Summary
Colder-than-normal weather is expected in many parts of the central and northern U.S. during Thanksgiving week. This weather is caused by a possible disturbance in the polar vortex, which could bring cold air from the Arctic south into the U.S. Forecasters are monitoring the situation to see how it develops.
Key Facts
- The National Weather Service forecasts below-normal temperatures from November 26 to 30 in parts of the central and northern U.S.
- Missouri, Iowa, Illinois, and Wisconsin have a 60% to 70% chance of seeing colder temperatures than usual.
- Other areas from Montana to northern Texas and east to New York could see temperatures below normal.
- Some areas in the west and Florida might experience warmer-than-normal temperatures.
- A disturbance in the polar vortex, caused by warming in the upper atmosphere, could let cold Arctic air move south.
- This cold pattern may also be influenced by La Niña, which involves cooler Pacific Ocean surface waters, and the Madden-Julian Oscillation, which affects weather patterns.
- Forecasters are still unsure if the vortex will be fully disrupted or just altered, but it could still lead to colder weather.
- Meteorologists note that disruptions in the polar vortex are a natural occurrence but are studying possible links to climate change.
