‘A sticky one across southern Ontario’: Heat, humidity and storm risk continues

The heat and humidity will persist in the London region Wednesday with a continued storm risk. Here's CTV's Julie Atchison.

Heat and humidity will linger across the region on Wednesday, bringing along with it a continued risk of rainfall and thunderstorms.

According to CTV News London Meteorologist Julie Atchison, a heat warning is currently in effect throughout Windsor-Essex, Chatham-Kent and Sarnia-Lambton, with temperatures set to peak at 39 in London with the humidex.

Atchison says the risk for scattered showers and thunderstorms continues Wednesday, with a 40 per cent probability during the afternoon. She adds however that the chance for storms will ramp up to a 60 per cent probability going into the night.

“This line of showers and thunderstorms looks to move into Essex County at about seven o’clock and then make its way into London anytime between 8 30 [p.m.] and 9 p.m.,” she explained.

The main threat of these storms she says will be heavy downpours due to “a lot of moisture” within the air mass. The overnight low will drop to 21 C.

The chance for showers and a risk of a thunderstorm will continue heading into Thursday morning, but by the afternoon there will be a mix of sun and cloud. Thursday’s daytime temperature will mirror Wednesday’s, with a high of 31 C, feeling like 39 with the humidity.

The heat will continue Friday and Saturday, but Atchison says temperatures drop back into the low to mid 20s during the latter half of the weekend, leading to “more comfortable conditions.”

Here is a look at London’s long-range forecast

Wednesday: A mix of sun and cloud. 40 percent chance of showers this afternoon with risk of a thunderstorm. Wind west 20 km/h. High 30. Humidex 39. UV index 9 or very high.

Wednesday night: Partly cloudy with 60 percent chance of showers. Risk of a thunderstorm. Wind west 20 km/h becoming south 20 this evening. Low 21.

Thursday: Cloudy with 60 percent chance of showers in the morning then a mix of sun and cloud. Risk of a thunderstorm in the morning. Wind southwest 20 km/h becoming light in the morning. Wind becoming southwest 30 late in the morning. High 31. Humidex 39. UV index 9 or very high.

Friday: Cloudy with 60 percent chance of showers. High 27.

Saturday: Sunny. High 27.

Sunday: Cloudy with 40 percent chance of showers. High 25.

Monday: A mix of sun and cloud. High 21.

Tuesday: A mix of sun and cloud with 30 percent chance of showers. High 21.