Weather watch

Times Contributor         

 

With the recent rash of tornados that devastated homes in the southern United States, it reminds us that emergencies can arise quickly anywhere.

Bill McMurtry, a warning preparedness meteorologist for south central Alberta working with the Meteorological Services of Canada, came to the County of Wheatland on April 30, to discuss exactly what weather events Albertans can prepare for ahead of time. He has 24 years of experience in weather and emergency event site analysis. 

McMurtry said tornados, wind and lighting storms, floods, hail, heat and cold temperatures and winter storms are all part of the southern Alberta weather watches. When they hit they can do considerable amounts of damage, and Albertans should know how to react.

“There are about 130 weather-related deaths in Canada per year and 85 per cent of deaths are from exposure to heat or cold. There were 10 deaths due to avalanches and earth movement, four from lightning strike, two in storms, three from other natural events,” said McMurtry.

He said to dispel peoples fear and put the statistics in perspective, there are about 2,600 motor vehicle deaths each year. So learning to drive safely is an important part of everyday living and emergency preparedness.

He said the central prairies are second largest in the world for tornado occurrences, but on average we see about 12 tornados in the Calgary area per year; overall, we really only have one tornado event per year. People may see the funnel cloud formations dipping down out of the sky, but they tend to dissipate before touching the earth. 

It doesn’t mean that Abertans should be complacent, for if the cloud does touch down, significant damage can occur. The width of the tornado doesn’t indicate force. Small clouds can pack large destructive power, and chasing them in vehicles or ignoring them because you don’t think you are in the path are bad ideas. McMurtry said they can shift direction quickly. 

The rating scale for tornados is not the same as that used for the hurricane winds seen in coastal areas. The scale used for tornados indicates the destructive power packed by the high force winds, with the higher rating indicating the winds in excess of 300 km per hour with enough force to scoop houses from secure concrete bases. 

McMurtry advised that if someone is unlucky enough to be in the area where the yearly tornado hits, they should seek shelter in buildings other than trailers, cars, or portable buildings, as they are not anchored down. In buildings, stay away from windows; this is especially important in urban high-rises. Go to a secure place in the interior of buildings, or go to the basement, or under stairways.

“This is the second highest area for extreme winds produced from thunderstorms, and these are not tornado winds, but outflow winds from thunderstorms. It is a big threat in summer. They produce more damage than tornados for this area,” said McMurtry. 

The leading winds to the storm can occur in a time period prior to the actual storm, packing destruction over a large area. One example is the damage that occurred at the Big Valley Music Festival in 2009. 

Best advice?

“When the thunder roars, go indoors,” said McMurtry.

Lightning strikes are also a concern in storms and can have a 16 km striking distance, with the offshoots searching for conductive sources. If you are outside in an electrical storm, gathering in groups and standing under tall objects is discouraged. McMurtry said they have seen pastures with whole herds of cattle killed from one lighting strike; and hits on a wire fence, two km away from workers, ending in lightning injuries. Last year there were 200 injuries from lightning in Canada, with 10 people killed. 

Flooding can occur from rain causing rivers to overflow. McMurtry said last year’s flood depended on a combination of the amount of rain, soil saturation and snowpack melt. Floods in this area usually occur anywhere from March to June. After last year, government agencies are diligently measuring rainfall and moisture levels and groups like the Bow Water Basin are trying to determine areas that would be affected by new river flooding. 

In areas under slow moving thunderstorms, a copious amount of rain can be produced over a short period of time; in this situation, small areas of flooding can occur. McMurtry advised people to move possessions to higher areas of the house, and if caught in a vehicle, avoid overpasses or low-lying restricted areas. If they are outside, avoid areas like culverts or hiking paths in ravines that could retain and intensify water flow.

The biggest property threat in the summer is hail and it is responsible for the most insurance claims for the entire province. He said 80 per cent of all insurable losses in Canada are weather-related and 50 per cent happened in Alberta. Meteorologists have seen evidence of golf-ball sized hail produced by a storm.

Forest fires and wildfires are also a concern, especially in dry weather conditions. Caution with fire is always a good idea, and avoid careless disposal of cigarette butts. Find out about local evacuation routes and have an emergency preparedness kit available. 

The average snow fall for this area per year is about 32 cm. McMurtry said this year had about four times that amount. Winter storms and exposure to freezing temperatures in blizzards, especially for motorists is a concern. Motorists should notify someone of where they are going, have an emergency kit in the vehicle and drive to a side road until help comes, or the storm abates.

The bottom line is be aware of your surroundings, monitoring the weather conditions, planning safe escape routes and having knowledge, information and resources that will prepare you for whatever Mother Nature throws your way.

For weather forecasts and warnings see www.weather.gc.ca/canada or listen to weather radio at www.ec.gc.ca/meteo-weather .