Tag: Quebec

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.


Quebec

Severe Thunderstorm Risk Pushes East into Quebec

  • by Troy Boone

A strong cold front will act as a trigger for isolated severe thunderstorms across the Eastern Townships and Southeastern Quebec Wednesday. Damaging winds, torrential rainfall giving 25-50mm of rain in a short duration, frequent lightning and isolated supercell(s) are risk factors with these storms.

Thunderstorms may track into Northern New Brunswick bringing heavy rainfall and lightning as they begin to weaken and become elevated. 

TECHNICAL ANALYSIS:

A developing area of low-pressure will track out of Northeastern Ontario into Quebec Wednesday, deepening rapidly. An area of height-falls & falling atmospheric pressure will overspread the warm sector, ahead of a seasonably sharp cold front. Temperatures will rise into the mid-20s with dew-points nearing 20c. Pockets of 1500J/kg of CAPE should develop across the warm sector. Largely unfavourable lapse rates will be compensated by a strong tendency for ascent. 65 knot, 500mb flow will overspread the Eastern Townships & Southeastern Quebec – ahead of an amplified, positively tilted trough. A modest low-level jet should be sufficient for moisture transport across the warm sector, and a damaging wind threat. Speed-shear and wind shear will be sufficient enough to sustain long-lived updrafts – well-tilted updrafts capable of rotating. A threat for stronger bowing-linear segments or super-cells exists between 1-5pm. Additional risks, include torrential downpours, frequent lightning and hail in the stronger updrafts.

Timing of the cold front and pre-frontal clearing will be important determining factors considering how severe thunderstorms will be. 

Ontario

Another Round of Severe Weather Targets Southern Ontario &…

  • by Troy Boone

Monday will be a pleasant seasonal day, dominated by high pressure and brilliant sunshine – across Southern Ontario & Quebec.

Wet, humid and stormy conditions start the week, with a risk of thunderstorms. Find out when and where.

SYNOPSIS:

Cloud, spotty showers, steady rainfall and humidity will make a return to Southwestern Ontario as early as tonight, with a warm front pushing northwards. Overspreading, the rest of Southern Ontario and Extreme Southern Quebec by Tuesday Morning.

Concurrently, an area of low pressure will strengthen along the Manitoba/Ontario border as it tracks towards Hudson Bay. 15-30mm of rainfall is expected in Northwestern Ontario. With wet snow mixing in across far Northern sections. 

2 WAVES OF PRECIPITATION

The first wave of precipitation will arrive overnight tonight into Tuesday morning across Southern Ontario, moving into Quebec by the morning – ending early afternoon. Some embedded heavy-downpours is expended in a swath from the shores of Lake Erie to Niagara. Elsewhere, expect light to moderate rainfall and predominantly cloudy, warm and humid conditions. Dry slot arrives in the late morning to afternoon.

We will be watching Southwestern Ontario closely Tuesday, as any clearing could further destabilize the atmosphere increasing the risk of evening thunderstorms ahead of the cold front.

SECOND WAVE; RISK OF ISOLATED SEVERE THUNDERSTORMS

Associated with a sharp cold front – along a developing strong area of low-pressure forecast to deepen as it tracks through Northeastern Ontario and Quebec.

SOUTHERN ONTARIO

Thunderstorms will develop ahead of a cold front Tuesday night, persisting into Wednesday morning from East of Georgian Bay through Southwest Ontario. Isolated severe storms are possible. Bringing isolated strong wind gusts and heavy downpours. 

SOUTHEASTERN QUEBEC

A risk of isolated severe thunderstorms develops for Extreme Eastern Ontario and Southeastern Quebec late Wednesday morning or early afternoon, ahead of a sharp cold front. The primary risk will be damaging winds and heavy downpours. Isolated supercell(s) cannot be ruled out in Southeastern Quebec, but the risk will largely depend on timing & clearing.

GUSTY WINDS

Gusty southwesterly winds of 40-60km/h will overspread the risk area Tuesday. Becoming northwesterly through Wednesday. The strongest wind gusts of 60-70km/h will remain draped across Central Quebec and Nova Scotia.

Ontario

Potent System: Severe Thunderstorms & Pattern Change for Ontario…

  • by Troy Boone

[UPDATED] A strong fall-like system will track across Ontario and Quebec Friday, bringing a risk of severe thunderstorms. Heavy rainfall, strong winds and a pattern change is expected. Find out where.

Through the day Thursday, an area of low-pressure will deepen as it tracks from the Midwest into Northeastern Ontario, Friday morning. The low will mature as it tracks into Quebec by Friday afternoon.

A warm front, associated with the seasonably-deep low will push north across Ontario and Quebec Thursday morning into Friday. Concurrently, temperatures will soar into the high-20s Friday afternoon across Southern Ontario and Southern Quebec (near the border). Increasing dew-points will lead to muggy conditions feeling into the mid-30s.

Instability, very-strong upper-level winds, wind-shear, and marginal energy will lead to severe thunderstorms Friday. Ahead of a vigorous cold front, and strong upper-level trough where heights will be falling.

RISK & COVERAGE

The greatest risk for severe thunderstorms in Ontario will stretch from Central Ontario to Eastern Ontario. Coverage will be more isolated in Ontario than Quebec. These thunderstorms will be capable of producing strong wind gusts. Upscale growth into a squall-line bringing straight-line winds, heavy downpours and frequent lightning is possible.

In Quebec, atmospheric energy & cooler temperatures will be less favorable than Southern Ontario, but better forcing, shear, and instability will lead to isolated-severe thunderstorms. Risks include damaging winds, frequent lightning and heavy downpours. This will include the risk of supercells. The strongest risk will largely affect rural, unpopulated municipalities.

WIND & HEAVY RAINFALL

Regardless of thunderstorms, synoptic winds will be strong across Southern Ontario and Southern Quebec with this fall-like system. Widespread gusts between 50-80km is expected across a large swath of Ontario and Quebec, preceding the cold front and after its passage.

UPDATE: latest model guidance is suggesting that localized wind gusts of 90-100km will impact Ontario and much of Quebec.

30-50mm of rainfall is expected along a swath East of Lake Superior through Northeastern Ontario.

PATTERN CHANGE INTO FALL

The passage of the cold front will usher is much cooler and drier conditions by Friday night. Temperatures will struggle to get into the mid-teens by the weekend. A hard freeze is looking probable across Northern Quebec and Northern Ontario.

Ontario

When Will it End? Early April Chill to Bring…


An early April chill will allow colder air from Northern Canada to funnel into much of the continent of North American and provide one residual and last remnant shot of winter; significant accumulating snow April 4th (Night) through April 5th is likely, especially for some regions.

We have prepared a risk map outlining the potential for significant snow (deemed in this case a minimum of 5cm or more), across Southern, Eastern, Central and Northern Ontario, as well as parts of Southern Quebec and the Townships.

At this point, it seems most of the coldest air should remain north of the 401, alongside the higher moisture content; most of the heaviest snow will reside around Cottage Country and near Lake Superior/Northern Ontario.

At this time, the 401 corridor with the exception of regions near Lake Erie, can except a swath of 5-10cm, while regions north of the 401 (and Quebec) can expect 8-12cm, locally 15cm, and regions in Cottage Country, Northern Ontario and Lake Superior region can expect 15-20cm+.

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Inevitable = >90%
Very High Chance = 80%+
High Chance = 70%+
Moderate Chance = 50%+
Slight Chance = 30%+
Minimal Chance = 10%+

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When will the cold relinquish?
As recently predicted and outlined in our Spring/Summer forecast, it is [and we expect] Spring to be relatively cool across much of Eastern Canada with above normal precipitation. However, we do believe more moderating temperatures will begin to enter the Eastern half of the country beginning very late April, and more prominently into early May.

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Please stay tuned, as we at TCW are monitoring this situation attentively.

Drive safe and always be alert during winter conditions.

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New Brunswick

[UPDATED] Unsettled Pattern Arrives in Eastern Canada

Unsettled week ahead for the Maritimes to Ontario, including Quebec.

A formidable late winter snow storm has dropped impressive snowfall totals across parts of the Canadian Prairies in recent days. The same storm system has weakened and stalled over the Great Lakes, while aiding in the formation of a new surface low that tracked into the Maritimes.

The newly-formed system tracked up the Eastern Seaboard concurrently as a trough sits over the Great Lakes, becoming a weather maker for much of Eastern Canada.

ONTARIO

Predominantly cloudy conditions, with periods of flurries and wet snow continues Thursday and Friday across Southern and Northeastern Ontario. Trace amounts are expected for most, but parts of Southwest Ontario and Eastern Ontario could see several day totals approach 10-20cm. Actual ground accumulation will be less considering melting and settling.

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A more substantial in addition to localized snowfall threat will develop Wednesday morning, spanning parts of southwest Ontario. As a result of moisture enhancement off of the Great Lakes and a stalled trough over the region. A few wet centimetres is likely to accumulate east of Lake Huron. The unsettled pattern continues into Wednesday, Thursday and perhaps Friday. 5-15 centimetres of accumulation spanning the work week is expected. Highest totals away from the lakeshore and in regions of higher elevation.

MARITIMES

A moisture-laden system approaching the Bay of Fundy will continue to spread snow and rain across the Maritimes. Moderate snowfall continues to impact central Nova Scotia, PEI and New Brunswick. An additional 3-8cm of wet snow is expected to accumulate today, before this low tracks north. Precipitation will likely end as rain showers as temperatures warm. The heaviest totals from this system will be across a swath of central New Brunswick where 15-20cm is expected.

A second powerful storm system is expected to develop Friday lasting into Sunday. Strong winds gusting 50-70km/h and heavy snowfall amounting to an additional 10-25cm will be a concern.

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Snow is expected to begin across Nova Scotia and PEI, transitioning to rain as the warm sector of the storm continues north throughout the day Thursday. Highest accumulations are expected in Cape Breton. Elsewhere, several wet centimetres will fall before a changeover to rainfall. There is still some uncertainties in exact track of this system(s). Once forecast confident increases, we will publish a region specific forecast for the maritimes promptly.

Primarily snowfall is expected in central and northern New Brunswick, with a changeover to rainfall near the Bay of Fundy.

QUEBEC

Flurries and light snowfall continue in Southwestern Quebec. A retrograding coastal low moving west-wards towards the Saint Lawrence river Thursday into Friday morning, will being heavier snow to Southeast Quebec and the Eastern Townships. Total accumulations are expected to be in the 10-20cm range by Friday evening.

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Ontario

Snow, Freezing Rain and Thundershowers for Ontario and Quebec

A Low Pressure System from Missouri Targets Ontario and Quebec This Weekend.

A quick moving Low Pressure System from Missouri will track and swing through Ontario and Quebec giving bountiful types of precipitation.

As a result of its fairly quick speed, precipitation amounts will not be overly significant, but, still pose a reasonable inconvenience depending on the region.

The heaviest snowfall will be due East of Lake Superior with moderate accumulations elsewhere across Northern/Northwestern Ontario and much of Quebec.

Parts of Ontario will be inundated with patchy freezing rain, however, significant accretions are not expected at this time.

Southern Ontario, along the 401 corridor and East to the Niagara region, can expect 10-20mm of rain with embedded non-severe thundershowers and gusty winds up to 60-75km/h.

Please adjust your driving accordingly based on the current driving conditions.

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New Brunswick

Treacherous Conditions for Quebec and New Brunswick

Respectable ice accretion is expected to build for parts of Quebec and West-Central regions of New Brunswick.

Freezing rain is expected to creep through both of the aforementioned provinces and pose an extended threat of widespread freezing rain. While not all regions are expected to be targeted, regions such as Quebec City and its Northern suburbs, as well as, regions in West-Central New Brunswick will become treacherous as upwards of 15mm of accretion could result. Regions elsewhere will receive minimal accretion, and thereby, only isolated and patchy icy conditions will be present.

Freezing rain is expected to linger into much of the day on Tuesday.

Predominantly rain will target Southern New Brunswick, and Eastern PEI.

At TransCanada Weather, we suggest you take extra care while walking outside or commuting to and from work.

Please adjust your driving habits accordingly and be prepared to allot extra time from traveling to and from your destination.

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