The Weather Network – blocked system could create problems for Southern Ontario next week

Friday, November 27, 2020, 9:38 am – As we prepare to enter December, forecasters are closely watching the threat of some impact storms and a more “ typical ” winter pattern being created for Southern Ontario.

After taking advantage of a weekend of calm weather and glorious late autumn sunshine on Sunday, all eyes will then turn to Southern Ontario as one of the most active weather locations nationwide for the start of the next. week. More on the very unstable model that is set to develop and a look at a more typical setup in early winter as we move into December, below.

HIGHLIGHTS OF WEATHER:

• All the rain and fog clears allowing for a pleasant double-digit day on Friday
• Short break in active weather this weekend, abundant sunshine and high daytime temperatures on Sundays
• Threat of heavy rain and snow for southern Ontario until Tuesday

FIRST WEEK AFTER: DEVELOPING AN UNSUSTAINABLE MODEL, EYES IN A STORM OF IMPACT

Now is the time to enjoy the unusually quiet late autumn weather, which will offer plenty of sunshine and above-seasonal temperatures across southern Ontario over the weekend.

By Monday, however, an active model is being established, which could continue to deliver throughout the first half of December.

WINTER FORECASTS: On Monday 30th November The Weather Network publishes the official 2020/21 winter forecast. Tune in!

This is how a highly amplified jet stream forms in the eastern United States and a storm develops along the Texas Gulf Coast. It then taps into Gulf moisture as it intensifies, following the northeast or just east of the Appalachians and southern Ontario on Monday.

“An Atlantic lock pattern will trap the system and stop it in the vicinity of southern Ontario until the middle of next week,” warns meteorologist for the meteorological network, Dr. Doug Gillham.

With moderate temperatures in place, widespread heavy rains and strong winds appear to be the main threats for much of the region for Monday and Tuesday.

“But we’re particularly focused on the swath of heavy wet snow that is likely to develop on the back side of the system,” says Gillham, adding that it’s still too early to know exactly where that heavy snow will be.

At this point, it appears that the dividing line between heavy rain and heavy snow will be in the vicinity of the GTA with rainfall mainly south and east of Toronto, including Ottawa and Montreal, and mainly heavy wet snows north and west of Toronto, including London, Kitchener-Waterloo and country cottages.

Small changes in the storm track will have a major impact on the snow totals for the GTA and will need to be closely monitored as the system develops over the weekend.

“In terms of totals, once again, it looks like we will see a wide range of snow totals across the GTA,” says Gillham. “Many areas north and west of the GTA could see 10-20 cm of snow with the potential for parts of the region to reach 20-30 + cm.”

As we approach December, forecasters are also looking at some preliminary signs showing a transition to a more “consistent” and “typical” early winter pattern by the second week of the month.

Be sure to check back as we continue to fine-tune this forecast and potential impact systems starting the month of December.