Slow-moving storms threaten Maine and New Hampshire with flash floods

A flood watch is in effect for much of Maine and parts of New Hampshire until early June 13: clusters of slow-moving thunderstorms may dump up to 75 mm of rain per hour.

The National Weather Service warns that storm development will support extreme rainfall rates — up to three inches (75 mm) an hour in the heaviest cells.

Because the storms are moving slowly, the same areas may be hit repeatedly, quickly overwhelming small streams, urban drains and low-lying roads. The watch covers the Central Highlands, the North Woods and north-central Maine, as well as northern Oxford, Franklin and Somerset counties.

The watch runs into the night and expires at 3:00 AM on June 13.

Why it is dangerous and what to do