Government UAS crew reported attempting to have UAS return for an auto landing. Due to high winds; an auto landing wasn't possible and they conducted a successful manual emergency landing without engine power.

Narrative

After a successful launch the aircraft flew for 45 minutes and started to conduct a landing. During the landing sequence the autopilot system aborted landing for crosswind variance and too high of wind on landing. After 23 aborted landings the aircraft started to give a low fuel warning. A tail wind landing was attempted as a last resort before [requesting priority with ATC] and conducting a emergency landing with the engine turned off. The tailwind landings were not successful and the emergency landing was started. While we flew the emergency loiter and landing a manned flight called into ZZZ for landing and we [advised ATC]. The aircraft stayed out of the ZZZ airspace while we landed the aircraft. Landing was successful and no damage or accident occurred. After the recovery; all aircrew conducted a root causation exercise to pin point any faults. After the exercise it was concluded that high heat and thermals were the cause of the inability to land within the parameters of the autopilot system.