Above normal temperatures, humidity expected in late summer
If you're hoping for hot or even warm weather in Newfoundland and Labrador anytime soon, you may be out of luck. But, warmer and more humid weather than normal is in the long-range forecast for the second half of the summer season.
AccuWeather, a meteorological service based in the United States, says the cool weather pattern that has dominated parts of central and eastern Canada this spring will prevail into the majority of the summer, while western Canada will have a warmer, drier summer compared to normal.
While Atlantic Canada will experience a cool start to summer, Brett Anderson. a senior meteorologist who writes a Canadian weather blog for AccuWeather.com, is predicting the region will transition to conditions warmer and more humid than normal for the second half of the summer.
Anderson says a persistent dip in the jet stream across central and eastern Canada will lead to an increase of cool spells in the region, especially during June and July. "In addition to the jet stream pattern, the record extent of ice coverage over the Great Lakes this spring has delayed the normal warming of the lakes. As a result, the lagging lake temperatures will have a cooling effect on the surrounding regions, including areas in and around Ontario, such as Thunder Bay, Sault Ste. Marie and Toronto, during the first half of the summer."
He says the combination of below-normal temperatures and lower humidity levels will also reduce the threat for severe weather this summer from the eastern Prairies into northwestern Ontario.
For the first half of summer, near-normal rainfall is expected across most of Atlantic Canada, including St. John's and Halifax, N.S. However, Anderson says, for the second half of the season, the region is expected to transition into a period of above-normal rainfall as a more moist, southerly flow takes over with the opportunity for heavier, tropical rainfall late in the summer.
Meanwhile, high pressure reigns, above-normal temperatures and less rainfall are predicted for much of British Columbia and in areas in extreme western Alberta this summer.
Anderson says this combination of increased heat and little rainfall, coupled with an ongoing Pine Bark Beetle infestation, will raise the risk for large wildfires along and west of the Continental Divide.
In Vancouver, B.C., the combination of high pressure and above-normal sea surface temperatures in the northeast Pacific is expected to lead to a slightly warmer-than-normal summer with reduced chances for rainfall.