The general lack of precipitation of the past month (except Indonesia) may be a contributor to a wet bias of operational and AI 15-day forecasts for North and South America plus Europe. The ECM ENS is characteristic of all operational forecast models producing a wet forecast bias in 15-day outlooks for the past 30 days for the Americas. AI models have a similar common problem as demonstrated by AIFS ENS for Europe.

Solar cycle maxima 25 has passed and the NOV-25 sunspot number indicates deceleration toward solar minima likely by 2030-31 is underway. Common questions are influences on climate which is minimal due to CO2 emissions although slightly colder North America winters are favored. There are minimal effects on solar panels due to a weaker sun during solar minimum.

The North America and Eurasia snow cover during November were near normal and consequently northern hemisphere snow cover was near normal and the least snowy since November 2009. Note one of the coldest winter seasons on record followed as DEC/JAN/FEB 2009-10 was frigid! Early season snow cover dictating the following winter weather pattern was a reasonably reliable climate diagnostic late last century but less so in this century.

Given the sharp increase in medium-range temperature anomaly forecasts for North America and Europe as meteorological winter 2025-26 arrives a review of 30-day skill scores using anomaly correlation is provided. For North America, as observed throughout most of 2025, AIFS ENS and ECM ENS are the top 2 forecast models. Anomaly correlation skill scores in the 0.85 range for the 6-to-10-day period are considered good too very good with a similar reliability near 0.70 in the 11-15-day period.