Tag: fall

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. 

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.

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.