A mix of Freezing Rain, Heavy Rain, Thunderstorm Risk, and Snow set to threaten Southern Ontario
A powerful and complex spring storm system is set to impact Ontario starting Wednesday morning, bringing multiple weather hazards across the province. This isn’t an april fools joke! This system will arrive on the heels of last weekend’s damaging ice storm, potentially slowing recovery efforts in hard-hit areas.
Key Points
- Heavy rainfall of 30-65+ mm expected in southern regions
- Risk of severe thunderstorms with wind gusts up to 100 km/h in southwestern Ontario
- Freezing rain and ice accretion up to 8 mm in some areas
- Significant snowfall up to 25 cm in northwestern regions
- Strong winds gusting 50-70 km/h possible
Regional Impacts
Southwestern Ontario
Heavy rainfall will be the primary concern, with amounts reaching 30-60+ mm by late Wednesday evening. There’s also a risk of severe thunderstorms developing late Wednesday afternoon and evening, capable of producing:
- Intense wind gusts up to 110 km/h
- Heavy downpours
- Possible brief tornado
- Rainfall amounts up to 60 mm east of Lake Huron
- Lesser amounts of 10-20 mm near Lake Erie
The Grand River Conservation Authority has issued a flood warning, with river flows remaining elevated from previous storm system that brought ice and thunderstorms to the area a few days back.
Grey-Bruce to Peterborough Region
Areas still recovering from the weekend ice storm face additional challenges:
- Freezing rain mixed with ice pellets
- Ice accretion of 4-8 mm, particularly over higher terrain
- Transitioning to rain with amounts up to 40 mm
- Impacts worsened due to ongoing storm recovery efforts
Greater Golden Horseshoe
- Beginning with snow (up to 5cm), changing to mixed precipitation, which will then later change to rain as warmer air rushes in.
- Warm ground may reduce snow accumation
- Brief period of freezing rain (1-2 mm ice accretion)
- Transitioning to rain with amounts up to 60 mm, risk of thunderstorms possible
- Higher terrain areas at greater risk for ice accumulation
Central, Eastern, and Northeastern Ontario
Expect a messy mix of winter precipitation:
- Initial snow and ice pellets (up to 5 cm)
- Transitioning to freezing rain
- Ice accretion of 3-6 mm possible, especially over higher terrain
Lake Ontario North Shore
- Brief period of ice pellets or freezing rain
- Mainly rain with amounts up to 20 mm
- Additional rainfall expected Thursday
Northwestern Ontario
Significant snowfall expected:
- Up to 25 cm west of Lake Superior
- Locally higher amounts over elevated terrain
- Blowing snow near Lake Superior reducing visibility
- Up to 15 cm in other northwestern regions
Timing
- System begins Wednesday morning in southwestern Ontario
- Spreads eastward through Wednesday afternoon
- Most precipitation ends early Thursday morning
- Northwestern snow event continues into Thursday
Current Recovery Status
Hydro One reports that 275,000+ customers remain without power from the weekend storm. Crews have restored service to more than 637,000 homes and businesses but expect restoration efforts in the hardest-hit areas to continue throughout the week. Remote areas may experience longer restoration times.
Safety Recommendations
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Travel Safety
- Avoid unnecessary travel during the worst conditions
- If driving is essential, adjust speed for conditions
- Watch for water pooling on roads and potential flash flooding
-
Power Outages
- Keep emergency kits stocked and accessible
- Have flashlights and batteries ready
- Keep devices charged when possible
- Have non-perishable food and water available
-
Property Protection
- Clear storm drains to prevent localized flooding
- Secure loose outdoor items before strong winds arrive
- Be prepared for potential basement flooding
Stay Informed
Report severe weather to Environment Canada:
- Email: ONstorm@ec.gc.ca
- Social Media: Use #ONStorm
- Monitor local forecasts and warnings