Tag: heavy rain

New Brunswick

Mixed Precipitation for Eastern Canada & First Appreciable Snowfall…

A system developing in the Southeastern United States will track up the Eastern Seaboard this weekend, becoming a weather story across Eastern Canada.

SYNOPSIS:

A developing coastal system will bring a wintery mix across Southern Ontario, Quebec, and Northern New Brunswick. 

A boundary will form in Southern Ontario between a cold & dry high-pressure system, and moist air arriving from the Southeast. Colder air will overspread Southern Ontario and Southern Quebec Saturday, owing to a cold Northeasterly wind. Concurrently, a large area of precipitation will push north into Southern Quebec and Southern Ontario.

Snow, mixing, rain and freezing rain is expected from Saturday morning to Sunday evening. Flurries will continue through Monday.

Across, Nova Scotia, PEI and much of New Brunswick will see primarily rain. Although, Northern New Brunswick could remain as a mix or snow depending on the track of the developing system.

WPC forecasted fronts & precipitation types. Valid Friday evening.

SOUTHERN ONTARIO:

Many residents East of Highway 6 and across the GTA have started the day with moderate wet snow.

A cold northeasterly wind will reinforce colder air by Saturday evening. Mixing or rain-showers will transition into a wintery mix of wet snow & ice pellets east of Highway 6, along/north of highway 407/7. Continuing through much of Central and Eastern Ontario (away from the lake shore). A few wet centimetres is possible. Especially for municipalities at higher elevation South and East of Georgian Bay. Please plan accordingly, as conditions will deteriorate through the day Saturday.

MARITIMES: Strong Winds & Heavy Rainfall

This system will be a rain and wind story across much of the Maritimes. The strongest winds, with gusts between 80-90km/h, will be located across the Bay of Fundy. Elsewhere winds across much of Nova Scotia, PEI and New Brunswick are expected to be gusting between 50-70km/h Sunday morning. Total rainfall amounts between 20-50mm is expected by Sunday afternoon. The heaviest rain falling in Southern New Brunswick and coastal Nova Scotia. Across Northern New Brunswick, a period of snow and mixing may persist into the overnight. 

Forecast precipitation type & accumulation.

QUEBEC:

Flurries will begin north of the St. Lawrence Saturday evening. Montreal, and the Eastern Townships will likely changeover to rain late Saturday evening/overnight, with the arrival of warmer air. 

For regions north of the St. Lawrence, this will be a snow and ice story. Stay tuned to further forecasts Saturday night through Sunday morning, this region could see a 5-8 hour window for freezing rain.

Model depiction showing precipitation types late-evening Saturday, continuing overnight.


Newfoundland and Labrador

Powerful Storm to Develop Across Newfoundland & Labrador Tuesday

A seasonably-deep low pressure system will develop rapidly Tuesday; impacting Newfoundland & Labrador.

The central pressure is forecast to deepen an incredible 22mb in 24 hours, almost reaching the criteria to be considered a “weatherbomb”.
#NLwx

Far, and largely unpopulated, Northeastern Labrador will see snow mix-in. Accumulating snow is possible in Greenland.

Expect pounding surf of 3-5m and beach erosion in Labrador. As well as, heavy rainfall and strong winds. Strongest winds to 90km/h will remain well off the coast.

Projected Wave Heights

NEWFOUNDLAND:

Western sections will see locally-heavy rainfall with this system. The biggest weather story is focused on a sudden change in weather pattern.

Warm & humid conditions dominating the Province will end, at least temporarily, with the passage of a cold front.

A cooler much-drier airmass will move across the province West to East throughout Tuesday.

 

Ontario

Severe Thunderstorm Risk Builds in Southern Ontario

Showers and a risk of severe thunderstorms for Southern Ontario. Heavy rainfall from East of Lake Superior to the Quebec border Wednesday (June 13th, 2018).

A strengthening low pressure system will track East of Lake Superior through the Nickel Belt Wednesday, bringing a risk for heavy rainfall for Northern Ontario and a risk of severe thunderstorms in Southern Ontario. 

WHAT’S EXPECTED 

A swath near the low track, from East of Lake Superior to the Quebec border will likely see rainfall amounts of 25-50mm between Wednesday morning to evening. 

Further south, across Southern Ontario – there will be 2 rounds of precipitation. The first, along a warm front as it edges north into Southwestern Ontario, bringing scattered showers Tuesday evening through Wednesday morning. Once the warm front moves north, there will be a clearing allowing for sunny breaks and energy to build ahead of a cold front acting as a trigger for thunderstorms Wednesday afternoon. Some of these thunderstorms may be severe with damaging winds as the primary threat.

A window for a low tornado threat is possible from mid to late afternoon in our red highlighted area. The greatest threat will be along a “triple-point” – between 1pm and 6pm. This region may expand to include municipalities near the Lake Ontario shoreline. 

Environment Canada (OSPC) is calling for a “moderate” risk of severe thunderstorms. The primary threats according to their risk map is damaging winds up to 100km/h. Please note: these maps are still in the experimental stage. 

STRONG WINDS

After the passage of the cold front the low will continue to deepen as it moves into Quebec. Strong wrap around winds will develop Wednesday evening and overnight. Gusts between 60-80km/h are expected across much of Southwestern, and South-central Ontario. Localized gusts to 90km/h are possible in higher elevation South of Georgian Bay, as well as, near the lakeshore.