Definition of Extraordinary Sorm
One which is not necessarily an unprecedented one, but one that happens so rarely that it is unusual and not ordinarily to be expected. Oklahoma City v. Evans, 173 Okl. 586, 50 P.2d 234, 238. See also Extraordinary flood.
That's the definition of Extraordinary Sorm in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.