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CINDY DAY: No relief from the heat under the dome

A clockwise flow around the stalled Bermuda High Aug. 1 continues to pull warm, humid air into eastern Canada.
A clockwise flow around the stalled Bermuda High Aug. 1 continues to pull warm, humid air into eastern Canada. - SaltWire Network

I’ve been talking about the stalled weather pattern responsible for the hot, dry weather – the Bermuda High – for a couple of weeks now.

I’ve described the upper air circulation that’s pulling warm, almost tropical air into our region.  But there’s more to it than just the flow of air – it’s something meteorologists refer to as a “heat dome.” A heat dome forms as the result of a couple of factors: a dramatic northern bulge on the jet stream and an area of high pressure south of the jet.  That area acts like a dome; under this dome you have sinking air.  As the air sinks, it is compressed and it warms, eventually becoming trapped under itself.  Day after day, the air gets warmer and warmer and becomes more and more difficult to dislodge.  Sinking air also keeps a cap on the atmosphere reducing the likelihood of any shower formation. 

This “heat dome” has been in place off our coasts for almost three weeks now.  Heat domes are not rare, but their size and duration vary, making some more dangerous than others.

The deadliest heat wave in Canadian history occurred from July 5 to 17, 1936; temperatures exceeded 44 C in Manitoba and Ontario and claimed the lives of 1,180 Canadians.

It’s so very important to heed the heat warnings.  Staying hydrated and reducing the amount of strenuous outdoor physical activity, if possible, is a good start. If you know someone – a senior, perhaps – who is struggling with the heat, be a good Samaritan and help them find some relief.  It’s really no different than giving someone a hand with snow-clearing in the winter.

It’s also important to keep an eye on your pets and make sure they have some shade and lots of water. 

Extreme, prolonged heat can be as dangerous as bitter cold, so let’s be smart about it!

Cindy Day is the chief meteorologist for SaltWire Network.

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