A day-long windstorm kept these downtown Vancouver flags flapping, while darkening homes and prompting ferry cancellations and road closures. (CBC)

A howling windstorm left tens of thousands of southwest B.C. residents in the Lower Mainland and Vancouver Island without power on the first day of the Easter weekend, while the heavy gusts also caused headaches for travellers.

BC Hydro said more than 100,000 customers were left in the dark at the storm's peak and that figure dropped only to about 90,000 by Friday afternoon.

There were reports of trees blown down in many locations in Metro Vancouver on Friday afternoon, including one on the Stanley Park Causeway, prompting the closure of the Lions Gate Bridge and all roads in adjoining Stanley Park for hours.

The high winds also caused havoc for BC Ferries, which announced numerous cancellations due to conditions so fierce one vessel suffered physical damage.

Wind warning

Environment Canada had issued a wind warning for much of Vancouver Island and predicted gusts between 60 and 80 kilometres an hour would batter the region for much of the day.

"I've had some BC Hydro people say that their own personal experience is that these are the strongest winds they've seen since 2006," said Dag Sharman, the company's spokesman.

He said crews were hoping to have power restored to to most customers sometime Friday.

"Each individual circumstance is different because of the nature of a storm like this," Sharman said.

"It depends on what the cause of the outage is. Typically, it's trees into our lines or equipment. But if that does damage to equipment and that equipment has to be replaced, it can sometimes take longer."

Winds of 50 to 70 kilometres an hour were also forecast for Metro Vancouver, though far fewer outages were reported.

The majority of the darkened homes and businesses occurred on the southern part of Vancouver Island.

Bolts snapped on ferry

Mark Stefanson, a spokesman for BC Ferries, said the agency had to cancel a number of morning sailings due to the wind.

"We've had some real challenges on our route between Horseshoe Bay and Nanaimo," he said.

"Some vessels were running late. In fact, in one case we had the bow doors of a vessel damaged because of the severe wind conditions and we had to turn the vessel around and take it back to Nanaimo."

The wind had pushed so hard on the doors that it snapped bolts holding the door closed.

BC Ferries had added 26 sailings to the long weekend run, anticipating heavy vehicle traffic.

By Friday afternoon, BC Ferries was warning potential travelers that if they hadn't already reached the West Vancouver terminal they were unlikely to get on a vessel unless they had a reservation.

Busy border

With the Canadian dollar nearly reaching parity with the U.S. dollar, border officials were expecting delays throughout the weekend and most of the major crossings reported hours-long waits.

"Please be advised that we are noticing unusually heavy volumes of travellers heading to the United States," Faith St. John, spokeswoman with the Canada Border Services Agency, said in a release.

St. John advised travellers to avoid peak times and to check border delays before heading out the door.