EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Flight Crew Regained Aircraft Control
Weather
Twenty minutes into the flight; reaching FL370; and on top of the last cloud layer; we encountered turbulence that became severe. Wind shear plus up and down drafts activated the shaker momentarily disconnecting the autopilot. First Officer maintained level attitude and second shaker activation followed; there were just seconds between the two shaker activations. We descended with a downdraft 3;500 feet leveling at FL330. All this time; we were in contact with Center and I notified them of our inability to maintain altitude.
ERJ-170 Captain reported stick shaker and inability to maintain altitude at FL370 in severe turbulence.