30-year Storm of the Bulhenian Mountains

There is a prophecy that every 30 years there is a Mammoth storm rolling out of the Bulhenian Mountains which circulates around the world with such regularity that calendars all over the northern half of Exflora record its regular arrivals.
The storm emanates from the highest reaches of the Bulhenian Mountains in the land controlled by the nation of Socotra. It first begins as a high mountain storm stopping any activity in the mountain peaks and forcing everyone into a shelter. After a few days, it descends below the mountain tops and circulates repeatedly in the upper third of the mountain range building up over a week or so. It seems to pull the winds across the mountain ranges from Seling Tso and Namana, feeding the tops of the storm and allowing it to grow.
After about a week it has grown to about 10 times its initial strength and then begins its rout travelling North East along the Bulhenian Mountains towards the ocean eventually crossing the Heptanomis Ocean and battering the continents of The Continent of Romalia and The Continent of Stabatia until it crosses the Lydia Ocean and eventually returning to The Continent of Zerebim where it returns to the same mountain peaks where it bagan roughly 2 or 3 months earlier.
What is unknown to the populations of Exflora is that the storm is derived from Magic. It is generated by the "Order of the Storm" which has a ceremony every 30 years and as part of the procedures is creating this superstorm and then unleashing upon the world.
The true purpose of the storm is only known to the members of the Order of the Storm and they guard the knowledge behind their tradition. However, it is believed that the purpose is to retrieve any errand magic that may have escaped from The Continent of Zerebim. It is uncertain how the storm would collect this magic as it passes over the non-magical lands however ever without the magical part of the story the storm brings death and destruction on a large scale. This thankfully is greatly mitigated due to the high predictability of its arrival and the ability of the population to shelter in place knowing it is expected to arrive on a certain date.