Slightly cooler weather week ahead for southern Quebec

A rare fire tornado erupts along the edge of the Loyalton Fire in Lassen County, California on Saturday. (Photo by Katelynn Hewlett via social media)

As I am writing this blog update, light to moderate rain is falling outside my office window in Saint Laurent. Since about 9:30am, nearly 20mm has fallen already in the west end of the city. The rain is associated with an extremely slow moving cold front that is draped across eastern Ontario. The front and a secondary trough will take the better part of the next 24 hours to clear the region. Until then we can expect a very muggy airmass, with temperatures in the middle 20s. Showers and isolated thunderstorms will prevail as well, with the bulk of the precipitation occurring Monday morning and again Tuesday afternoon.

Behind the front, cooler and drier air will push into the region. The weather will not be cold, but will feel very refreshing after the prolonged heat this summer. The pleasant weather will prevail to end the week, unfortunately another round of showers and thunderstorms will be possible by the upcoming weekend. 

The sun peeks through the clouds on another humid August afternoon in Montreal. The summer of 2020 will likely be one of the warmest on record for the city, with a record-setting 24 days over 30C (86F) already and another 9 days over 29C (85F). (ValleyWeather Photo)

August has featured just one day of 30C weather to date in Montreal, bringing the total to a record-breaking 24 days since late May. If you add the 9 days where the temperature fell just short of that mark, between 29C and 29.9C, nearly one third of the summer has had high temperatures over 85F in Montreal.

It is now western Canada's turn to experience high heat. A strong ridge of high pressure over Utah, is pumping hot air from Arizona and California, northward into BC and Alberta. Strong south winds are acting like a blast furnace, with daily highs soaring into the upper 30s and 40s on Sunday. Over 20 record highs were broken in BC and Alberta on Sunday. The hot spot was Lytton, B.C. where the temperature reached a scorching 41.2C (106F). The hot weather is expected to persist most of the upcoming week from BC to Saskatchewan. 

The weather was much the same south of the border from the Pacific Northwest south towards the Mexican border. In southern California and Arizona, highs in some locations have reached the upper 40s (110-115F). The hot, dry weather is fuelling massive forest fires across western North America. In B.C., 24 active fires are burning, an increase of 10 in just the last 24 hours. One of the largest fires in recent history is burning in Colorado, west of Denver. In Lassen County, California, nearly 10,000 acres have burned in the Hog Fire. The raging infernos produced a rare fire tornado in the Loyalton fire complex close to the Nevada border on Saturday. 

The heatwave is expected to persist for the entire upcoming week across the west, with only some slight relief occurring along the Canadian border.