Expressjet E145 near London on Sep 5th 2014, altitude deviation of -3300/+600 feet due to extreme turbulence

An Expressjet Embraer ERJ-145 on behalf of United, registration N16954 performing flight EV-4538/UA-4538 from Grand Rapids,MI to Newark,NJ (USA), was enroute at FL370 about 50nm west of London,ON (Canada) deviating around severe weather at about 23:19Z, when air traffic control observed the aircraft climbing to about FL376 then rapidly descending to FL337 before the aircraft returned to the assigned FL370 reporting extreme turbulence. The aircraft continued to Newark for a safe landing.

The Canadian TSB reported that ATC observed the aircraft climbing and then rapidly descending to FL340 at about 8800 feet per minute. There were no injuries and no damage reported.

NAV Canada reported the aircraft was observed climbing to FL376 without clearance then descending rapidly to FL337 before the aircraft returned to FL370 reporting extreme turbulence. NAV Canada advised the Canadian Transportation Safety Board (TSB).

Infrared Satellite Image GOES-E Sep 6th 2014 00:00Z (Graphics: AVH/NASA):