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'Beast of a jet stream' a big boost to flights Wednesday

Tuesday, December 10th 2019, 5:30 pm - Lucky travellers will get a boost from Mother Nature this week.

Flights from eastern Canada and the northeastern U.S. are in line to get a helping hand from the jet stream through Wednesday, as winds at flight level strengthen to nearly 200 knots (370 km/h).

Generally speaking, flights between New York's JFK International and London's Heathrow take between 5.5 and 6.5 hours, depending in part on the wind. Favourable winds blowing in the same direction as the plane are tailwinds, and a decent tailwind can shave time off your flight. The opposite, a headwind, can stretch your time in the air.


Back in February, record-breaking winds at the 200 Mb level gifted a Los Angeles to London flight with a scorching ground speed of nearly 1300 km/h. That's the speed relative to the ground, not relative to the air around the plane (the true airspeed), so there was no sonic boom, but the ferocious jet stream did help shave an hour and a half off of the total flight time.

On Wednesday morning, as the jet stream strengthens over eastern North America, we may see flights challenging that turbo-charged speed.

sounding records for new york Record for atmospheric sounding data for the New York City area, showing the average, maximum, and minimum wind speeds at the 300 Mb level (approx. 30,000 ft/9150 m). Image courtesy NWS.

Some model forecasts have the jet stream's maximum winds at 300 Mb cracking the 200-knot mark early Wednesday, with the core of the strongest winds stretching from the U.S. Northeast across Atlantic Canada. That means flights heading across the Atlantic (from North America to Europe) will be well-placed to take advantage of a hefty tailwind.


While the opposite is also true -- flights travelling the other direction, Europe to North America -- will face a challenging headwind, typically airlines adjust flights accordingly, either by altering course or altitude, to avoid those kinds of jet stream obstacles.

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