DAYS 1-5 (JANUARY 24-28)
An arctic cold front went through our region last night. Some you may have heard the wind gusts in the 35 to 45 MPH range. Some of you may, mainly northwest of Boston, saw a snow shower prior to midnight (I did). If you step outside this morning or any time today you will feel the deep chill of air delivered from far north of our area and it will be accompanied by wind, making it feel even colder during the day today. As the wind relaxes we’ll be in for a frigid night, but high clouds that start to filter the sunshine today will thicken up tonight ahead of an approaching winter storm. This system is a low pressure area elongating and redeveloping to our south, taking a track close to and possibly just north of the 40N/70W “benchmark” Sunday night into Monday, with the remains of the primary low following it up Monday. Result: An extended bout of precipitation, falling as snow across a great majority of the region. Complication: The track of the surface low allows some warmer air to intrude aloft, and as of early this morning a couple of short range models disagree on the degree of warming aloft, and resultant mix with sleet (and even potential change to rain briefly). One brings sleet to the South Coast / Cape Cod, but that’s the extent of it. The other brings the sleet area as far north as about Plymouth and more extensively along the South Coast, and a period of liquid rain to Cape Cod and the Islands. Right now I’m leaning to a compromise between the two solutions, with sleet more than just right on the South Coast, but not quite to Plymouth, and any rain at all being confined to Nantucket for a brief period of time. The other aspect of the storm to consider is a probable coastal front along near the eastern coastline, and where this sets up results in a little snowfall enhancement just to its west and slightly higher water content snow to its east. This may end up as far west as the I-95 belt, but is more likely to run from near Cape Ann to Boston to the MA South Shore or just inland from there, to west of the Cape Cod Canal. I’ll watch for that. During Monday, the passage of the back end of the low pressure area results in a wind shift and colder air anyway. Another wild card is a potential mid level slot of dry air that would cut some of the precipitation off south of I-90 and lessen amounts somewhat. But these areas would see additional snow showers on Monday. Obviously, with not much time to go, there are still some aspects of this short-term forecast to fine-tune. Behind this system comes more cold weather, though not as cold as our current air mass. Fair weather is expected Tuesday and a disturbance may bring a few snow showers to the region on Wednesday.
TODAY: Sun becomes filtered through increasing high clouds. Highs 12-19. Wind WNW 5-15 MPH, higher gusts. Wind chill below 10 at times.
TONIGHT: Increasing clouds. Lows 3-10. Wind N 5-15 MPH, diminishing.
SUNDAY: Overcast. Snow arrives southwest to northeast between mid morning and early afternoon. Temperatures slowly rise to 18-25. Wind N to NE 5-15 MPH except 15-25 MPH Cape Cod by late-day.
SUNDAY NIGHT: Overcast. Snow, heavy at times through midnight, tapering off in intensity overnight. Snow may mix with or change to sleet near the South Coast especially Cape Cod and a slight chance of a period of rain at Nantucket. Temperatures steady 18-25 but can rise to 26-33 South Coast / Cape Cod and potentially as far north as the MA South Shore. Wind NE 15-25 MPH Cape Cod / Islands, NE to N 5-15 MPH elsewhere.
MONDAY: Mostly cloudy. Lingering snow or flurries. Total storm accumulation expectation is 10 to 16 inches, but pockets of 16 to 22 inches are likely, and areas of under 10 inches are possible mainly Cape Cod / Islands, pending the impact of potential sleet (and rain that would be most likely on Nantucket). Temperatures remain generally steady or fall slightly. Wind N to NW 10-20 MPH, a few higher gusts.
MONDAY NIGHT: Partly cloudy. A lingering snow flurry possible. Lows 12-18. Wind NW 10-20 MPH.
TUESDAY: Partly cloudy. Highs 22-29. Wind NW 10-20 MPH.
TUESDAY NIGHT: Partly cloudy. Lows 8-15. Wind NW 5-15 MPH.
WEDNESDAY: Partly sunny. Chance of snow showers. Highs 23-30. Wind W 5-15 MPH.
DAYS 6-10 (JANUARY 29 – FEBRUARY 2)
Watching for the next potential storm in the January 31 to February 2 time frame. Temperatures below normal.
DAYS 11-15 (FEBRUARY 3-7)
Another potential winter weather threat around February 5 in a still active and cold weather pattern.