CONCORD, N.H. (AP) – The deluge that’s washing out roads and flooding homes is a historic event, state climatologist David Brown said Monday.

The intense storm has broken all kinds of 48- and 72-hour rainfall records, he said.

An unusual weather pattern is to blame for as much as a foot of rain falling in places. A high pressure system parked in northeastern Canada blocked a low pressure system to New Hampshire’s west, creating a funnel that drew tropical moisture into the region.

Brown said the storm pattern is especially unusual in May. Normally major rain storms hit in October, as one did last year.

“This is comparable to the great New England historical weather events, the 1938 hurricane and the 1936 winter floods,” said Brown.

National Weather Service meteorologist Bill Simpson in Taunton, Mass., said the weather pattern usually only lasts a few hours, not days.

The low pressure system is slowing moving east, pushing out the heavier rain but bringing with it showers over the next few days, Brown said.