Flight Crew Last 90 Days 313
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance; Flight Crew FLC Overrode Automation
Weather
Climbing through about FL355 for FL370 at approximately M.78 in VNAV; we noticed an uncommanded rise in airspeed along with the large increase in Vertical Speed. The airspeed trend arrow went up into the barber pole; (we never got the clacker) so the Captain reduced power; as the airspeed and Vertical Speed continued to increase very rapidly; the Captain continued to reduce power and increase the pitch in an attempt to prevent the aircraft from overspeeding. The airspeed and Vertical Speed increased at such a rapid rate that we were unable to level off the FL370; with the airspeed continuing to increase. We did not have any indications of mountain wave or windshear leading up to this point. I believe we were able to get the aircraft to slow down and level off at approximate FL380; with idle thrust. I immediately notified ATC of the severe updraft we had experienced and our deviation in altitude. The windshear event appeared to be over and we returned back to FL370 promptly. I called the Flight Attendants to check the status of the cabin; everyone was ok thankfully. We notified Dispatch of the severe updraft/windshear; and the Captain wrote the aircraft up when we got to ZZZ. Maintenance met the airplane in with a printed report of the flight data; showing a 7900 fpm climb during the peak of the windshear event. The rest of the flight was mostly light chop/turbulence. We didn't encounter any more mountain wave or windshear. There isn't anything that we could have done to prevent this event. I believe we handled it as well as possible; given the extreme nature of the windshear/turbulence.
Leveling off to cruise at FL370 climbing out in mostly smooth conditions we encountered severe turbulence in the form of a significant updraft. Pitch and thrust were managed as to not exceed aircraft limitations while maintaining positive aircraft control.
B737 flight crew reported an increase in airspeed and vertical speed that resulted in a max climb rate of 7;900 feet per minute and overshooting the assigned cruise altitude by approximately 1;000 feet.