Oregon Public Broadcasting

Government scientists announced Thursday that the El Niño weather pattern is returning. Correspondent Tom Banse reports on what conditions that typically brings to our region.

Scientists at the federal government's Climate Prediction Center have detected significant warming in the tropical waters of the Eastern Pacific.

Periodic warming in that vast body of ocean has a cascading effect on world weather known as El Niño.

Here in the Northwest, the biggest change El Niño usually brings is a milder winter. This according to University of Washington atmospheric scientist Cliff Mass.

Cliff Mass: “Snowpack tends to be less in the mountains. We also tend to have less snow in the lowlands. Also in terms of precipitation, we tend not to get those ‘Pineapple Expresses' in El Niño years.”

Mass says the pattern often splits the storm track as it approaches the West Coast.

Scientists at NOAA expect this El Niño to strengthen into the fall and last through this coming winter. Our last El Niño was in 2006.