A 'weather bomb' could bring power outages to Montreal as heavy winds and rain hit Quebec

A powerful and fast-growing storm heading toward Quebec could make for a rough end to the workweek in Montreal.

According to a new report from MétéoMédia, the system meets the criteria of a 'weather bomb,' a rare type of storm that strengthens extremely quickly and often brings disruptive conditions. Environment Canada has now issued a wind warning for the Montreal area, citing the risk of damaging gusts by Friday.

While northern Quebec is bracing for heavy snow, Montreal's biggest concerns will be strong winds, periods of heavy rain and a sharp temperature drop once the system moves through.

Environment Canada says southwesterly wind gusts reaching up to 90 km/h are expected in the Greater Montreal Area on Friday afternoon and Friday evening.

The federal weather agency has assigned the warning a moderate impact level with high forecast confidence, noting that local power outages are possible. Loose outdoor objects could be blown around, and high-sided vehicles may be pushed by the wind.

The warning is in effect for the Montreal Island area, as well as nearby regions including Drummondville and Bois-Francs.

What a 'weather bomb' actually means

MétéoMédia explains that a weather bomb occurs when a storm's atmospheric pressure drops by at least 24 hectopascals in 24 hours or less.

In this case, forecasters expect pressure to plunge from 982 hPa to 954 hPa between Friday afternoon and Saturday afternoon. That rapid intensification can dramatically increase wind strength and precipitation rates.

Heavy rain before temperatures crash

Thanks to a surge of unusually mild air pushing north from the U.S., precipitation in Montreal is expected to fall mainly as rain.

MétéoMédia forecasts about 10 to 20 mm of rain for Montreal by Friday evening. Temperatures could climb well above seasonal norms on Thursday and Friday, nearing or even exceeding 10 C in some areas, before quickly dropping again.

Hold on to your hats

Even though parts of eastern Quebec could see wind gusts exceeding 100 km/h, MétéoMédia says gusts of 60 to 90 km/h are possible in the St. Lawrence Valley, which includes Montreal.

With already saturated ground, those winds could lead to downed branches, fallen trees and isolated power outages. MétéoMédia is also advising residents with temporary car shelters to secure them ahead of time.

Flash freeze risk heading into the weekend

Once the storm passes, Arctic air is expected to rush back into the province.

MétéoMédia warns that rain and melting snow, followed by a rapid temperature drop, could quickly turn roads and sidewalks icy. Drivers and pedestrians should be especially cautious late Friday night into Saturday.

While Montreal avoids the snowstorm portion of this system, conditions will be much more intense farther north. MétéoMédia says areas between Waskaganish in Jamésie and Schefferville near the Labrador border could see between 40 and 50 cm of snow.