EMB ERJ 140 ER/LR
Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 2111
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Flight Crew Regained Aircraft Control
Procedure; Weather
We were set up for approach to land on Runway 13R at ZZZ and ATC changed our Runway to 18R and instructed us to descend down to 4;000 feet.  ATC then reported that other airplanes on approach to 18R had started initiating go arounds and gave us a heading to depart the area southwest.  We then encountered severe turbulence which included the autopilot disconnecting and an altitude loss of approximately 400 ft. with airspeed variations of plus or minus 30 knots.  We then exited the turbulence and coordinated with dispatch and ATC to divert to our alternate of ZZZ1.Rapidly changing; unforecasted weather conditions were the cause of the turbulence and more pilot reports would have helped as we were not given any prior notification for anything greater than standard turbulence associated with the weather.
We deviated from our assigned altitude clearance by approximately 400 ft. as the airplane was uncontrollable but corrected as soon as we were able. We were encountering unforecasted and unwarned severe turbulence at the time of the event. We tried to climb but were being pushed down at approximately 2;000 fpm until we could counter the forces. We were vectored in too close to approaching thunderstorms by ATC in a corridor that should have already been cut off to traffic. We were not in precipitation but were within 5 miles of heavy to extreme moving toward the airport and were being cut in close by ATC to try and attempt an approach. We could also have called off the descent had we heard about previous reports but heard nothing until ATC relayed all traffic beginning to go around at ZZZ for wind shear.
EMB-140 flight crew reported they encountered severe turbulence on approach.