Ontario is getting a preview of mid-summer-like heat, with a strong ridge ushering in 30-degree temperatures and humidity for the start of this week. With heat warnings in place in the south, it hangs on for a final day Tuesday. Meanwhile, northeastern sections will see the chance for severe again storms Tuesday as the boundary pushes east. Southern Ontario will cool down Wednesday as a cold front cuts through the region just as June begins, also bringing a threat of severe storms. More on what to expect through mid-week and for the start of June, below.
NORTHEAST: SEVERE STORM THREAT MONDAY AND TUESDAY
An elongated boundary of active weather remains draped across northern Ontario, bringing rain and thunderstorms.
While the focus of severe weather Monday will lie in northwestern Ontario, there is also the risk of some isolated severe thunderstorms in northeastern Ontario near Timmins and Kapuskasing.
With a little bit more lift and instability located in this region, any isolated storms that develop in the early evening have better atmospheric dynamics to possibly turn severe. Small hail and locally strong wind gusts would be the primary threats.
Much of northern Ontario will be under the threat for seeing thunderstorms Tuesday with communities north and east of Lake Superior looking to be the most favourable location for severe weather as the cold front marches through a hot and humid air mass.
SOUTH: MAY ENDS WITH BLAST OF HIGH HEAT AND HUMIDITY
A strong ridge of high pressure anchored over the U.S. Midwest is responsible for ushering in summer-like heat from the Gulf of Mexico. It will even reach into northern Ontario, however brief.
Heat warnings and special weather statements are in place for southern Ontario including Windsor, Leamington and Chatham-Kent. Maximum temperatures in these specified areas may see both low- to mid-30s Tuesday.
Humidex readings will be into the mid-to-upper 30s in the south, accompanied by plenty of sunshine and high UV rays, so be prepared with sun protection if going outside.
Tuesday will see more heat, spreading into northern sections with widespread 30°C temperatures, as well. Similar feels-like values can be expected, with even higher readings for some locales while they will also be felt in northern Ontario.
"These conditions pose a health risk when you are not used to the heat," says Environment and Climate Change Canada in the special weather statement that spans the south. "Everyone is at risk from heat, especially older adults; infants and young children; and people with chronic illnesses."
To battle the heat, residents are urged to drink plenty of cool liquids before feeling thirsty and to keep cool by dressing for the weather and spending more time in a cool place.
Although the heat will extend into northern areas Tuesday, extreme eastern sections along the Quebec border will feel the effects of a sharp temperature boundary as cooler air attemps to push back in but the ridge won't budge much.
So, as a result, a considerable temperature contrast ranging from the low 20s to near 30°C are expected over a rather short distance -- with Ottawa still sitting in the upper 20s.
Savour the warmth while it lasts, though, because temperatures will moderate beyond Wednesday. Temperatures will still be warm Wednesday, but will drop back below the 30-degree mark and humidity will linger.
A cold front is expected to cross the region late Wednesday with a period of showers and thunderstorms. There may be strong to severe storms with locally very heavy rain, strong winds and hail. Much cooler weather behind the front on Thursday.
Beyond, temperatures will be near or slightly below seasonal through the weekend and most of next week. After the current heat wave, there is no hot weather in sight for the next two weeks. Forecasters are watching the potential for the pattern to become more unsettled next week, as well.
Don't forget to check out our Summer Forecast reveal on Tuesday, May 31!
WATCH BELOW: WHY SHOULD YOU NOT SEEK SHELTER UNDER AN OVERPASS DURING A SEVERE STORM
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