NOAA Ups Odds of Record-Shattering El Nino to 90 Percent for This Winter

NOAA's Climate Prediction Center now says there's a greater than 90 percent chance this El Nino becomes "very strong" by the end of 2026, and a 69 percent chance it becomes the strongest event on record dating back to 1950. That's up from forecasts issued in July, according to the Washington Post's tracking of monthly ocean temperature data.

The numbers matter because this event has been building for months. Sea surface temperatures in the central equatorial Pacific have sat at record levels for more than two months straight, the Washington Post reported, and the latest projections show ocean temps peaking around 4.1 degrees Celsius above average in December. That would beat the previous record-holder, the 2015-16 El Nino, by more than a full degree.

"Our team has become more confident in the possibility of a very strong El Nino by the end of this year," said Michelle L'Heureux, a physical scientist at NOAA's Climate Prediction Center, in comments to ABC News. "There is a greater than 90% chance of a 'very strong' El Nino, which is the highest chance to date, and expresses our confidence in the growth and development of a potentially historic El Nino event."

Nat Johnson, a meteorologist with NOAA's Geophysical Fluid Dynamics Laboratory, told CNN the event is shaping up to be "something that's very unusual, if not a once in a lifetime type of" strength. NOAA is careful to note that a historically strong El Nino doesn't guarantee historically extreme weather. It just raises the odds certain patterns show up.

What that means region by region

The mechanics are straightforward. El Nino typically shoves the jet stream south, dragging more storms into the southern U.S. while the northern tier turns drier and warmer. CNN reports that translates to wetter, cooler conditions across the South and less snow than average for the Northeast, a reversal of what a lot of ski towns and snow lovers want to hear.

Florida faces a specific risk: more severe thunderstorms along the Gulf Coast from late fall into early winter, according to Michael Tippett, a climate scientist at Columbia University who spoke with CNN. Other parts of the Gulf Coast, oddly, get quieter than normal during the same stretch.

Down in South Carolina, Beaufort County and the Hilton Head area are bracing for a wetter fall and winter. The Island Packet reported nine of the last 12 strong-to-very-strong El Ninos brought above-average precipitation to the region in December, January and February, and noted the area's snowfall record of 6 inches came during the very strong El Nino of 1972-73. Temperature is harder to call. Beaufort County's CPC outlook gives just a 50-60% chance of above-normal temps over the next three months, with no clear lean on precipitation until El Nino's influence kicks in more fully after October.

The upside: a quieter hurricane season, so far

One place El Nino is already showing its hand: the Atlantic hurricane season. NOAA's updated outlook gives a 75% chance of a below-normal season, and the Island Packet notes that's borne out so far, with only three systems forming as weak tropical storms through mid-August. Wind shear tied to El Nino tends to choke off tropical development in the Atlantic even as it fuels typhoons in the western Pacific.

What's actually new versus what's been said before

The headline shift since NOAA's August 13 outlook, reported by ABC News, is the upward revision. Confidence in a very strong El Nino has climbed past 90%, and the record-breaking probability has ticked up to 69% based on the Washington Post's early-August data update. Both outlets are working off the same NOAA modeling, and neither claims the event has peaked. It hasn't. NOAA and the outlets agree the peak arrives in December, months from now.

None of the six historically comparable El Ninos—1877-78, 1888-89, 1972-73, 1982-83, 1997-98, and 2015-16—hit the sea-surface temperature levels current forecasts project for this winter, according to the Washington Post's data tracking. If the December projection holds, it would be the strongest event of its kind since consistent record-keeping began.

The open question is how much of that ocean heat translates into disruptive weather on the ground. NOAA's own scientists are the ones cautioning against assuming a direct match between record ocean temperatures and record storm damage or crop losses. The Climate Prediction Center will issue updated seasonal outlooks in the coming months as El Nino approaches its projected December peak, and that's when farmers, insurers, and coastal planners will get a clearer read on whether the ocean data translates into an equally historic winter on land.