MagicFairyStorm
The name "Fairy Storm" comes from the rare and dangerous magical storms brought about by an abundance of Fairies.
In the valley, magic is usually a constant trickle. But occasionally, for unknown reasons, an area will suddenly swarm with Fairies and receive an abundance of magic.
People who survive Fairy Storms often describe them as nearly blinding from the cumulative glimmers of swarming Fairies.
Fairy Storms vary in intensity but can be extremely dangerous as small natural spells and effects in the area suddenly surge and cause random, often dangerous results.
Enchanted items can shatter under the onslaught of power. Scrolls smolder and turn to ash. Even unenchanted items can develop magical effects, and normal animals can transform into wild magical versions of their former selves.
Natural gems can either develop powerful abilities or be drained of their luster. Mages have been killed when the power overwhelms their minds.
Fairy Storms can last from hours to days to months. Regions have been cut off from the outside world by walls of wild magic.
Fortunately, Fairy Storms are rare for any given place. Most are small and affect only a limited area or even just a single forest clearing.
In most remote towns, Fairy Storms are little more than myth.