Climate forcing by colder than normal conditions in the stratosphere during meteorological winter 2024-25 centered on Greenland produced a mostly warmer than normal winter across the northern hemisphere, especially Canada and Eurasia. However, there was a notable exception. Two brief stratospheric warming events took place across Canada, one just after mid-January and another during mid-February. Each event caused a polar vortex episode in North America.

The International Research Institute (IRI) for Climate and Society released a collection of Nino34 SSTA forecasts for 2025 earlier today. The consensus of dynamic (and especially) statistical Nino34 SSTA forecasts is a trend toward a “double dip” La Nina for later this year. Previously, Climate Impact Company issued a Nino34 SSTA constructed analog forecast indicating a second La Nina later in 2025 somewhat more intense than the 2024-25 version.

Another cold peak is ahead for next week in the U.S. causing natural gas prices to rise. Forecasts are trending colder, and additional price rise is possible. Next week's cold is impressive but not quite as strong as the mid-winter episode.

The Climate Impact Company ENSO, PDO, AMO, and IOD constructed analog forecasts are updated. The ENSO outlook increasingly favors 2025 as a La Nina year while cool phase PDO continues until a possible phase change early next year.