Generally, sudden stratospheric warming (SSW) events capable of producing arctic outbreaks are considered more likely during easterly phase of the quasi-biennial oscillation (-QBO). Past winter seasons when -QBO was developing in November, similar with 2025, and peaking during the winter season, similar with winter 2025-26 expectation, are identified (since 1979).

STRIKING is the weakening of anomalous cool waters in the equatorial East Pacific during October. Note that the cool anomalies present in the subsurface equatorial Pacific are about 30% of the strength present this past January which supported a moderate strength La Nina episode. Unless upper ocean heat across the equatorial Pacific to the east of the Dateline cools dramatically over the next few weeks, the current La Nina will end.

The anomalous warm middle/northern latitude oceans help to bias North America and Europe warmer than normal well into November. However, ECM indicates potential for cooling to near normal in the U.S> during Thanksgiving week.

October was wet across much of the Black Sea region eroding drought conditions. However, the weather pattern changes as November approaches. Forecast models indicate a very dry pattern through the first half of November in the Black Sea AG regions. Lack of snow cover across Northwest/North Eurasia biases the climate pattern warm. Snow cover continues to reach far southward in Northeast Asia.