Looking at the latest guidance, it looks like a significant pattern change is in store in about a week across Canada. Between Aug. 21 and 25, there will be a surge of cool air coming down into the Prairies and perhaps a portion of British Columbia. At the same time, very warm and increasingly humid air will spread northward into the Midwest U.S., eastern Canada and the Northeast U.S., which is more typical of what we expect in August. Farther northeast, a persistent upper-level low will likely bring Newfoundland a stretch of cooler and showery weather during the above time period.
Going farther ahead, below is my latest interpretation of the European long-range forecast model weeklies going out through the second week of September.
Note**** I will be releasing the AccuWeather Canada Fall Forecast on Monday.
Mild air masses likely to outnumber the chilly air masses for a good part of October.
Jet stream pattern across North America will become amplified across North America into next week, which means more extremes in weather.
Warm weather will dominate in the eastern half of the country for the next week. Pattern change possible during the last week of September.
The jet stream will strengthen from the Pacific across southern Canada over the next 1-2 weeks which will keep any sustained chilly/cold air masses up across western Alaska and eastern Siberia.
The latest clues to the long range into the month of October.
Late-season heat in the East and mountain snow in the West. Welcome to the fall season!