Tag: Freezing 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

Sorry Newfoundland – Some Regions to Receive Substantial Snow!


A strengthening low-pressure system will lead to a substantial – and unseemly – amounts of snow for parts of Newfoundland this week. Heavy snow, isolated freezing rain and heavy rain are probable.

Timing
Late Wednesday through Thursday.

Snow
The heaviest snow will reside around NE regions of Newfoundland where around, or slightly above 30cm, is possible. Undulating drier air and waves of moist air for N and NE regions of Newfoundland will allow for appreciable snowfall amounts, although somewhat localized on the upper-end of the aforementioned range due to the drier air. Elsewhere, 10-20cm is possible with slightly lesser amounts for Eastern regions of the province.

Freezing Rain
Localized freezing rain is possible south of Glovertown and SW of Eastport. Up to 7-8mm of accretion is not out-of-the-question, however, impact will be extremely localized; a mixed bag of precipitation – including rain showers – will melt much of the ice, nonetheless.

Rain
Heavy rain will inundate much of the Avalon Peninsula and the Southern Newfoundland shoreline and somewhat lesser, although still prevalent, near regions such as: Carbonear, Clarenville and Bonavista.

Wet snow for this entire region cannot be ruled out.

This is expected to be a reasonably significant system given the time of year – we know this it not the news Newfoundlanders want to hear!

Please adjust your driving habits accordingly.

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] – 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

New Brunswick

April Snow Brings May Flowers? Hmm…


The feisty Colorado Low inevitably set to move into Ontario will impact Quebec, the Maritimes and Newfoundland with mostly snow [of varying intensities], Wednesday PM into Thursday PM – lingering until Friday AM.

Snow and Ice

Beginning late Wednesday, snow will quickly spread across Quebec and bring alongside, heavy accumulating snow, particularly for the Northeastern Quebec Suburbs where 30cm or more could potentially fall. For Quebec City, 20-30cm is probable.

For New Brunswick, there will be a drastic and sharp transition line between heavy snow, freezing rain and rain. Currently, regions around the Bathurst region SW of a line to just south of Edmundston could receive significant freezing rain (10-15mm), thereby an inverse relationship will form: higher ice accretion, and lower snow accumulations. Elsewhere across New Brunswick, snowfall amounts will become significantly reduced the further south one travels (and higher probability of rain).

Across Newfoundland, light snow will encompass much of the province, however, there is reasonable certainty sea-effect enhancement will provide further snowfall for regions such as Corner Brook and Stephenville.

Rain

Nova Scotia, most of PEI, Cape Breton and parts of New Brunswick will experience rain. For most regions, the rain will be a non-factor, however, Southern and South-Central regions of New Brunswick, could receive 30-45mm of Rain, locally near 50mm.

Widespread gusty winds will be a noteworthy concern.

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

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.
https://twitter.com/TransCANWeather

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.

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