Greater Victoria is often caught bragging about its favourable climate to other Canadians and a “great blue hole” that sometimes hovers over the area is further proof of just how great the weather can be.
Due to the mountains that surround the region and other parts of B.C., such as the Okanagan, weather can vary over small distances. In the Victoria area and sometimes further up Island to Nanaimo, this means a patch of blue sky in the form of a line or hole can form when frontal systems move through, sparing the regions from excess rainfall.
“What happens with fronts a lot times is the Olympic Mountains or mountains on the Island cause moisture to drop on the west side like Tofino,” said Environment Canada meteorologist Doug Lundquist. “When it comes back down on our side the subsiding air causes it to warm, evaporate and dissipate.”
The evaporating moisture causes breaks or holes in the clouds. The phenomenon is often called the rain shadow effect, Lundquist said, or a “subsidence break” in the clouds.
Much of the south Island, particularly Greater Victoria, is in the rain shadow of the Olympic Mountains.
Similar weather effects are also found in the interior of B.C., Lundquist said, making the clearer skies a constant for people who live on the eastern side of a mountain.
“These are all the beautiful results of living in a mountainous terrain,” Lundquist said.