See this M.Y. question regarding the brachot to say on witnessing a hurricane.
Upon seeing/feeling uncommonly strong winds (a hurricane would qualify), on feeling an earthquake, lightning, or thunder, the Shulchan Aruch says to say Oseh Ma'aseh vereshit, and "if you want" Shekocho u'gvurato malei olam. (OC 227) The nosei kelim there say that the custom is to say Oseh Ma'aseh vereshit on lightning, and Shekocho u'gvurato malei olam on thunder
So, the same bracha or possibly both brachot that are said for the hurricane winds are also said for lightning and thunder. A hurricane includes winds and frequently lightning and thunder. If one has said the barchot on the wind, does this exempt saying the brachot when seeing the lightning and hearing the thunder?
How often should one say these brachot? Every hurricane has an eye, which is an area of clear skies (usually) and calm winds in the center of the storm. This M.Y. answer says that if the sky clears, and then clouds return, one should make a new bracha.
However, this M.Y. answer proposes that it may not apply if it's the same storm. The answer is vague, b/c O.C. only says "if the sky clears." If the eye passes over your area, should you make a new set of brachot when the thunder & lightning and wind return? Is it considered a "new" storm, in terms of halacha?