spot is the ground floor in the centre of the house. Small rooms tend to be more structurally sound so seek shelter in a hallway, small room, closet or bathroom (the plumbing may provide some structural stability). Lying in the bathtub with a mattress on top of you may provide good protection
- However, there is no way of knowing how strong or violent a tornado is without the proper tools, so the safest strategy is to get out of the vehicle. As a last resort, lie in a ditch or culvert but be aware of flooding
- Avoid wide-span buildings, such as barns, auditoriums, shopping centres and supermarkets with large roofs
- Go to a nearby sturdy shelter, preferably, on the lower floor, an inside room, restroom or hallway, or get underneath a sturdy piece of furniture
- At school, seek shelter in small windowless rooms such as a washroom instead of a gymnasium
- Avoid areas near high walls or large chimneys which may collapse
- In shopping centres, stay out of aisles and away from exterior walls and windows. Do not go to your parked car
- In high-rise buildings, move to lower levels, small interior rooms or stairwells. Stay away from elevators and windows
If disaster does strike, remember:
- Remain calm. Coordinated emergency services are responding
- Help family members and neighbours
- Don’t forget your pets!
Download the PDF fact sheet here.
Winter weather
Freezing rain, ice pellets, snowsqualls, white-outs, heavy snow and high winds can cause extensive delays and inconvenience to your daily schedule, but they can also bring with them damage, power outages and even life-threatening conditions.
Take the time to know what to watch for, and what to do if there is a weather watch or warning issued for where you live or where you are traveling to.
Tips for preparing for severe winter weather
Consider these tips when preparing for severe winter weather:
- Don’t wait for a storm to hit. Begin preparing now and you’ll be able to react quickly when a storm is forecast.
- Assemble multi-day emergency kit. Have it stocked, ready and in a place where you can easily access it.
- Pay close attention to the weather. Some types of nasty winter weather can develop very quickly with little warning, so be sure to regularly check weather forecasts.
- Travel safely. Give your car a winter tune-up in mid-autumn and have your snow tires installed early in fall. Assemble a car emergency kit including basic items like high-energy snacks, a flashlight or road hazard light, new batteries, a blanket and warm gel packs.
- Work and play safe. Winter storms and high wind chills can be hazardous to you, your employees, your children and your pets. Be aware of conditions worsening and always dress to suit the weather – wear a hat and thin layers of loose clothing with water-repellent and wind-resistant outer layers. Watch carefully for symptoms signaling hypothermia: shivering, confusion and loss of muscle control. Frostbite can occur in minutes; watch for numbness or whiteness in ears, nose, fingers and toes.
- Respect advisories and evacuation orders. If local emergency responders are advising you to stay inside and not travel – do that. Take cover inside and stay there until the storm has subsided and the danger has passed. Keep your vehicles off the roadways to allow emergency responders and snow removal crews better access.
- Remember that after-storm conditions can pose hazards, too. Downed tree limbs and power lines can be dangerous. Be extremely cautious if you tackle tree removal yourself. Better yet, leave it to the professionals! Even falling ice and snow can be deadly.
The best safety precaution to take during severe winter weather conditions is to avoid traveling at all. However, if you must travel, be aware and be prepared. Listen to Environment Canada’s weather forecasts and the various watch and warnings bulletins before you decide if it is safe to travel. Also, make sure to check the forecast to see what is happening - both en route and at your planned destination when you are scheduled to arrive.
Winter watches and warnings
A watch is issued by Environment Canada as a heads up that severe and possibly dangerous weather conditions are expected soon, such as a blizzard, heavy snowfall, a winter storm, freezing rain or possible future weather warning. A Winter Storm Watch is usually issued 12 to 48 hours in advance of the approaching bad weather. You should watch the skies and monitor local radio/television broadcasts or Environment Canada for new developments. Environment Canada with either end the Winter Storm Watch or upgrade it to a Winter Weather Warning, depending on the conditions.
A warning is issued by Environment Canada when a combination of hazardous winter conditions are occurring or expected to develop no more than 12 to 14 hours in advance. You should continue to watch the skies and monitor local radio/television broadcasts or the Environment Canada for new developments.
A snow squall is a combination of heavy snowfalls, strong winds and reduced visibilities to the lee of the Great Lakes or other large lakes.
A blizzard is when wind combined with very cold temperatures create outdoor conditions hazardous to human activity.
Download the PDF fact sheet here.
Flood preparedness
According to the Government of Canada’s Get Prepared webpage, floods are the most frequent natural hazard in Canada. There are ways you can reduce the possibility of flooding to your property, and preparations you can make to ensure your safety in the event that your property does flood.
Reducing the possibility of flooding to your property
Follow these tips to reduce the possibilty of flooding to your property:
- Ensure the ground slopes away from your house and downspouts are extended away from the building envelope
- Ensure lot grading is maintained to convey water away from your house and neighbouring houses
- Ensure window wells are free draining and raised to prevent the overtopping of water
- Visit here for more information about managing stormwater
- If you must store important documents or items in the basement, ensure they are elevated well above floor level in a water-resistant container
- Inspect your plumbing and drainage system regularly to ensure proper operation
- Consider installing additional features as required, such as a sump pump and backwater valve
- Visit here for more information about basement flooding and the Basement Flooding Grant Program.
If flooding is imminent:
- Turn off your basement furnace
- Keep valuables and cleaning products elevated
If your basement floods:
Do not enter your basement if water has come into contact with electrical outlets, baseboard heaters, the furnace and/or the electrical panel. Visit here for more information.
Flood evacuations
Follow these steps if you need to evacuate because of a flood:
- If an evacuation is ordered, leave your home. Staying may put your safety and others at risk
- Bring your emergency kit with you as you evacuate
- Do not cross flooded areas on foot or in a vehicle. The water can be much deeper than it appears, and fast flowing water, even if shallow, can sweep you away
- DO NOT attempt to turn off your electricity if any water is present. Water and live electrical wires are an electrocution hazard. Leave your home immediately and inform authorities. Do not return until told it is safe.
After a flood
To ensure your safety, follow these steps after a flood:
- Do not return home until authorities say it is safe to do so. This may include the need to complete an electrical inspection. For more information, call London Hydro or visit the Electrical Safety Authority's Flood Safety webpage.
- Watch for any dangerous flood debris, including sewage contamination and broken glass
- Call your home insurance company and seek guidance before returning to your home
- Wiring in flooded electrical appliances may be damaged. If so, they can short circuit and catch fire or give off an electrical shock. Make sure they are cleaned, dried and inspected by an electrician before use, or replace the items
Download the PDF fact sheet here.