Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 342
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Flight Crew Returned To Clearance; Flight Crew Regained Aircraft Control; Flight Crew Took Evasive Action
Weather
Aircraft encountered severe turbulence over PNT VOR while in the turn to JOT VOR. The aircraft banked 45 degrees due to turbulence; Bank Angle Warning sounded and autopilot disengaged. The aircraft lost 200 feet to 500 feet of altitude; and heading was 30 degrees off course to avoid additional turbulence. ATC was notified of event and further instructions were to fly direct CADON when able. [The] rest of [the] flight was uneventful.I could see the frontal system ahead of us on radar and it appeared we would stay clear of weather over PNT. Ten miles prior; I queried the First Officer to ask for 20 degrees right. The First Officer was unable to get a clearance due to heavy radio congestion. We stayed on vector and subsequently encountered the turbulence. I should have used my emergency authority to begin the turn prior to ATC clearance but due to compressed vectors in and out of weather; I wasn't quick enough to react to the situation.
[Report narrative contained no additional information.]
Air carrier flight crew reported an encounter with severe turbulence.