Citation V/Ultra/Encore (C560)
Flight Crew Air Transport Pilot (ATP)
Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Flight Crew Regained Aircraft Control
Weather
Upon departure we were given a 180 heading to 'stay clear of weather'. We had the weather radar on and weren't indicating any precipitation at all. While we were in the turn to the 180 heading we entered clouds and encountered IMC conditions. Still no precipitation was being indicated on the weather radar. We started to get heavy raindrops on the windshield and almost immediately were jolted with severe turbulence. The turbulence disabled the autopilot; sent several things flying around the cockpit and back of the airplane; and put us into a bit of a turn. Our first priority was making sure we had control of the airplane. Once we got that reestablished we were off course a bit. ATC enquired a bit later where we were navigating to.  Consulted with company and diverted aircraft to [nearby airport] for inspection and maintenance
Upon departure; climbing out on RNAV SID we were given a shortcut to avoid weather. Encountered severe turbulence which triggered Master Caution; Master Warning indicators; loss of autopilot; and momentary upset of aircraft control. Manually took over controls; slowed; and took evasive maneuvers to avoid additional cells. Radar showed nothing on screen. Climbed to assigned altitude and resumed flight.
A Citation crew encountered severe turbulence on departure and diverted for required inspection and maintenance.