Monday, April 13th 2020, 5:30 am - Intense wind gusts bring the potential for power outages and flooding in the south, while parts of northern Ontario will see heavy snow with the potential for over 40 cm.
A potent low pressure system will bring a variety of impacts on Monday with widespread rain in the south and heavy snow in the north. Intense winds will occur as this system exits the region and gusts between 70-100 km/h have the potential to cause damages and power outages. There is also the potential for flooding along the shores of Lake Ontario and Lake Erie. Details and timing, below.
- Up to 50 cm of snow in parts northern Ontaro
- Potentially damaging winds of 70-100 km/h in southern Ontario
- Keep track of ALERTS in your area
MONDAY: RAIN, SNOW AND STRONG WINDS
Most of the rain that is associated with this system will fall during the early hours on Monday and 20 to 30 mm of rain is possible for much of southern Ontario. Scattered rain will continue throughout the day and there is the potential for embedded thunderstorms.
Up to 35 mm of rain is possible in eastern regions and along parts of the Lake Erie shores. Lakeshore flooding is possible in typically prone areas as the winds intensify throughout the day.
Weather Network meteorologist Matt Grinter says a seiche is possible on some shorelines tomorrow, which occurs when winds gust between 60 to 80 km/h around a body of water and cause water levels to drop on one end and rise at the other end. This can cause strong waves to form and major flooding in the impacted areas.
"All ingredients are there to create a severe flooding event for Lake Erie shorelines,” adds Weather Network meteorologist Tyler Hamilton.
According to the Grand River Conservation Authority (GRCA)'s latest flood message for Monday, Lake Erie is forecasted to rise in the Port Colborne and Port Maitland areas by about one metre above the current level to an elevation of 176.0 metres. Peak levels are expected to occur between late Monday afternoon and Monday evening, due to the winds.
"Wave heights are forecast to reach up to 2 metres. Wave uprush and increased shoreline erosion can be expected from this event," the GRCA statement says, adding those within the GRCA watershed should be prepared for possible flooding. The next update will be issued at noon on Monday.
Strong winds will develop on the backside of the low pressure system as it tracks eastward and could gust between 70 to 100 km/h throughout Monday afternoon and evening. Environment Canada has issued special weather statements across southern Ontario that warn of the potential for power outages during the afternoon and evening.
The precipitation associated with this system will fall as snow in northern Ontario. Regions along and northeast of Lake Superior will see heavy snow with accumulations ranging between 30 to 50 cm range for isolated areas northeast of Lake Superior. The snow will end for the Nickel Belt on Monday and on Tuesday morning for the James Bay area.
The silver lining with this system is a surge of warmth that comes with it, however, it will be short-lived. In fact, the warmth extends all the way up to the Timmins area by Monday afternoon. In the south, it will send daytime highs up to the mid-teens for a short period of time, though accompanied by rain and blustery winds, so it will be tough to enjoy.
The system's effects will last into early Tuesday morning for some areas, including possible flurries on the backside of the system, but will be brief.
Check back frequently as we continue to monitor the forecast.