The pattern had been predicted to form for several months, and weak La Niña conditions were finally officially met this week.

According to the NOAA’s website, the El Niño-Southern Oscillation cycle is a phenomenon ... “That’s the bottom line with weather in the [Pacific] Northwest, is it can vary quite a bit ...

These temperature swings were more intense in the past, and the oscillation occurred even ... either side of the equator in the eastern Pacific Ocean, because it can alter the jet stream, drying out ...