The Washington Post

NOAA calls off El Niño forecast

Ocean temperatures over the tropical Pacific are just marginally above normal - not warm enough to meet El Niño criteria. (NOAA)

Since the summer, NOAA’s Climate Prediction Center (CPC) had been favoring the gradual development of El Niño conditions, going so far as to issue an El Niño watch in recent months. But no more.

[T]he previous El Niño Watch has been discontinued as the chance of El Niño has decreased,” CPC writes in a monthly El Niño discussion released today.

Instead of El Niño, NOAA predicts that the neutral phase of the El Niño Southern Oscillation (ENSO) index will prevail. This neutral phase, sometimes called “La Nada”, is the murky middle ground between El Niño and its sister La Niña (associated with cool water in the equatorial Pacific).

“Relative to last month, the [sea surface temperature] model predictions more strongly favor ENSO-neutral,” CPC writes.

Models generally predict ocean temperatures in the tropical Pacific to remain stagnant through the winter. (CPC/IRI)

“[T]he tropical ocean and atmosphere may resemble a weak El Niño at times,” CPC writes.

What does all of this mean with respect to winter weather across the U.S. and the Mid-Atlantic, in particular?

That’s anyone’s guess. Recognizing El Niño might be muted, NOAA was decidedly undecided about how the winter would play out in its seasonal outlook released in mid-October. It called for equal chances of above or below average temperatures and precipitation over large parts of the U.S.

“This is one of the most challenging outlooks we’ve produced in recent years because El Niño decided not to show up as expected,” said CPC deputy director Michael Halpert.

When a full-fleged El Niño or La Niña is present, if often serves a useful guide as to the general temperature and precipitation patterns. Without one or the other, these patterns are much less predictable.

Instead, weather conditions become subject to the whims of the North Atlantic Oscillation (NAO), which can change every couple of weeks. When the NAO is negative, the jet stream buckles over Eastern North America, allowing cold air to plunge south, sometimes inciting storminess along the East Coast, like it did often in the Snowmageddon winter of 2009-2010. But when the NAO is positive, the jet stream is displaced far to the north, allowing warm air to flood much of the Eastern half of the country, like last winter.

Some researchers, like Judah Cohen of Atmospheric and Environmental Research (AER) are employing new techniques to predict the prevailing phase of the NAO. Cohen has linked October snow cover in Siberia to the NAO’s dominant winter mode. When there’s high Siberia snow cover and it advances quickly in October, it favors a negative NAO in months that follow.

“Snow cover [in Siberia] is more extensive than last year,” Cohen told the Worcester Telegram.

Capital Weather Gang’s winter outlook will be released on Tuesday, November 13.

Jason is currently the Washington Post’s weather editor. A native Washingtonian, Jason has been a weather enthusiast since age 10.


Success! Check your inbox for details. You might also like:

Please enter a valid email address

See all newsletters

Show Comments
Most Read


Success! Check your inbox for details.

See all newsletters

Your Three. Videos curated for you.
Play Videos
How to make Sean Brock's 'Heritage' cornbread
New limbs for Pakistani soldiers
The signature dish of Charleston, S.C.
Play Videos
Why seasonal allergies make you miserable
John Lewis, 'Marv the Barb' and the politics of barber shops
What you need to know about filming the police
Play Videos
The Post taste tests Pizza Hut's new hot dog pizza
5 tips for using your thermostat
Michael Bolton's cinematic serenade to Detroit
Play Videos
Full disclosure: 3 bedrooms, 2 baths, 1 ghoul
Pandas, from birth to milk to mom
The signature drink of New Orleans