Unsettled wet weather week ahead for Montreal

Unsettled, wet weather is expected in Montreal for most of the upcoming week.

A series of frontal systems will provide southern Quebec with a rather cloudy, wet week. The first system is on our doorstep Tuesday morning, as low pressure and a trailing cold front move across Ontario and Quebec. Light showers are already occurring in Montreal, with coverage and intensity of the precipitation rather light. We will have a few breaks in the cloud through midday, allowing the atmosphere to destabilize somewhat. Winds will begin to increase out of the southwest ahead of the cold front this afternoon, up to 50km/h, along with the increased risk of showers and perhaps a rumble or two of thunder. Showers will continue overnight. Rainfall amounts by Wednesday morning will be in the 15 to 20mm range for Montreal, with up to 50mm possible across eastern Ontario.

Wednesday though Friday will be rather unsettled, with more clouds than sun and the risk of showers all three days. Our rain chances unfortunately will only increase this weekend, as another low pressure system will approach Quebec from the Ohio Valley. Temperatures will be close to seasonable, with highs in the low 20s and overnight lows in the middle teens.

Meteorological summer has started off rather cool in Montreal, after a hot May. The average high through June 6 has been 22.1C (71.8F), very close the the normal of 22.3C (72.1F). It has been dry so far, with only 2mm of rain, following what was a drier-than-normal May, with 58mm of rain compared to the normal of 81mm. Most of that fell in less than an hour during one thunderstorm on May 16.

Our May heatwave was one for the record books in Montreal. The May 12 to 14 heatwave featured three consecutive record highs, and was the earliest such period on record for the city. The previous "earliest" heatwave was May 27 to 30, 1978. The four daily highs over 30C tied a record set in both 1977 and 1978.

Despite the cooler, wet weather break anticipated this week, it is still looking like a rather hot and humid summer for Montreal.

A high water rescue vehicle evacuates residents from a Miami suburb last Saturday morning after 275mm of rain fell from what would become tropical storm Alex. (Photo: Miami-Dade Fire Rescue)

The Atlantic hurricane season got off to an early start, with tropical storm Alex forming east of Florida this past weekend. The system developed from the remains of Hurricane Agatha that had moved inland over central Mexico last week before crossing into the Gulf of Mexico and reforming as Alex. Alex dumped copious amounts of rain on south Florida over the weekend, producing flash flooding. As much as 275mm of rain fell on Miami Friday and Saturday. The storm then brushed Bermuda before dissipating in the open water of the Atlantic. This is likely just the beginning of what promises to be a busy season according to forecasters at the National Hurricane Centre.