Wild magic storms. Pure, untamed magic with no discretion on its victims.

Once upon a time, there were no such storms, in fact, the worst that could happen if a spell went haywire, was that it might be a bit misguided, but that was the worst that could occur.

However, during the War of a Thousand Masks, great spell casters began trying to eliminate one another, hoping for arcane supremacy. They were so intent on having power, that they were even resorting to the breaking the ley lines of magic themselves. Later into the war, too many ley lines broke, and unleashed raw chaotic magic into the sky.

This stray magic would later be called wild magic, and would form into the storms of Wild Magic.

Ever since then, they spontaneously forms above random locations, unleashing their destruction, then retreating into the skies and flow of magic, only to wreck their havoc elsewhere.

While it is odd that such a storm happened, it could be that something was tampering with the ley lines again, or worse.