During DEC-24, the equatorial Pacific Ocean to the east of the Dateline produced a sharp drop in upper ocean heat. The observation is by far the coolest of 2024, a year when La Nina has struggled to develop. The dramatic subsurface cooling coupled with increased trade winds helped the Nino34 SSTA surge to a moderate-strength La Nina-like value of -1.1C Christmas Week. However, since that time waters have warmed slightly.

The Southeast Coastal Region of Australia was very dry in both DEC-24 and OCT/NOV/DEC-24. Otherwise, precipitation has averaged above normal to excessively wet across many parts of the continent during that time. Helping to aggravate the Coastal Southeast Drought is anomalous warmth during Q4/2024 which became somewhat hotter than normal for East-central and Southeast Australia during DEC-24. The anomalous heat accelerated the drying of soil. Consequently, a massive bushfire regime has developed from Victoria to New South Wales.

Upper ridge pattern evolves across Europe mid-to-late January and supports a warmer reversal in the previous chilly forecast. Additionally, due to the high pressure a somewhat drier than normal climate is forecast for January as storminess shifts to West-central Russia.

The cold burst into the East during the first half of January biases the previous January 2025 temperature anomaly outlook slightly colder in the East and the adjustment is indicated above. A La Nina climate is developing and should bias the East U.S. warmer in February while cold risk shifts to the northwest quadrant of the U.S.