B777 Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
ATC Issue All Types; 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
Human Factors; Procedure; Weather
Operating flight as Pilot Monitoring. We were deviating to avoid weather along the route. We were cleared direct to ZZZZZ waypoint and asked for a deviation around weather but was initially denied. We were only authorized a deviation right of course in which were able to avoid the first TCU (Towering Cumulus) but the wind direction and velocity forced us into the second TCU as we were turning back onto course. Prior to entering the TCU the wings were leveled and we experienced a climb of approximately 700-800 ft. During the altitude excursion ATC asked why we had deviated and I replied that we were currently in the TCU. The autopilot remained engaged and within approximately 10 seconds the aircraft recovering back to the assigned altitude. ATC asked again for the reason and I replied that we had entered the TCU momentarily and was back on course and assigned altitude. ATC inability to provide deviations in either direction due to weather. Better communication between ATC facilities and increased tolerances left or right of course for hazardous weather conditions.
B777 flight crew reported altitude deviation due to weather.