Surging Squall is a Weapon Art of Verdant Tempest Bow in Derelict.
"Unleash a volley of 12 wind arrows in an area, dealing 70% Power as Arcane damage. Each hit grants a stack of Rising Tempest."
Acquisition
Surging Squall is a weapon art of Verdant Tempest Bow which is obtained as a drop by Vorraeth, The Hollow Gale
Tips
Use Umbral Grasp to grab the enemy in one place before using the spell on them (only works with players and normal mobs), for bosses, use surging squall when their stance is broken or they're stunned in one place after an attack.