Tracking through the warm ocean waters of the Bahamas, Hurricane Joaquin exploded in intensity while becoming a dangerous Category 4 storm Thursday. But, at the same time, the forecast track for Joaquin shifted markedly east and it is now very likely the storm will remain out to sea rather than slamming into the East Coast. While Joaquin may remain offshore, parts of the East Coast remain at risk for flooding from a predecessor surge of moisture streaming up the eastern seaboard Friday into Saturday.