With most of Vancouver Island under both wind and rainfall warnings earlier this week, the Comox Valley bore a lot of the brunt of two major weather systems bringing high winds and heavy rainfall.
Thanks to tropical moisture, the deep trough over the Pacific Ocean formed along with moisture brought up in the atmosphere from the typhoon in the Philippines, explained Jennifer Hay, meteorologist at Environment Canada.
“The stream across the ocean taps into the sub-tropical moisture and transverses over to the west coast,” she said, and added although it appeared intense with back-to-back systems, the storms are not unusual for this time of the year.
Monday, the Comox weather station received 59mm of rain, and while the initial storm eased late Tuesday morning and afternoon, a second wind and rainfall warning were issued for another frontal system for the area overnight.
Reports indicate areas outside Comox and Courtenay received even higher rainfall amounts, with Black Creek receiving nearly 95mm.
Stephen Watson, stakeholder engagement and communication co-ordinator with BC Hydro, said 100mm of rain fell above the Comox Lake reservoir Monday, and more than 94mm fell Tuesday.
Additionally, water inflows have been massive, he noted.
“The Cruikshank River hit a high of 530 m3/s (Tuesday) morning and is coming off that peak. The peak water inflows into the reservoir hit about 1,000 m3/s — that’s the equivalent of the water within an Olympic-sized swimming pool entering the reservoir every 2.5 seconds.”
The Comox Lake Reservoir has risen about 1.5 metres from noon Monday to lunchtime Tuesday. Watson explained as the level increases, BC Hydro’s downstream operational flexibility diminishes.
“A water survey gauge at the Fifth Street Bridge reached a maximum of 4.61m at 8:30 a.m. (Tuesday) around the peak tide before slowly receding,” he said. “Isolated flooding can begin at 4.2 metres.”
Tuesday, the rate of discharge from the dam was about 200 m3/s, while water inflows into the reservoir upstream of the dam have been four to five times that amount.
Watson said the Tsolum River hit a high of 282 m3/s Tuesday — a new record — while the Browns River hit 250 m3/s.
As of 6 a.m. Tuesday morning during the initial storm, wind gusts topped off at 85 km/h at the Comox airport.
Meteorologists at Environment Canada added the second storm overnight Tuesday and into Wednesday morning brought with it more rain and winds, as the weather station received 41mm of precipitation and winds which reached 89 km/h.
The system did bring with it warm weather, as Tuesday’s temperature broke a record for all-time high for Dec. 9 at 14.2C, breaking the old record of 8.3C from 1962.
Hay said while a small low bringing more rain and wind is tracking towards Vancouver Island for Thursday evening, the brunt of it should hit the west coast of the U.S. from California to Washington state.
“It looks like we’re through the worst of it,” Hay added.
Visit www.comoxvalleyrecord.com for the latest updates on the storm.