National Weather Service issues coastal flood warning for Eastern Massachusetts tonight, Monday

By Jaclyn Reiss, Globe Correspondent

The National Weather Service in Taunton issued a coastal flood warning tonight for the eastern Massachusetts coast and the northern shore of Cape Cod — a rarity for this time of year, National Weather officials said.

The warning is in effect from Salisbury south to Cape Cod from 10 p.m. tonight through 3 a.m. Monday morning, and again Monday night from 9 p.m. through 5 a.m. Tuesday morning.

There could be minor to moderate flooding tonight, while Monday night may bring moderate to high-end moderate flooding, according to the service’s online announcement.

The combination of a high tide from a full moon and a strong low pressure system off the coast contributed to the rare summertime cautionary message, said National Weather Service meteorologist Hayden Frank.

The warnings are more common in October to April, Frank said.

Frank said the last warning outside the normal season he could recall was in late May 2005.

Frank said the National Weather Service usually issues coastal flood warnings when they are 80 percent or more confident that flooding will occur.

“When we issue something, we are very confident it will happen,” Frank said.

Frank said residents should avoid roads and areas that are typically susceptible to flooding during the warning’s time span.

Flooding is likely to occur along low-lying areas and roads along the shoreline, the online announcement said.

Beach erosion is also likely, as high water levels combine with large breaking waves over multiple tide cycles, according to the online announcement.

Jaclyn Reiss can be reached at jaclyn.reiss@globe.com. Follow her on Twitter at @JaclynReiss.