Heavy fog, playing havoc on air transport in the Harbour City this last week had cleared for takeoff by Wednesday.
Flights all over Vancouver Island and the Lower Mainland had to be cancelled or rescheduled due to an unusual upper ridge of high pressure which rolled in last week.
“It’s normally a summer time pattern,” said John McIntyre, forecaster with Environment Canada.
“In the summer if that had happened it would be sunny and hot, but this time of year, when you get a ridge like that, it ends up producing a temperature inversion where you get the warm air aloft and you get this trapped marine air on the lower levels and any moisture that comes from the water gets trapped … so you end up with fog.”
At the Nanaimo Airport, a total of three flights were cancelled to and from Vancouver Sunday, with a further four delayed.
By Monday, all flights to and from Nanaimo to Vancouver were cancelled, with service able to resume with clearing conditions mid day Tuesday, albeit delayed.
“It’s disappointing when we have that kind of weather,” said Mike Hooper, Nanaimo Airport president and CEO. “This has been one of the worst months [for fog] we’ve had for a number of years, even decades.”
Harbour Air, which flies out of downtown Nanaimo, also had to cancel service at all locations Sunday through Tuesday, but was back up and operating by Wednesday.
“We’re in good shape. It should be business as usual,” said Randy Wright, executive vice-president for Harbour Air/West Coast Air. “Safety is our No. 1 priority and so we can’t fool with mother nature.”
Hooper said no runway can sustain 100 per cent reliability, particularly when it comes to fog which reaches the ground, as it has in the past week.
“The navigation systems help, but when you have fog right down to the ground, then you can’t land,” he said.
He said it is hard to say at this point how this week’s cancellations will affect Nanaimo Airport’s reliability for the year. Airport reliability is calculated by total the number of flights versus the number of cancelled ones.
“We’ll see, because if this is the only event that causes us grief then we’d [rate] highly reliable.”
In 2009-10, Nanaimo Airport brought a new instrument landing system on board, as well as high-intensity lights which drastically increased the number of flights able to take off during inclement weather.
“We used to have, for the winter months, 74-per cent reliability before we put them in, now we have over 99.9 per cent,” Hooper said.
Nanaimo's weather patterns are due to return to more normal levels by Thursday afternoon with another front bringing steady rain, gusty winds and temperatures of about 6 C.
"Current indications are it's going to get a little milder after the weekend, we're going to probably see some above normal temperatures in the next work week, but we'll see over the next few days," McIntyre said.