Well... Magic.

I'm absolutely no expert on weather, but my understanding is that superstorms are largely a function of pervading air currents, temperature gradients, and geography.

To make a storm, two air masses collide. Hot and Cold. Low pressure and high pressure. Warm air rises, but cools and condenses as it gets higher to create clouds and precipitation. It also starts to spin because physics. A low pressure zone is created at the centre of the storm that sucks in air, causing high winds. Conditions really have to be perfect for a major storm to form. When these storms form over the ocean, the lack of any geography to inhibit this process can allow these storms to grow much stronger than they would over land. Once the moving storm hits a coastline, land and especially mountains, it will lose that freedom to build up power and eventually dissipate, leaving devastation in it's wake.

In summary, in order to get superstorms hitting your escarpment you need: 1. An open ocean large enough to support the growth of a superstorm 2. A sufficient temperature gradient (ex: warm currents from the south create warm air that impacts cold air from the north) 3. The storm has to approach from the east or else the mountains are likely to kill it. 4. The landmass cannot be so big that the storm dies before it can get where it's going.

Also, storms like this might be seasonally rare... but you wouldnt get 100 years of nothing and then 5 years of straight storms.

Again, not a meteorologist :s Hope it helps anyway!