Cumulus Glacibus Avalanche Surge (CUE-muh-lus Glas-EE-bus AH-vah-lanch)
This natural phenomenon is as rare as it is terrific. Beggining high up in the glacier-clad peaks of the Bellever Mountains, this event has only two causes: either a piece of the glacier breaks off (known as calving), or a high volume of powder snow is shed from atop the glacier.
The first scenario, calving, is less likely to result in a full Cumulus Glacibus Avalanche Surge. It would require the glacier, once broken free, to smash up as it tumbled down the mountainside building into an avalanche. The reason this is less likely to create the full phenomenon, is that it is unlikely that this activity would generate the snowclouds required for the thundersnowstorms. It would also require the avalanche to be concentrated into a ravine, so that the volume of ice can reach the River Glanwyn, creating the icefloes.
The second scenario, however, is almost certain to create the exact circumstances required. A large volume of snow shedding from atop the glacier would undoubtedly create plumes of snow-mist that would get swept up in the high winds running down the mountain, forming the Cumulus Glacibus, or ice clouds, that precipate snow and ice, often with thunderstorms. The heavier snow not caught in the winds tumbles down the mountain, often following a path carved by previous glacier calving activity, picking up pace and compacting on itself creating huge chunks of ice. These chunks then roll even faster within the avalanche, making their way into the river where they choke the stream with icefloes: a slush-like blanket of ice in the surface of the river that moves with such force it can destroy most obstacles in it's path. If these floes make their way all the way downstream, they disperse in the ocean, fanning out as individual icebergs on the currents, posing a significant danger to shipping and local wildlife.
Scholars have devoted much time to predicting when these events will occur; the last one to occur resulted in the blocking of the main pass through the mountains, cutting off Tamaria from Aberval. It also led to the destruction of several of the River Folk's barges, scuppered two of the Admirals' Ships, and although the fishing fleet were able to return to port unscathed, the unseasonably cold waters put many fisherman out of business due to the lack of fish in their nets.
The first scenario, calving, is less likely to result in a full Cumulus Glacibus Avalanche Surge. It would require the glacier, once broken free, to smash up as it tumbled down the mountainside building into an avalanche. The reason this is less likely to create the full phenomenon, is that it is unlikely that this activity would generate the snowclouds required for the thundersnowstorms. It would also require the avalanche to be concentrated into a ravine, so that the volume of ice can reach the River Glanwyn, creating the icefloes.
The second scenario, however, is almost certain to create the exact circumstances required. A large volume of snow shedding from atop the glacier would undoubtedly create plumes of snow-mist that would get swept up in the high winds running down the mountain, forming the Cumulus Glacibus, or ice clouds, that precipate snow and ice, often with thunderstorms. The heavier snow not caught in the winds tumbles down the mountain, often following a path carved by previous glacier calving activity, picking up pace and compacting on itself creating huge chunks of ice. These chunks then roll even faster within the avalanche, making their way into the river where they choke the stream with icefloes: a slush-like blanket of ice in the surface of the river that moves with such force it can destroy most obstacles in it's path. If these floes make their way all the way downstream, they disperse in the ocean, fanning out as individual icebergs on the currents, posing a significant danger to shipping and local wildlife.
Scholars have devoted much time to predicting when these events will occur; the last one to occur resulted in the blocking of the main pass through the mountains, cutting off Tamaria from Aberval. It also led to the destruction of several of the River Folk's barges, scuppered two of the Admirals' Ships, and although the fishing fleet were able to return to port unscathed, the unseasonably cold waters put many fisherman out of business due to the lack of fish in their nets.
Type
Natural
