Time to dig out your rain gear... heavy rain takes over Friday. Umbrellas may not be a good idea since the wind will be strong too. We're also tracking coastal flooding and urban flooding in this storm.
Soaking rain moves in by daybreak Friday and the wind will increase from the south, southeast. A batch of heavy rain moves through in the morning, showers become more scattered in the afternoon, then another round of soaking rain and some embedded thunderstorms make their way across Massachusetts. Some of the storms could be severe with damaging wind gusts. There is also a small chance for a brief, spin-up tornado or waterspout along the south coast of Massachusetts, Cape Cod, and the islands Friday afternoon.
Widespread 1-3 inches of rain is likely. We have flood watches posted for all of New England through Saturday morning for urban and small stream flooding. River flooding through the weekend is also a possibility with the already saturated ground.
Damaging wind gusts will occur Friday night. Strong winds from the south, southeast steadily increase tonight through Friday morning. Afternoon and evening gusts approach the 60 mph mark across coastal Plymouth County, Cape Cod, and the islands. Isolated wind damage and power outages may occur.
Tides are astronomically high due to the full moon this weekend. Because of the south, southeast wind the wave heights increase to 10-20 feet. Add around a 2-foot storm surge on top of the high tides, and we expect minor flooding on the south-facing beaches Friday morning, possibly Friday night. Boston, in particular, may see some splash over and very minor flooding in typical low-lying areas during Saturday morning’s high tide.
The system tapers off Saturday morning/afternoon. A secondary front may help trigger a wintry mix or light snow across high terrain in northern New England Saturday afternoon. It will be dry on Sunday with sunshine and temperatures in the 30s. There will be more 30s for much of next week.
A weak system may bring a wintry mix in for Christmas Eve. It will be dry for Christmas Day.
Another system on Thursday into Friday could give us another round of rain across southern New England with a mix north. The last weekend of 2018 is looking dry for now with highs in the 30s.