Why It Happens Here
The valley makes its own weather.
Kelowna sits in a long trough with a lake down the middle, and wind funnels along it. A gust coming up off the water hits a roof sideways and from below, which is exactly the direction a shingle’s seal strip was never designed to resist. One strip lets go, the wind gets under the course above, and a band of shingles peels back in seconds, usually taking a vent with it.
The other half is the dry heat. Weeks without rain bake sealant, shrink pipe boots and let needles and grit pack the drains and valleys. Then the first real downpour arrives all at once, finds every detail that dried out and cracked over the summer, and a roof that never leaked in July leaks in September. Winter adds snow load and freeze-thaw, which pries at anything the wind and heat already loosened.
So the emergency is rarely a surprise from the roof’s point of view. It is a detail that was already failing, plus one hard day of weather.