The National Weather Service’s Aviation Weather Center (AWC) has issued a Severe Turbulence alert for air travelers over the northeastern U.S.; specifically, parts of New Jersey, New York, Delaware, Maryland, West Virginia, Virginia, Connecticut, Rhode Island, and Massachusetts are covered by the advisory. Included in this alert is the airspace over all New York area airports including Newark Liberty (EWR), John F. Kennedy Airport (JFK), and LaGuardia (LGA), Philadelphia’s International Airport (PHL), and all the airports around Washington, DC including Washington-Dulles (IAD), Washington-National (DCA), and Thurgood Marshall Airport (BWI.)
Specifically, SIGMET QUEBEC 1 has been issued through at least 1802 UTC today.
According to the AWC, there is occasional severe turbulence between 30,000 feet and 40,000 feet, the typical cruising altitude of most commercial aircraft. This turbulence is being created by wind shear associated with the jet stream.
Wind shear is a difference in wind speed and/or direction over a very short distance in the atmosphere. Airline pilots generally regard significant wind shear to be a horizontal change in airspeed of 30 knots (15 m/s or 34 mph) for light aircraft and 45 knots (23 m/s or 51 mph) for traditional airliners flying at flight altitude.