Note that two the storms you're referring to (Iselle and Julio) may have similar predicted paths, but they currently 1000 miles away from each other, and will definitely not merge. Iselle is already impacting Hawaii, while Julio will not approach for several days (assuming the current forecast verifies).
Both FTDNA and Ancestry sponsor groups or projects where people in the same haplogroup can exchange information and maybe even find an ancient connection. But Y-DNA and mtDNA are intended to check ancient bloodlines, 10,000-50,000 or so years ago. They are not generally useful by themselves for genealogy.
Race and ethnicity have no real biological meaning. DNA can tell us all kinds of things. Genetic information can be used to uniquely identify a specific person using just a hair or a few drops of saliva. That data can also tell you if you have certain genetic ailments or are at an increased risk for others. But one of the most common services provided by companies who do consumer DNA testing is an analysis of your ancestry based on your genetics, and there are real problems with that idea, geneticist Manolis Dermitzakis argued in a Reddit AMA question-and-answer session on November 17.