Just after 5 p.m., the National Weather Service issued a flash flood warning effective until 9 p.m. tonight in eastern Hillsborough County and until 8 p.m. in much of the rest of New Hampshire.
Doppler radar indicated a band of heavy rain expected to cross through the Manchester to Nashua corridor south to Middlesex County in Massachusetts through 7 p.m.
"The potential exists for rainfall rates of 1 to 2 inches per hour during this timeframe," the warning states. "As a result, there is a threat for flash flooding. The main threat is for rapid urban and poor drainage inundation, though some small streams may experience bank-full levels."
Locations expected to experience flooding include Manchester, Nashua, Merrimack, Hudson, Concord, Goffstown, Milford, Bedford, Pelham, Weare and Litchfield.