No re­lief under the dome

The Western Star - - WEATHER - CINDY DAY Chief Me­te­o­rol­o­gist Cindy Day

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, and 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 snow­clear­ing 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!

A clock­wise flow around the stalled Ber­muda High con­tin­ues to pull warm, hu­mid air into eastern Canada.

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