Okanagan water conference delegates were told that more intense and destructive rainstorms are likely around the world unless greenhouse gas emissions are curbed. See story on page A3.
Widespread flooding that devastates communities and imperils agriculture are often the result of a meandering jet stream, guest speaker Bob Sandford told people attending the annual general meeting of the Okanagan Basin Water Board.
The jet stream's movements are less predictable than ever, Sandford said, largely as a result of a reduction in the size and thickness of the polar ice cap, due to global warming.
With the temperature difference between the poles and the tropics lessening, long-term weather patterns have become destabilized, with floods, fires, and droughts all occurring within a single year in the same river valley, Sandford said.
"People are complaining the weather is all over the place - and it is," said Sandford, chairman of the Canadian partnership initiative in support of the UN's Water for Life promotion.
Disastrous floods in Manitoba in 2011 and in Southern Alberta earlier this year are examples of intense rainstorms that are likely to become more common, Sandford said.
With the jet stream now ranging over a wider area, moisture-laden weather systems from the Gulf of Mexico and Pacific Ocean are now more likely to reach the middle of the North American and European continents, Sandford said.
As a result, there has been an observable increases in flooding in the northern hemisphere during just the last three years, he said.
The on-going, persistent flooding is a risk to agriculture, he said. The torrential downpours can also cause more pesticide and fecal matter to find its way into rivers and streams, he said.
Scientists have noted the creation of so-called 'atmospheric rivers,'or intense weather corridors packed with unusually high winds and water levels, Sandford said.
As well as being evidence of a need to reduce greenhouse gas emissions, Sandford said hydro-geological changes should warrant modifications to water management strategies.
Examples include expanding flood plains, designing infrastructure to withstand more frequent and more serious flooding, and managing water use more effectively.
During his address, Sandford noted the Environment Canada weather forecast calls for more rain to fall on the Okanagan in just a few days than normally occurs during September.
"These are very interesting days, to say the least," he said.
Storm knocks power out in Vernon
Hundreds of residents in the North Okanagan were without power Friday morning after a thunderstorm hit the area.
The heavy storm rolled through Vernon, causing a blackout that affected roughly 2,200 residences.
Environment Canada had
issued weather warnings for the Similkameen and Okanagan Valley, saying a strong upper low pressure system over Washington state was moving northeastward through B.C.
The bands of showers and thunderstorms were expected to continue on and off throughout the day.
A thunder-and-lightning storm swept through the province's south coast Thursday night, causing power outages in Metro Vancouver and the Sunshine Coast, and even delaying flights at Vancouver's airport.