September 2025 Weather Alert: Rare Polar Flow and Severe Weather Events Sweep Across Continents

Unprecedented Weather Patterns Emerge

September has ushered in a rare cross-polar flow into the United States and Canada, accompanied by unusual development of the Polar Vortex. This dramatic shift in weather patterns is creating significant implications for both North America and Europe.

North American Weather Developments

The forecast indicates warmer-than-normal conditions over the western United States, with a belt of warm anomalies extending across the Midwest and into the Northeastern United States, alongside a weaker warm temperature zone over the far north and upper Midwest.

Current pressure patterns show a high-pressure system in the North Pacific, with another high-pressure area extending from the northeastern United States into the Atlantic. A low-pressure zone over Canada may extend into the U.S. later in the season as winter approaches.

European Weather Alert

Extremely intense rainfall is currently forecast for parts of Europe, with expectations of excessive rainfall within 6-12 hours. Rainfall accumulations are predicted to reach 100-200 mm across wide areas, with some locations potentially experiencing more than 300 mm.

A large upper-level trough positioned over the North Atlantic and Western Europe, with its secondary wave moving into central Europe, is expected to deepen considerably. This setup is creating particularly volatile conditions for the north Mediterranean and North Adriatic region, leading to an extreme risk of flooding.

Looking Ahead

New atmospheric data reveals strong easterly winds descending through the tropical stratosphere, which could bring notable changes across the United States, Canada, and Europe. Historical patterns suggest this could lead to colder and snowier conditions across these regions, with fresh forecasts indicating potential influences on Winter 2025/2026.