2fc7bb06_UO_Player_Guide___Spellweaving__Effect
[Spell] Thunderstorm Erelonia [Secs] 1.5 [Mana] 32 [Skill] 10 [Effect] 
Performs an area energy attack surrounding the caster. If one of the targets is casting a spell and disrupted by the thunderstorm, they will receive a faster cast recovery penalty of one second (resistable), plus additional seconds if the caster has an arcane focus. The FCR penalty lasts for a few seconds. The penalty does not change the FCR cap; if you wear enough FCR you will be unaffected by this spell.
ABCUO Player Guide - Spellweaving
Effect