User blog comment:WarrenWitch/Operation exterminate Grimm/@comment-3146930-20141020235634

As far as Semblance goes, Glynda is in this weird area where certain information may contradict other information. For example when Pyrrha is describing her Semblance to Weiss and Ruby, she mentions that Weiss' Glyphs are her Semblance. Going back to the fight between Glynda and Cinder, Glynda uses large Glyphs twice (once to defend Ruby and again to attack the airship) and each time storm clouds appear. However only after shooting a purple light the second time do the clouds start raining hail. Anyway going by this I would say that her Semblance is making storm clouds that she can manipulate with Dust (making it rain water, ice, lightning, or maybe even fire).

As far as her moving stuff, I originally thought that the debris she was controlling was maybe Dust that could manipulate earth, using the small fragments of rock in the debris. However this was disproved when she fixed the cafeteria. Another idea is that there is a certain combination of Dust that allows her to move objects. I mean if Weiss has time-Dust in her weapon, I'm sure Glynda can make movement-Dust.