Category: Ontario

Ontario

Fall Windstorm Targets Great Lakes Tuesday

A classic fall windstorm will track through the Great Lakes Tuesday, bringing strong winds, snow, and rain across Ontario.

A compact area of low-pressure is forecast to deepen overnight Monday, as it tracks through Michigan. Bringing strong wind & rain across Southern Ontario. Concurrently, bringing snow to Northwestern Ontario.

SOUTHERN ONTARIO: STRONG WINDS & RAIN SHOWERS

By Tuesday morning, rain showers will become more numerous as a large area of precipitation moves north from the United States. 5-15mm of rainfall in the morning, preceded by sunny breaks across South Central & Southwestern Ontario by the early/mid afternoon. Temperatures will likely spike into the low teens by the afternoon.

Winds will become stronger throughout the late morning. Becoming the strongest through the afternoon and evening. Widespread wind gusts between 60-80km/h is expected through the afternoon/evening Tuesday. The strongest winds, potentially exceeding 90km/h, are possible in the Niagara Region, Prince Edward, Bruce & Grey Counties.

Projected wind gusts Tuesday 4pm EST. Wind speeds are in knots. 1 knot=1.85km/h.

The strong winds will likely strip many of the remaining leaves from trees. Remember to clean fallen leaves from storm drains.

NORTHWESTERN ONTARIO

While the South contends with wind & rain, Northwestern Ontario will see snowfall. The heaviest snowfall is expected across far-Northwestern Ontario. Another area of snowfall is expected northwest of Thunder Bay. General amounts between 5-10cms is expected Tuesday.

Much colder air with light-snow, is expected for Thunder Bay through Wednesday & Thursday.

Snowfall projections for Northwestern Ontario through Tuesday.

COLDEST AIR OF THE SEASON IS ON THE HORIZON

The warm up will be short-lived. The coldest air of the season, accompanied by lake effect snow arrives this weekend. Daily low temperatures will become consistently negative beyond Friday, November 9th across Southern Ontario. With daytime highs around the freezing mark for several days. Lake effect snow will really begin to ramp up beginning late week. 

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.


Ontario

Reinforcing Cold Shot & Wet Snow Risk for Southern…

A frosty Saturday night ahead across much of Southern Ontario. Pleasant conditions Sunday, give way to a pair of clipper systems to start the work week. 

It will be a cool and frosty Sunday morning across Southern Ontario. Sunny conditions, and light southwesterly winds, will allow temperatures to rebound in the afternoon.  The first of two clipper systems brings rain showers (beginning) Monday morning. Dreary and cool conditions continue through the afternoon. 

Frost advisory issued by Environment Canada Saturday night.

First Shot of Lake Effect Snow?

A clipper system will track through the Great Lakes late Tuesday through Wednesday. The passage of the low will be followed by a reinforcing shot of cold and dry air. Lake effect rainfall may bring graupel or hail to some locales in Central Ontario (Tuesday evening into Wednesday morning). Owing to, instability, and seasonably cold air building aloft.

Lake effect rainfall bands will transition to wet snowfall Wednesday night, Southeast of Lake Huron, and Georgian Bay.

A few wet centimetres may accumulate through Wednesday night. Especially across higher elevations. 

Seasonably cool air 1.5km above the surface, will support lake effect snow. Abundant dry air, warm ground temperatures, and a building area of high pressure, should mitigate any risk of significant accumulation. We will monitor the risk over the coming days. 

Ontario

Winter Reminder: Lake Effect Rain Showers across The Great…

Colder air is beginning it’s decent across Southern & Central Ontario. Gusty winds this evening gives-way to Lake Effect rainfall Thursday night through Friday. First ‘bout of the season serves as a reminder that winter is coming.     

Inland sections surrounding Agawa Bay to Montreal River Harbour will see Lake Effect rainfall beginning this evening. A transition to mixing or large flakes of wet snow is anticipated during the early morning hours Friday.     Location: East of Lake Superior.

Accumulating snow will develop in Lake Effect bands near Wawa Friday night through Saturday.

Lake Effect model simulation for early Friday morning. Animation curtesy of Weather Bell Analytics

Southern Ontario

Lake effect rainbands will setup tonight southwest of Georgian Bay and East of Lake huron. Owen Sound to Barrie to Orillia will be in for a chilly wet reminder that winter is coming. With rainfall bands meandering through the area.

Fairweather waterspouts are possible late Friday over Lakes Erie and Ontario, given the cold air aloft.

Manitoba

Tale of Two Seasons: Heavy Snow, Rain, & Summer…

An area of low pressure will strengthen as it tracks through the Upper Midwestern United States. Bringing accumulating snow and gusty winds across Northwestern Ontario. Summer-like heat & humdity returns to Southern Ontario.

TIMING & ACCUMULATIONS 

Snow flurries will begin mixing in along Highway 17 late Wednesday evening. With wet snow falling by Thursday morning. By Thursday afternoon, anywhere along and south of Highway 11 will likely be seeing rain. 

North of Lake Superior, precipitation will fall as a cold rain with gusty winds. Including the Thunder Bay area, where cold rain and gusty winds will lead to a miserable day. 

Projected snowfall divisible by Postal Code. 
PostalCast©: NW. ON SNOWSTORM – Wednesday through Thursday
— MOST Impacted Locales (Based on First 3 Digits of a Postal Code) —
P0L (10-15cm for Southern Regions; 15-25cm for Northern)
P0T (<5cm near Superior; 25-30cm+ for Northern Regions)
P0V (<5cm for Northern Regions; 15-25cm for Southern)
P0W (10-15cm)
P0X (15-20cm)
P0Y (15-20cm)
P8N (20-25cm+)
P8T (20-25cm+)
P9A (8-15cm)
P9N (10-20cm)

By Wednesday afternoon or late evening, cold air will wrap around the deepening system. Heavy snowfall will begin accumulating in a line from Kenora to Dryden to Sioux Lookout to Pickle Lake. Continuing into extreme Southeastern Manitoba. Moderate to heavy snowfall and gusty winds will persist, increasing in coverage across Northwestern Ontario through the day Thursday. 

Projected amounts are subject to change based on the track & timing of the low + Hurricane Michael. Current guidance suggests a large swath of 20-30cm. 30-40cm could fall locally.

Preliminary snowfall projections will be updated throughout the week.

Actual accumulations will be largely dependant upon key factors: track of the low, temperature, and snowfall ratios. Moisture won’t be an issue with tropical moisture from Hurricane Michael. 

HEAVY RAINFALL 

While Northwestern Ontario deals with heavy snow, Northeastern Ontario will be dealing with heavy rainfall. A large swath of 50-75mm is expected East of Lake Superior. 

THE TALE OF TWO SEASONS 

As Northern Ontario deals with heavy rain and snow, Southern Ontario will get one last blast of summer. Temperatures Wednesday will likely be soaring into the mid or high-20s. With abundant humidity making it feel into the 30s. Forecast temperature & humidity readings will challenge all-time October records Tuesday and Wednesday.

Ontario

Stormy Evening & Overnight for Northeastern Ontario

Heavy showers & thunderstorms beginning this afternoon in Sudbury and Algoma District. Continuing through the overnight.

An area of low pressure will rapidly intensify as it tracks through Northern Ontario towards James Bay. A sharp cold front will trigger heavy rainfall and thunderstorms today and tonight across Northeastern Ontario.

THREATS

The primary threat will be torrential rainfall leading to minor flooding. Additionally, small hail and locally strong winds are possible in stronger thunderstorms.

NAM model rainfall projection for Wednesday into Thursday.

Rainfall totals in the range of 30-60mm is expected north of Manitoulin Island & East of Lake Superior.

Thunderstorm Outlook from Environment Canada

Ontario

Another Round of Severe Weather Targets Southern Ontario &…

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.

Alberta

Canada Winter 2018-2019 Forecast: Frigid Prairies and Significant Lake-Effect…

Canada-Wide 2018-2019 Preliminary Forecast.
Finalized Outlook by Christmas!

Frigid Air and Heavy Squalls Loom

The winter across Canada for many this season is expected to be cold, particularly for Saskatchewan, Manitoba, Ontario, and Quebec.

Through careful analysis of meteorological data, we have compiled a preliminary forecast for the winter across Canada for this winter. We will issue an updated version, should the situation warrant, in December.

For many places, we expect an early start to winter. Some places in Manitoba have already received accumulating snow. For Southern Ontario, we expect accumulating snow perhaps as early as late October.

Key Highlights
– Frigid & Snowy Winter for Saskatchewan and Manitoba
– Cold & Stormy for Ontario and Quebec
– Potentially Historic Squalls for Great Lakes (NW and W Flow)
– Several Winter Storms for Maritimes and NL but Not All Snow

British Columbia
For this winter BC is expected to receive a relatively typical winter season. Normal precipitation amounts with normal temperatures will be present in the region. While a few colder outbreaks are certainly likely with some snow getting into the mainland, we expect nothing out of the ordinary.

Prairies
From Alberta to Saskatchewan to Manitoba, we expect a frigid winter overall. While Alberta is expected to receive moderating temperatures throughout the winter from Pacific air flows, Saskatchewan and Manitoba are expected to be exceptionally cold, and at times, record-breaking with several rounds of ‘deep-freezes’. Precipitation is expected to be slightly above normal for Alberta, and above normal for Saskatchewan and Manitoba.

Ontario & Quebec
Ontario is expected to be overall, cold this winter. Northwestern and Northern Ontario are expected to parallel the frigid air likewise to the Prairies. With the set-up of the storm track this winter, we expect more rounds of Colorado and Texas lows to infiltrate the Great Lakes and Southern Quebec for the first time in what has seemed to be a number of years.
The cold air from Manitoba and Saskatchewan will provide flourishing variables to allow a well-above and significantly active lake-effect season in an NW to W flow. Preliminary indications represent a repeat of December 2010 across the region.

Quebec is expected to receive above-normal snowfall this year as several storms track through the interior NE of the USA this year. Temperatures will become vastly more frigid through Northern regions of the province.


Maritimes and Newfoundland & Labrador
While the Maritimes and NL are expected to be active this year, it is expected at times, slightly milder air will target the regions, therefore, not all systems this year will be snow-makers. The regions will certainly be stormy this year, but several storms may end up more of a ‘wintry-mix’, rather than snowstorms. Temperatures will be slightly more moderated at times, although at times, cold bouts are certainly likely.

Territories
The Yukon is expected to receive slight benefits from Pacific air and a slight ridge at times over Western Canada/Western USA, providing relief at times relative to the typical winter in the region. Conversely, NWT and Nunavut are expected to receive normal precipitation


– TCW

Ontario

Potent System: Severe Thunderstorms & Pattern Change for Ontario…

[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

Wet & Stormy Tuesday Across the Lower Great Lakes

Heavy thunderstorms expected Tuesday (August 21st, 2018) across Southern Ontario.

Rain-showers or thunderstorms are expected to begin moving into deep Southwestern Ontario overnight Monday into Tuesday. Convection will spread throughout Southern Ontario throughout the morning and afternoon as a maturing-low approaches from the US. Another round is possible by the mid-evening along the shores of Lake Huron.

BRIEF CLEARING? & HEAVY RAINFALL

There may be some brief clearing stretching from the Golden Horseshoe into Southwestern Ontario. This would add more energy and instability, allowing for some isolated severe thunderstorms capable of very-strong winds and short-lived rotation.

Much of the day however, is expected to be dominated by cloud, showers and passing heavy thunderstorms – perhaps several rounds. This could lead to locally significant rainfall-totals. With the threat of localized flooding. Widespread amounts between 30-50mm is expected.

BENEFICIAL RAIN:

East of Georgian Bay stretching into East of Superior will see a beneficial, soaking rainfall from this system. Which will help alleviate forest fire concerns, plaguing the region this summer.

WIND:

This will be an early fall-like system for the Great Lakes. As we move deeper into August we are beginning to enter a transitional period, where low-pressure systems produce synoptic rain and wind over a larger area. Widespread winds gusting between 50-70km/h are expected between Tuesday late-afternoon, and through the evening.

No need for “the end of sunmer blues” quite yet, temperatures by this weekend will be near 30c feeling closer to 40c with the humdity factored in.