A sudden surge of warm, summer-like air will herald in the risk of thunderstorms across the Lower Great Lakes. These thunderstorms may turn severe; capable of producing damaging winds & hail across portions of Southern Ontario.
SURGING TEMPERATURES, THUNDERSTORMS & RAIN
An area of low-pressure will transverse through the Midwestern United States towards Ontario, throughout the day Sunday. Ahead of the system, temperatures will surge into the mid-20s and humidity readings into the low-30s. Near the Lake-shore, cooler conditions are expected.
Showers are expected before midnight tonight, lasting into the pre-dawn hours. Persistent rain-showers and embedded thunderstorms are expected for Central Ontario – mainly East of Georgian Bay. Sunny breaks are anticipated through the morning hours, allowing for some instability to build before the arrival of a cold front.
At this point, it appears the setup will feature two potential waves of thunderstorms. The primary wave will consist of a complex of heavy rain showers with embedded thunderstorms impacting Southern Ontario between 4-10 pm. Initiating at approximately 4 pm in Windsor and exiting Eastern Ontario by 11 pm. Risks include: torrential downpours, lighting and isolated damaging winds. A potentially stronger second round of thunderstorms (along an advancing cold front) may happen on Sunday evening/overnight, across Extreme Southwestern Ontario. There is some uncertainty regarding the evolution of thunderstorm development. If thunderstorms do develop, risk factors include: hail and isolated damaging wind gusts.
Across Northern Ontario, a large swath of heavy rainfall is expected. Local rainfall totals nearing 50mm is anticipated.
Don’t let the calendar fool you – a bitter sweet transition to spring is expected. The final two weeks of winter will feature drastic temperature swings and at least one notable storm system this weekend.
An area of low-pressure will form lee of the Rockies in Colorado Friday. Deepening as it tracks northeastwards through the United States towards the Great Lakes Region Saturday evening.
Key Details: 15-25mm of rain across deep Southwestern Ontario & North of Lake Erie. Rain combined with snow-melt may lead to localized flooding. 10-20cm of snow for Northern Ontario. Heaviest snow falling East of Lake Superior & across the Nickel Belt. Strong to damaging wind gusts for Southwestern & Central Ontario. A surge of warm air in Southern Ontario precedes wrap around strong winds & snow
SNOW FOR NORTHERN ONTARIO
Like many of the storms this season, this system will feature appreciable snow across Northern Ontario. A large swath of 10-15cm is forecast for Wawa, Timmins and Sudbury areas. Local amounts may approach 20cm.
MESSY WINDSTORM FOR SOUTHERN ONTARIO
First and foremost, this is a messy system for Southern Ontario. Precipitation will move into Windsor in deep Southwestern Ontario around 6pm Saturday. Progressing Northeastwards across Southern Ontario during the evening and overnight. Main concern for along the Lake Erie shoreline will be heavy downpours combined with warmer temperatures, snow melt, and runoff. Minor flooding is possible; stretching into the GTA. Be sure to monitor any statements from your local conservation authority, as we progress through the weekend.
Strong to damaging easterly winds will develop ahead of the storm Saturday evening & overnight. The strongest wind gusts are expected East of Lake Huron. Including Goderich, where peak winds could exceed 100km/h late Saturday evening & overnight. The rest of Southern Ontario will have to contend with strong easterly winds gusting 60-90km/h through the overnight into Sunday morning. Once again, winds will strengthen out of the West Sunday, with the passage of a cold front. Frequent gusts between 50-70km/h is expected.
Considering temperatures will be teetering around the freezing mark, precipitation may begin as snow, freezing rain or ice pellets. Especially, South of Georgian Bay where elevation and heavy precipitation rates will aide in keeping temperatures below freezing for a longer duration. For Eastern Ontario, this system will bring more wet snow than rain. Refer to our forecast map for further details.
Temperatures soar above freezing today in the Rockies and Foothills – including Banff, Jasper and Calgary. Double-digit highs for Lower Mainland and Southern Interior British Columbia today and Tuesday. Dense fog this morning in Southeast Alberta degrades to abundant sunshine.
A broad area of high pressure combined with plentiful sunshine, and light changeable winds, will send temperatures soaring above freezing today and Tuesday across Southern British Columbia and Southern Alberta.
Overnight-lows in Calgary, Red Deer, Airdrie, Lethbridge, Medicine Hat – and much of Southern Alberta were close to or below negative 10c. The same locales today will be in the upper single digits. The warm above seasonal weather will persist into Tuesday. Temperatures will (once again) fall well below freezing tonight, quickly rising into the upper single digits Tuesday Afternoon. Pleasant temperatures are expected to persist for much of the week.
Much of the same conditions is expected for Southern British Columbia. Locales in the Lower Mainland – including Abbotsford can expect highs in the teens today.
Forecast daytime-high temperatures Monday, March 12, 2018. Zoom-in on mobile to navigate to your location. Courtesy of darksky.net
Forecast daytime-high temperatures Tuesday, March 13, 2018. Zoom-in on mobile to navigate to your location. Courtesy of darksky.net
It will be an excellent day to get outside and enjoy some needed sunshine. If you like this story, share the ‘warm weather’ with your friends and family!
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