A returning El Niño could mean milder, less snowy Northwest

Barely emerged from the hottest day of the year so far, what better time to think about our upcoming winter weather?

Though still early, signs are growing that a disruption is brewing in the Pacific Ocean that could profoundly impact weather patterns worldwide.

As announced last week, there’s a 70 percent chance of El Niño conditions from December through February, according to an updated forecast by scientists at the U.S. Climate Prediction Center. That’s a rise from 64‑percent chance predicted only a month earlier.

Which means, El Niño is likely coming back.

The climate phenomenon is triggered by periodic warming of ocean water in the tropical Pacific and influences weather that varies by region. A strong El Niño in the United States typically brings warmer than average winters to the Pacific Northwest, lots of rain to California and cool, stormy conditions to the southern-tier states.

You may recall that in winter 2015-16, a robust El Niño threw the Northwest off balance by causing unusually warm weather and a low mountain snowpack that contributed to summertime drought conditions.

There’s no way to know for certain if the now-developing El Niño will ultimately turn into a monster or a shrimp. After all, El Niño is but one factor in a complex global weather machine. Nevertheless, because a powerful one has the potential to shape global weather systems, scientists will continue to assign probabilities based on observations and computational models.

Should an El Niño emerge, how might it affect Washington state?  Warmer than normal temperatures, along with less snow at lowland levels and in the mountains.

It’s strange to think that heating-up seawater thousands of miles away could play a role in how many layers of clothes we’ll wear this winter or much snow we’ll have to shovel. As for the more immediate future, we know with more certainty that shorts, sunglasses, plenty of fans and fire caution will help us get through the rest of summer. Hot, dry weather that includes periodic heatwaves and intervals of high fire danger are expected.