Australia’s Bureau of Meteorology (BoM) has said sea surface temperatures (SSTs) are likely to decline below the La Nina threshold in January, though SSTs will remain in El Nino-Southern Oscillation (ENSO) neutral range until April. 

The National Oceanic and Atmospheric Administration (NOAA) of the US said chances of a strong La Nina is near zero, though there is a 72 per cent chance of La Nina emerging during December-January-February.

BoM said besides its model forecasts that SSTs in the central tropical Pacific will remain in the ENSO-neutral range, 4 of the 6 other international climate models also point to this.

ENSO neutral

The Australian weather agency said global SSTs remain substantially above average. “ENSO is currently in the neutral range. Since November, atmospheric indices such as the SOI and trade winds have strengthened towards La Nina with oceanic indices responding in recent weeks,” it said in its latest update.

NOAA said neutral ENSO conditions are favoured by the Spring. It said near-to below average sea surface temperatures were observed across most of the eastern and central Pacific Ocean near the equator.  “The oceanic and atmospheric observations currently reflect neutral conditions,” it said.

BoM said some oceanic and atmospheric patterns in the Pacific have at times shown weak La Niña characteristics in 2024 but with little coupling. “For an event to become established, both atmospheric and oceanic indices would need to be sustained at La Nina levels for at least 3 months,” it said.

IOD neutral

The Australian weather agency said the Indian Ocean Dipole (IOD) is neutral. “The IOD had been tending negative from mid-October but returned to neutral values at the start of December,” it said.

BoM said its model forecasts that the IOD will remain neutral throughout the forecast period to April 2025. This is consistent with 5 of the 6 other international climate models surveyed and typical IOD behaviour at this time of year.

The US weather agency said the upper-level temperatures, above 30,000 feet, were warmer during August-October, while the wind shear was relatively higher in September but low in October. 

2024 the warmest on record?

NOAA said global land and ocean temperature was +1.34°C higher in November than the 1991-2020 average and was the second warmest on record for November. The global land temperature was +2.31°C higher than the 1991-2020 average and the second warmest for November on record, while the global ocean was +0.91°C higher than the 1991-2020 average and the second warmest for November on record. 

NOAA said there was over 99 per chance for 2024 to end up as the warmest year on record, a view shared by the European weather agency Copernicus Climate Change Service and the World Meteorological Organization.