Thrasher was quite the show boat when he was younger. When he was in training he was the most aggressive of flyers. Even when it was apparent he could not handle the task or situation he gave it his all even if it meant a crash landing. Reckless would be a polite way of describing him.
But his mentors and flight instructors promoted this attitude and though he would make great flying material if he got his wings under control.
After his first summer of training he was recruited into the Wonderbolts team. He did everything he could to make the crowds leap and cheer, even if it meant pushing his team mates out of the way. He just loved the attention, loved the squealing fillies, he loved the admiration which provoked him to do more and more daring stunts in each flight.
Before the season was over Storm Thrasher wanted to try a new trick. To collect storm clouds and whip them into a tornado like motion as they sparked lightning. Then he would fly through the eye from the bottom to the top giving it a good kick to send lightning flying like fireworks as he exploded from the top!
His team mates though he was nuts for wanting to try something so ridiculous and dangerous. Frustrated with his team members he went off on his own to do it in the middle of one of their shows. Without the extra support to control the collected clouds and wind - Storm Thrasher nearly had his wings ripped off when he flew inside the clouds trying to disperse them.
His flying career was over. A heavily damaged wing that would no longer allow his acrobatic flying again. Thrasher learned his lesson very hard that day, now he actively avoids the Wonderbolts subject best he can and hates taking praise for his youthful negligence.
Now he works as a weather manager like his father did before him. Thrasher follows out the major storms and does his best to contain them so they don’t accidently harm any pony or their residence. He also works with young pegasus recruits and teaches them how to handle storms. He’s known to be a tough boss but looks out for his ponies.