Regional Jet 700 ER/LR (CRJ700)
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Other / Unknown
Deviation - Altitude Overshoot; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Flight Crew FLC Overrode Automation; Flight Crew Overcame Equipment Problem; Flight Crew Returned To Clearance
Human Factors
After departing OKC we were climbing at 250 knots with autopilot engaged in Speed Mode. We were in continuous moderate turbulence using radar and ATC guidance to deviate through a line of growing thunderstorms. As we passed through FL310 near TUL VOR we encountered a large updraft that increased our airspeed; and caused the autopilot to respond by pitching to an extremely high nose attitude in speed mode. I instructed the FO (First Officer) who was flying pilot to check climb rate; and then advised him to level off. By the time we overrode the automation the plane was climbing through FL320 at 4;000 feet per minute with airspeed decreasing. The FO leveled the aircraft and selected take off go around thrust. Airspeed continued to decrease with altitude level; and as it dropped to our minimum acceptable speed of VMD (225 knots) we initiated a descent to gain airspeed. We recovered airspeed to 250 knots losing about 500 feet of altitude; and then resumed the climb at 250 knots.Using speed mode in moderate turbulence at high altitude caused the plane to chase airspeed and pitch to an unrealistically high pitch and vertical speed rate considering our altitude. Weather significantly contributed to the event as we were task saturated flying in IMC at night; using radar to deviate; talking to ATC about weather deviations; and encountering moderate turbulence with up and down drafts associated with the thunderstorms.Using speed mode at FL310 in moderate turbulence was a poor use of automation. As Captain I should have had the FO switch to vertical speed mode earlier knowing we may encounter changing winds. Climbing at 250 knots was a poor decision as it left very little buffer between our climb speed and Vmd. Climbing at 280 knots for maximum turbulence penetration speed would have been more appropriate. The FO wanted to climb at 250 knots in order to try to get on top of some of the weather; and at the time I felt comfortable with his decision. In hindsight we should have climbed at 280 knots and the speed likely would have never dropped near Vmd.
CRJ-700 Captain reported encountering a large updraft causing an airspeed increase and extremely high nose attitude with minimum acceptable airspeed.