Category: Ontario

Ontario

[UPDATED] – Historic Weekend Ice-Storm and Strong Wind Gusts…


A strengthening, and ultimately a strong low pressure system from the Central Plains of the USA will approach Ontario and Quebec this weekend and stall as strong High Pressure in Northern Canada will force the low to become incredibly stagnant over the regions. There will be breaks in the precipitation at times [and a couple pulses of significant moisture, especially Sunday], but overall, the ‘quantitative precipitation forecast (QPF)’, or measurable total precipitation will be high from Saturday through Monday.

It is important to note that this storm will have EXTREMELY tight gradients between precipitation types and amounts (and hence, temperature). One region to the next in as little as 20 or 30 kilometers could receive drastically different amounts of snow, ice-pellets, and/or freezing rain. The difference between -1 and +1 could pose significant changes in traveling conditions for residents across ON/QC.

Importantly, regions who receive ice-pellets should note that the water content for snow and ice-pellets are drastically different. While snow is, on average, 10:1, ice-pellets are typically 2 or 3:1. This means, that 20-30mm worth of ice-pellets will “look” drastically different than 20-30cm of snow. On our forecast map, ice precipitation totals are displayed in mm. Please note that this is the equivalent amount of moisture that will fall as ice pellets. If 25mm falls – 75mm worth of ice pellets would accumulate; 3:1 ratio.

What to Expect

1) Heaviest Snow Region: Colder air will invade much of this region leading to mostly exclusively heavy snow. Some snow will occur Saturday/Monday; significant snow through Sunday.

2) Mostly Heavy Snow Region: Colder air will also invade much of this region. Most impacts through Sunday and residual on Monday.

3) DRY-SLOT. Some of: Snow/Ice/Rain Region: There appears to be somewhat of a dry-slot that will force itself within the large pulses of moisture – one across Northern Ontario – one across Southern Ontario. This dry-slot appears to encompass a large swath. However, while impacts will be reduced, they will still exist. This region can expect between 5-10cm of snow (locally up to 15cm), and a mixture of 5-10mm of ice precipitation in the form of ice and/or ice-pellets. Regions around Parry Sound and east will likely receive more freezing rain (than snow), while regions around Ottawa will receive more snow (than ice). It is possible, that regions just south of Ottawa could receive ~15cm. Ottawa itself is likely to receive closer to ~10cm and brief ice or ice pellets.

4) Wintry Mix Zone Region: Much of this region will receive snow, ice-pellets and light freezing rain. The colder air appears to be digging in more and more, and as such, freezing rain will likely no longer be a large threat (but will still lightly mix within at times). Regions such as Wiarton, Owen Sound, Barrie, Orillia, Midland, Collingwood, Meaford, Bracebridge, Gravenhurst, Peterborough, Bancroft and Muskoka are more likely to receive snow (>15cm); ice pellets (>15mm) for regions a little south of a line from Owen Sound east to Barrie and due east to Brockville.

5) Ice-Pellets [possibly Snow] and Ice Region #1: The Northern Lake Ontario shoreline is expected to receive a mixture of heavy ice-pellets and some ice. There is some potential that snow alongside ice-pellets could fall thereby reducing ice-pellet amount and increasing snowfall amounts in the 10-20cm range (lesser snow and more ice-pellets closer to the Western and Central Lake Ontario shoreline, such as: Ajax, Oshawa and Pickering; more ice for Eastern Lake Ontario sections such as Kingston and Brockville).

6) Ice Pellets [possibly Snow] and Ice Region #2: This region in Southern Ontario is expected to receive a mixture of ice-pellets and ice. There is some potential that snow alongside ice-pellets could fall thereby reducing ice-pellet amount and increasing snowfall amounts in the 5-15cm range (the lesser snow and more ice-pellets will be towards the Lake Huron shore-line, such as Goderich – higher amounts of snow for regions closer to Owen Sound and Barrie, than regions further away).

7) Highest ICE STORM Threat Region: This region continues to represent the highest potential for significant ice. Widespread 25mm is likely with some evidence suggesting 30mm or more by late Sunday.

8) High ICE STORM Threat Region: This region continues to represent a reasonably high potential for significant ice. Widespread 20mm is likely with some evidence suggesting closer to 25mm.

9) Moderate ICE STORM Threat Region: This region now shows some risk of an ice-storm. Early rainfall on Saturday may keep the ground warm enough where impacts for much of Saturday will be somewhat limited until early to mid evening. Impacts however by the end of Sunday could still pose a significant impact/risk. Depending on the cold air, it is possible this region may extend due west along the 402 through Komoka, Strathroy, Watford, Petrolia and Sarnia.

10) Risk of Non-Severe Thundershowers Region: Extreme SW Ontario is expected to receive mostly rain. Non-severe thundershowers are indeed also possible early Saturday. Expect a heavy and soaking rain. Very brief or slight ice is possible (1-3mm).

11) Critical Zone – Heavy Rain and Ice vs. Location Region: The Toronto region represents one of the hardest forecasts in this entire ‘storm’. Toronto will be extremely location dependent. People who live near the lake-shore will likely experience mostly rain with negligible amounts of ice. However, within the city there could be roughly 5-10mm of ice, and regions outside the city, 10mm+ of ice is possible.

This is due to a strong easterly and stiff (but shallow) wind off Lake Ontario which will create a small plume of far less freezing rain than surrounding counterparts.

[UPDATED] Which Regions are most likely to be Hit the Hardest from Ice? How Much?

25mm or more of accretion is expected.

St. Thomas
London,
Woodstock
St. Mary’s
Ingersoll
Brantford
Port Dover
Tilsonburg
Stratford
Mitchell

[UPDATED] In Southern Ontario which Regions are most likely to Receive the most Snow? How much?

Snowfall of 20-30cm, locally higher.

Owen Sound
Wiarton
Barrie
Orillia
Collingwood
Meaford
Gravenhurst
Minden
Haliburton
Angus
Bancroft
Whitney

City of Toronto – A ‘Tough Call’

For right in the City of Toronto, it is expected that a strong easterly wind will result in a slightly milder air-mass at the surface. As such, we at TCW believe the city itself should escape some of the ice, in comparison to regions further (although slightly outside) the city.

Therefore, we expect Toronto to receive mostly rain [especially the lake-shore] – perhaps still some freezing rain at times, late Saturday into early Sunday — however, rain will likely infiltrate before and after any freezing rain, thereby melting most of the ice that happens to fall and/or stick to the surrounding environment.

Nearby cities such as Mississauga, Brampton, Oakville, Ajax, Bowmanville, etc, are expected to see some ice. The closer one is directly to Toronto itself, the greater chance of more rain, and less ice. Once you reach roughly 10-15km outside of Toronto however, it is expected ice will be of concern.

Notice: QEW Region (Niagara, St. Catharines. Welland, etc)

This region is also an important place of interest due to again, slight warming from Lake Erie and Lake Ontario. This means regions very close to Lake Ontario and Lake Erie (within 10km of the shorelines or less) will receive 15-20% less ice than regions further away. However, irrespective of proximity towards the lake-shores, it is expected still, significant icing will occur.

How Bad Will This “Ice-Storm” Be?

This ice-storm has the potential to be significant. While it may be slightly less significant than if this event occurred in the typical winter months (due to stronger April diurnal heating in addition to a wet ground from late Fri to early Sat), it will still pose a significant threat to travel, trees and could lead to widespread and significant power-outages.

When Will Most of the Icing Occur?

Regardless of location, even regions who receive lesser ice accretions, the most widepsread, and heaviest icing will occur between the late morning or early to mid afternoon hours on Saturday, through Sunday. Even more specifically, most of the heaviest freezing rain will occur early to mid Sunday morning.

Monday Temperatures

Many regions are expected to transition to rain of some magnitude during Monday (slowly beginning later on Sunday).

Northern Ontario is expected to continue with further snow however, therefore temperatures although may climb above 0C, relatively humidity will be quite low and moisture will be quite high, therefore, regions will continue with snow.

On Monday Night, snow (3-7cm) may usher in towards the highlands and regions such as Shelburne and north of Toronto as cooler air returns.

Watch for widespread gusty winds for many regions up to 80km/h.

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

Drive safe and always be alert during hazardous conditions.

For hourly and live storm updates around the clock, follow us on Twitter.
https://twitter.com/TransCANWeather

Ontario

More Snow on the Way; Big Pattern Change Coming


More snow is set to sweep through most of Ontario Thursday Night into Friday, with the heaviest accumulations near Lake Erie and the traditional 401 corridor, including several major cities.

The tempestuous conditions that recently caused headaches across Southern Ontario bringing thunderstorms, heavy lake-effect flurries and winds will be superseded by further accumulating snow one more time this year.

The recent Colorado Low led to several accidents, including a closure on WB 401 near Kitchener-Waterloo and a significant 50 car pile-up on HWY 400 near Barrie.

The two images below show the hazardous conditions on HWY 400 near Barrie today, Wednesday, April 4th.

Thursday Night
Conditions will deteriorate somewhat from west to east and snow will engulf much of the aforementioned regions bringing a widespread swath of 2-4cm, with heavier amounts near the traditional 401, 402, 403 and QEW corridors.
Watch for slight SW enhancement off Lake Erie providing potentially, slightly increased amounts near the St. Thomas-London-Woodstock-Brantford corridors, with particularly higher confidence around the St. Thomas-London corridor.

Friday Morning
Conditions will slowly begin to improve by early morning from west to east.

The Warmup? Where is it?
A pattern change is set to change weather across Eastern Canada through the 3rd and 4th week of April and thereafter, particularly into early May.

Conditions will drastically and exponentially warm to the low to mid to eventually, upper teens in May.

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

Drive safe and always be alert during hazardous conditions.

For hourly and live storm updates around the clock, follow us on Twitter.
https://twitter.com/TransCANWeather

Ontario

[UPDATED 04/03/2018] Intense April Storm: Snow, Thunderstorms and Powerful…


An incoming system will bring a mixed-bag of wet snow, heavy accumulating snow, rain and thunderstorms across Southern, Central, Eastern and Northern Ontario, as well as, Quebec.

Tuesday
Through the overnight Monday, an arctic front will descend south coalescing with a strengthening area of low-pressure tracking through the Midwest United States. Temperatures will be falling across Northeastern Ontario, the Nickel Belt, Manitoulin Island, and, the Bruce Peninsula with the passage of the cold front. Light snowfall will begin in the aforementioned regions overnight Monday into Tuesday. Continuing through the day Tuesday – lasting into Wednesday. Total accumulation will range from 15-25cm by Wednesday evening.

Tuesday Thunderstorm and Rainfall Risk: Southwestern Ontario
An associated warm front looks to be staying south of Lake Erie Tuesday afternoon, lessening the arrival of a warmer airmass into extreme Southwestern Ontario. Nevertheless, the track of the low will bring rainfall and embedded thunderstorms ahead of a cold front Tuesday evening. Primary threats include embedded heavy downpours, and gusty winds to 60-80km/h.

A cloudy and wet day is expected cross Southern Ontario. Generally, 15-25mm of rainfall is expected across a large swath of Southern and Eastern Ontario. Locally higher amounts of 20-40mm is expected in extreme Southwest Ontario (with local thunderstorms) and a parts of Eastern Ontario.

Wednesday
The strengthening area of low-pressure will continue on a north-east trajectory towards Quebec Wednesday. The passage of the low will be accompanied by colder air and powerful wind gusts across Southern Ontario. Gusts between 70-90km are expected Wednesday.

Residual snowfall will continue in parts of Northeast Ontario. Some Lake effect flurries may impact the snow-belts.

What’s to come?
Cold temperatures will continue through the first week of April, with continuing below seasonal temperatures through the 2nd and 3rd week of April. There is some confidence continued snow-systems will embed themselves across the region, with the potential for snow reaching as far south as the 401 corridor.

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.

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

Drive safe and always be alert during winter conditions.

For hourly and live storm updates around the clock, follow us on Twitter.
https://twitter.com/TransCANWeather

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+.

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

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.

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

Drive safe and always be alert during winter conditions.

For hourly and live storm updates around the clock, follow us on Twitter.
https://twitter.com/TransCANWeather

Alberta

Canada Spring and Summer Highlights: Summer to Arrive; Will…



Canada’s Summer Highlights; Spring Temperatures and Spring Precipitation Forecast: From TransCanada Weather

Through careful analysis of ocean temperatures, atmospheric patterns and continental, national and global temperatures, we have formulated and depicted our predictions across the country for Spring and Summer 2018.

Spring

Atlantic Canada
A relatively active storm track across the entire region as listed, will provide ample opportunities for a mixed bag of precipitation for eastern sections, with snow for western sections through late March into early April.

Parts of New Brunswick, PEI, Western Nova Scotia, Western Newfoundland and most of Labrador can expect opportunities for snow.

Temperatures will be below seasonal, particularly through early April and slowly begin to moderate from late April into May for all of Atlantic Canada.

Ontario and Quebec
A relatively active storm track will also be present particularly from late March into early April. Opportunities for snow exist, however, temperatures will likely be slightly too mild for significant snow accumulations. However, below seasonal temperatures and slightly above precipitation are expected until mid April.

Temperatures will begin to moderate particularly later in April and seasonal weather will become more prevalent and consistent in May.

Prairies
The Prairies will continue to remain fairly seasonal this spring with dry conditions at times, particularly later in spring; average precipitation early in the spring.

British Columbia
Much of British Columbia will experience warm surges of Pacific air with an inundation at times, of moisture from Pacific low pressure systems.

Northern Territories
The NWT are expected to be seasonal and dry for much of April and May.

Summer

Atlantic Canada
An active storm track at times will provide for soaking rains and isolated severe thunderstorms at times, throughout the summer. This summer will be fairly consistently warm across the entire region with periods of hot and humid weather.

Summer will arrive, but some time will be required.

It is expected that warmth will begin to build into late June through July and August.

Ontario and Quebec
An active storm track will provide surges of heat across the region, particularly in late June through August. Severe weather will make visits at times this summer, however, it is expected the early portion of summer will remain somewhat dry, and slightly cool, with active and a widespread severe risk building from late July into August.

There is reasonable certainty that June will provide some bouts of cooler and drier weather relative to the norm.

Prairies
The Prairies will receive a typical summer; warm with periods of stiffing temperatures, severe thunderstorms and large hail and isolated tornadic risks, particularly across Alberta and Saskatchewan.

British Columbia
British Columbia is expected to be slightly cooler this summer, although not exceptionally cool. Surges of hot and dry weather that typically show through July-September may be somewhat limited this summer, although not non-existent.

Its not all bad news for the BC coast as moisture is expected to be to the north and south.

Northern Territories
The NWT are expected to be seasonal and dry for much of June, July and August.

https://twitter.com/TransCANWeather

– TCW

Ontario

[UPDATED] Waves of Snow for Southern Ontario; Slippery Conditions


Waves of light to moderate snow to inundate Southern Ontario from Wednesday into the weekend.

The remnants of the Prairie snowstorm from recent days has further disintegrated and become stagnant over Southern Ontario. Concurrently, moisture off Lake Huron will aid in a localized snowfall event for much of Southwestern Ontario.

Snow will be somewhat scattered and inconsistent in nature, however, due to the duration, locally slippery conditions are likely. Especially for the Sarnia to London corridor continuing north to encompass everywhere east of Lake Huron. Due to lake enhancement, regions particularly just east of Lake Huron – likely just south of the city of Goderich itself – will be the most impacted.

Totals depicted are over the course of several days with minimal impacts in South-Central Ontario and the Golden Horseshoe/GTA. Flurries with trace amounts to a few centimetres of accumulation is expected.

The heaviest accumulations will be confined to Southwestern Ontario and parts Eastern Ontario where several day totals could be 10-20cm. Actual accumulation will be less considering melting and settling.

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

Drive safe and always be alert during winter conditions.

For hourly and live storm updates around the clock, follow us on Twitter.
https://twitter.com/TransCANWeather

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.

—-

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.

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.

For hourly and live storm updates around the clock, follow us on Twitter.
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Ontario

Departure of Spring; Winter to Make a Fierce Return…


Heavy Snow and Blowing Snow for Parts of Southern Thursday into Friday.

 

As expected, we are watching for the continued evolution of a series of complex forms of energy dispersing from the Northern Prairies & USA, and strengthening near the Great Lakes bringing mostly heavy snow, some freezing rain (near Lake Erie), and some rain (mainly Ex. SW Ontario).

Rain should be almost exclusively present towards Extreme Southwestern Ontario (and begin Thursday morning); freezing rain will be limited to the Northern Lake Erie shoreline (and begin mid Thursday morning); for most other regions, the predominant precipitation will be snow.

Generally, the system will begin for many, in the Afternoon hours, and continue throughout the Evening and Overnight. Lingering light snow is possible for the Friday AM commute contingent alongside further blowing snow.

The evening commute, particularly Western GTA and Southwards along the 401 down to the London region, in addition to the QEW, will be significantly impacted. Conditions will rapidly and exponentially deteriorate through Thursday Mid-Late Evening and Overnight.

Blowing snow will also be of significant concern for many, Thursday into Friday. Due to this weather phenomena being present, it is important to be prepared for brief whiteout conditions, particularly those who will be traveling after sunset on Thursday PM or Pre-Dawn on Friday.

Vorticity, moisture, lift and instability remain very high, thereby allowing this storm to blossom and otherwise overachieve more-so compared to normal.

 

UPDATE 03/01/2018 @ 7:15PM

Snowstorm continues to develop and push towards Southern Ontario as expected.
 
Significant blowing snow with totals reaching what we previously posted prior, is likely.
 
A deformation band from SW of and including London, to Woodstock and NE around the Hamilton area is possible, thereby allowing totals for this swath to be potentially closer to the 20-25cm+ range.
 
There is reasonable certainty along the QEW, either Niagara or somewhere near the region could potentially reach 35-45cm.
 
Watch for significant blowing snow across most of Southern Ontario.
 

The Windsor region will likely overachieve compared to our forecast map above, and as such, that region can expect 15-20cm rather than the 6-12cm originally forecasted.

 

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

Drive safe and always be alert during wintery conditions. After this recent “warm-up” in prior days, it is crucial to remain extra vigilant for negligent drivers on the road.

For hourly and live storm updates around the clock, follow us on Twitter.
https://twitter.com/TransCANWeather

Ontario

Above Seasonal and Abundant Sunshine for Southern Ontario


An area of high pressure south of the border is expected to move eastwards on Monday and cement its presence until Wednesday, thereby keeping tempestuous weather at bay.

Beginning Monday, February 26th, abundant sunshine is expected to spread and flourish across the entire region giving residents a “taste” of spring weather.

While temperatures on Monday are expected to reach the upper single-digits, on Tuesday and Wednesday, residents can welcome temperatures into the low-teens. On the contrary, temperatures will be sliced in half on Thursday and thereafter for the foreseeable future.

High Temperatures for Southern Ontario on Monday.

High Temperatures for Southern Ontario on Tuesday [and Wednesday].

This short period of above seasonal temperatures are expected to cause further concern regarding relevant regions impacted by flooding. It is important to remain diligent and refrain from close presence near high rivers and fast-moving waters.

Now, get outside and lets welcome these temperatures together!

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.

For hourly and live storm updates around the clock, follow us on Twitter.
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