Update: Debby’s track shifts towards Montreal

Post-tropical Storm Debby has veered inland, currently tracking for a direct hit on Montreal Friday night.

The Canadian National Hurricane Centre has updated its map of Debby’s projected path, which has shifted eastward. Ottawa is currently in the projected outermost western radius of the storm’s track, while now many of the Maritime provinces are outside the storm’s easternmost projected radius.

AccuWeather is forecasting 96 mm of rain for Montreal Friday night and 40 mm for Ottawa, with winds gusting more than 60 km/h.

The Weather Network projects more than 50 mm of rain for Montreal and Ottawa over a 24-hour period, and 50 km/h winds starting Friday.

“There is still some uncertainty with regard to the system’s track,” Canadian Hurricane Centre says in an update Wednesday. “This will have a great impact on precipitation amounts to come, and on which areas will be the most affected. Flooding is possible in low-lying areas.”

Debby made landfall in Florida Monday morning as a Category 1 hurricane (wind speeds of 130 km/h) and brought intense winds, torrential rains, coastal flooding and tornadoes to the area Monday. The storm dropped between 200 mm and 400 mm of rain on parts of Florida, The Weather Network reported Tuesday.

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As of Wednesday, the storm dumped about 150 mm in some parts of New Jersey over four hours. In some New York communities, residents living in basement apartments have been warned they may have to evacuate at a moment’s notice, AP reports.

Debby is forecast to hover over North Carolina about a day before reaching Canada, causing widespread flood damage. The storm is currently stalled over Georgia and the Carolinas.

“Potentially historic heavy rainfall across eastern South Carolina through Friday will likely result in areas of catastrophic flooding,” the U.S. National Hurricane Centre predicted Tuesday. “Heavy rainfall will likely result in flooding impacts from northern North Carolina through portions of Mid-Atlantic States and southern New England through Sunday morning.”

Debby’s time spent inland “will serve to weaken the storm, as it will be largely cut off from its warm oceanic fuel,” The Weather Network said Tuesday.

A trough (a low atmospheric pressure) in Ontario will allow the storm to make its way north through Quebec just as the weekend approaches, The Weather Network forecasts.

Two high-pressure systems on the U.S. eastern seaboard are making it hard to forecast the storm’s precise track, said The Weather Network. Also, they have had a ‘push-pull’ effect on the storm, causing it to stall in Georgia and the Carolinas.

“Across portions of southeast Georgia and South Carolina, 250 mm to 500 mm of rainfall is expected, with local amounts potentially reaching 760 mm,” The Weather Network predicted Tuesday.

On July 16, 2024, southern Ontario experienced flash flooding due to a series of strong thunderstorms that produced more than 100 mm of rainfall within a few hours. Toronto saw major flooding after a storm dumped more than 90 mm of rain on the area.

Ontario’s July 2024 storm is estimated to cost about $1 billion in insured damage.

 

Feature image courtesy of Canadian Hurricane Centre