Alberto's remnant moisture hits Ontario after deadly impact
Tuesday, May 29, 2018, 9:37 AM - Following the uncomfortable heat and humidity that kicked off the work week in Ontario, much more pleasant early summer-like conditions now dominate the forecast. That's as the threat for severe thunderstorms with tornado potential spread across northwestern regions.
It's a perfect complement to the official 2018 SUMMER FORECAST, which highlights the upcoming heat and storm activity this summer season. We're also keeping a close eye on how the remnants of subtropical storm Alberto could dampen the weather here late week. More on that below.
- Temperatures return to the 20s on Tuesday, heat warnings drop across northern Ontario
- Heat and humidity builds back in on Wednesday with a wide range in temperatures across the region
- Remnants from Subtropical Storm Alberto impact southern Ontario later this week, increased threat for showers and thunderstorms
WATCH BELOW: TUESDAY'S ROUGH STORM TIMING
EXTREME HEAT EASES, WARNINGS DROPPED
After the first "heat event" of the year so far, temperatures return to more tolerable values through Wednesday. A heat warning that was issued for parts of northwestern Ontario on Monday has also been discontinued.
"Normally, heat warnings in this portion of the province are issued when at least two consecutive days reach or surpass 29 degrees with overnight lows that fail to fall below 18 degrees. Although today will be very warm and somewhat humid, latest analysis is suggesting that temperatures tonight will cool below the 18 degree threshold," explains Environment Canada.
Residents are still urged to drink plenty of cool liquids and dress accordingly to the weather.
(Visit our Complete Guide to SUMMER 2018 for an in depth look at the Summer Forecast, tips to plan for it and much more)
"We will get some relief from the heat as a light easterly flow off of Lake Ontario will keep temperatures near seasonal temperatures (low to mid 20s) across most of southern Ontario Tuesday, but near 20°C right along the lake shore with sunshine and low humidity," says Weather Network meteorologist Dr. Doug Gillham.
By Wednesday, heat and humidity returns, although a wide range in temperatures are likely.
"Across southern Niagara and the northern Greater Toronto Area, temperatures will climb into the upper 20s with a humidex well into the 30s," Gillham says.
TUESDAY'S SEVERE THUNDERSTORM THREAT
The risk for strong to severe thunderstorms stretches into northwestern Ontario on Tuesday with the greatest area of concern closer to the international and Manitoba border. That includes places such as Kenora, Dryden and Fort Frances.
"Morning convection will lead to scattered showers and non-severe thunderstorms across southeastern Saskatchewan and through northwestern Ontario as a warm front nudges northward," says Weather Network meteorologist Erin Wenckstern. "Some clearing is expected into the late morning and early afternoon, allowing the atmosphere to heat up and destabilize for the afternoon and evening hours."
WHAT THAT MEANS FOR STORMS
"High heat and increasing moisture will lead to ripe conditions for thunderstorms to blossom during the afternoon and evening, with heavy rainfall, large hail and strong wind gusts the main threats," Wenckstern adds. "A few supercells - rotating thunderstorms - are possible, but storms are more favourable to become linear, heightening the wind threat."
According to Wenckstern, modest atmospheric spin (shear) will create an isolated tornado risk, but it is not the primary threat. Rain and thunderstorms will linger through Wednesday across the northwest, slowly spreading into the northeast.
REMNANTS OF SUBTROPICAL STORM ALBERTO
The impact from Alberto will be nothing like what's happened across Florida and the U.S. Southeast, where two journalists were killed in North Carolina while covering the storm Monday. Remnants from the now subtropical depression however, will still bring moisture from the Gulf of Mexico into southern Ontario later this week.
"This will bring an increasing threat for showers and thunderstorms for Thursday and Friday, but at this point it looks like the system will be disorganized and track well to our west," Gillham says. "So, neither day will be a washout and most of the time it will not be raining."
WATCH BELOW: REMNANTS OF ALBERTO TRACK INTO THE GREAT LAKES
The timing of Alberto and how quickly the remnants track out of the region will play a role in this weekend's forecast, but at this point, it looks to be dry aside from some lingering cloud cover into Saturday.
"Temperatures will be much cooler, especially in areas where the clouds linger longer on Saturday. Sunday should be mostly dry and just a couple of degrees cooler than seasonal," adds Gillham.
JUNE: COOLER START, HOT FINISH
Aside from the sluggish start to June, things look optimistic for a warm finish.
"Overall, June is expected to be warmer than normal. A couple periods of cooler weather are possible during June 5 to 15, but warmer than normal temperatures should dominate the month, especially during the first few days and the second half of the month," says Gillham.