ROANOKE, Va. – The same system that brought wide spread rain to southwest Virginia Thursday night helped slingshot a passenger plane across the Atlantic Friday night. The jet stream is one of the driving forces behind our weather. It is a fast-moving ribbon of air that resides up where jet aircraft fly, hence the name jet stream. It is the dividing line between warm and cold air and the pathway in which storms travel.
The jet stream is fueled by temperature differences. The bigger the difference, the stronger the jet stream. This is why the jet stream is much stronger in winter than in the summer. Oftentimes in winter it can be in the 80s in Florida and well below zero in the Upper Midwest or Canada.
In winter, the winds within the jet stream can be well over 200 mph, as was the case Friday night. The temperature and pressure gradient (difference) was extreme in between the Bermuda High and Icelandic Low fueling the intense winds at about 35,000 feet.
KLM Flight 644 took off just before 9:30 p.m. Friday, Feb. 7 from New York’s JFK airport en route to Amsterdam. A little more than an hour into the flight, the ground speed reached more than 800 mph! At 11:10 p.m. as the plane was flying over Newfoundland, the ground speed reached 821 mph. The filed speed for the flight was 564 mph.