Learjet 60
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Other LR60; ERJ170/190
Flight Crew Last 90 Days 100; Flight Crew Total 5100; Flight Crew Type 150
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Loss Of Aircraft Control
Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Weather
Flying ZZZ-ZZZ1 the flight experienced a severe updraft in clear air at FL270; which caused the airplane to climb 1;600 ft. despite any attempt to arrest the ascent for roughly 20 seconds. I instructed the Pilot Monitoring to request priority handling once it was evident that the altitude was uncontrollable. ATC responded that we were cleared down to FL250 when able. We regained control of our altitude and ensured that nobody was injured during the event. We determined that the event did not exceed any of the airplane limitations and continued on to ZZZ1.
LR60 Captain reported a severe updraft caused the aircraft to climb 1;600 ft before crew could regain control.