7:54AM

DAYS 1-5 (JANUARY 3-7)
A “Scandinavian Heatwave” hits today as the temperatures reach the middle to upper 20s. This will end Boston’s record-tying streak of days below 20 that belongs to this year, and 100 years ago. As we are enjoying are balmy respite, a storm will be brewing down the coast. The track of this storm has presented a forecasting headache for many, but after riding a veritable roller coaster of information and speculation, it comes down to an update in which I’m not going to make a whole lot of changes to the forecast issued on the last blog. Significant snow will occur Thursday for much of the region, though it is not likely to be of epic proportion anywhere, just a solid snowfall, except starting as rain east of a line from near Plymouth MA to Newport RI including all of Cape Cod before changing to snow during the course of the storm. Based on the current expected track I’m expecting the following…
Snow accumulation: 8-12 inches in a wide swath from eastern CT and western RI to Worcester to Metro West of Boston to southeastern NH but with pockets of 12-16 inches possible favoring interior eastern MA mainly to the southwest of Boston and possibly along the North Shore communities, 4-8 inches of fluffy snow to the west of this area, and 4-8 inches of wetter snow to the east of this area lowering to 2-4 inches Outer Cape Cod and Nantucket as these areas start as rain first.
Visibility: Blizzard conditions are likely especially along the coast from near Boston and its immediate southern suburbs northward to the North Shore of MA and NH Seacoast, extending down through the South Shore and eventually Cape Cod after rain changes to snow – blizzard conditions are defined as very low visibility due to falling and/or blowing snow with winds sustained or frequently gusting to 35 MPH or greater.
Wind: Gusts as high as 45 MPH inland, 55 MPH coast, and 65 MPH or greater Cape Cod (see detailed forecast for more).
Coastal impact: Moderate to significant flooding likely especially at the time of high tide, especially northeast and north facing shores. Also, ice shoves are possible where ice has formed along the shore due to persistent very cold.
Timing of storm: Snow (rain Cape) arrives between 4AM and 7AM from south to north, peaks early to mid afternoon, ends early evening.
After the storm comes a blast of arctic air equal to or more intense than the one just-departed for Friday and Saturday.
Other notes: There could be a few surprises including a track wobble, dry slots, and synoptic bands of heavier snow, so please check the comments below and the Facebook page if you have access to it for updates.
Forecast details…
TODAY: Mostly sunny. Highs 22-29. Wind S under 10 MPH becoming variable.
TONIGHT: Increasing clouds. Snow developing south to north 4AM through dawn except rain much of southeastern MA and southeastern RI. Temperatures remain stead interior but rise to 30-37 coast with warmest Cape Cod. Wind variable under 10 MPH becoming N.
THURSDAY: Overcast. Snow except rain changing to snow far southeastern areas. Snow will be heavy at times in bands. See above for details of snow accumulation and other storm impacts. Highs 25-37, mildest Cape Cod, in the morning, with slowly falling temperatures during the afternoon. Wind N increasing to 15-30 MPH interior and 25-40 MPH coast with higher gusts (see above for peak expected gusts).
THURSDAY NIGHT: Snow ending south to north evening. Clearing overnight. Temperatures fall to 15-22. Wind N to NW 25-35 MPH, higher gusts. Blowing and drifting snow where dry snow fell and a flash freeze where wetter snow fell.
FRIDAY: Mostly sunny. Temperatures fall to 5-12. Wind NW 25-35 MPH, higher gusts. Wind chill falling well below 0 at times. Blowing and drifting snow where dry snow fell.
SATURDAY: Partly cloudy. Isolated snow showers. Lows -5 to +5. Highs 5-15.
SUNDAY: Mostly sunny. Lows -15 to 0. Highs 10-20.

DAYS 6-10 (JANUARY 8-12)
Potential unsettled weather (snow/mix) at the start and end of this period. Fair in between. Temperatures below normal overall but variable.

DAYS 11-15 (JANUARY 13-17)
Potential unsettled weather early in the period (favoring snow but possible mix). Variable temperatures remaining below normal overall.

7:37AM

DAYS 1-5 (JANUARY 2-6)
Arctic cold hangs on today and moderates at midweek, but during this time a very large ocean storm will pass southeast of New England. It’s large enough that even though it may not pass across the “prime region” for a big hit, it will still likely bring significant snowfall. Warm enough air may be blown from over the ocean onto Cape Cod for a change to rain there. Following the storm will be another shot of pure arctic air, perhaps the coldest of the series.
TODAY: Mostly sunny. Highs 12-19. Wind W 5-15 MPH.
TONIGHT: Mostly clear. Lows -3 to +8, coldest interior valleys. Wind light W.
WEDNESDAY: Mostly sunny. Highs 22-29. Wind W 5-15 MPH.
WEDNESDAY NIGHT: Increasing clouds. Lows 12-19. Wind light N.
THURSDAY: Cloudy with snow likely except changing to rain outer Cape Cod and Nantucket. Minor to moderate coastal flooding and ice shoves possible near high tide times, especially north-facing shorelines. Snow accumulation of 5 to 9 inches Boston through South Shore southwestward to most of RI, 3-5 inches in a 25-mile strip either side of this, with a fluffy 1-3 inches to the far west and north and a wetter 1-3 inches Cape Cod before a period of rain. Highs ranging from near 20 far north and west of Boston to near 40 Cape Cod. Wind NE to N 15-35 MPH with gusts 25-55 MPH, strongest along the coast.
FRIDAY: Mostly sunny. Windy. Lows 0-10. Highs 10-20.
SATURDAY: Partly cloudy. Chance of snow showers. Lows -10 to 0. Highs 0-10.

DAYS 6-10 (JANUARY 7-11)
Dry, extreme cold January 7. Chance of snow January 8. Clearing/windy/cold January 9. Fair and cold January 10-11 but not as frigid as recent outbreaks.

DAYS 11-15 (JANUARY 12-16)
Another storm threat during the early to middle portion of this period. Temperatures generally below normal.

7:34AM

Happy New Year to all!

DAYS 1-5 (JANUARY 1-5)
Arctic cold that arrived as 2017 wound down remains in place as 2018 begins. It will ease up slightly by midweek and at this time a large and powerful ocean storm will develop to the south of New England. Current indications are that it will track too far east for a direct hit, but may bring a moderate snowfall and a lot of wind to Cape Cod, and a glancing blow to the remainder of southeastern New England. Will continue to watch. A reinforcement of Arctic air arrives at the end of the week. Forecast details…
TODAY: Mostly sunny. Highs 7-14. Wind NW 5-15 MPH, higher gusts. Wind chill below 0 at times.
TONIGHT: Partly cloudy. Lows -6 to -1 interior valleys, 0-6 elsewhere. Wind NW 5-15 MPH, higher gusts. Wind chill around -10 at times.
TUESDAY: Partly cloudy. Highs 12-19. Wind W 5-15 MPH.
TUESDAY NIGHT: Mostly clear. Lows -3 to +8, coldest interior valleys. Wind light W.
WEDNESDAY: Mostly sunny. Highs 22-29. Wind W 5-15 MPH.
THURSDAY: Mostly cloudy. Snow likely east, slight chance of snow west, ending late. Lows in the 10s. Highs in the 20s.
FRIDAY: Mostly sunny. Windy. Lows in the 0s. Highs in the 10s.

DAYS 6-10 (JANUARY 6-10)
Risk of snow showers early in the weekend then fair and extremely cold. A risk of snow/mix with moderating temperatures January 8 followed by colder and drier again later in the period.

DAYS 11-15 (JANUARY 11-15)
Another storm threat during the middle of this period. Temperatures generally below normal.