Messy Ontario storm raises flood risk with rain and snow impacts
Ontario will see a tale of two seasons with its next storm, with rainy and snowy impacts, perhaps even thundery, too, for parts of the province this week
March's reputation for volatile weather at times will ring true in Ontario this week, thanks to a potent Colorado low.
The stateside system will bring a myriad of spring-like and wintry weather to the province, with rain and warmth to the south, and perhaps thunderstorms, too, and colder temperatures and heavy snowfall in northern sections. Expect travel will be impacted in northern and southern Ontario at times.
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Because of the amount of rainfall and warm temperatures expected in southern Ontario, there is a raised threat of localized flooding and ice jams as the low pushes through. Local conservation authorities are on alert for possible river flooding.
Stay up-to-date on your local weather alerts, and be sure to check the latest highway conditions before heading out on the roads.
Big spring and wintry impacts set to hit Ontario
Ontario began to climb out of the freezer on Monday. The sudden warm-up will arrive courtesy of a system approaching from the U.S.
Mild and rainy systems have been few and far between in Ontario so far this winter, but one is already brewing and it’ll swirl its way toward the Great Lakes.
Wednesday will be the main event for northern and southern Ontario with heavy rain and snow filling in across the province.
Southern Ontario: Warmth and rain create flood and ice jam threats
While southern Ontario will find itself on the milder end of the low, the region could still see a brief dose of icy precipitation as the warm front arrives for the Tuesday morning commute. Travel could be affected across the region, so plan ahead.
By the afternoon, with the warmer temperatures, expect a changeover to rain in the southern sections. Meanwhile, a burst of snow is expected in Ottawa. It might see approximately 5 cm.
Expect Wednesday to be a washout across the southern and eastern sections of the province. A swath of 10-30 mm of rainfall is possible, elevating the localized flood risk with rapid snowmelt, particularly in areas with a considerable snowpack. Ice jams will also be possible, so ensure your gutters are clear of any snow and ice.
Southern Ontario, including the Greater Toronto Area (GTA), could even hear a rumble or two with a little more instability and dynamics in place. The most favourable setup for severe weather, however, will remain far south of the border.
As the storm exits east out of the province on Thursday, a noticeable drop in temperatures will see rainfall change into blowing snow for parts of southern and eastern Ontario.
Colder-than-normal temperatures are expected through the weekend, but will then trend much milder during the following week. Above-seasonal temperatures are expected to dominate from mid-March into near the end of the month.
Northern Ontario: Significant travel impacts from heavy snowfall
Meanwhile, more wintry weather will be felt in parts of northern Ontario as it will be on the colder side of the low.
The system will dump heavy snowfall and generate blustery winds on Wednesday, leading to treacherous winter weather near Sudbury, North Bay, Sault Ste. Marie and Timmins.
A swath of 10-20+ cm of snow is possible, so avoid travel if you can. Hazardous travel is expected on Highway 11 and Highway 17.
Blowing snow is then expected on Thursday as the storm exits east, especially for some of the snowbelt regions.
Stay with The Weather Network for all the latest on conditions across Ontario.