Yep, you are right, Stormraider is pretty weak, I changed it out.

Stormraider's Surge isn't very viable on Fiora. Stormraider's Surge requires too much damage to be dished out in 2 seconds for it to be the best option for a champ that isn't really bursty. Fiora also has plenty of way to slow and catch enemies with her moves and possible build. Also, it's bad for chasing itself because there is a high chance you can be going after one target in a group and get cutoff from your teammates. I just truly believe you're better off building items that slow and using your E, so your team reach the enemy champ easier, instead of investing into a tree that is subpar for Fiora and getting a less than satisfactory result. Along with that, you should be investing into the Resolve Tree. Fiora benefits very much from the Resolve tree with it's health regen boost and bonus armor masteries. Since you typically build at least 2 items that boost defenses, the bonus is awesome. The regen works perfectly with your ult and Stormraider's Surge should be overlooked since with your ult you got speed, with your items you got slows, and with your mastery you get enhanced healing from ult; so Resolve is definitely the way to go. Now onto the Ferocity masteries. Fervor may seem useless, but in actuality it's great for melee laners since it allows stronger pokes which Fiora is the master of and More AA damage in general which Fiora only does. Also, if you're doing enough damage to proc Stormraider's with Fiora, you don't need Stormraider's.