Thunderstorms don't involve a huge dump of mass arriving at hundreds of miles an hour. The MQ-9 cruise speed is about 200 mph. The Su-27 cruise speed is hard to estimate, but quite possibly in the range of 600 mph. That would be an overtaking speed of 400 mph, much worse than any flight through a thunderstorm (which I doubt is a desired flight environment). The engine ingestion problem was already analyzed, but it strains credibility to think that the engine would ingest anything coming from the aft direction, since the intakes are facing forward. (The Su-27 went upward after the fuel dump. Standard maneuver for a what was essentially a bomb drop. The fuel kept on going.)
Thunderstorms don't involve a huge dump of mass arriving at hundreds of miles an hour. The MQ-9 cruise speed is about 200 mph. The Su-27 cruise speed is hard to estimate, but quite possibly in the range of 600 mph. That would be an overtaking speed of 400 mph, much worse than any flight through a thunderstorm (which I doubt is a desired flight environment). The engine ingestion problem was already analyzed, but it strains credibility to think that the engine would ingest anything coming from the aft direction, since the intakes are facing forward. (The Su-27 went upward after the fuel dump. Standard maneuver for a what was essentially a bomb drop. The fuel kept on going.)