"On The Edge Pots
Michael Hilgers offers a modern take on the traditional window flower box with his On The Edge Pots (2006). Designed to straddle the railing of a balcony, the pots are made from water-resistant polyethylene and can rest on any railing with a maximum thickness of 60mm. Two separate compartments offer multiple planting options. The On The Edge Pot is ideally suited for urban dwellers with limited outdoor space, but can easily be used in the workspace or restaurants to liven up a patio. Available in orange, white, green, black and white. Design Within Reach."

Wouldn't trust that in a tropical storm unless a) the pot is very deep and b) I didn't have anything tall in it. Meaning anything more than 1 or 2 times the height of the planter. And the pot would need to have sand or something heavier in it.

My neighbor downstairs is mad about plastic saucers, bottles, etc. that kept being blown off the patio. I think anything that is wide enough to go through the railing could do so in a heavy storm.

I just looked at the DWR site and didn't find this.