Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Training / Qualification
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Flight Crew FLC complied w / Automation / Advisory; General Maintenance Action
Weather; Procedure; Human Factors
During descent below 18;000 feet we encountered severe/extreme turbulence we advised air traffic control Los Angeles center and also SoCal approach. The Captain entered a numbered item report in the maintenance logbook and we advised/briefed the outbound crew. We were pretty shaken up during the arrival since neither the captain or myself had experienced this type of turbulence before. We thought we had done all required actions until this morning we were debriefing our performance and in revisiting flight manual part one under required reports we realized we had kept dispatch out of the loop. A report to dispatch was required after landing when encountering severe turbulence. In retrospect we tend to forget about dispatch once the flight lands and we leave the aircraft.  Hence mentally we remove our attachment to them. Inflight we depend on the great support that they provide and we make the required position/ride reports as necessary to keep them abreast of our progress. During events like the one reported above the only thing that I personally think could help is to develop a habit/muscle memory to include dispatch in the loop of things to do anytime anything on a flight is not routine.
[Report narrative contained no additional information.]
A large transport aircraft on descent into a Southern California airport encountered severe turbulence. The crew made a PIREP and a maintenance logbook entry; but failed to notify dispatch as per company policy.