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.
A DNA test will indicate where one of your very, very distant ancestors came from, 10,000 years ago or more. Just search on DNA tests for more help. If you want to know where your great great grandparents came from, you will have to do the research.owever, DNA test will not tell you who you ancestors are. So whether it is worth it depends on you. SMGF use to do Y & Mitochondrial for free but would not give you any analysis. They at one time contracted with GeneTree to do the analysis for about $20 which is extremely reasonable.