Winter’s Grip on Ontario Continues With Freezing Rain Risk in the South and Heavy Snow in the North Between Wednesday and Thursday

It might be officially spring, but it appears that Mother Nature missed the memo as we are expecting a system to bring a messy mix of wintery precipitation across Ontario over the next few days. The effects of this storm will begin to be felt in Deep Southwestern Ontario during the predawn hours on Wednesday. This includes Windsor, Chatham, Sarnia and London where temperatures will be hovering near the freezing mark throughout the morning. As a result, there is the risk of freezing rain for several hours as the precipitation works its way throughout the region. Do note that this will be very temperature dependent and some areas may see just all rain if it’s slightly warmer than expected.

Later in the morning on Wednesday, we will see the precipitation push to the northeast into the rest of Southwestern Ontario and the GTA with the risk of freezing drizzle or rain. Again, this will be very dependent on the temperature so the worst conditions will be found in the higher elevations (K/W, Guelph and Orangeville etc.) with less of an impact closer to the lakeshore. This could lead to some icy driving conditions during the morning commute on Wednesday so be sure to leave plenty of time to get to your destination.

In terms of ice accretion, the heavier precipitation will be found throughout Deep Southwestern Ontario southeast of Lake Huron so they could pick up around 2-4mm of ice accretion. The rest of Southwestern Ontario and the GTA is expected to experience more scattered freezing rain so it won’t be as sustained with less than 2mm of total icing. We will see the freezing rain risk linger into the afternoon as temperatures still remain slightly below the freezing mark, but there will be a break in the precipitation which should help limit the impact. Temptarues will slowly rise above the freezing mark towards the evening and overnight into Thursday.

Another area of concern we’re closely watching is east of Georgian Bay and up into Northeastern Ontario. This area has the risk of freezing rain starting late Wednesday afternoon continuing into the overnight and Thursday morning. Those in Central and Eastern Ontario can expect between 2-6mm of ice accretion by Thursday morning as temperatures climb above the freezing mark overnight. The more prolonged freezing rain will be found north of Georgian Bay including Elliot Lake, Sudbury and North Bay. Several hours of heavy freezing rain with up to 6-10mm of ice accretion is possible. This amount of icing will likely lead to some power outages and impact to travel so consider avoiding any non-essential travel through the region.

Conditions on Thursday will do a complete 180 across Southern Ontario as warmer air push temperatures into the double digits during the morning and afternoon. This will be accompanied by scattered showers and rain with even the risk of an isolated non-severe thunderstorm. Strong to damaging wind gusts will also be an issue early Thursday morning and into the afternoon. Current indications suggest that regions east of Lake Huron into the GTA could see wind gusts ranging between 70-90km/h with locally stronger gusts up to 100km/h along the shorelines. More details on this will be covered in a separate wind forecast to be issued on Wednesday as we get closer to Thursday.

For Northern Ontario, the story will be more of a traditional snowstorm for a wide swath of the area. Along with the aforementioned prolonged freezing rain just north of Georgian Bay. Snow has already begun to move into Northwestern Ontario this evening around the Manitoba border. It is expected to spread eastward throughout the overnight and into Wednesday. The heaviest snow will be found from Thunder Bay through Geraldton and Moosonee starting Wednesday afternoon and evening. Conditions here will be quite poor with blowing snow and rapid accumulation - road and highway closures are likely later in the day on Wednesday. There will be a short break for the snow early Thursday morning, but another round of heavy snow is expected to move through Northeastern Ontario (it should remain east of Thunder Bay closer to Wawa and Timmins) during the day on Thursday.

Total snowfall accumulation in the hardest-hit regions will likely exceed 20cm and could even approach 30cm by the end of Thursday. This includes Geraldton, Kapuskasing, Wawa and Cochrane while Thunder Bay will likely top out at around 15cm. Lower snowfall accumulation of around 5-15cm is expected through Chapleau and Timmins where sleet and freezing rain mixing in will reduce accumulation. Sault Ste. Marie, Elliot Lake, Sudbury and Temiskaming Shores will experience mainly freezing rain with significant icing of 6mm+ possible. The freezing rain will transition over to regular rain Thursday morning as the temperature climbs above the freezing mark.