Overview
- Operational models and national agencies are now describing an unusually early weakening of the stratospheric polar vortex that could become a major sudden stratospheric warming, though a full wind reversal required for a major event remains uncertain.
- Scientists emphasize any effects at the surface would lag by weeks because changes high in the stratosphere typically take two to six weeks to alter the jet stream and regional weather patterns.
- A record‑strong El Niño is complicating the picture by both raising the odds of a stratospheric disturbance and by favoring a stronger Pacific jet that tends to keep much of the northern United States milder.
- Energy analysts warn that even short bursts of colder weather in late November or December could sharply raise heating demand and threaten Europe’s already thin natural gas storage buffers.
- Sudden stratospheric warming occurs when rapid heating high above the Arctic weakens or reverses the polar vortex and can promote North Atlantic or Scandinavian blocking that sends cold, dry air and possible snow to northern Europe and the UK.