Originally Posted by
wxguy
The other day I was on a 757 flight that had continuous moderate turbulence for about 15 minutes. (I know the definitions because I'm an aviation meteorologist and have used/taught the official definitions from the FAA and American Meteorological Society). An FA got on the PA and reminded the pax to stay seated because, "We are experiencing SEVERE turbulence." Trust me -- it wasn't severe -- everyone would have known it if it was!
These are the definitions I'm aware of (at least for lay people); are they the same as the AMS definitions? Or I suppose, for this thread, are they the same as what UA uses internally?
Light - Momentarily causes slight, erratic changes in altitude or attitude - Unsecure objects may be displaced slightly, food service easily continued. No difficulty walking.
Moderate - Changes in altitude and/or altitude. Aircraft remains in positive control; variations in indicated air speed. - Unsecured objects dislodged. Food service and walking difficult.
Severe - Large abrupt changes in altitude and/or attitude. Large variations in indicated airspeed. Aircraft may be momentarily out of control. - Food service and walking impossible.
Extreme - Aircraft violently tossed about and is practically impossible to control. May cause structural damage - Strong desire to land.
I've noticed FAs have a tendency to inflate the turbulence level -- I'm guessing to get more people to comply with their requests. In one case pre-pandemic the flight deck made a "moderate" turbulence PA which the FAs then followed up with their own "as you can tell we're experiencing
severe turbulence"