Already reeling from the one-two punch of record low snowpack on the mountains and record low precipitation in the spring, B.C.’s drought-stricken south coast and Vancouver Island could be staggering into the path of an uppercut as an El Niño event strengthens in the Pacific Ocean.
The El Niño tends to bring wetter, but warmer, air to the coast of North and South America through the winter.
While this pattern suggests far more rain than snow could be coming to coastal mountains again this winter, salvation could arrive in the form of isolated cold-weather events.
“It’s the local events that provide our snowfall over the winter,” said Tobi Gardner, a hydrologist with the B.C. Rivers Forecast Centre. “It could happen that we get a few storms run through and get short phases of cooler temperatures with good dump of snow.
“Even though in the broader view El Niño is warmer, occasionally there’s gonna be a dip of cool weather.”
Vancouver Island and the south coast are currently in the grip of a Level 4 drought — the highest rating issued by B.C.’s Ministry of Environment — and many streams have been closed to fishing due to extreme low flows.
It’s a situation that has its roots in a winter that left very little snow in the mountains, and which when the typical rains of May and June failed to materialize.
“What we’ve seen this year, and I think they’re pretty much related, was the very low snowpacks, a very early spring runoff from the snow that was there, and a very quick transition into very low summer flow conditions, record low conditions.
“The really dry June kind of set the table for the rest of the season.”
The impacts are both environmental and economic. The inability to fish on Vancouver Island streams can hurt both tourism and river-based guides. Last winter, Mount Washington Ski Resort was forced to shut down skiing in early February while waiting for more snow that never did come.
Mount Cain, on North Vancouver Island, and the Fraser Valley’s Hemlock Resort never opened at all.
In April, a survey location in the mountains outside Powell River showed record-low snowpack for that time of year, Gardner said.
Another winter of low or no snow could again wreak havoc on skiers, but does not necessarily guarantee a repeat or a worsening of this summer’s drought conditions.
“We do tend to get a lot of rain, and another factor in flow rates is groundwater recharge, and that is directly related to how much precipitation we get,” said Gardner. “Typically on the Island we do run into low-flow conditions in the summer anyway. It’s just that this summer is much lower than usual.”
Gardner noted long-term projections for precipitation are notoriously difficult to make, due to isolated, local weather events that can occur within wider climactic trends like the looming El Niño.
Another wild card in the mix is a 1,600-kilometre wide “blob” of warm water that has been parked off the west coast of North America for two years straight.
“Typically, meteorologists forecast what we might get in a typical El Niño year based on the last couple of El Niño cycles,” said Gardner. “But we haven’t had this blob of warm water sitting off the coast at the same time. In terms of our predictive capacity, it’s challenged because our precedent is based on a different set of conditions.”