Winter is coming, and climate researchers say there’s an 87% chance that there will be La Niña conditions across the northern hemisphere between December and February. That means winter in Southeast Alaska likely will be colder and snowier than usual.
If the forecasters’ prediction is right, this will be the second La Niña winter in a row. The phenomenon on average occurs every two to seven years.
La Niña is a climate pattern marked by strong trade winds blowing toward Asia off the west coast of South America. The winds carry warm surface water with them, enabling colder water to well up from the deep. The colder surface water lowers air temperatures and pushes Pacific jet streams north, channeling frosty winds toward Alaska.
“So when we do get precipitation, it can be more snowy,” said National Weather Service meteorologist Wes Adkins in Juneau. While La Niña causes a dip in temperature in Alaska, it doesn’t always have the same effect on precipitation. (Some La Niñas lean dry, others wet.) “We probably are looking at cooler conditions across Southeast, which could mean pretty snowy conditions in parts…but drier elsewhere,” Adkins said.
According to the Climate Prediction Center in Washington, D.C., this winter in Southeast probably will be wetter than normal. But with microclimates across the region it’s impossible to know with certainty what the Chilkat Valley’s winter will look like.
Haines is already experiencing a wetter and (slightly) colder climate this fall. It has had its sixth wettest start to fall and tenth coldest in the last 30 years.