Severe Weather

Tornado

Tornadoes are violent windstorms characterized by a twisting funnel‑shaped cloud, which forms at the base of a cloud bank and points towards the ground. They occur between April and October in the Ottawa‑Carleton region with June and July being the peak months. Severe thunderstorms, lightning and rain normally accompany tornadoes. The destructive force comes from high winds of 150 km/hr or higher. Listen for severe weather warnings during thunderstorms as tornadoes are more likely at this time. There is usually no warning that a tornado is coming; only a loud roaring noise.

The Fujita Scale

F0 Gale tornado 64-115 km/h (40-72 mph)
F1 Moderate tornado 116-180 km/h (73-112 mph)
F2 Significant tornado 181-252 km/h (113-157 mph)
F3 Severe tornado 253-331 km/h (158-206 mph)
F4 Devastating tornado 332-418 km/h (207-260 mph)
F5 Incredible tornado 419-511 km/h (261-318 mph)
F6 Inconceivable tornado 512-609 km/h (319-379 mph)

 

In the event of a Tornado select a sheltered space in your work area in advance. An inner hallway or small inner room away from windows makes a good shelter. Avoid large halls and cafeterias as their roofs may collapse. Sit close to the ground underneath heavy furniture and protect your head from debris.


Hurricane

Hurricanes are violent tropical storms which blow up from the Caribbean and occasionally hit Eastern Canada, usually between June and November, with September being the peak month. Hurricanes cause more widespread damage than tornadoes because they are bigger. Some are as large as 1,000 kilometres across.

The Saffir-Simpson Hurricane Wind Scale

Category 1 119-153 km/hr 74-95 mph
Category 2 154-177 km/hr 96-110 mph

Category 3 178-209 km/hr 111-130 mph
Category 4 210-249 km/hr 131-155 mph

Category 5 >249 km/hr >155 mph

In the event of a hurricane in your area, you should:

  • Listen to the radio or TV for information.
  • Secure your premises and secure outdoor objects or bring them indoors.
  • Stay indoors during the hurricane and away from windows and glass doors.
  • Close all interior doors—secure and brace external doors.
  • Keep curtains and blinds closed. Do not be fooled if there is a lull; it could be the eye of the storm – winds will pick up again.
  • Take refuge in a small interior room, closet, or hallway on the lowest level.
  • Lie on the floor under a table or another sturdy object.
  • Turn off utilities if instructed to do so.
  • Avoid using the phone, except for serious emergencies.
  • Ensure a supply of water for sanitary purposes such as cleaning and flushing toilets. If in the residence, fill the bathtub and other large containers with water.

You should evacuate under the following conditions:

  • If you are directed by College or local authorities to do so. Be sure to follow their instructions.
  • If you are outside in a temporary structure—such shelters are particularly hazardous during hurricanes no matter how well fastened to the ground.
  • If you are in a high-rise building, as hurricane winds are stronger at higher elevations, move to ground or underground locations.

Weather Warnings

Weather warnings are issued when severe weather is happening or hazardous weather is highly probable. For example, if a weather warning is issued for a tornado, it means that one or more tornadoes have been observed or are forecast for the specified area. Other weather warnings include those for a severe thunderstorms, blizzards, high winds, heavy snow, snow squalls, heavy rain and significant freezing rain.

Winter Storms

Winter storms can range from a moderate snow over a few hours to a blizzard with blinding, wind­-driven snow that lasts for several days. Some winter storms are large enough to affect several provinces, while others affect only a single community. Many winter storms are accompanied by dangerously low temperatures and sometimes by strong winds, icing, sleet and freezing rain.

Understanding and following community based advisories regarding weather conditions is important for your safety both on campus and off campus. The College will take measures to close one or more campuses due to inclement weather in accordance with College Directive C-01 “Emergency Campus Closing”

The college adheres to weather alerts issued by Environment Canada; for further details on weather alerts, please visit this link: https://www.canada.ca/en/environment-climate-change/services/types-weather-forecasts-use/public/criteria-alerts.html#winterStorm

 


Heat Wave

A heat wave is a prolonged period of excessive heat, often combined with excessive humidity. Generally temperatures are 10 degrees or more above the average high temperature for the region during summer months, last for a long period of time and occur with high humidity as well.

Know the Difference

Excessive Heat Watch

Conditions are favorable for an excessive heat event to meet or exceed local Excessive Heat Warning criteria in the next 24 to 72 hours.

Excessive Heat Warning

Heat Index values are forecast to meet or exceed locally defined warning criteria for at least 2 days (daytime highs = 40° Celsius or 105° Fahrenheit).

Heat Advisory

Heat Index values are forecast to meet locally defined advisory criteria for 1 to 2 days (daytime highs = 37° Celsius or 100° Fahrenheit).

Heat Wave

Heat wave has been defined as three or more consecutive days in which the maximum temperature is greater than or equal to 32° Celsius or 90° Fahrenheit).