A frontal boundary lies across northern New England today. To the north of the front it remains cold and wintry while areas south of the front experience milder temperatures and damp conditions through the weekend. Several waves of low pressure are expected to ripple along the front into Monday bringing periods of showers to the area.
Along with the mild air and showers will be areas of developing fog, which may become quite dense later tonight and early on Sunday. The National Weather Service may issue a Dense Fog Advisory for tonight and tomorrow if conditions warrant.
Saturday will most likely be the drier of the two weekend days. Although there is a chance for an isolated shower most of the day should be dry. However, the shower threat increases tonight and Sunday when periods of showers are most likely after midnight tonight through a good part of the day on Sunday.
The showers continue Sunday night into Monday as another wave of low pressure moves just to our north. Meanwhile, a cold front approaches. The front is forecast to swing through the Pioneer Valley early Monday with the possibility of yet another wave of low pressure forming on the front, which in turn would keep it wet here through the day and into Monday night. Behind the front much colder air begins to overspread the region. Temperatures will actually fall through Monday afternoon with sub freezing temperatures Monday night.
High pressure brings fair and dry weather Tuesday and Christmas Day but with a return to below normal cold as well.
If you are traveling this weekend expect much colder weather through central and northern New England with significant icing through most of northern New England, perhaps as far south as southern New Hampshire Saturday night and early Sunday. If you travel southward it will be much warmer with no threat of wintry weather.
72 Hour Outlook:
Saturday: Mostly cloudy with a chance of a spot shower this afternoon. Mild, high temperatures in the low 50s. Southwest winds 5 to 10 mph.
Tonight: Overcast skies with numerous showers developing. Widespread fog possible. Mild, temperatures only falling into the mid 40s. Light southwest winds.
Sunday and Sunday night: Areas of fog. Numerous showers and mild. Highs in the mid to upper 50s with overnight lows in the upper 40s. Light southwest winds.
Monday: Showers early, becoming less numerous in the afternoon. Areas of fog. Mild, highs in the low 50s but then falling through the 40s during the afternoon.
Monday night: Showers taper off, possibly mixing with snow before ending. Turning colder. Lows in the mid 20s by morning.