Super El Niños may lose their punch in a warming world

In any case it’s well-known that no two El Niños are the same, making timing and magnitude tricky to forecast. Here we have climate models suggesting ‘blockbuster’ El Niño weather may decline at some point if the warming trend continues for long enough. As one seems about to arrive, is now too soon for a real world test?
– – –
In a strong El Niño winter, normally dry regions can suddenly drown in rain, says Phys.org.

NASA notes that “typically dry regions can experience nearly two times as much rain during a strong El Niño.” Indeed, the blockbuster El Niños of 1982–83 and 1997–98 unleashed record-breaking California storms and unusually mild Northeast winters.

These far-reaching effects—atmospheric “teleconnections” linking the tropics to North America—arise because Pacific warming steers the jet stream south and east.

Observations confirm that nearly every significant El Niño year ranks among the hottest on record. This rising global baseline means the classic El Niño signal is riding on top of an ever-warmer world. [Talkshop comment – since the Little Ice Age, that is].

Climate change is already raising tropical Pacific temperatures, so scientists have begun to wonder: Will future “super” El Niños still pack a punch? [Talkshop comment – rising temperatures are indicators of climate change].

In a new study, published in Geophysical Research Letters, researchers put this to the test.
. . .
Less punch in a warmer world
The findings from the climate models were striking. As global temperatures rise, even the most intense El Niño patterns, which are part of a larger climate phenomenon known as the El Niño-Southern Oscillation (ENSO), appear to lose their distinctive “punch.”
. . .
As the researchers observed, “Extreme El Niño teleconnections shift even farther eastward, weaken, and develop a negative North Atlantic Oscillation–like response, echoing the changes seen in moderate El Niño–Southern Oscillation phases.”

These profound shifts are consistent with climate model predictions of eastward migration in tropical convection and jet-stream patterns.
. . .
Rethinking winter forecasts
These findings flip a common assumption. Strong El Niños will still occur, but not necessarily with the blockbuster weather people expect.
. . .
The broader takeaway is clear: Climate change is not just about juiced-up extremes, but about familiar patterns behaving in unexpected ways. In a warmer future, even a once-mighty El Niño could deliver a surprisingly ordinary winter.

The next time a big El Niño is brewing, the question may no longer be “how big?” but “how ordinary?”

Full article here.