The west to east “weather conveyor belt” high up in the atmosphere called the jet stream was cranked into overdrive yesterday as winds within a portion of the jet reached record setting speeds up to 230 mph!
You’ve heard us talk a lot about the jet stream in our forecasts as it is the fast moving line between cold air to its north and warmer air to its south. It is a bit hard to visualize as it is very high up in the atmosphere- but you have likely taken a trip there if you’ve ever boarded a plane.
Commercial flights have a cruising altitude between 30,000 to 35,000 feet, this is roughly the same height in which the jet stream lives. Pilots can use this to their advantage if their flight path includes a portion of the jet stream as they can pick up a tailwind and get you to your destination a bit quicker. That is if your flight is eastbound, as westbound flights will have to flight against the jet stream. If you’ve ever flown across the country, you’ll know what I’m talking about as your westbound flight will be roughly a half an hour longer compared to your eastbound.
Earlier this week, a flight from LA to London got caught up in one the faster portions of the already speedy jet stream and managed to pick up a 200 mph tailwind over Pennsylvania, increasing its ground speed to over 800 mph! That Boeing 787-9, a portion of which was built right here in Charleston, Dreamliner’s normal cruising speed is around 590 mph. There is an important distinction between ground speed and air speed here, as if the aircraft’s air speed was 800 mph (which it was not) it would be supersonic- faster than the speed of sound. Relative to the air, moving at nearly 200 mph, surrounding it, the flight would be moving at an air speed nowhere close to that sound barrier. After that short lived boost, the flight managed to arrive over 45 minutes early.
From Storm Team 2 Meteorologist David Dickson