EXPLAINER: Stuck jet stream, La Nina causing weird weather

Meteorologists attribute the latest batch of record-shattering weather extremes to a stuck jet stream and the effects of a La Nina weather pattern from cooling waters in the equatorial Pacific.

The Olympic and Cascade mountains got hit harder, with more than 50 inches (127 centimeters) in three months, according to the National Weather Service.

There’s a slight possibility of snow Monday night, according to the weather service.

That means low pressure on one part of the stream is bringing rain to the Pacific Northwest, while high pressure hovering over about two-thirds of the nation produces dry and warmer weather, said Brian Hurley, a senior meteorologist at the weather service’s Weather Prediction Center in College Park, Maryland.

If the jet stream moves more or bends differently, rain and other extreme weather won’t be as concentrated, Hurley said.

This is a typical weather pattern with a natural La Nina weather oscillation, he said.

These bouts of extreme weather happen more frequently as the world warms, said meteorologist Jeff Masters, founder of Weather Underground who now works at Yale Climate Connections.