Heightened threat for damaging winds in Quebec storms
Wednesday, September 26, 2018, 9:45 AM - As the tornado count continues to climb from last week's outbreak across eastern Ontario and Quebec, another dynamic fall storm deepening over the Great Lakes through Wednesday will impact clean-up efforts amid a severe thunderstorm threat. More on the timing and guarantee for damaging winds with this system, below.
MORE GATINEAU TORNADO COVERAGE
- Hundreds displaced as tornado hits Gatineau, Quebec
- Widespread damages following Ottawa-area tornadoes
- VIDEO: Local describes tornado damage
WATCH: LATEST TORNADO COUNT UP TO SIX WITH LAST FRIDAY'S OUTBREAK:
WEDNESDAY'S SEVERE WEATHER SETUP
On Wednesday, scattered thunderstorms and mainly cloudy skies will prevail across the province. As the region enters the warm sector of the system -- an area where instability grows as temperatures rise -- the atmosphere will become primed for severe weather ahead of a cold front. However, this system will be messy and mostly cloudy skies will keep instability on the lower end, with only patches of moderate instability forming as clouds sporadically thin out.
But what the system lacks in energy, it makes up for with strong dynamics and wind shear, heightening the threat for damaging wind gusts and a slight tornado risk (more on this below).
TIMING & LOCATIONS
Through Wednesday morning, scattered showers, mainly cloudy skies and a few embedded thunderstorms will continue to work across the province. Through the afternoon, as the instability grows, stronger thunderstorms will bubble up across much of the south, with potential to become severe with a few supercells. To the west, the system's cold front will develop a broken line of thunderstorms, swinging through the Ottawa-Gatineau region roughly between 1-3 pm, Montreal between 3-5 pm and Quebec City from 6-8 pm. Beyond those time frames, winds will be gusty but drier conditions return.
CLICK TO PLAY: ROUGH OUTLOOK ON PRECIPITATION TIMING ON WEDNESDAY
One area of greater concern and complication is in a region bounded by the St. Lawrence River and U.S. border which includes the Eastern Townships, where there is slight, but conditional tornado risk. Areas in the red below should monitor the forecast closely from the afternoon through mid evening hours. Otherwise, a few isolated severe thunderstorms are possible across much of southern and eastern Quebec, with damaging winds the primary threat.
Regardless of severe weather, the system will bring gusty winds of 50-60 km/h widespread over Quebec, which will jeopardize structures and homes already vulnerable from last week's severe weather.
By the late evening hours, the system will have cleared out of Quebec, with mainly sunny skies forecast for Thursday.
Stay tuned for more updates as we continue to monitor and update the forecast.
LONG RANGE OUTLOOK
Late this week an even colder blast of Arctic air will descend upon the Prairies and attempt to spread east into Eastern Canada, Weather Network meteorologist Dr. Doug Gillham writes in his long range national forecast. But the air will meet resistance, much like what we've experienced through September, from a strong Bermuda High in the Atlantic. Due to this resistance, the cold air and associated front will stall across southern Ontario and Quebec on Saturday and a large range in temperatures will be found over the provinces -- rather chilly air in the north and very warm air to the south.
"Another fall storm early next week tracks into the Great Lakes with a couple days of milder weather expected to surge north into southern Ontario and Quebec ahead of system," adds Gillham. "Cooler weather expected to shift east somewhat heading into Thanksgiving weekend."