Severe Weather

Storm clouds gathering

The City of Windsor and The County of Essex are no strangers to severe weather conditions. These phenomena include blizzards, ice storms, severe thunderstorms with heavy rain and damaging winds, hail and fog. There is not much we can do to affect the weather on any given day, but with sufficient advance notice we can prepare ourselves and our families for bad weather and try to mitigate or offset some of the negative affects of severe weather. During the winter season, lead times for predicting severe weather conditions can range from hours to days. During the summer, lead times are reduced and we might only have minutes or hours to react. Having good information will help you to better prepare.

Weather watches, warning and advisories:

  • Environment Canada monitors weather systems throughout the country. In the event of severe weather, Environment Canada will issue weather watches, warnings and advisories for the purposes of public safety.
  • The following descriptions (from Environment Canada) summarize what a weather warning, watch and advisory mean.


  • Actual or expected weather conditions may cause general inconvenience or concern but are not expected to pose a serious enough threat to warrant a warning.


  • Conditions are favourable for the development of severe weather. Caution should be taken. Watch the skies and listen for updates.


  • A severe weather condition is occurring or hazardous weather is highly probable. Severe thunderstorms or tornado warnings can be issued less than one hour in advance of the actual event. Other weather warnings can be issued six to twelve hours in advance.
  • Your local radio or TV stations are good sources for up-to-date weather warnings. Descriptions of the following warnings are provided to give you an understanding of what they could mean, as well as some possible precautions:

Severe Thunderstorm Warning:

  • Severe storms, within the area specified, are occurring with one or more of the following conditions: heavy rain, damaging winds, hail at least 20 millimetres in diameter or intense lightning. A severe thunderstorm can produce tornados. You should take precautions including sheltering indoors, preferably in an interior room away from windows and doors.

Tornado Warning:

  • One or more tornados have occurred or are occurring in the area specified or have been spotted. Take appropriate precautions. Go inside to the basement, if you have one. An interior room with no doors and windows is preferable, away from the flying debris that can accompany a tornado. A closet or bathtub can be used as a safe spot too. If outside, lie flat in a ditch or low area, and be aware of the potential for flash flooding in these areas.

Freezing Rain Warning:

  • Expect slippery walking and driving conditions, possible damage to trees and power lines due to rain freezing on contact. Travel will be hazardous. Avoid travel in such conditions.

Heavy Rain Warning:

  • Heavy or prolonged rainfall totalling 50 millimetres of rain over a 12 hour period or less, or 80 millimetres of rain over a 24 hour period or less, is sufficient to cause local or widespread flooding. Heavy rainfall resulted in the Peterborough floods of 2004.

Wind Warning:

  • Steady winds of 60 kilometres per hour or more, or gusts of 90 kilometres per hour or more for at least one hour will trigger this warning. Take precautions by securing or putting away loose objects. Put your car away so that flying objects will not damage it.

Blizzard Warning:

  • This arises from heavy snowfall, severe wind chill and reduced visibility to less than 1 kilometre. During the winter months, be prepared for blizzard conditions, and be prepared to stay at home to wait out the storm. This is a good time to have a survival kit standing by.

Heavy Snowfall Warning:

  • This warning indicates that snowfall is expected to accumulate to 15 centimetres within 12 hours. Travel could be hazardous.

Winter Storm Warning:

  • In Ontario, this warning is issued when two or more winter conditions (wind, snowfall, wind chill) reach warning proportions. Stay indoors, and do not travel. Again, this is a good time to have a survival kit ready.

Wind chill Warning:

  • Very cold temperatures along with wind create outdoor conditions hazardous to human activity. Stay indoors.

This information is found on the Environment Canada website. Environment Canada maintains an Internet weather office at that provides information on current weather conditions and weather warnings.

If you are looking for information on weather hazard trends for Ontario, the atmospheric website at is a good source. This website was created by Environment Canada and Emergency Management Ontario for use by the public and government departments/officials.