This evening, expect a very cold night away from the coast, with isolated ocean effect snow showers or flurries likely throughout Cape Cod and the Islands.
Mainly dry weather is predicted Monday through Tuesday, while a coastal low-pressure system moving far to our south may bring isolated showers and thunderstorms south and east of Interstate 95 on Wednesday and Thursday.
Afterward, the dry weather resumes until Christmas Eve. A warm front may bring with it a stretch of wintry weather, which might culminate in the rain on Christmas Day.
A few light snow/rain showers are expected to persist over the Outer Cape as the low-pressure system that brought the wintry mix continues to move away from the region.
A strong northwest flow across the Appalachian Mountains has resulted in an impressive line of gravity waves stretching from West Virginia to Maine on visible satellite images.
Highs in the 30s have been recorded this afternoon, courtesy of severe cold advection and 925Mb temperatures between -6 and -10 degrees Celsius.
Though cloud cover has continued throughout the day, there are growing indications of clearing, and the clearing trend is expected to continue through this evening, coupled with a decrease in wind speed.
Cold advection will be little affected by the shift in the flow direction to the north. As a result of clearing sky and moderate breezes, we were confident enough to drop evening lows to approximately the 10th percentile.
On Monday, a ridge of high pressure will provide plenty of sunlight to the region.
As the winds move to the west and southwest, we anticipate the ocean effect clouds formed throughout Cape Cod and the Islands to dissipate.
While the temperature in the upper atmosphere warms up to roughly -28 degrees Fahrenheit by late afternoon, the combination of a cold start, minimal mixing, and a low December solar angle will maintain daytime temperatures mainly in the 30s or around 5 degrees below climatological normal.
On the other hand, Cape Cod and the Islands should experience temperatures in the low 40s. Because the winds will be mild, it will feel far more pleasant than it did on Sunday afternoon.