polar vortex collapse forecast

Strong polar winds creates a strong vortex which keeps cold air trapped at the pole. And weak polar winds weakens the vortex which allows cold air to spill southward. When that happens, Arctic air chills temperatures in other regions.

Winter 2025-2026 Temperature Outlook: We continue to expect higher odds of above-normal winter temperatures across California, the Southwest, and the Southern and Central Rockies.

A strong polar vortex doesn't cause cold weather — it does the opposite. Here's what to know about polar vortices, how they work

However, so far, the return to La Niña in 2025 has brought only relatively modest cooling. This is sufficient to help 2025 be cooler than 2024