Emb-140 flight crew reported they encountered severe turbulence on approach.

Attributes
ACN	1679760
Time
Date	201908
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	EMB ERJ 140 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Descent
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 2111
Person 2
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Events
Anomaly	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

Narrative:

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.

Original NASA ASRS Text

Title: EMB-140 flight crew reported they encountered severe turbulence on approach.

Narrative: 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.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.