Author: Jordin Lantos

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

Alberta

Post-Storm Summary: Alberta Severe Thunderstorms on Friday, July 13,…




INFORMATION TAKEN FROM ENVIRONMENT CANADA AND SERVED AS A SUMMARY FOR THE INTEREST OF THE WEATHER COMMUNITY.

ALL CITIES ON THE MAP ARE ACCURATELY PLOTTED TO WITHIN ONE-MILLIONTH OF A DEGREE USING ENHANCED LATITUDE AND LONGITUDE MAPPING.

Discussion.

Severe thunderstorms moved through parts of Alberta on Friday, July 
13, 2018. The severe storms generally moved eastward in the region 
between Edmonton and Olds during the late afternoon and evening 
hours. Large hail was the main threat with these storms; there were 
frequent reports of golf ball sized hail received at the Prairie and 
Arctic Storm Prediction Centre (PASPC). Additionally, as the storms 
moved east, an elongated gust front moved quickly south giving 
strong wind gusts to many regions in central and southern Alberta 
through the late evening hours. 

The following is a summary of severe weather reports received by 
Environment Canada as of 9 P.M. MDT. 

HAIL: 

5:50 P.M. Crestomere, AB - 27 mm (Loonie) 
6:00 P.M. Ponoka, AB - 75 to 95 mm (Baseball to Softball) 

6:50 P.M. Alix, AB - 45 to 64 mm (Golf Ball to Tennis Ball) 
7:20 P.M. Stettler, AB - 40 mm (Ping Pong Ball) 

7:15 P.M. Vermillion, AB - 45 mm (Golf Ball) 

7:50 P.M. Bowden, AB - 45 mm (Golf Ball) 
7:55 P.M. Trochu, AB - 35 mm (Walnut) 

8:50 P.M. Olds, AB - 21 mm (Nickel) 

WIND: 

Bellshill, AB - 105 km/h 
Calgary International Airport - 96 km/h 
Crestomere, AB - 91 km/h 
Beiseker, AB - 93 km/h 
Strathmore, AB - 80 km/h

Please note that this summary may contain preliminary or unofficial 
information and does not constitute a complete or final report.

End/PASPC
Ontario

Isolated to Scattered Severe Thunderstorms for Ontario – Monday,…


A few rounds of Isolated to Scattered Severe Thunderstorms will arrive for a large swath of Ontario for Monday.

Beginning early on Monday, several rounds of severe thunderstorms will arrive for Ontario. While initially on radar, it may look like only certain regions will be encompassed by Severe Weather, there will be a few rounds throughout the day.

The initial round looks to be from Sarnia to Windsor, with a secondary and tertiary line of storms for the rest of Southern and Eastern Ontario mid to late day.

A few severe thunderstorms are also possible early on due east of Georgian Bay.

Key Highlights
– The best chance of severe thunderstorms near the Canada/USA border from a line including Sarnia SW to Windsor; primary risk is wind gusts up to or above 100km/h
– Some indications of isolated cluster cells SE of Georgian Bay, and all along the GTA, as well as, much of Eastern Ontario; primary risks are winds up to 90km/h, small hail and torrential rain
– Elsewhere, a few isolated severe thunderstorms are likely

Remember, summer thunderstorm forecasts  – severe and/or non-severe – represent a plausible scenario based on extensive weather calculations, parameters and up-to-date atmospheric data. Nothing is for certain, but outlines a possible or likely scenario based on the aforementioned points.

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

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Ontario

Severe Thunderstorm Risk; Brief Cool-Down; Another Blast of Heat…

Conditions will become favourable for the development of severe thunderstorms for a large area across Southwestern, Southern, Central and Eastern Ontario for Thursday, July 5th.

What to Expect
With continued rising temperatures, high dew-points, and daytime heating, a weak front will slice through the aforementioned regions and provide enough instability to bring-about some severe thunderstorms later in the day on Thursday.

While the dynamics are not entirely conducive to significant supercell development, a lack of shear, ultimately, will mitigate rapid intensification and development. The primary risk therefore, with these thunderstorms, will be quick flooding rains (25-50mm).

The greatest threat for severe thunderstorms will likely occur just east of Lake Huron, but likely 15-20km west of the major 401 corridor. The GTA and QEW should remain non-severe (overall) and regions around Cottage Country should receive rain showers.

1 or 2 severe thunderstorms on the northern edge of Lake Ontario cannot be ruled out.

Cool-Down
A brief / slight cool-down (24-27C; less humid; and drier conditions), will arrive for the aforementioned regions on/for Friday, Saturday and Sunday.

What’s Next?
From te brief cool-down outlined above, temperatures are expected to rebound back into the upper 20s and low 30s for the next severel weeks (avg: 29-32C). This time around however, conditions will be less humid than the more recent surge of warmth.

As outlined in our summer prediction, isolated severe thunderstorms will continue across Ontario and Quebec for much of the summer.

Long-Range Outlook: Manitoba, Ontario and Quebec.
Continued above normal temperatures and relatively dry conditions are still expected for Manitoba, Ontario and Quebec. There is some potential for record-breaking heat once again somewhere in the last few days of July into early August for about a week.

Remember, summer thunderstorm forecasts  – severe and/or non-severe – represent a plausible scenario based on extensive weather calculations, parameters and up-to-date atmospheric data. Nothing is for certain, but outlines a possible or likely scenario based on the aforementioned points.

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

June 30 and July 1: Extreme Humidex Values to…

Humidex values across parts of Ontario this weekend are ‘all set’ to arrive for millions this weekend – just in time for Canada-Day festivities. This will be one of the hottest Canada-Day’s in years.

 

Across Southwestern and Southern Ontario, the hottest of the two days will be on Saturday with humidex values into the 40s; regions north of Toronto and extreme Southwestern Ontario will ultimately top the mid 40s.

Across Eastern Ontario, such as the Ottawa-Valley, the hottest of the two days will be on Sunday, with humidex values nearing the upper 40s to potentially 50C in some regions. Records will certainly be broken by the end of Sunday.

Temperatures across a multitude of regions this weekend will be in the neighbourhood of 32-36C with certain regions in the Ottawa-Valley potentially reaching 37-38C.

If you plan on enjoying the weekend heat – or Canada-Day/weekend festivities – remain hydrated and be fully cognisant of all potential heat exhaustion signs to prevent heat stroke.

Look-out for one another.

Be safe and have an incredible Canada Day!

After this weekend, temperatures will cool slightly but remain consistently warm for quite some-time. Watch for drought-like conditions for Ontario and Quebec for the remainder of the summer, overall, with intermittent periods of isolated severe thunderstorms.

For a quick view regarding our updated Summer Forecast from a few days ago, please view the image below.

Updated Summer Temperature Forecast.

 

TCW

Alberta

Updated Summer Forecast: Heat Expected to Dominate Ontario, Manitoba…


2018 Canada Summer Outlook and Higlights Depicted Below —- July and August

Key Highlights

– Heat Builds for Northern, Southwestern, Southern, Central and Eastern Ontario and Southern Quebec Beginning June 29th.

– Many Canadians are Expected to Receive a Warm or Hot July 1st (Canada Day!).

– Unusually Dry for Ontario and Quebec.

– Intermittent Rounds of Isolated Severe Thunderstorms for MB, ON, and QC.

– Decently Warm for SK and AB; Some Periods of Very Warm to Hot Weather.

– Wet BC Coast; Warmer and Drier Interior.

– Newfoundland and Labrador Likely to be Disappointed this Summer Due to Cooler and Wetter Conditions.

– ‘Bone-Dry’ for the Yukon, NWT, and Nunavut.

*Some Potential for Record-Breaking Heat (the Upper 30s) for Parts of ON and Parts of QC for the Last Week of July or 1st Week of August.

Brief Discussion

We at TCW are expecting overall, the country to be slightly above seasonal for the majority of the two months. We expect consistent heat to surge into Manitoba, Ontario and Quebec. While the heat will be slightly less humid as is typical, the heat will be quite consistent for the months of July and August.

It is expected that Manitoba, Ontario and Quebec will be quite dry for these two months, but, become inundated with intermittent days of isolated severe thunderstorms as a result of day-time heating.

The Maritimes are expected to warm-up as the summer progresses, while Newfoundland and Labrador is expected to remain cool and somewhat wet.

Saskatchewan and Alberta will have a few periods of hot weather (especially Saskatchewan), however temperatures will overall, be more warm to very-warm than hot.

British Columbia will remain seasonal and wet near the immediate coast, with the interior being drier and a few degrees above seasonal.

The Yukon, NWT and Nunavut will be slightly above seasonal and very dry.

– TCW

Manitoba

Powerful Supercells for SE Saskatchewan Bring Tornado Risk and…


An associated warm front will set the stage for parameters conducive for strong Tornadoes today for isolated regions in SE Saskatchewan.

Residents in Southeastern Saskatchewan should be extra vigilant to the sky as the current risk leads to a threat for 1 or 2 strong Tornadoes (EF2+), large hail (nickel to ‘ping-pong’ size) and damaging winds (100-120km+).

As the cells form mainly just west of Weyburn, quick evolution and a track E to ENE as LP (low precipitative) supercells will be prevalent. These cells are representative of large hail (in this case, ‘ping-pong size), and a risk for a Tornado a little after their original formation as shear levels drop a slightly.

As the cells continue to track into Manitoba, the cells will become more of a ‘line’ just across the border into Virden, Melita and Brandon – winds up to 120km/h+ are the main threat and the Tornado threat will diminish rapidly.

Elsewhere, isolated severe cells over a large swath of Saskatchewan and Manitoba are possible.

Amongst the most interesting parameter (one among many) is the LCL (lifted condensation level: represents the lowest level in which condensation can occur). Generally, the strongest Tornadoes in history are between 300-600m. LCL levels, in this case, are somewhat conducive to Tornadoes of EF2 or stronger nature.

Remember, summer thunderstorm forecasts  – severe and/or non-severe – represent a plausible scenario based on extensive weather calculations, parameters and up-to-date atmospheric data. Nothing is for certain, but outlines a possible or likely scenario based on the aforementioned points.

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

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

First Noteworthy Severe Thunderstorm Risk in Ontario for 2018


For the first time in the 2018 season, a risk of widespread thunderstorms across Ontario could occur on Friday, May 4th, 2018 – some potentially severe.

Synopsis
During Friday morning, many regions across Southwestern, Southern and Central Ontario will experience widespread moderate rain: an isolated non-severe thunderstorm cannot be ruled out. As the morning and day progresses, conditions will become drier, sunny at times, more humid and potentially lead to some severe thunderstorms. The severe thunderstorms that do occur will bring mainly a wind threat.

A somewhat secondary line of isolated severe thunderstorms could also sweep into eastern sections of the Niagara region as a linear set-up of storms will form near upstate Pennsylvania and western New York state; where this line of storms exactly forms will be incredibly relevant for this region. Should it form quickly and near the CAN/USA border (as current atmospheric parameters suggest), the region will be impacted; a formation more eastwards will reduce the risk and impact substantially, to virtually nil.

Potential Severe-Threat Timing
Afternoon to early evening from west to east.

Scientific Analysis
The greatest risk for isolated severe thunderstorms can be depicted in the ‘darker orange region’.
A slight risk for isolated severe thunderstorms can be depicted in the ‘lighter orange region’.
Mainly non-severe thunderstorms can be depicted in the ‘yellow region’. One or two severe thunderstorms cannot be ruled out in this region, particularly along HWY 402, HWY 403 near Brantford and HWY 401 near the London-Woodstock corridor. Later on Friday, it is possible along eastern sections (ex. Kingston to Brockville and 50-60km east of Ottawa), an isolated severe thunderstorm is also possible.

Sufficient atmospheric energy at the immediate surface, as well as, 100mb and 300mb above the surface (SB, ML and MU CAPE) could be adequate to lead to severe thunderstorms. While energy is not astronomically high, and lower in comparison to the more traditional summer months, relatively strong dynamic forces should act as a sufficient trigger for isolated severe thunderstorms. Convective inhibition (CIN) at the surface as well as 100mb above the surface (ML-CIN), should reduce the risk of severe thunderstorms, and thunderstorms all together along the immediate northern shoreline of Lake Ontario: this will lead to cells rapidly weakening as they form near or just east of Lake Huron and usher eastwards. A relatively moderate lifted index (LI) will aid in dynamic instability leading to the greatest threat of isolated severe thunderstorms particularly near or just inland of Lake Huron and SE Georgian Bay. Storm relative helicity (SR) remains weak at the 0-1km threshold, and slightly stronger at the 3km threshold; this will allow for an increased threat of isolated severe thunderstorms in more of a linear format (although not encompassing a large area). Cyclonic updraft at the surface is virtually non-existent at the 0-1km threshold thereby limiting any tornado touchdown to virtually nil.

Other parameters including: Bulk Richardson Number, Cross-Totals, Total-Totals, Thompson Index and shear at the high atmosphere (6km) support isolated severe thunderstorms; although not super-cells; with a risk for strong wind gusts mainly to 90-100km/h as being the primary threat.

Non-conducive lapse-rates and wet-bulb zero (WBZ) coefficients will mitigate the hail risk overall to pea-size to nil.

Precipitable water (PWAT – surface to 300mb) is somewhat low for ‘torrential downpours’, therefore, residents should be spared a ‘flooding risk’ as typical with some severe thunderstorms.

Ultimately, the deepening of the approaching low-pressure system will be well-timed with strong uni-directional winds aloft, 500mb height-falls, and a jet-streak. Further, a sharp cold front is expected to eject through Southern Ontario between ~2-6pm thereby providing a trigger for these thunderstorms.

Across much of Southern Ontario, residents can expect winds gusting to 80km/h for many regions and locally up to 100km/h, irrespective if regions see thunderstorms or not.

Tie down loose patio furniture, patio umbrellas and chairs.

Remember, summer thunderstorm forecasts  – severe and/or non-severe – represent a plausible scenario based on extensive weather calculations, parameters and up-to-date atmospheric data. Nothing is for certain, but outlines a possible or likely scenario based on the aforementioned points.

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