From tornadoes to frost: Temperatures plunge as potential for frost envelops much of the region

Much of southern Ontario is under a risk of frost Wednesday night as temperatures will plunge to near freezing. CTV's Julie Atchison explains.

It’s a week of whiplash weather, as London finds itself under the risk of frost Wednesday night, only one day after a severe thunderstorm and confirmed tornado impacted the region.

According to CTV News London Meteorologist Julie Atchison a frost advisory is in effect for much of southern Ontario Wednesday night, as temperatures will drop near the freezing mark in parts of Huron, Bruce, Grey and Perth counties overnight.

PHOTOS: High speed storm sweeps through southern Ontario

While London is not under the advisory, Environment Canada warns that the overnight low will drop to 3 C, and a risk of frost is possible.

“Our next weather system not arriving until Friday night, so you’re in for some sunshine,” Atchison said. “Your Thursday is looking beautiful, and temperatures are slowly recovering after a cool day across the region.”

Sunny skies and a high of 16 C are in store on Thursday, with gusty winds of up to 40 km/h and a UV index of eight.

Cloud cover increases come Friday, with overcast skies and a high of 21 C expected.

“Friday night we have rain and the temperature dips a bit heading into Saturday,” Atchison said. “Saturday looks fairly wet through the day, so it won’t be a quick cold front coming through. This looks like an area of low pressure to the south that will drive moisture northwards. So, Saturday could be one of those wet rainy days.”

In addition to the rain on Saturday it will also be on the cooler side, with a daytime high of 14 C.

“Daytime highs recovering next week. We’re back up between 23 and 25 degrees [Celsius], heating back up and we could see a nice blocking pattern develop next week,” said Atchison. “I’ll keep you posted on that.”

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

Wednesday night: Clearing early this evening. Wind northwest 20 km/h becoming light this evening. Low plus 3 with risk of frost.

Thursday: Sunny. Wind becoming east 20 km/h gusting to 40 then light late in the morning. High 16. UV index 8 or very high.

Friday: Cloudy. High 21.

Saturday: Showers. High 14.

Sunday: Cloudy with 40 percent chance of showers. High 21.

Monday: Cloudy with 30 percent chance of showers. High 23.

Tuesday: A mix of sun and cloud. High 24.