Another round of heavy rain and thunderstorms on the way for Montreal

Precipitation was well-above normal in Quebec and Ontario during the month of July, and it appears that trend is continuing into August. Widespread rainfall warnings are in effect for a large portion of the region.

Wash. Rinse. Repeat. What a summer it has been across North America and particularly here in eastern Canada. We managed two rare spectacular weather days days in a row without severe thunderstorm, flood or heavy rain warnings, but sadly that has come to an end. Widespread rainfall warnings and special weather statements are now in effect across Ontario and Quebec as strong low pressure is forecast to move across the region.

Our attention now turns to a moisture latent low pressure system and warm front lifting northeast from the Great Lakes down the Saint Lawrence Valley over the next 36 hours. Heavy rain is already falling in the Ottawa Valley and will move into Quebec during the day today. The rain will come in waves, with showers and embedded thunderstorms. Amounts will range from 25mm (1 inch) up to as much as 75mm (3 inches). Some of the storms may become strong, with heavy rain and gusty winds, especially overnight Monday.

Unseasonably strong low pressure is forecast to move down the Saint Lawrence Valley over the next 24 hours resulting in heavy rain and thunderstorms for southern Quebec and severe weather over the Ohio Valley into the Northeast and New England. (AccuWeather.com)

While August has been a little better in the Montreal region, with only 9mm of rain at Trudeau Airport since the start of the month, other parts of Quebec have not been so fortunate, with a soggy July basically turning into a soggy August. Quebec City had a record breaking 264.7mm of rain in July, and already 19.8mm to date for August. They will addd to that total considerably this week.

The rain has produced widespread flooding in many parts of the province and across New England. Over the weekend, more heavy rain lifted northward across Maine and into New Brunswick and Nova Scotia. Halifax measured 60mm of rain in just a few hours Saturday morning, with more flooding reported.

Over the upcoming week, the heavy rain and thunderstorms will result in additional flash flooding from the Ohio Valley across the northeast and New England and into southern Ontario, Quebec and Atlantic Canada. Dry air will try to return by Friday, but it will be short-lived, with more showers by the weekend for Montreal.

Temperatures will be in the low to middle 20s for highs and middle teens for lows. The weather will feel quite muggy for most of the week.