7:21AM

DAYS 1-5 (DECEMBER 30-JANUARY 3)
A messy low pressure area will bother the region for the last couple days of 2019 like annoying relatives that overstayed their visit… However, this could have been a worse situation, with air just mild enough to limit the amount of sleet and freezing rain. Today will be the worst of it, and still some significant icing will occur but mainly over interior areas from central MA into southern NH. A secondary low that formed just southwest of the region will come up and across far southeastern New England early Tuesday before accelerating away via the Gulf of Maine, a little more quickly than previously thought, and the original parent low, or what’s left of it, will pass north of the region Tuesday evening, dragging a trough of low pressure through. So we’ll get rid of the rain/ice part of the storm tonight and early Tuesday, then we may just see a few passing snow showers for New Year’s Eve. A westerly flow behind all of this greets 2020 with a decent day Wednesday, and then high pressure will build in for a nice Thursday, before another low moving into the Great Lakes sends clouds in during Friday and eventually a light rain threat as warm front approaches.
Forecast details…
TODAY: Overcast. Rain with pockets of sleet and freezing rain. Most vulnerable areas for icing interior MA (mainly Worcester County) and interior southern NH. Highs 30-37, coldest Worcester County MA an southwestern NH. Wind E to NE 5-15 MPH.
TONIGHT: Overcast. Rain but pockets of freezing rain and sleet still possible early interior northern MA and southern NH. Temperatures rising slowly to 35-40 interior and 40-45 coast. Wind E 10-20 MPH, strongest coast with higher gusts.
TUESDAY: Cloudy with lingering rain/drizzle early, then mostly cloudy with intervals of sun possible. Highs 40-47. Wind variable 5-15 MPH morning, W 10-20 MPH afternoon.
TUESDAY NIGHT (NEW YEAR’S EVE): Variably cloudy. Isolated to scattered snow showers. Lows 28-35. Wind W 5-15 MPH.
WEDNESDAY (NEW YEAR’S DAY): Partly sunny. Highs 38-45. Wind W 5-15 MPH, higher gusts.
WEDNESDAY NIGHT: Mostly clear. Lows 22-29. Wind NW under 10 MPH.
THURSDAY: Mostly sunny. Highs 36-43. Wind light variable.
THURSDAY NIGHT: Partly cloudy. Lows 25-32. Wind light variable.
FRIDAY: Mostly cloudy. Chance of light rain late. Highs 40-47. Wind SE up to 10 MPH.

DAYS 6-10 (JANUARY 4-8)
Trending colder. Rain showers early January 4. Risk of snow or snow showers may increase later in the period.

DAYS 11-15 (JANUARY 9-13)
Cold, mainly dry to start, then moderating temperatures and more unsettled weather later in the period.

7:26AM

DAYS 1-5 (DECEMBER 29-JANUARY 2)
High pressure slides offshore today and clouds advance ahead of a complex low pressure system, the initial center of which heads into the Great Lakes but redevelops along its occluding frontal system to pass over southeastern New England sometime Tuesday. This scenario, with marginal cold air, means a messy storm system to wrap up 2019. A link in the first comment to my colleague’s special blog on this system will provide some graphs / maps to show details of the storm’s impact on this area. Snow will be a minor component, with minor accumulation at the start late tonight over northeastern MA and southern NH. The big question is sleet vs. freezing rain. There may be a long period of sleet just in from the coast over much of eastern and central MA northward, and a shorter period of sleet before going to freezing rain to the south. During the heart of the storm, it is the lower elevations of interior eastern MA northward that may see the longest period of sleet due to the depth of the cold air at the surface while it warms aloft, and higher elevations which may see more freezing rain due to a shallower cold air layer between the ground there and the warmth above. Toward the South Coast, we should see mostly plain rain out of this, although for a time some borderline temperatures may mean pockets of sleet and freezing rain there as well. Eventually the warmer air gets into surface areas to transition everyone to rain as the system gets set to taper off Tuesday, and then it all moves out New Year’s Eve. The first 2 days of 2020, in contrast, look much nicer as high pressure moves in.
Forecast details…
TODAY: Increasing clouds. Highs 38-45. Wind SE up to 10 MPH.
TONIGHT: Thickening overcast. Precipitation arriving west to east as snow and/or sleet southern NH and the MA border, sleet & some freezing most other areas except rain immediate South Coast. Lows 28-35. Wind E 5-15 MPH.
MONDAY: Overcast. Sleet and freezing rain likely interior areas with rain coast. Highs 30-35 interior, 35-40 coast. Wind E to NE 5-15 MPH.
MONDAY NIGHT: Overcast. Rain but pockets of freezing rain and sleet still possible early interior northern MA and southern NH. Temperatures rising slowly to 35-40 interior and 40-45 coast. Wind E 10-20 MPH, strongest coast with higher gusts.
TUESDAY: Cloudy. Rain morning, ending afternoon but with areas of fog forming. Highs 38-45. Wind NE to N 5-15 MPH.
TUESDAY NIGHT (NEW YEAR’S EVE): Mostly cloudy. Areas of fog. Lows 32-39. Wind W under 10 MPH.
WEDNESDAY (NEW YEAR’S DAY): Mostly sunny. Highs 40-47. Wind W 5-15 MPH.
WEDNESDAY NIGHT: Mostly clear. Lows 22-29. Wind light variable.
THURSDAY: Mostly sunny. Highs 38-45. Wind light variable.

DAYS 6-10 (JANUARY 3-7)
Minor precipitation event early January 3 (rain showers favored) as a disturbance passes. Colder air follows and another low pressure system threatens with mix/snow around January 5, though this is low confidence. It may turn colder still behind this with dry weather returning.

DAYS 11-15 (JANUARY 8-12)
Cold, mainly dry to start, then a warm up and may end the period with a storm system favoring mix to rain over any snow.

10:29AM

DAYS 1-5 (DECEMBER 28-JANUARY 1)
High pressure moves over the region today and slides offshore Sunday when clouds will arrive ahead of an approaching low pressure system, but we’ll have a very nice last weekend of 2019 before all of that. The main focus for a sprawling low pressure area affecting the region will be precipitation type, mainly rain vs. freezing rain vs. sleet. The synoptics of the situation will be a broad low pressure area moving into the Great Lakes but not being allowed to race into Canada thanks to blocking high pressure there, so as we have seen many times in that general set-up, we get an occlusion of the fronts and low pressure redevelops along the point where they meet and the actual center(s) of low pressure end up passing over or just south of the region. This process will take place Monday through Tuesday, with the ultimate result being a new low pressure area moving right across southeastern New England on Tuesday. As the initial shield of precipitation slides in, the expectation is that it will be cold enough to support a brief period of snow in southern NH and perhaps northeastern MA (though borderline there), and too warm aloft for snow anywhere else. But then the focus for where precipitation will be falling toward the ground as rain will be the temperature profile of the lower atmosphere. For a good portion of northern MA it may be cold enough in enough of the atmosphere to support sleet (ice pellets) for a while, and colder air more concentrated nearer ground level would mean freezing rain (glaze) for areas to the south – probably southern MA away from the coastline and northern RI to northeastern CT. Closer to the coast milder surface temperatures probably mean just rain there. Most of this would take place during Monday morning and midday. With time, the atmosphere should warm sufficiently to turn most of this to regular rain, although interior locations may still see pockets of sleet and freezing rain well into the day Monday, maybe even to the evening. During the overnight hours into early Tuesday, the track of low pressure should be close enough to transport enough milder air into the lower atmosphere for the entire WHW forecast area to see rain, before it tapers off as low pressure finally exits via the Gulf of Maine by New Year’s Eve. This should at least allow some improvement for that evening’s activities, although we may be left with some fog behind it all. So there is your nice weekend then messy finish to the year. What about the first day of 2020? Looking great as high pressure returns to the region!
Forecast details…
TODAY: Mostly sunny. Highs 42-49. Wind NW 5-15 MPH.
TONIGHT: Mostly clear. Lows 30-37. Wind light variable.
SUNDAY: Increasing clouds. Highs 38-45. Wind SE up to 10 MPH.
SUNDAY NIGHT: Thickening overcast. Precipitation arriving west to east as snow and/or sleet southern NH and the MA border, sleet & freezing rain much of northern MA, freezing rain to the south except rain South Coast. Lows 30-37. Wind E 5-15 MPH.
MONDAY: Overcast. Sleet and freezing rain likely interior areas with rain coast. Highs 30-35 interior, 35-40 coast. Wind E to NE 5-15 MPH.
MONDAY NIGHT: Overcast. Rain but pockets of freezing rain and sleet still possible early interior northern MA and southern NH. Temperatures rising slowly to 35-40 interior and 40-45 coast. Wind E 10-20 MPH, strongest coast with higher gusts.
TUESDAY: Cloudy. Rain morning, ending afternoon but with areas of fog forming. Highs 38-45. Wind NE to N 5-15 MPH.
TUESDAY NIGHT (NEW YEAR’S EVE): Mostly cloudy. Areas of fog. Lows 32-39. Wind W under 10 MPH.
WEDNESDAY (NEW YEAR’S DAY): Mostly sunny. Highs 40-47. Wind W 5-15 MPH.

DAYS 6-10 (JANUARY 2-6)
Split jet stream flow, polar near and north of the US/Canada border, subtropical mainly south of New England, and timing energy moving along each stream and any potential interaction will be difficult at best until we are much closer to any possible events, so the easiest way to sum up the first 5 days of 2020 is that we will have to watch 1 or 2 low pressure systems that may impact the region with some precipitation, but that we will also have a fair amount of dry weather as well, with temperature fluctuation.

DAYS 11-15 (JANUARY 7-11)
Cold, mainly dry to start, then a warm up and may end the period with a storm system favoring mix to rain over any snow.

7:37AM

DAYS 1-5 (DECEMBER 27-31)
Down the home stretch and to the finish line of 2019 the next 5 days, and we’ll have some active weather to follow after a quiet period. First, we have a warm front crossing the region this morning and producing spotty light rain, which is freezing on contact with untreated surfaces in portions of north central to northeastern MA and southern NH as temperatures sit at to slightly below 32 to start out the day. Use caution if traveling in these areas early this morning. The issue will quickly disappear by mid morning as the front goes by and temperatures go up, and just a few rain showers will cross the region during this afternoon as a cold front approaches from the northwest. This front goes through and clears the region out tonight and high pressure builds in with a very nice late December day on Saturday. High pressure shifts offshore Sunday, still not a bad day but clouds will be on the increase ahead of an approaching low pressure area which initially moves into the Great Lakes, but comes to a halt due to a high pressure road block in eastern Canada. This forces a redevelopment of the system along its occluding frontal system, which will take place over or just south of southern New England Monday through Tuesday, finishing off 2019 on an unsettled note. There will be enough cold air around for some possible freezing and frozen precipitation, favoring southern NH and northern MA, although at days 4 and 5 the details of this are rather uncertain. Also somewhat uncertain is if the precipitation will move out earlier or later on New Year’s Eve, which will impact travel and event plans for the final evening of the year. Forecast details…
TODAY: Mostly cloudy. Patchy light rain early morning with some freezing rain northern Worcester County through Merrimack Valley and southern NH. Isolated to scattered rain showers afternoon. Highs 44-51. Wind SW 5-15 MPH.
TONIGHT: Clearing. Lows 20-27. Wind SW 5-15 MPH shifting to NW.
SATURDAY: Sunny. Highs 42-49. Wind NW 5-15 MPH.
SATURDAY NIGHT: Mostly clear. Lows 30-37. Wind light variable.
SUNDAY: Increasing clouds. Highs 37-44. Wind SE up to 10 MPH.
SUNDAY NIGHT: Thickening overcast. Precipitation arriving west to east – mainly dry but possible snow/ice northern areas. Lows 32-40. Wind E 5-15 MPH.
MONDAY: Overcast with periods of rain, except some snow/ice possible portions of northern MA and southern NH. Highs 33-38 north, 38-43 south. Wind E to NE 5-15 MPH, higher gusts.
MONDAY NIGHT: Overcast with periods of rain except some snow/ice possible north. Lows 30-35 north, 35-40 south. Wind NE to N 5-15 MPH, higher gusts.
TUESDAY (NEW YEAR’S EVE): Mostly cloudy. Additional precipitation possible, favoring the morning. Temperatures steady in the 30s. Wind N 5-15 MPH, higher gusts.

DAYS 6-10 (JANUARY 1-5)
Split jet stream flow, polar near and north of the US/Canada border, subtropical mainly south of New England, and timing energy moving along each stream and any potential interaction will be difficult at best until we are much closer to any possible events, so the easiest way to sum up the first 5 days of 2020 is that we will have to watch 1 or 2 low pressure systems that may impact the region with some precipitation, but that we will also have a fair amount of dry weather as well, with temperature fluctuation. Early call is that potential low pressure systems time for January 2 and 4.

DAYS 11-15 (JANUARY 6-10)
Still with lower than average confidence leaning toward a colder and mostly dry theme due to domination by the polar jet stream and suppression of the southern jet stream.

7:22AM

DAYS 1-5 (DECEMBER 26-30)
A warm front approaches today with some cloudiness at times, though high pressure to the northeast of the region supplies enough dry air to hold the thickest clouds at bay and allow for some sunshine as well. This warm front will cross the region early Friday and may produce an episode of freezing rain and sleet in northern MA and southern NH, so there could be some locally slippery travel for the Friday morning rush. Behind this it turns a little milder and only a few rain showers are expected behind the warm front and ahead of a cold front, which will pass through Friday evening, followed by an area of high pressure and fair weather for Saturday. And then we get a more important storm system to impact the region later Sunday through Monday. The track of the parent low will be into the Great Lakes, but a bit of a block in the atmosphere will likely force the energy more eastward and a frontal boundary will push into but never really through southern New England, likely becoming a running board for the development of new low pressure, which never really gets going until its offshore, but a system that will largely produce rain may end as some freezing and/or frozen precipitation for parts of the region sometime on Monday, depending on the speed of evolution and exact track, the details of which still need to be ironed out over the next few days.
Forecast details…
TODAY: Partly sunny. Highs 37-44. Wind light variable.
TONIGHT: Mostly cloudy. Lows 25-32. Wind light variable.
FRIDAY: Mostly cloudy. Brief freezing rain/sleet (maybe even snow mix) possible southern NH and northern MA morning. Isolated to scattered rain showers afternoon. Highs 40-47. Wind SW 5-15 MPH.
FRIDAY NIGHT: Clearing. Lows 20-27. Wind SW 5-15 MPH shifting to NW.
SATURDAY: Sunny. Highs 42-49. Wind NW 5-15 MPH.
SATURDAY NIGHT: Mostly clear. Lows 30-37. Wind light variable.
SUNDAY: Increasing clouds. Chance of rain by late-day. Highs 37-44. Wind SE up to 10 MPH.
SUNDAY NIGHT: Overcast. Rain likely. Lows 35-42. Wind SE to E up to 10 MPH.
MONDAY: Overcast. Rain likely, may mix with or turn to ice/snow especially northern areas later in the day. Highs 38-45. Wind E to N 5-15 MPH, higher gusts.

DAYS 6-10 (DECEMBER 31-JANUARY 4)
There is a little lower than average confidence in this forecast, but the current idea is that low pressure departs December 31 leaving colder air and a few snow showers behind, and that the northern and southern jet streams stay separated with another southern jet stream system passing south of the region late January 1 or January 2 and a northern stream system just bringing a few snow showers and additional cold air. This is a slightly different scenario than the one I described on yesterday’s update. Bottom line: It may change again so don’t put too much stock in it at this point.

DAYS 11-15 (JANUARY 5-9)
Overall theme, cold and dry, due to domination by the polar jet stream and suppression of the southern jet stream. Again, not a high confidence outlook.

9:23AM

DAYS 1-5 (DECEMBER 25-29)
Merry Christmas and since I did not say it a few days ago when it began Happy Hanukkah to all celebrating either or both of these holidays! A quiet weather interlude has been timed very nicely for local and regional travel, and this continues today as well as tomorrow, which is one of the busiest of not the busiest travel day between Thanksgiving Weekend and New Year’s Day. We actually have a frontal boundary nearby, but there is not a lot of moisture available for it to work with for now so there will just be a varying amount of cloudiness these couple days. It is not until Friday when an impulse of low pressure passing north of the region will pull enough moisture into the area, along with milder air, for a rain shower threat. Behind that come a bubble of high pressure for a nice early winter day on Saturday. But as we approach year’s end we’ll start to see a little more activity in our weather once again. Now you’ve often heard me not to worry too much about what models have to say, detail-wise, beyond a few days out, but when making a forecast for day 5, and your two most reliable medium range models have completely different solutions as to how a storm system tracks, it gets .. interesting .. in terms of making an outlook. Now while I don’t often mention the models by name in my discussions here, preferring to save that for discussions in the comments section, I will point out that as we get to Sunday, we’ll be watching the approach of a low pressure system that I am pretty certain moves into the Great Lakes, and this is depicted by both the European (ECMWF) and US (GFS) models. It is what happens after this that is interesting, but since that is beyond day 5, this part of the discussion will be continued below, and I will move onto the 5-day forecast details here…
TODAY (CHRISTMAS): Partly sunny. Highs 37-44. Wind light variable.
TONIGHT: Mostly cloudy. Lows 25-32. Wind light variable.
THURSDAY: Partly sunny. Highs 37-44. Wind light variable.
THURSDAY NIGHT: Mostly cloudy. Lows 25-32. Wind light variable.
FRIDAY: Mostly cloudy. Scattered rain showers afternoon. Highs 40-47. Wind SW 5-15 MPH.
FRIDAY NIGHT: Clearing. Lows 20-27. Wind SW 5-15 MPH shifting to NW.
SATURDAY: Sunny. Highs 42-49. Wind NW 5-15 MPH.
SATURDAY NIGHT: Mostly clear. Lows 30-37. Wind light variable.
SUNDAY: Increasing clouds. Chance of mix/rain by late-day. Highs 37-44. Wind SE up to 10 MPH.

DAYS 6-10 (DECEMBER 30-JANUARY 3)
December 30, unsettled weather is likely, but hmmm, what form will it take? Probably rain, yes, but will it stay rain? If the ECMWF solution is correct, the low center from the Great Lakes reforms and passes just to the south, with high pressure to the north supplying cold enough air so that ice and/or snow could become involved for at least portions of the region, while the GFS model just keeps the primary low dominant and a secondary low is a feeble attempt at best and further north, a milder solution, and nothing in the way of freezing or frozen precipitation. I am currently leaning a little closer to the GFS scenario for that, which also means a quicker exit as well and dry/chilly weather for the final day of 2019. Beyond that, I don’t trust either model much, but I am generally thinking that we see a quick-moving system deliver rain showers (storm track to north of region) later January 1 or early January 2, followed by a sharp turn to colder weather possibly accompanied by snow showers, but we’re now out to 8-10 days on this forecast so it’s obviously low confidence and probably contains more detail than it should.

DAYS 11-15 (JANUARY 4-8)
Overall theme, cold and dry. A lot of fine-tuning to come.

7:41AM

DAYS 1-5 (DECEMBER 24-28)
And here we are, on the eve of Christmas, in the early days of Hanukkah, and in the midst of a fairly quiet holiday time, weather-wise. Not to say there are not things to talk about and systems to track, but we’re lacking major events, and that’s good news especially if you travel about the area during this time. So the theme continues during these 5 days. We had a cold front quietly slip through in the early hours today, and it will bring a more seasonable chill back to the air after a couple milder days just gone by. By later Christmas Day and into Thursday the front that went by will return as a warm front, with some cloudiness, but lacking any precipitation, until low pressure tracks through the Great Lakes then drags a cold front back across the region Friday, but by then milder air will be back and we’ll be looking at a rain shower risk. High pressure returns with a chill-down for Saturday.
Forecast details…
TODAY: Mostly sunny. Highs 33-40. Wind N 5-15 MPH.
TONIGHT (CHRISTMAS EVE): Mostly clear. Lows 20-27. Wind light variable.
WEDNESDAY (CHRISTMAS DAY): Variably cloudy. Highs 32-39. Wind light variable.
WEDNESDAY NIGHT: Mostly cloudy. Lows 20-27. Wind light variable.
THURSDAY: Partly sunny. Highs 35-42. Wind NW 5-15 MPH.
THURSDAY NIGHT: Mostly cloudy with light rain/mix possible overnight. Lows 32-39. Wind light variable.
FRIDAY: Variably cloudy. Risk of passing rain showers. Highs 40-47. Wind W 5-15 MPH.
FRIDAY NIGHT: Mostly clear. Lows 18-25. Wind NW 5-15 MPH, higher gusts.
SATURDAY: Mostly sunny. Highs 33-40. Wind NW 5-15 MPH.

DAYS 6-10 (DECEMBER 29-JANUARY 2)
Low pressure tracks through the Great Lakes December 29-30 with a warm front / cold front combo bringing a round of rain/mix and then a round of rain showers. Fair, briefly colder December 31, then a similar system may repeat a similar result January 1-2.

DAYS 11-15 (JANUARY 3-7)
Trend is for more polar jet stream, slightly colder and mostly dry weather with a couple minor light snow or snow shower events.

8:38AM

DAYS 1-5 (DECEMBER 23-27)
High pressure south of the region brings fair, milder weather today. A cold front drops through the region from north to south tonight with no more than just some cloudiness, but brings seasonably chilly air back to the region for Christmas Eve and Christmas Day. High pressure will keep Christmas Eve fair, but a boundary to the south will allow some cloudiness to arrive from the west during Christmas Day, although it will likely be too dry for the festive flakes I previously mentioned. But this will quietly start a run of disturbances impacting the region about every other day, as we’ll have another weak system passing by early on December 27 with a touch of rain or mix, as we’ll be lacking cold enough air for snow.
Forecast details…
TODAY: Mostly sunny. Highs 40-47. Wind W 5-15 MPH.
TONIGHT: Partly cloudy. Lows 20-27. Wind W 5-15 MPH.
TUESDAY: Partly cloudy. Highs 33-40. Wind N 5-15 MPH.
TUESDAY NIGHT (CHRISTMAS EVE): Partly cloudy. Lows 20-27. Wind light variable.
WEDNESDAY (CHRISTMAS DAY): Mostly cloudy. Highs 32-39. Wind light variable.
WEDNESDAY NIGHT: Mostly cloudy. Lows 20-27. Wind light variable.
THURSDAY: Partly sunny. Highs 35-42. Wind NW 5-15 MPH.
THURSDAY NIGHT: Mostly cloudy with light rain/mix possible overnight. Lows 32-39. Wind light variable.
FRIDAY: Mostly cloudy with light rain/mix possible morning. Clearing afternoon. Highs 40-47. Wind W 5-15 MPH.

DAYS 6-10 (DECEMBER 28-JANUARY 1)
Progressive pattern with low pressure systems passing by about every other day (current timing December 29 and 31) with minor precipitation events favoring rain/mix over snow. Temperatures near to above normal.

DAYS 11-15 (JANUARY 2-6)
Trend is for more polar jet stream, slightly colder and mostly dry weather with a couple minor light snow or snow shower events.

7:10AM

DAYS 1-5 (DECEMBER 22-26)
On this first full day of winter we will enjoy a fair amount of sunshine for the limited number of hours we have it available to us, as high pressure controls the weather. You’ll notice a slightly milder feel to the air in comparison to recent days, and this will be even more evident, temperature-wise, but accompanied by a bit more of a breeze on Monday as high pressure slips off to the south of the region. A moisture-starved cold front will sneak through from north to south early Tuesday, setting up a fair and seasonably chilly Christmas Eve. Weak low pressure approaches from the west on Christmas Day, spreading cloudiness into the region, and perhaps a few festive flakes of snow or not-as-festive drops of rain to the south during the afternoon. After this system passes offshore at night, it’ll intensify enough to drag a little more potent cold air mass into the region for Thursday as high pressure approaches from the northwest.
Forecast details…
TODAY: Partly sunny. Highs 37-44. Wind SW up to 10 MPH.
TONIGHT: Mostly clear. Lows 24-31. Wind W up to 10 MPH.
MONDAY: Mostly sunny. Highs 40-47. Wind W 5-15 MPH.
MONDAY NIGHT: Partly cloudy. Lows 20-27. Wind W 5-15 MPH.
TUESDAY: Partly cloudy. Highs 33-40. Wind N 5-15 MPH.
TUESDAY NIGHT (CHRISTMAS EVE): Partly cloudy. Lows 20-27. Wind light variable.
WEDNESDAY (CHRISTMAS DAY): Mostly cloudy. Slight chance of afternoon very light snow (mix far south). Highs 32-39. Wind light variable.
WEDNESDAY NIGHT: Mostly cloudy. Lows 20-27. Wind light variable.
THURSDAY: Mostly sunny. Highs 28-35. Wind N 10-20 MPH.

DAYS 6-10 (DECEMBER 27-31)
Progressive pattern with fairly weak systems passing by about every other day (current timing December 27, 29, 31) with minor precipitation events. Temperatures not far from normal overall.

DAYS 11-15 (JANUARY 1-5)
Low confidence but trend is for colder, mostly dry weather in the early days of January 2020.

5:52AM

DAYS 1-5 (DECEMBER 21-25)
Today we say goodbye to autumn and hello to winter, by astronomical definition, although not until after 11PM tonight when the solstice occurs. But we have seen our share of wintry weather in the final days of autumn this December, with below normal temperatures and above normal snowfall. But as winter arrives, we’ll be having a break in what was quite the active weather pattern. It’s not to say there won’t be “weather events”. There are always weather events. Weather is 24/7. But if you are looking for major storminess to impact the region, that won’t be happening for the next 5 days (at least). High pressure dominates the weekend weather and a weak disturbance I was eyeing for a possible delivery of meaningless light snow tonight will keep its feeble precipitation north of the region. After a temperature moderation through Monday, a cold front will drop through the region from north to south Monday night and bring slightly colder air back during Christmas Eve. A weak low pressure area approaching from the west will bring cloudiness for Christmas Day and possibly enough moisture to squeeze a few snowflakes out of the atmosphere. We won’t have a genuine white Christmas for much of the region this year, with just patchy snow cover left by then, although some areas in north central MA and southwestern NH will hold onto their slightly more substantial snow cover, though it will be a crusty type due to melt/freeze cycles, rather than a fresh one. That’s the way it goes here. Some years you have it, many you don’t.
Forecast details…
TODAY: Partly sunny. Highs 30-37. Wind light variable.
TONIGHT: Mostly cloudy. Lows 20-27. Wind light variable.
SUNDAY: Partly sunny. Highs 37-44. Wind light variable.
SUNDAY NIGHT: Clear. Lows 24-31. Wind W up to 10 MPH.
MONDAY: Sunny morning. Partly cloudy afternoon. Highs 40-47. Wind W 5-15 MPH.
MONDAY NIGHT: Partly cloudy. Lows 20-27. Wind W 5-15 MPH.
TUESDAY: Partly cloudy. Highs 33-40. Wind N 5-15 MPH.
TUESDAY NIGHT (CHRISTMAS EVE): Partly cloudy. Lows 20-27. Wind light variable.
WEDNESDAY (CHRISTMAS DAY): Mostly cloudy. Slight chance of light snow (mix far south). Highs 32-39. Wind light variable.

DAYS 6-10 (DECEMBER 26-30)
Colder weather December 26-27 with a clipper system possibly bringing light snow or snow showers most likely early December 27. Next precipitation threat comes later December 29 into December 30.

DAYS 11-15 (DECEMBER 31-JANUARY 4)
Uncertainty in this period with a huge spread in medium range guidance. At this point like the idea of storminess passing to the south early in the period and perhaps a rain/snow event around late January 1 to early January 2, then a fair/cold end to the period.

7:21AM

DAYS 1-5 (DECEMBER 20-24)
And now for some “in-between” time as southeastern New England sits between 2 jet streams – polar near the US / Canada border and subtropical far to the south. This is a fairly quiet pattern, with changes not containing much fanfare. We start out under the influence of a very cold high pressure area that will move across the region through Saturday then off to the south after that. A weak upper disturbance brings the only shot at any precipitation during this 5-day stretch, and that would only be a few flakes of snow Saturday night if it occurred at all. A milder westerly air flow arrives Sunday into Monday, then a cold front drops out of Canada with slightly colder air by Christmas Eve.
Forecast details…
TODAY: Sunny. Highs 22-29. Wind NW 5-15 MPH.
TONIGHT: Clear. Lows 0-5 interior valleys, 5-10 elsewhere except 10-15 urban centers. Wind light variable.
SATURDAY: Partly sunny. Highs 30-37. Wind light variable.
SATURDAY NIGHT: Mostly cloudy. A few snow showers possible. Lows 20-27. Wind light variable.
SUNDAY: Partly sunny. Highs 34-41. Wind light variable.
SUNDAY NIGHT: Clear. Lows 24-31. Wind W up to 10 MPH.
MONDAY: Sunny morning. Partly cloudy afternoon. Highs 35-42. Wind W 5-15 MPH.
MONDAY NIGHT: Partly cloudy. Lows 20-27. Wind W 5-15 MPH.
TUESDAY: Partly cloudy. Highs 30-37. Wind N 5-15 MPH.

DAYS 6-10 (DECEMBER 25-29)
Weak low pressure from the west brings clouds and possibly a bit of light mix/snow December 25 with lingering snow showers early December 26 before fair and colder weather is in place through December 27. A temperature moderation follows and there may be a minor precipitation event by the end of the period, pending the track of an approaching low pressure area.

DAYS 11-15 (DECEMBER 30-JANUARY 3)
Precipitation threat early in the period, pending the track of low pressure passing through the Northeast. Mostly fair, colder weather to end 2019 and start 2020 as the polar jet stream dips down into the region with a mainly west to northwest air flow.

6:45AM

DAYS 1-5 (DECEMBER 19-23)
Departing low pressure via eastern Canada and high pressure pressing slowly southeastward from central Canada means a cold, windy day for southeastern New England today. Cold will continue through Friday with a little less wind as the pressure gradient loosens up somewhat. The upcoming weather pattern will find us between split jet streams, quite far apart – the polar jet stream near the US / Canada border while the subtropical jet stream is located near the Gulf Coast, the latter having no influence on the weather here, while the former will bring a brief shot at snow showers as it carries a weak disturbance across the region Saturday night. It will then send a cold front toward the region later Monday but with little fanfare as the pattern will be on the quiet side as we count the days down toward Christmas.
TODAY: Sunny. Highs 18-25. Wind NW 15-25 MPH. Wind chill near to below 0 at times.
TONIGHT: Clear. Lows 9-16. Wind NW 5-15 MPH. Wind chill near 0 at times.
FRIDAY: Sunny. Highs 22-29. Wind NW 5-15 MPH.
FRIDAY NIGHT: Clear. Lows 0-5 interior valleys, 5-10 elsewhere except 10-15 urban centers. Wind light variable.
SATURDAY: Partly sunny. Highs 30-37. Wind light variable.
SATURDAY NIGHT: Mostly cloudy. A few snow showers possible. Lows 20-27. Wind light variable.
SUNDAY: Partly sunny. Highs 34-41. Wind light variable.
SUNDAY NIGHT: Clear. Lows 24-31. Wind W up to 10 MPH.
MONDAY: Sunny morning. Partly cloudy afternoon. Highs 35-42. Wind W 5-15 MPH.

DAYS 6-10 (DECEMBER 24-28)
High pressure moves down from Canada with fair and seasonable weather December 24. A low pressure area approaches from the west and brings the risk of light snow/mix for December 25 and lingering snow showers into early December 26 as systems will be moving even more quickly than previously expected and this low should pass just south of the region. Beyond this high pressure approaches from the west with dry and chilly weather.

DAYS 11-15 (DECEMBER 29-JANUARY 2)
Next risk of precipitation comes in the December 29-30 window before fair weather arrives for the transition from 2019 to 2020, along with a trend toward colder weather.

7:31AM

DAYS 1-5 (DECEMBER 18-22)
A disturbance behind the departing low triggers early to mid morning flakes for some eastern areas before the system is completely offshore today, but an arctic cold front will slice through the region later today with a snow shower / snow squall threat. So in addition to the lingering snow/ice making for slippery travel today, it can be added to a little bit more by the early day snow east and scattered squalls later, in addition to any squalls producing briefly strong wind and extremely low visibility. And then in comes very cold air tonight through Thursday along with wind with air temperatures struggling to get back to 20 in some areas Thursday while wind chills are below 0. Easing of the wind should make Friday more tolerable though it will still be cold. At this point, the weekend looks mostly dry but a weak trough moving eastward across the region can trigger some light snow or snow showers any time from late Saturday to early Sunday.
The forecast details…
TODAY: Cloudy with snow showers NH Seacoast and far eastern MA early morning, otherwise clearing with sun emerging from west to east this morning. Clouds return from west to east mid to late afternoon with scattered snow showers and snow squalls. Highs 33-40. Wind W increasing to 10-20 MPH.
TONIGHT: Variably cloudy with scattered snow showers and snow squalls early evening, then mostly clear. Lows 8-15. Wind NW 15-25 MPH, higher gusts. Wind chill below 0.
THURSDAY: Mostly sunny. Highs 18-25. Wind NW 10-20 MPH. Wind chill near to below 0 at times.
THURSDAY NIGHT: Clear. Lows 5-12. Wind NW 5-15 MPH. Wind chill near to below 0 at times.
FRIDAY: Mostly sunny. Highs 23-30. Wind N 5-15 MPH, higher gusts. Wind chill in the 10s.
FRIDAY NIGHT: Clear. Lows 5-10 interior valleys, 10-15 elsewhere. Wind light variable.
SATURDAY: Increasing clouds. Late-day or evening light snow or snow showers possible. Highs 28-35. Wind light variable.
SATURDAY NIGHT: Mostly cloudy. Light snow or snow showers possible. Lows 20-27. Wind light variable.
SUNDAY: Light snow or snow showers possible early. Increasing sun. Highs 30-37. Wind light variable.

DAYS 6-10 (DECEMBER 23-27)
Our region will be in between far-separated jet streams (polar near the US/Canada border) and subtropical over the far southern US. Overall this is a fairly dry pattern with temperatures briefly milder December 23 then back to seasonably chilly for the balance of the period. Weak disturbances may bring some cloudiness at times with a remote risk of a passing rain/snow shower December 24 and a little light snow or snow showers December 25 and again a minor precipitation threat possible at the end of the period.

DAYS 11-15 (DECEMBER 28-JANUARY 1)
A little uncertainty for this period but overall looks like a similar pattern to start. We’ll see a lot of cold re-building in Canada and some of it may make a run into New England depending on the timing of polar jet stream disturbances.

7:13AM

DAYS 1-5 (DECEMBER 17-21)
Low pressure tracking east northeastward, passing across the South Coast region or just to the south of New England by this evening, will bring a messy day of weather to southeastern New England with snow/sleet/ice/rain, the precipitation type and duration dependent on location, and unfolding pretty much as described yesterday, with snow for most except a quick turn to rain and freezing rain already taking place as of 6AM on the South Coast. The change-over line, which will have more sleet involved in it soon, will progress northward slowly during the morning and first half of the afternoon so that it is in the I-90 / I-95 (to the north) areas while remaining mainly snow near and north of Route 2, and then late in the day through evening the line will head back to the south and southeast allowing all areas to end as snow tonight. See the detailed forecast below for accumulations of snow/ice. As the temperature drops tonight, watch for icy ground especially where rain/mix had occurred. On the heels of this departing system comes an arctic cold front Wednesday, which will produce snow showers and potentially heavier snow squalls sometime from mid afternoon to mid evening. These can cause brief but significant reductions to visibility and also quickly cover surfaces with snow, which can be even more dangerous if there are still areas of ice on the ground. Use caution if walking and/or driving. A blast of arctic air arrives Wednesday night through Thursday, along with wind. As high pressure moves in Friday, it will remain cold but be much more tranquil with lighter wind. The process of fine-tuning an unsettled weather threat for sometime over the weekend continues, and the current idea is that separate jet streams will be the case with a larger system staying well to the south while a weaker one moves in later Saturday with a lighter snow or snow shower threat. Will continue that idea for now.
The forecast details…
TODAY: Overcast. Snow to rain South Coast, snow to mix I-95 corridor which may include sleet and/or freezing rain, snow NW of I-95 area. Ice accretion of up to 1/4 inch possible eastern CT, northern RI, and adjacent south central MA. Snow accumulation a coating to 1 inch South Coast including Cape Cod, 1-3 inches most of southeastern MA and RI to near Boston, 3-6 inches most areas NW of I-95 from about Route 2 northward. Highs 28-33 I-95 northwestward, 33-38 elsewhere. Wind E to NE 5-15 MPH.
TUESDAY NIGHT: Cloudy evening with any rain/mix changing back to snow with additional minor accumulation before ending west to east late evening. Clearing overnight. Lows 22-30. Wind N 5-15 MPH.
WEDNESDAY: Variably cloudy. Afternoon snow showers/squalls likely. Highs 33-40. Wind W 10-20 MPH shifting to NW late.
WEDNESDAY NIGHT: Variably cloudy with evening snow showers possible. Clear overnight. Lows 10-17. Wind NW 15-25 MPH, higher gusts. Wind chill 0-10 at times.
THURSDAY: Mostly sunny. Highs 18-25. Wind NW 10-20 MPH. Wind chill near to below 0 at times.
THURSDAY NIGHT: Clear. Lows 5-12. Wind NW 5-15 MPH. Wind chill near to below 0 at times.
FRIDAY: Mostly sunny. Highs 23-30. Wind N up to 10 MPH.
FRIDAY NIGHT: Clear. Lows 5-10 interior valleys, 10-15 elsewhere. Wind light variable.
SATURDAY: Increasing clouds. Late-day or evening light snow or snow showers possible. Highs 28-35. Wind light variable.

DAYS 6-10 (DECEMBER 22-26)
Weak system departs December 22 after an early risk of light snow or snow showers. Fair, seasonably cold weather for the balance of the period with the exception of a risk of a few snow showers sometime December 24 and/or December 25 as a weak disturbance passes through.

DAYS 11-15 (DECEMBER 27-31)
Down the home stretch of 2019, and expect a moisture-starved low, probably passing north of the region with milder air and a rain shower risk early in the period, then overall fairly dry and seasonably chilly weather as the polar jet stream dominates and a weak subtropical jet stream is held far to the south for the final days of the year.

7:29AM

DAYS 1-5 (DECEMBER 16-20)
High pressure positions itself north of our area today, delivering cold air which will be a factor in the visit of our next low pressure system, which will be Tuesday, bringing snow/ice/rain to the region. While most areas start as snow (possible snow/rain start immediate South Coast), mild air aloft will help flip the precipitation to rain/ice mainly south of I-90 (rain favoring the coast, freezing rain & sleet interior), while areas to the north of I-90, while possibly mixing with or turning to sleet for a while, will be mostly snow. This is not to be a big storm, in terms of precipitation amounts, but it will impact travel around the region during Tuesday. This system exits Tuesday night and a potent upper level disturbance and accompanying arctic cold front will cross the region Wednesday with a snow shower and snow squall threat. While this will not likely be a widespread snow event, it can have temporarily but significant local impact. Exact timing and placement of snow showers/squalls will not be able to be determined until the day itself, the time period most likely to see activity is early afternoon to early evening based on current expected timing. The Montreal Express visits us on Thursday which will be one of our coldest days so far this “winter” (it technically won’t be winter yet). The cold remains in place though easing very slightly on Friday as high pressure builds in, but it will feel nicer than Thursday due to a lack of wind.
The forecast details…
TODAY: High clouds increase. Highs 30-37. Wind variable up to 10 MPH.
TONIGHT: Cloudy. Snow develops pre-dawn west to east except snow/rain immediate South Coast. Lows 25-32. Wind light variable.
TUESDAY: Overcast. Snow to rain South Coast, snow to mix I-95 corridor which may include sleet and/or freezing rain, snow NW of I-95 area. Snow accumulation a coating to 1 inch South Coast including Cape Cod, 1-3 inches most of southeastern MA and RI to near Boston, 3-6 inches from I-95 area northwestward. Highs 30-37. Wind E to NE 5-15 MPH.
TUESDAY NIGHT: Mostly cloudy with lingering snow showers evening. Clearing overnight. Lows 22-30. Wind N 5-15 MPH.
WEDNESDAY: Variably cloudy. Afternoon snow showers/squalls likely. Highs 33-40. Wind W 10-20 MPH shifting to NW late.
WEDNESDAY NIGHT: Variably cloudy with evening snow showers possible. Clear overnight. Lows 10-17. Wind NW 15-25 MPH, higher gusts. Wind chill 0-10 at times.
THURSDAY: Mostly sunny. Highs 18-25. Wind NW 10-20 MPH. Wind chill near to below 0 at times.
THURSDAY NIGHT: Clear. Lows 5-12. Wind NW 5-15 MPH. Wind chill near to below 0 at times.
FRIDAY: Mostly sunny. Highs 23-30. Wind N up to 10 MPH.

DAYS 6-10 (DECEMBER 21-25)
Near to below normal temperatures December 21-22 weekend while we watch low pressure passing to the south and trough connecting to a weaker northern stream system passing through the region. This brings a chance of at least some light snow (and possible coastal mix south) later Saturday into Sunday – not likely a big storm. If enough onshore flow is involved, ocean-enhanced snowfall bands cannot be ruled out. Generally dry overall with seasonable to slightly below normal temperatures for the remainder of the period, however with a risk of a few passing snow showers from a weak disturbance sometime December 24 and/or 25.

DAYS 11-15 (DECEMBER 26-30)
A little more activity in the subtropical jet stream may send some moisture with a rain/snow threat later December 26 or December 27, with fair and colder weather returning for the balance of the period.