For daily wit & wisdom, sign up for the Almanac newsletter.
Zip! This January, a passenger jet broke all records for crossing “The Pond”.
A British Airlines flight reached speeds as high as 745 mph as it surfed the jet stream crossing the Atlantic. It arrived in England only 5 hours 16 minutes after it started, cutting a full hour and a half off the normal flight time.
The key to fast airplane travel: Ride the jet stream. Source: NOAA
So how does this relate to warm weather? It’s all in the jet stream, the narrow band of extremely fast winds in the upper atmosphere. Whether it’s an airplane or a winter storm, it will travel fast if it rides the polar jet stream. As cold as temperatures may get this winter, we have been helped by strong westerly winds encouraging the weather to move on out.
That’s where the North Atlantic Oscillation (NAO) comes in. This is a weather pattern that determines how fast or slow the jet stream and the storms it carries will cross the Atlantic Ocean. Think of it acting like a crossing guard.
The North Atlantic Oscillation acts like a crossing guard, allowing or forbidding storms from crossing the Atlantic Ocean. Credit: Microsoft
When the high and low pressure areas in the North Atlantic are very strong and different, the NAO is positive. This allows the jet stream to cross the ocean. It zips across quickly, along with any cold fronts, storms or airplanes the winds are carrying. This leaves the East Coast relatively warm.
When the high and low pressure areas are weak, the NAO is negative. This stops the cold fronts. Instead of flowing out of North America into the Atlantic, it lingers on the coast. Cold front after cold front piles up, waiting to cross the ocean.
Most of this winter, the NAO has been positive, allowing East Coast storms to flow into the Atlantic. Source NOAA
A lot of cold air has poured into the US this month. However, most of the time, the NAO has been positive and the storms rapidly streamed out into the Atlantic.
The pilot of the zippy British Airlines flight might have been grateful for the quick flight, but not as grateful as anyone in the East who didn’t have to endure a solid month of cold miserable weather.