Ontario spring storm unleashes thunderstorms, snow, and 20°C temperature swing
Southern Ontario is set to experience dynamic and shifting weather in the coming days before April arrives, highlighting the variability typical of spring
Ontario braces for a turbulent end to March as a powerful spring storm moves in. Southern Ontario faces a risk of severe thunderstorms early this week, while northern areas contend with snow and freezing rain.
The storm’s clash of air masses will deliver summer-like warmth to some regions and lingering winter chill to others. Rounds of snow, ice, rain, and thunderstorms will hit the province Monday, Tuesday, and into Wednesday morning.
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As April approaches, spring’s inconsistent pattern looks set to persist. While temperatures will trend in the right direction, with warmer peaks and less intense cold dips, consistently warm, above-normal weather is not anticipated as we move deeper into the month.
Northern Ontario: Snow and ice risks Tuesday
A developing system will bring a mix of snow and ice to northern Ontario starting early Tuesday.
Snow is expected to spread across areas including Thunder Bay and regions east of Lake Superior in the pre-dawn hours, with varying intensities through the day as waves of precipitation move in. The heaviest snowfall is anticipated Tuesday afternoon near Lake Superior, with accumulations ranging from 5-15 cm across areas north and east of the lake.
Farther south, freezing rain and ice pellets may begin Tuesday morning in communities northeast of Georgian Bay, extending across the Nickel Belt.
Rates of precipitation are expected to remain light during the morning, with minimal ice accumulation. However, conditions could worsen by Tuesday evening, with steadier freezing rain and ice pellets potentially impacting the region.
The exact location of the highest ice accumulation risk remains uncertain as the system’s track may shift farther north or south, potentially leading to changes in local impacts.
Southern Ontario: Thunderstorms and 20°C temperatures ahead
Southern Ontario saw a surge of warmth Monday, with temperatures rising to the upper teens and low 20s. However, shower chances will arise in southwestern Ontario by dinnertime, spreading into the Greater Toronto Area (GTA) overnight.
Widespread showers and thunderstorms are expected overnight into early Tuesday, including the possibility of organized clusters with frequent lightning. Periods of rain and storms will continue Tuesday morning, with breaks into the early afternoon before activity picks up again later in the day.
Tuesday’s temperatures will remain similar to Monday, climbing to the upper teens and low 20s. However, a cold front arriving Tuesday evening will bring another round of thunderstorms, potentially more widespread and severe. Hazards include heavy rainfall, isolated, strong winds, and small hail.
Rainfall amounts of 20-40 mm are expected across southern Ontario by Tuesday night, with locally higher totals in thunderstorms.
More stormy weather ahead
Active weather continues late this week into the weekend, with additional rounds of precipitation and fluctuating temperatures.
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Multiple precipitation types are possible as another dynamic system approaches.