NEW : Ana formed overnight and was expected to gain strength as it moved west toward the Leeward Islands , where forecasters expect it to hit on Monday . Ana is 40 mph east of Virgin Islands , moving west at 17mph . Puerto Rico , Virgin Islands advised to monitor storm 's progress . Storm has maximum sustained winds of 17mph , hurricane center says .
NEW : Ana is 40 mph east of Virgin Islands , moving west at 17mph . Puerto Rico , Virgin Islands advised to monitor storm 's progress . Storm has maximum sustained winds of 17mph , hurricane center says .