Medium-range forecasts are trending warmer across North America and especially the U.S. The catalyst to this warmer trend is a cold stratosphere over the polar region stretching south across Canada as indicated by the GFS in 5 days. As a review, the cooling and constricting stratosphere is compensated for by the warming troposphere below. Consequently, the upper-level pattern in the troposphere creating our weather is less able to produce cold air and arctic air generation is cutoff. Arctic air already present will retreat to deep snow cover.

The seasonal totals of tropical cyclone activity for the North Atlantic basin during the 2022 season was 14 tropical storms, 8 hurricanes and 2 major hurricanes. The accumulated cyclone energy (ACE) index was 95.1. The observed totals are very close to normal while ACE index was 78% of normal.

Evolution of a titanic negative North Atlantic oscillation (-NAO) pattern is indicated during the medium-range. The effect of -NAO is to produce anomalous upper-level high-pressure blocking over Greenland. The high-pressure block is certainly evident in the “most likely” upper air forecast for the northern hemisphere by the mega-cluster ensemble.

In a worse case scenario, the evolving cold pattern in Western Russia is trending stronger and is now more expansive into Europe likely reaching U.K. in the medium range. The Canadian Ensemble most effectively illustrates the cold risk.