Article By: Jason Samenow
The present El Niño event, on the cusp of attaining “strong” intensity, has a chance to become the most powerful on record. The event — defined by the expanding, deepening pool of warmer-than-normal ocean water in the tropical Pacific — has steadily grown stronger since the spring.
The presence of a strong El Niño almost ensures that 2015 will become the warmest on record for Earth & will have ripple effects on weather patterns all over the world. A strong El Niño event would likely lead to enhanced rainfall in California this fall & winter, a quieter than normal Atlantic hurricane season, a warmer than normal winter over large parts of the U.S., & a very active hurricane & typhoon season in the Pacific. Some of these El Niño-related effects have already manifested themselves &, over the U.S., will become particularly apparent by the fall & winter.
Frequent & persistent bursts of wind from the west, counter to the prevailing easterly direction, have helped this year’s El Niño sustain itself & grow. Warm water from the western Pacific has sloshed eastward, piling up in the central & eastern part of the basin. The sprawling area of warm waters has proven to be a boon for Pacific tropical cyclone activity, near record levels through mid-summer. Through a positive feedback mechanism, these cyclones have likely helped to reinforce the westerly push of warm waters, Slate’s Eric Holthaus reported.
The 2015 El Niño event is now neck-&-neck w/record-setting event of 1997-1998 in terms of its mid-summer intensity.
That 1997-1998 event was notorious for its winter flash floods & mudslides in California.
Michael Ventrice, a meteorologist for the Weather Company, said the atmospheric footprint of this year’s event — given the time of year — is statistically extremely rare & has a less than 1 in 1,000 chance of occurrence:
Although the El Niño is still officially classified as a “moderate” strength event, Tony Barnston, 1 of the world’s leading El Niño experts, explained it could well become a “strong” event by the end of the month.
“The strength of the departure from normal sea surface temperatures was enough to call it a strong event for just last week,” Barnston, of Columbia’s International Research Institute for Climate & Society (IRI), said. “But to call it an officially strong event, we need for it to stay at that level or higher for a full month. & the average for July could make it.”
The large group of El Niño models, both dynamic (based on physical processes) & statistical (based historical data), mostly forecast at least a strong event — likely to peak in the fall. Collectively, the IRI described the model simulations as “off-the-charts”:
“[El Niño] is growing & the prediction models say it’s going to get stronger,” Barnston said. “& that’s our prediction, that it will become a strong event, most likely.”
A few models, notably the European model & the National Weather Service CFS model, point to the possibility of a near-record event in which a very strong or “super” El Niño develops.
The only 2 super (or very strong) El Ninos in the historic record occurred in 1982-83 & 1997-98. Perhaps hinting at an El Niño rivaling history, models have been trending stronger w/their forecast month after month after month — as they absorb more data reflecting the true state of the current event & how it’s evolving:
While some models show El Niño possibly maxing out in record territory, NOAA climate analyst Michelle L’Heureux expressed some skepticism about such projections in an interview w/Mashable’s Andrew Freedman.
“L’Heureux noted that none of the major forecasting centers responsible for monitoring El Nino are predicting a record event at this time,” Freedman reported.
NOAA says the “forecaster consensus” is for a strong event but doesn’t specify how strong. Its forecast calls for El Niño to persist through the winter (90% chance) & early spring (80% chance).