A weak wave of low pressure will pass near Cape Cod early this afternoon then travel out to sea taking with it a shield of showers and mist. Damp weather will continue through midday with any leftover spotty mist ending this afternoon. Murky, dismal conditions will linger until a cold frontal passage takes place in the early morning hours. Temperatures will only creep up to the lower 40s over the hills of north central MA to the middle 40s closer to Boston to the upper 40s just south of the city to the lower 50s on Cape Cod. There will be little or no wind all day. There is no danger of any icing during the day but there might be a few slick spots well north and west of Boston later tonight as temperatures decline to 35-40. With the arrival of drier air tomorrow, the sky should feature breaking and decreasing clouds yielding at least some sunshine. Thus, temperatures may flirt with 50 which is about a half-dozen degrees above the average for December 9.
Rain returns later tomorrow night ahead of an approaching warm front. The wet weather should continue through the Monday morning commute with only scattered showers probable after the warm frontal passage. The warm air has a high chance of penetrating across all of southeastern MA up into the Boston area. The chance decreases the farther north and west of Boston you are as the front loses momentum draped over north central MA into southeastern NH. Consequently, it may only rise into the 40s to near 50 there while the Boston area southward potentially warms to 60-64 via a brisk south-southwesterly wind. Expect a ribbon of dense fog near and north of the warm frontal boundary migrating northward with the front during the day on Monday. There is a slight chance of a few breaks of sunshine in the warm sector but it is more likely that additional showers will be breaking out especially as a cold front pushes in from the west. Presently, it appears that showers are likely during the Patriots/Texans Game at Gillette Stadium Monday evening. It should start out mild with middle 50s but a wind shift to north-northwesterly is possible later in the game as the cold front passes. That means it will cool into the upper 40s by 11pm-midnight.
Looking ahead, a weak impulse may introduce a period of light rain starting around midday and ending early in the evening on Tuesday. The air may become sufficiently cold to produce a mixing with or change to wet snow especially west of the I-95 corridor between Providence and Boston. Once this system exits, a ridge of high pressure will build into the Northeast providing ample sunshine Wednesday through Friday. Seasonal high temperatures in the lower 40s are projected for those days. Fortunately, there will be no storms on those three days when the scheduled height of the high tides will be near or over 12 feet due to the New Moon.
The week before Christmas may be active with 2 or 3 storm threats. As time draws closer, we’ll have to see if any of these will create a White Christmas for the region.
I will return later in the day and publish a fresh blog if new data warrants any change.
Have a happy and safe weekend.