Monday's flash flooding sees a 'rare phenomenon' of high rainfall throughout the South Okanagan, more may be coming

'Rare phenomenon' of rain

Environment Canada meteorologist Bobby Sekhon said the rain that fell on Monday throughout the Okanagan Valley has a return rate of a one in a 10-year event with how much poured down that afternoon.

"It's a pretty rare phenomenon to see that much rain all at once, in that part of the Okanagan," he said.

According to the climatologists, 12.3 millimetres of rain were recorded at Penticton Airport, Osoyoos saw 14.1 millimetres and Summerland reached a whopping 15.7 millimetres in that afternoon window.

While July is one of the wettest months of the year for the Interior, carrying with it thunderstorms, high winds or hail, the amount of rain was something unusual.

"It's not often that we see this intensity of thunderstorms go through a populated area, such as Penticton, and obviously caused some devastating damage," Sekhon said.

Penticton has sixteen individuals who are still evacuated from their homes and saw 86 reports of damage through their rapid response assessment team come in from the floods.

The Okanagan isn't out of the woods yet either.

"Wednesday we're going to have a risk of thunderstorms in the area. Those thunderstorms could give downpours, giving up to 20 millimetres of precipitation," Sekhon said.

"Now, that doesn't necessarily mean that we're going to see the same event as we saw [on Monday], but we know the possibilities that can occur if the intense thunderstorms fall in those kinds of vulnerable areas where they can cause those impacts."

On Thursday, an upper low will be tracking through B.C. and with that, Sekhon said there's going to be more instability with the risk of an intense thunderstorm.

"That's going to be something to watch, because those could get heavy downpours, too. ...There's the possibility of some locally heavy downpours that we're just going to have to watch for."

The reminder stands as "When thunder roars, go indoors," and to keep drains clear, with an eye on the forecast from Environment Canada and the River Forecast Center.

In the longer-range forecast, Sekhon said things will start to settle down a bit on Friday and into Saturday as well, with a ridge of high pressure on Sunday starting to build into next week, which is looking quite hot for the Okanagan.

"We'll see an increase in temperatures and some hot dry weather probably next week."

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