DAYS 1-5 (DECEMBER 16-20)

Welcome to the weather forecast for the final five days of autumn! There are some changes we’ll be going through, so let’s get to a summary of them. Today, cloud cover will be dominant but from a disturbance that’s running into dry air and falling apart as it does so. Initially, I expected more precipitation from this system, but it’s not to be, and other than some rain across the South Coast region and some lighter freezing rain and/or snow to the north of there, mainly southwest of Boston, for a while this morning, not much will take place today. A broad area of low pressure passing to our north tonight and Tuesday will drag a warm front across the region, accompanied by a period of rain overnight / Tuesday morning, followed by a cold front that may produce a brief rain shower in the midday to mid afternoon hours Tuesday, but it will be a mild day, with high temperatures exceeding 50 across the region. Cooler air settles back in behind the cold front Tuesday night, and the next low pressure system races our way from the west southwest Wednesday, spreading clouds back in, and a shield of precipitation at night into Thursday morning. The air will be mild enough for rain in bulk of the region, but cold enough for a mix or some wet snow at the start and possibly again at the end in interior northern MA and southern NH. Another batch of cold air follows this system, and is reinforced on Friday when a disturbance goes by bringing with it a chance of snow showers.

TODAY: Mostly cloudy. A period of rain South Coast, light snow and/or freezing rain west of I-95 in the I-90 / I-86 areas with some minor snow accumulation and light glazing possible during the morning. Highs 36-43. Wind variable up to 10 MPH.

TONIGHT: Cloudy. Rain arrives overnight. Lows 33-40 evening followed by a slow temperature rise overnight. Wind variable to SE up to 10 MPH.

TUESDAY: Cloudy through mid morning with rain tapering off west to east. Cloud/sun mix late morning on with an additional rain shower possible midday or early afternoon. Highs 50-57. Wind S 5-15 MPH, shifting to W, with higher gusts possible.

TUESDAY NIGHT: Clearing. Lows 25-32. Wind W 5-15 MPH.

WEDNESDAY: Clouding over. Rain arrives by late-day, may be mixed with snow initially interior locations of southern NH and northern MA. Highs 41-48. Wind variable up to 10 MPH.

WEDNESDAY NIGHT: Cloudy. Rain likely. Areas of fog. Lows 36-43. Wind NE 5-15 MPH.

THURSDAY: Cloudy start with rain ending, possibly mixed with snow, especially north and west of Boston. Clouds decrease thereafter. Highs 38-45. Wind NE to N 10-20 MPH.

THURSDAY NIGHT: Mostly clear. Lows 21-28. Wind NW 10-20 MPH.

FRIDAY: Variably cloudy. Chance of snow showers. Highs 30-37. Wind NW to N 10-20 MPH.

DAYS 6-10 (DECEMBER 21-25)

The winter solstice occurs at 4:20 a.m. on December 21, and the weekend of December 21-22 looks cold as we watch additional storminess to the south, but probably have high pressure to the north more dominant with mostly dry weather and some potential coastal snow showers. High pressure builds in with tranquil weather December 23 through Christmas Day, staring out with below normal temperatures then followed by a moderation.

DAYS 11-15 (DECEMBER 26-30)

A more active period for precipitation chances but also milder weather as a Pacific flow overtakes the large scale pattern.

DAYS 1-5 (DECEMBER 15-19)

A large high pressure area sat overhead overnight and it got cold! Sunrise temperatures sat in the 10s for most of the region, with some lower 20s in the urban centers (heat island effect) and over the outer part of Cape Cod (surrounded by warmer water). The high pressure area starts to drift off toward the east today and as it does so our sunshine will become more limited as high to mid level clouds increase from the west ahead of an approaching low pressure area. At the same time an evolving weak onshore air flow will cause some lower clouds to come in from the ocean in eastern areas. Tonight, clouds collect and consolidate from both sources, and Monday is expected to be a cloudy day as a weak low pressure system approaches. This system will have cold enough air to work with so that some light snow can occur over inland areas, and eventually some freezing drizzle / rain, while closer to the coast I’d expect mainly a rain event. However, this system will also be running into a lot of dry air and falling apart as it moves in, so it’s quite probable that the precipitation is nearly insignificant for much of the region. Monday night, a more southerly air flow takes over with increasing moisture so expect a thicker overcast with spotty drizzle and patchy fog to form, and then as a larger area of low pressure begins to pass north of our region, a frontal boundary will be dragged eastward across the region, bringing with it widespread rain showers for Tuesday morning. This system will be moving right along and we’ll dry out that afternoon into early Wednesday. The next low pressure wave on its heels will spread clouds back in on Wednesday with a batch of rain (that can begin as mixed rain/snow for some interior areas) later Wednesday and early Thursday (which can end as mix/snow for some areas) as colder air returns.

TODAY: Sunshine becomes less abundant as clouds increase. Highs 33-40. Wind variable up to 10 MPH.

TONIGHT: Becoming cloudy. Lows 25-32. Wind variable to S under 10 MPH.

MONDAY: Cloudy. A period of light snow to mix inland and mix to rain coast. Some potential for icing from freezing rain/drizzle away from the coast. Highs 35-42. Wind variable up to 10 MPH.

MONDAY NIGHT: Cloudy. Fog patches. Chance of drizzle. Temperatures 35-42, slowly rising overnight. Wind SE to S up to 10 MPH.

TUESDAY: Mostly cloudy with rain showers likely morning to midday. Clouds break for intervals of sun afternoon. Highs 46-53. Wind S 5-15 MPH, shifting to W with higher gusts.

TUESDAY NIGHT: Clearing. Lows 25-32. Wind W 5-15 MPH.

WEDNESDAY: Clouding over. Rain arrives by late-day, may be mixed with snow initially interior locations. Highs 40-47. Wind variable up to 10 MPH.

WEDNESDAY NIGHT: Cloudy. Rain likely. Areas of fog. Lows 36-43. Wind NE 5-15 MPH.

THURSDAY: Cloudy start with rain ending, possibly mixed with snow. Clouds decrease thereafter. Highs 38-45. Wind NE to N 10-20 MPH.

DAYS 6-10 (DECEMBER 20-24)

Opportunities for snow or snow showers about 3 times (every other day). Temperatures below normal. We’ll be in a trough position here, and medium range guidance has trouble handling “pieces of energy” and therefore presents inconsistent representations of what can happen on run-to-run simulations. That’s why these are talked about as non-specific opportunities until each “chance” gets closer.

DAYS 11-15 (DECEMBER 25-29)

A temperature moderating trend with a couple of rain/mix/snow chances.

DAYS 1-5 (DECEMBER 14-18)

Our weekend weather will be dominated by a large area of high pressure. This high moves in from the west today with below normal temperatures and a subtle northwesterly breeze, lighter than yesterday’s wind, and unlimited sunshine – a halcyon day. The center of the strong high will be right over us tonight, providing the perfect set-up for any solar heat escaping quickly to space, sending temperatures below 20 (except in urban centers), and below 10 in the normal cold spots. Despite the bright, nearly full moon, tonight will be another good night for observing Geminid meteors as we are just coming off the peak of this active meteor shower. Dress for the cold if you decide to head out for that! Best time to view is late night. Open sky / low light pollution areas are best. While the moon can hinder the view of the meteors, it will add to the spectacle of the night sky in close proximity to Jupiter and Mars, the constellation Orion, and other bright stars. High pressure drifts off to the east on Sunday. As this happens, a very cold morning will be followed by a recovery in temperatures to just slightly “warmer” than today’s highs, but still running below normal for mid December. We may see some low clouds start to drift in from the ocean as a light east to southeast air flow begins. Additionally, the approach of a trough of low pressure from the west will make itself first known with an increase in high level clouds from the west during the course of the day. This leads us to some unsettled weather for early next week. Low pressure will organize in the northern Plains of the US and track toward eastern Canada via the northern Great Lakes. A warm front extending from this low will approach on Monday, and this will initiate a batch of light precipitation moving into our region from the west that day. With enough cold air in place, some light snow can occur, especially from the Boston area north and west, with odds favoring a light mix to rain to the south. As warm air moves in aloft, the snow would flip to rain / drizzle, still on the light side, but surface temperatures can still be cold enough away from the coast to promote some icing, so we’ll have to watch for that and fine-tune the short term forecast as we get closer to that event. Finally, the warm front will be just making it into and across the region as the system is occluding, and this occluded / cold front will sweep west to east across the region Tuesday morning and midday with a band of rain showers with milder air in place. This system will be a far cry from the bigger rain producer earlier this week. Dry weather returns during the day Tuesday and lasts through much of Wednesday, but clouds will already be making an increase ahead of the next low pressure system later Wednesday.

TODAY: Sunny. Highs 28-35. Wind NW up to 10 MPH.

TONIGHT: Clear. Lows 15-22. Wind calm.

SUNDAY: Partly sunny. Highs 33-40. Wind variable up to 10 MPH.

SUNDAY NIGHT: Mostly cloudy. Lows 25-32. Wind variable under 10 MPH.

MONDAY: Cloudy. A period of light snow to mix inland and mix to rain coast. Some potential for icing from freezing rain/drizzle away from the coast. Highs 35-42. Wind variable up to 10 MPH.

MONDAY NIGHT: Cloudy. Fog patches. Chance of drizzle. Temperatures 35-42, slowly rising overnight. Wind variable to SE up to 10 MPH.

TUESDAY: Mostly cloudy with rain showers likely morning to midday. Clouds break for intervals of sun afternoon. Highs 46-53. Wind S 5-15 MPH, shifting to W with higher gusts.

TUESDAY NIGHT: Clearing. Lows 25-32. Wind W 5-15 MPH.

WEDNESDAY: Sunny start / cloudy finish. Highs 40-47. Wind W 5-15 MPH becoming variable.

DAYS 6-10 (DECEMBER 19-23)

Unsettled weather early period with odds favoring rain but a potential mix/snow ending of the system on December 19. A colder trend follows. A snow shower chance exists later December 20 and a snow or snow shower opportunity is a potential for December 22 and/or 23. A more detailed look at these systems will appear in tomorrow’s blog post.

DAYS 11-15 (DECEMBER 24-28)

Potential for 2 precipitation events. Temperatures below normal through Christmas, then a moderating trend.

DAYS 1-5 (DECEMBER 13-17)

A colder westerly air flow continues today between a large low pressure area in eastern Canada and high pressure building into the Great Lakes. High pressure will build eastward into New England with dry and chilly but more tranquil weather this weekend. Early next week, our weather will turn unsettled. Monday, a warm front will approach and a batch of moisture with it will start to dry up as it runs into drier air with high pressure hanging on just to our east. The air will be cold enough so that any precipitation that makes it in can be in the form of snow, especially over inland areas, with rain more likely near the coast. However, this system may end up quite moisture-starved and quite minor. Low pressure will pass north of the region Tuesday, dragging a cold front through with associated rain showers as the air will be milder as that system passes by.

TODAY: Sun/cloud mix. Highs 31-38. Wind W 10-20 MPH, higher gusts.

TONIGHT: Mostly clear. Lows 15-22. Wind NW under 10 MPH.

SATURDAY: Mostly sunny. Highs 32-39. Wind variable up to 10 MPH.

SATURDAY NIGHT: Mostly clear. Lows 15-22. Wind calm.

SUNDAY: Partly sunny. Highs 33-40. Wind variable up to 10 MPH.

SUNDAY NIGHT: Mostly cloudy. Lows 25-32. Wind variable under 10 MPH.

MONDAY: Cloudy. Chance of light rain/mix coast, mix/snow inland. Highs 38-45. Wind variable up to 10 MPH.

MONDAY NIGHT: Cloudy. Fog patches. Chance of drizzle. Lows 35-42. Wind variable up to 10 MPH.

TUESDAY: Mostly cloudy. Rain showers likely. Highs 48-55. Wind S 5-15 MPH, shifting to W with higher gusts.

DAYS 6-10 (DECEMBER 18-22)

Trending colder. A couple of precipitation opportunities (December 20 & 22).

DAYS 11-15 (DECEMBER 23-27)

Potential for 2 precipitation events. Temperatures near to slightly below normal.

DAYS 1-5 (DECEMBER 12-16)

A healthy westerly air flow today and Friday brings colder air back to us. There will be some low level moisture that the atmosphere can squeeze out in the form of a few snow showers this afternoon and to a slightly lesser extent on Friday, which will be the colder of the 2 days. The weekend will feature dry weather with high pressure building into the region. A weakening low pressure area will approach Monday, bringing back the clouds and some precipitation – looking like a fairly minor system.

TODAY: Sun/cloud mix. Slight chance of a passing snow shower in the afternoon, mainly north of I-90. Highs 37-44. Wind W 15-25 MPH, gusts 30+.

TONIGHT: Partly cloudy. Slight chance of a passing snow shower early. Lows 20-27. Wind W 10-20 MPH, higher gusts. Wind chill below 20.

FRIDAY: Sun/cloud mix. Slight chance of a passing snow shower. Highs 32-39. Wind W 10-20 MPH, gusts around 25 MPH.

FRIDAY NIGHT: Mostly clear. Lows 16-23. Wind NW under 10 MPH.

SATURDAY: Mostly sunny. Highs 32-39. Wind variable up to 10 MPH.

SATURDAY NIGHT: Mostly clear. Lows 15-22. Wind calm.

SUNDAY: Partly sunny. Highs 33-40. Wind variable up to 10 MPH.

SUNDAY NIGHT: Mostly cloudy. Lows 25-32. Wind variable under 10 MPH.

MONDAY: Cloudy. Chance of light rain (some mixed precipitation inland). Highs 36-43. Wind variable up to 10 MPH.

DAYS 6-10 (DECEMBER 17-21)

Precipitation potentials December 17 (rain) and December 20 (rain/mix/snow). Temperatures near to slightly above normal.

DAYS 11-15 (DECEMBER 22-26)

Potential for 2 precipitation events. Temperatures near to slightly below normal.

DAYS 1-5 (DECEMBER 11-15)

A strong cold front approaches from the west today, passing through the region this evening. This slow-moving boundary will see a couple waves of low pressure move up along it, the last of which will help swing the front through later this evening. Before that, the last of the cold air trapped at the surface is in the process of being scoured out and the balance of today will be dominated by waves of widespread rain showers, some heavy, which may include thunder this evening as the last of it moves through, as well as a strong, gusty southerly wind and a push of much milder air as well. Hazards today include ponding of water on roadways, especially poor-drainage areas, with some flooding during the heavier rainfall episodes, as well as damaging wind gusts which can lead to isolated power outages. Later tonight, behind the front, we clear out and get colder, and some areas of black ice may form by morning as the wind shifts and drops off. Thursday and Friday will be windy days with a colder trend in a westerly flow behind the front, with mainly dry weather and just a chance of a few passing rain/snow showers later Thursday and snow flurries on Friday. High pressure brings dry weather and more tranquil conditions this weekend, with most sun and Saturday and somewhat less sun on Sunday as the next low pressure area tries to approach, but is held off by the high pressure area.

TODAY: Cloudy. Numerous to widespread rain showers. Highs 55-62. Wind S 15-30 MPH, gusts 35-55 MPH, strongest in coastal locations.

TONIGHT: Cloudy evening with widespread rain showers and a chance of a thunderstorm. Rain showers ending with clouds breaking overnight. Lows 32-39. Wind S 15-35 MPH with higher gusts, shifting to W from west to east and diminishing overnight.

THURSDAY: Sun/cloud mix. A slight chance of a passing snow shower late in the day except rain or snow shower near the coast. Highs 38-45. Wind W 15-25 MPH, higher gusts.

THURSDAY NIGHT: Partly cloudy. Slight chance of a passing snow shower. Lows 20-27. Wind W 10-20 MPH, higher gusts. Wind chill below 20.

FRIDAY: Sun/cloud mix. Slight chance of a passing snow shower. Highs 32-39. Wind W 10-20 MPH.

FRIDAY NIGHT: Mostly clear. Lows 16-23. Wind NW under 10 MPH.

SATURDAY: Mostly sunny. Highs 32-39. Wind variable up to 10 MPH.

SATURDAY NIGHT: Mostly clear. Lows 15-22. Wind calm.

SUNDAY: Partly sunny. Highs 33-40. Wind variable up to 10 MPH.

DAYS 6-10 (DECEMBER 17-21)

Rain/mix/snow potential December 17-18. Mainly dry weather thereafter. Temperatures near to slightly above normal. More detailed discussion soon.

DAYS 11-15 (DECEMBER 22-26)

Precipitation threat early in the period. Mainly dry weather thereafter. Temperatures near to slightly below normal. More detailed discussion soon.

DAYS 1-5 (DECEMBER 10-14)

Today is our “in-between” day after last night’s slug of rain (and some snow well to the northwest) and the upcoming wind and rain event for tomorrow. Weak low pressure just to the east slowly drifts away but low level moisture will remain trapped over the region today so we’ll be under an overcast and there can be periods of drizzle. Low level cold air dominates, and the air temps are near to just below freezing early this morning from the immediate north and northwest suburbs of Boston northward into southern NH and northwestern into north central MA. Watch for black ice in these locations, and any drizzle that falls can also freeze on surfaces until the temperature goes above freezing. There will be only a very modest temperature rise during the day today as the cold air remains trapped near the surface. Warmer air will finally invade the region from south to north tonight in response to a stronger southerly air flow ahead of an approaching front, driven by a low pressure trough moving in from the west. Low pressure waves ride up this front and we get waves of numerous to widespread rain showers and potential embedded thunderstorms Wednesday. Heavy rain can cause some ponding and road flooding, and watch for some strong wind gusts that can result in tree damage and some resultant power outages. If you have any holiday decorations vulnerable to wind, take steps to secure (or temporarily remove) them if possible. Out goes the rain, and in comes the dry and cold weather for late this week, accompanied by plenty of wind Thursday into Friday, which settles down by Saturday as high pressure builds in. The door is open for a few stray snow showers in our area Thursday and/or Friday, but these are not expected to be heavy enough to cause any travel issues.

TODAY: Overcast. Areas of fog / drizzle. Watch for black ice north and west of Boston along with some freezing drizzle. Highs 33-40 north and west of Boston, coldest southwestern NH and north central MA, 41-48 elsewhere, mildest South Coast. Wind N under 10 MPH north and west of Boston, E up to 10 MPH elsewhere.

TONIGHT: Overcast. Areas of fog / drizzle. Temperatures steady or slowly rising. Wind SE up to 10 MPH.

WEDNESDAY: Cloudy. Numerous to widespread rain showers. Highs 55-62. Wind S 15-30 MPH, gusts 35-50 MPH, strongest in coastal locations.

WEDNESDAY NIGHT: Cloudy evening with widespread rain showers and a chance of a thunderstorm. Rain showers ending with clouds breaking overnight. Lows 32-39. Wind S 15-35 MPH, shifting to W, higher gusts.

THURSDAY: Sun/cloud mix. A slight chance of a passing snow shower late in the day. Highs 38-45. Wind W 15-25 MPH, higher gusts.

THURSDAY NIGHT: Partly cloudy. Slight chance of a passing snow shower. Lows 20-27. Wind W 10-20 MPH, higher gusts. Wind chill below 20.

FRIDAY: Sun/cloud mix. Slight chance of a passing snow shower. Highs 32-39. Wind W 10-20 MPH.

FRIDAY NIGHT: Mostly clear. Lows 16-23. Wind NW under 10 MPH.

SATURDAY: Mostly sunny. Highs 32-39. Wind variable up to 10 MPH.

DAYS 6-10 (DECEMBER 15-19)

Main precipitation threats December 15 (minor) and December 17. Up and down temperatures averaging around normal.

DAYS 11-15 (DECEMBER 20-24)

Pattern hints at colder and minor precipitation (mainly snow) threats every other day but no major storms.

DAYS 1-5 (DECEMBER 9-13)

Unsettled weather is the theme into midweek. Today, an early nice sunrise for many will be replaced quickly by advancing clouds. Rain arrives ahead of a warm front which will never quite make it through the region, at least not before a very lengthy delay. As is typical, cold air trapped at the surface will allow it to warm aloft but not really at ground level, and this will be most evident over interior locations, particularly well north and northwest of Boston. Precipitation arrives later today in the form of rain for most of the region, but it will be cold enough for some wet snow over south central and southwestern NH and far north central MA, particularly higher elevations. Also elevated valleys stand the highest chance of seeing some icing at times this evening and even into a portion of Tuesday as the coldest air remains trapped right at the ground, and the lowest temperatures will be around the freezing point. Even when the main precipitation shield exists and we’re left with low clouds and areas of drizzle Tuesday, with the help of a weak secondary low pressure area just off our coast, there can be some pockets of freezing drizzle in those same locations. Elsewhere, above freezing temperatures will prevent that. It will not be until Wednesday, when a deeper trough of low pressure approaches. A stronger southerly air flow ahead of this will push the stubborn warm front through the region, but at the same time a stronger cold front will be approaching from the west, with a couple areas of low pressure to slide up along the boundary, passing just to our west as they move north northeastward. This brings in warmer air, but also a stronger south wind, along with waves of widespread rain showers. Even embedded thunderstorms cannot be ruled out in this set-up. Finally, the cold front moves across the region late Wednesday night and early Thursday morning. This puts an end to the rainfall, and I do think it happens quickly enough so that we won’t see cold enough air for snow to mix in before precipitation ends. However, a fairly rapid temperature drop can cause icy areas to form where the ground is wet from rain by the time many people are heading out on Thursday morning. Keep this in mind! We’ll have windy, colder, generally dry weather during the day Thursday, which continues with some modest wind diminishment on Friday. While it looks mainly dry both days, I can’t rule out a few stray snow showers.

TODAY: Any early sun is fleeting as it becomes overcast from west to east. Rain arrives later, but snow/ice likely south central and southwestern NH and adjacent north central MA. Highs 33-40 southwestern NH and north central MA, 40-47 elsewhere, mildest along the South Coast. Wind N to NE under 10 MPH interior valleys, E to SE 5-15 MPH elsewhere.

TONIGHT: Overcast. Areas of fog. Rain likely evening including areas of icing in portions of south central NH and far north central MA. Lows 31-38 west of the I-95 belt – coldest in valley areas, 39-46 elsewhere – mildest South Coast. Wind N to E up to 10 MPH.

TUESDAY: Overcast. Areas of fog / drizzle. Highs 34-41 interior valleys, 42-49 elsewhere. Wind NE to SE up to 10 MPH.

TUESDAY NIGHT: Overcast. Areas of fog / drizzle. Temperatures steady or slowly rising. Wind SE up to 10 MPH.

WEDNESDAY: Cloudy. Widespread rain showers. Highs 50-57. Wind S 10-20 with gusts to 30 MPH inland, 20-30 MPH with gusts above 40 MPH coastal areas.

WEDNESDAY NIGHT: Cloudy evening with widespread rain showers and a chance of a thunderstorm. Rain showers ending with clouds breaking overnight. Lows 32-39. Wind S 15-35 MPH, shifting to W, higher gusts.

THURSDAY: Sun/cloud mix. Slight chance of a passing snow shower. Temperatures steady in the 30s. Wind W 10-20 MPH, higher gusts.

THURSDAY NIGHT: Partly cloudy. Slight chance of a passing snow shower. Lows 20-27. Wind W 10-20 MPH, higher gusts. Wind chill below 20.

FRIDAY: Sun/cloud mix. Slight chance of a passing snow shower. Highs 32-39. Wind W 10-20 MPH.

DAYS 6-10 (DECEMBER 14-18)

Main precipitation threats December 15 (minor) and December 17. Up and down temperatures averaging around normal.

DAYS 11-15 (DECEMBER 19-23)

Main precipitation threats December 20 (minor) and December 22, but lower confidence with this being further into the future. Temperatures near to below normal.

DAYS 1-5 (DECEMBER 8-12)

Not much change to the expectations for this Sunday blog update, so after I tell you that the light snowfall from the clipper low passing to our north has basically ended, we basically summarize what I wrote here yesterday. Expect some clearing during the day today, and a milder day overall, melting most of the light snowfall that occurred. An unsettled stretch is ours through Wednesday. A warm front approaches and enters the region later Monday but low pressure forming on it and high pressure in eastern Canada results in colder air being stubborn to dislodge at the surface. While the airmass is essentially mild enough for rain, we’ll have to watch for brief wet snow in higher elevations well northwest of Boston at the onset of precipitation late Monday, and maybe a brief period of time where freezing rain can occur just after that in these locations – which are generally the Monadnock Region of southwestern NH to the hills of northern Worcester Country in MA. I do expect a weak surface low to hang around just to our east Tuesday, keeping us socked in with low clouds and patchy drizzle. If breaks in the clouds occur, they favor areas further west. Finally, a stronger cold frontal boundary pushes slowly eastward across the region Wednesday to the early hours of Thursday, with a couple low pressure waves riding along it, passing just to our west. This is a milder, rain showery set-up. I can’t even rule out a couple embedded thunderstorms before the front pushes through. I’ve been watching for the possibility of a switch to a mix or snow as the front goes through, but at the moment I’m leaning toward the moisture exiting ahead of the air cold enough to create a change in precipitation-type, so I’m just going with a dry, windy, colder Thursday.

TODAY: Cloudy with any lingering light snow exiting by mid morning, then increasing sun but still a few passing clouds from late morning on. Highs 40-47. Wind variable to W up to 10 MPH.

TONIGHT: Increasing clouds. Lows 27-34. Wind N up to 10 MPH.

MONDAY: Thickening overcast. Rain arrives during the afternoon but may be mixed with snow/sleet/ice over some interior locations north of I-90. Highs 33-40 southwestern NH and north central MA, 40-47 elsewhere, mildest along the South Coast. Wind N to NE under 10 MPH interior valleys, E to SE 5-15 MPH elsewhere.

MONDAY NIGHT: Overcast. Areas of fog. Rain likely. Temperatures generally steady. Wind N to E up to 10 MPH.

TUESDAY: Overcast. Areas of fog / drizzle. Highs 35-42 interior valleys, 42-49 elsewhere. Wind NE to SE up to 10 MPH.

TUESDAY NIGHT: Overcast. Areas of fog / drizzle. Temperatures steady or slowly rising. Wind SE up to 10 MPH.

WEDNESDAY: Cloudy. Widespread rain showers. Highs 50-57. Wind S 10-20 MPH, higher gusts along the coast and in elevated locations.

WEDNESDAY NIGHT: Cloudy evening with widespread rain showers and a chance of a thunderstorm. Rain showers ending with clouds breaking overnight. Lows 32-39. Wind S 10-20 MPH, shifting to W, higher gusts.

THURSDAY: Sun/cloud mix. Temperatures steady in the 30s. Wind W 10-20 MPH, higher gusts.

DAYS 6-10 (DECEMBER 13-17)

Generally fair and seasonably chilly weather expected December 13-14. Minor systems can bring minor snow/mix threats December 15 and again at the end of the period.

DAYS 11-15 (DECEMBER 18-22)

Overall pattern features 2 opportunities for snow/mix, but neither look like “big” storms at this point. Fine-tuning to come. Temperatures variable, averaging near normal.

DAYS 1-5 (DECEMBER 7-11)

A west northwest flow of cold air and a passing disturbance turns what moisture is in the air a few thousand feet up into areas of clouds today. Sunrise this morning presented an opportunity for me to see a sunlit batch of snow virga (which I photographed), and this indicates that these clouds can produce a little flurry of snow in a few places if the flakes can overcome drier air near the ground, so I leave that slight chance in the forecast today. Tonight, a fast moving low pressure area moves our way via the Great Lakes. A warm front ahead of the system will generate a swath of snow across the region, producing a minor accumulation, especially from I-90 northward. The combination of less intensity and slightly milder air nearer the South Coast lessens the ability for snow to accumulate down that way. This system exits Sunday morning and we see fair weather return for the day. But our pattern is also injected with systems from an active Pacific jet stream and the next one moves in by later Monday. The set-up in the atmosphere will be a little more complex for the arrival of this system. While a weak cold front drops through the region as the Sunday system departs, it will sit to our south and try to be lifted back through as a warm front as the next low pressure area approaches later Monday, but will struggle to do so as low level cold will be hard or impossible to push out of the way, especially over inland locations. This means when that area of precipitation moves in, while warmer air aloft means it likely falls as rain in coastal areas up through the I-95 belt, inland areas to the northwest can see a variety of precipitation. And while this does not look like a big precipitation producer, even modest amounts of frozen or freezing precipitation will cause some travel trouble. I’ll take a shot at pinpointing this in detail on tomorrow’s update. This thrust of moisture exits by early Tuesday, and it looks like between that and the next Pacific system, much of our region will be sitting just north of a frontal boundary with a chilly, raw day Tuesday with stubborn cloud cover and even some drizzle around. We may have to watch surface temperatures over inland valleys for potential freezing drizzle. Again, I’ll revisit this potential tomorrow and try to detail it. This is particularly important because if we should see a slightly more defined low pressure area along the frontal boundary that gets to our east, it could pull in a little bit of dry air and thin out or even break up the overcast for a while that day, and it would be less “dank” than I’m predicting on this post. Finally, a frontal boundary will approach from the west Wednesday. A southerly air flow should finally be strong enough to push warmer air into the entire region at least for a few hours while a wave or two of low pressure pass by just to our west. This will bring widespread rain showers to the region, which provide further benefit in reducing the drought.

TODAY: Variably cloudy. Very slight chance of brief passing snow flurries. Highs 29-36. Wind W 5-15 MPH, higher gusts possible.

TONIGHT: Becoming cloudy. Light snow from late evening on, arriving from west northwest to east southeast. Lows 21-28. Wind variable up to 10 MPH.

SUNDAY: Cloudy early morning with snow ending – accumulations of 1/2 to 2 inches except for under 1/2 southeastern MA and RI. Clearing thereafter. Highs 37-44. Wind variable to W up to 10 MPH.

SUNDAY NIGHT: Increasing clouds. Lows 27-34. Wind N up to 10 MPH.

MONDAY: Thickening overcast. Rain arrives during the afternoon but may be mixed with snow/sleet/ice over some interior locations north of I-90. Highs 33-40 interior valleys, 40-47 elsewhere, mildest along the South Coast. Wind N to NE under 10 MPH interior valleys, E to SE 5-15 MPH elsewhere.

MONDAY NIGHT: Overcast. Areas of fog. Rain likely. Temperatures generally steady 33-40 interior valleys to 40-47 elsewhere. Wind N to E up to 10 MPH.

TUESDAY: Overcast. Areas of fog / drizzle. Highs 35-42 interior valleys, 42-49 elsewhere. Wind NE to SE up to 10 MPH.

TUESDAY NIGHT: Overcast. Areas of fog / drizzle. Temperatures steady or slowly rising. Wind SE up to 10 MPH.

WEDNESDAY: Cloudy. Widespread rain showers. Highs 50-57. Wind S 10-20 MPH, higher gusts along the coast and in elevated locations.

DAYS 6-10 (DECEMBER 12-16)

A strong cold front passes by early morning December 12 and we’ll have to watch for rain ending as a mix/snow if the cold air arrives quickly enough. Remainder of December 12 trends drier but windy and turning colder. Generally fair and seasonably chilly weather expected December 13-14. Watch for a minor system to bring a precipitation threat December 15-16 (though probably not that entire time frame).

DAYS 11-15 (DECEMBER 17-21)

This outlook brings us through the final few days of astronomical autumn up to the winter solstice. Currently, the pattern looks fairly quiet overall with perhaps one minor system / precipitation threat in the December 18-20 window. I realize this is a broad window of time but guidance in medium range struggles to accurately simulate which disturbances may have noticeable impact in any given region. While the pattern does not look persistently cold, it doesn’t look warm either. So for now let’s just say “variable / seasonable”!

DAYS 1-5 (DECEMBER 6-10)

Cold weather is ours for the next couple days. It will be mainly dry with a northwesterly air flow and I cannot rule out a few isolated snow showers. A wave of low pressure is set to move quickly across northern New England early Sunday, and the warm front from this system will produce a swath of fluffy snow with a minor accumulation in much of the region before we clear out during the day on Sunday. We enter another period of unsettled weather early next week. The trend indicates chilly air tough to dislodge. This means that precipitation that arrives on Monday will probably be in the form of snow/mix over some interior areas and is more likely to be rain at the coast, and even after that moves off on Tuesday, low level moisture will likely keep us socked in with clouds and drizzle Tuesday, maybe even some freezing drizzle with cold air trapped over the interior. These details can be brought into better focus as we get closer to the event.

TODAY: Mostly sunny to partly cloudy. Highs 29-36. Wind NW 10-20 MPH, higher gusts. Wind chill as low as 20.

TONIGHT: Mostly clear to partly cloudy. Lows 16-23. Wind NW 5-15 MPH. Wind chill as low as 10.

SATURDAY: Partly cloudy. A slight chance of a passing light snow shower. Highs 29-36. Wind W 5-15 MPH, higher gusts.

SATURDAY NIGHT: Clouding up. Light snow arriving overnight, especially from the I-90 belt northward. Lows 21-28. Wind variable up to 10 MPH.

SUNDAY: Cloudy early with light snow ending – accumulation a coating to 2 inches across the region, with above 1 inch amounts most likely north of I-90. A mix of clouds and sun mid morning on. Highs 36-43. Wind W 5-15 MPH diminishing late.

SUNDAY NIGHT: Increasing clouds. Lows 27-34. Wind N up to 10 MPH.

MONDAY: Thickening overcast. Rain arrives during the afternoon but may be mixed with snow/sleet/ice over some interior locations north of I-90. Highs 35-42 interior valleys, 43-50 elsewhere, mildest along the South Coast. Wind N to NE under 10 MPH interior valleys, E to SE 5-15 MPH elsewhere.

MONDAY NIGHT: Overcast. Areas of fog. Rain likely. Temperatures steady 35-42 interior valley, 43-50 elsewhere. Wind NE to SE up to 10 MPH.

TUESDAY: Overcast. Areas of fog / drizzle. A slight chance of rain. Temperatures remain generally steady. Wind NE to SE up to 10 MPH.

DAYS 6-10 (DECEMBER 11-15)

A stronger push of southerly wind December 11 as low pressure tracks by to the west with rain showers likely. Cloudy start then clearing December 12 with a wind shift to northwest and colder trend. Fair, seasonable late next week.

DAYS 11-15 (DECEMBER 16-20)

More of a west to northwest flow and variable but mostly seasonable temperatures expected during this period with a minor precipitation threat mid to late period.

DAYS 1-5 (DECEMBER 5-9)

Late last night I made the remark “I don’t think anybody will see any surprises with this one” in the comments and then had a nervous sense of worry after I sent it. Two surprises of sorts: 1) A rain/snow line that made it further east sooner, allowing minor accumulating snow into the I-95 belt. 2) A heavier 3 to 5+ inch accumulation bullseye in parts of south central MA to northeastern CT. This part of the system still has one more swath of snow and rain to throw across the area this morning before it moves out of the region. Most of the pavement / cement surfaces should be able to be cleared, melt off, or be treated before temperatures drop tonight. But the cold front triggering that temperature drop can produce some convective showers this afternoon – mainly in the form of snow with some rain possibly mixed in further east and south at first. These should be brief in any one area, but even briefly heavy snow showers can coat the ground and set up slippery conditions into this evening with falling temperatures. Many surfaces can be dried off by wind before freeze-up, pending snow shower details. But keep all this in mind if you have to travel by car or on foot this evening. The cold air that settles in hangs around Friday and Saturday. Most Great Lakes snow showers should make it only to about the mountains to our west, but I can’t rule out a few making it into the WHW forecast area, especially Saturday with the help of a weak disturbance passing through. Then the large scale set-up shifts around late in the weekend and to start next week as the upper level flow shifts to the west then southwest. Sunday, a low pressure area passing quickly to our north will send a warm front through the region and this can generate a period of snow with some minor accumulation in the early morning hours. The balance of Sunday will feature fair weather with a notable moderation in temperature. The milder weather continues Monday and a strong low pressure area passing to our west later in the day will send a surge of moisture our way in the form of rain.

TODAY: Cloudy this morning with additional snow/mix except mix/rain southeastern MA/RI – some minor additional snow accumulation expected. Variably cloudy this afternoon with passing snow and rain showers, a few of which can be briefly heavy with quick minor accumulation in snow showers. Highs 38-45, but a quick temperature drop west to east later on. Wind S up to 10 MPH early, shifting to SW increasing to 5-15 MPH midday then NW 10-20 MPH with higher gusts from west to east this afternoon.

TONIGHT: Partly cloudy with a chance of snow showers early, then clearing. Lows 17-24. Wind NW 10-20 MPH. Wind chill as low as 10.

FRIDAY: Mostly sunny to partly cloudy. Highs 29-36. Wind NW 10-20 MPH, higher gusts. Wind chill as low as 20.

FRIDAY NIGHT: Mostly clear to partly cloudy. Lows 16-23. Wind NW 5-15 MPH.

SATURDAY: Variably cloudy. Chance of snow showers. Highs 29-36. Wind W 5-15 MPH, higher gusts.

SATURDAY NIGHT: Clouds dominate. A chance of light snow overnight, favoring areas near and north of I-90. Lows 21-28. Wind variable up to 10 MPH.

SUNDAY: Early clouds and lingering snow flurries followed by sunshine. Highs 38-45. Wind SW 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 32-39. Wind SW 5-15 MPH.

MONDAY: Mostly cloudy. Rain arrives during the afternoon or evening. Highs 43-50. Wind S 5-15 MPH.

DAYS 6-10 (DECEMBER 10-14)

Above normal temperatures December 10-11, with one more low pressure system to deliver rain during that period of time, favoring December 11. Fair, seasonably colder weather returns mid to late period behind that system.

DAYS 11-15 (DECEMBER 15-19)

More of a west to northwest flow and variable but mostly seasonable temperatures expected during this period with what appear to be minor precipitation threats early and again late in the period.

DAYS 1-5 (DECEMBER 4-8)

In the short term, our attention now turns to a low pressure system that will impact our weather today, especially tonight, into Thursday as well. This system is a kind-of clipper, a fast-moving low pressure area moving east southeast from Canada, and the jet stream in this case will steer it eastward across the St. Lawrence Valley. While we get a blossoming area of fairly steady precipitation late this evening and overnight / early Thursday, the impact of a southerly air flow due to the storm’s track will keep the all-important boundary layer, an important region in the lower atmosphere for determining precipitation type, too mild to support snow for much of the time in the I-95 belt and most certainly the coastal areas. Further inland, the opportunity for snow is greater, and there will be some accumulation from the I-495 belt / I-86 belt westward, favoring higher elevations. During the day Thursday a strong cold front trailing from the low center will trigger some snow showers / squalls. These can be mixed with rain or even start as rain the closer to the coast you get, but even there they can end in the form of a quick burst of snow. Other than a few lingering snow flurries, dry and much colder weather arrives at night and takes hold through Friday, although the wind that makes it feel even colder on Friday should start to ease by Friday evening. Another disturbance crosses the region on Saturday with the potential for some snow showers. This system is not expect to have any significant impact. High pressure provides dry and chilly weather Sunday.

TODAY: Sun gives way to clouds. Highs 37-44. Wind S up to 10 MPH.

TONIGHT: Cloudy. Brief light snow and rain around during early evening. Steadier rain coast, snow inland with a coating to 2 inches late evening on. Lows 31-38. Wind variable up to 10 MPH evening, S 5-15 MPH overnight.

THURSDAY: Cloudy early morning with rain and snow ending west to east. Sun/cloud mix with passing snow showers (rain or snow showers coast) midday on. Highs 38-45. Wind SW 5-15 MPH, higher gusts, shifting to WNW.

THURSDAY NIGHT: Partly cloudy with a chance of snow showers early, then clearing. Lows 17-24. Wind NW 10-20 MPH. Wind chill as low as 10.

FRIDAY: Mostly sunny. Highs 29-36. Wind NW 10-20 MPH, higher gusts. Wind chill as low as 20.

FRIDAY NIGHT: Mostly clear to partly cloudy. Lows 16-23. Wind NW 5-15 MPH.

SATURDAY: Variably cloudy. Chance of snow showers. Highs 29-36. Wind W 5-15 MPH, higher gusts.

SATURDAY NIGHT: Partly cloudy. Lows 15-22. Wind NW up to 10 MPH.

SUNDAY: Sunny. Highs 32-39. Wind NW up to 10 MPH.

DAYS 6-10 (DECEMBER 9-13)

A cold start and milder finish December 9 leads to a milder and unsettled period with a couple periods of rain favored December 10-11. Another low pressure area can pass close by December 12-13, timing and track uncertain, but additional unsettled weather possible.

DAYS 11-15 (DECEMBER 14-18)

Trend back to a drier northwesterly flow and colder trend anticipated during this period.

DAYS 1-5 (DECEMBER 3-7)

A chilly pattern and some changing weather in the upcoming several days. High pressure will be in control today through most of Wednesday with dry weather, although today an inversion delivers a blanket of clouds to start the day especially north and west of Boston, which will break up with time. Sunshine will be most dominant from midday through the afternoon hours. One other exception will be Outer Cape Cod which will see more persistent clouds and a few light snow showers due to ocean effect. Wednesday, clouds increase from the west in advance of approaching low pressure, as the high pressure ridge slides off to the east. This system will present itself as a broad low pressure area, the center of which will pass to our north on Thursday. Precipitation arrives Wednesday evening from west to east and blossoms over the region overnight, mainly in the form of rain at the coast and snow over the interior, with some accumulation of snow most likely from about I-95 / I-495 of southeastern NH / northeastern MA westward, as far south as south central MA, especially higher elevations. This tapers off from west to east Thursday morning, with some breaks in the clouds as the first part of the disturbance exits to the east, but a strong cold front will sweep across the region during the afternoon and will likely produce at least scattered convective showers, in the form of snow for most except rain or snow further south of Boston as temperatures will be marginal there. Behind the front, a few additional light snow showers can wander eastward from the hills and mountains to our west and northwest as the coldest air of the season so far flows into the region Thursday night. This air mass will be with us on Friday and Saturday with a blustery northwesterly wind on Friday, easing off somewhat by later in the day. Another disturbance passing through the region Saturday can trigger some snow showers.

TODAY: Sun/cloud mix – most clouds morning and most sun midday on. Chance of snow showers Outer Cape Cod. Highs 36-43. Wind W 5-15 MPH.

TONIGHT: Mostly clear. Lows 18-25. Wind W under 10 MPH.

WEDNESDAY: Sun followed by clouds. Highs 37-44. Wind variable to S up to 10 MPH.

WEDNESDAY NIGHT: Cloudy. Brief light snow inland / rain coast evening. Steadier period of snow inland (coating to 2 inches) / rain coast overnight. Lows 31-38. Wind variable up to 10 MPH evening, S 5-15 MPH overnight.

THURSDAY: Cloudy early morning with rain and snow ending west to east. Sun/cloud mix with passing snow showers (rain or snow showers coast) midday on. Highs 38-45. Wind SW 5-15 MPH, higher gusts, shifting to WNW.

THURSDAY NIGHT: Partly cloudy with a chance of snow showers early, then clearing. Lows 17-24. Wind NW 10-20 MPH. Wind chill as low as 10.

FRIDAY: Mostly sunny. Highs 29-36. Wind NW 10-20 MPH, higher gusts. Wind chill as low as 20.

FRIDAY NIGHT: Mostly clear to partly cloudy. Lows 16-23. Wind NW 5-15 MPH.

SATURDAY: Variably cloudy. Chance of snow showers. Highs 29-36. Wind W 5-15 MPH, higher gusts.

DAYS 6-10 (DECEMBER 8-12)

Dry weather and below normal temperatures to round on the weekend on December 8. Moderating temperatures with fair weather to start December 9 then watching potential / likely impact from low pressure later December 9 and December 10, the track of which will determine precipitation type and other details. Brief drier interlude before next system approaches at end of period in a more active pattern heading toward mid month.

DAYS 11-15 (DECEMBER 13-17)

Another low pressure area threatens some precipitation early in the period, then drier weather returns. Temperatures near to slightly below normal.

DAYS 1-5 (DECEMBER 2-6)

A cold spell marks the first week of December. High pressure sits over the Tennessee Valley and low pressure over eastern Canada. We’ll be in an air flow from the northwest to west. This provides dry weather for the region, the exception being some ocean-effect clouds than can produce a few rain and/or snow showers over the outer portion of Cape Cod today and Tuesday, and perhaps a few locations along the South Coast, most especially Nantucket and Martha’s Vineyard, during Tuesday. Wednesday, the daytime hours will be dry but we’ll see sun give way to clouds ahead of an approaching warm front, parented by low pressure moving east southeastward from Canada into the Great Lakes. This broad but fast moving circulation will take a bit of a left turn and pass to our north Wednesday night and Thursday. Its warm front will produce a swath of light precipitation across our region Wednesday night and early Thursday morning, bringing some light snowfall accumulation to inland areas. Closer to the coast, where it’ll be a little milder, look for more inconsequential wet snow or mixed precipitation transitioning to rain before ending with the front’s passage. The air behind the “warm front” won’t be particularly warm – just a bit milder than the 3 days that precede it. But the cold front that trails from the passing low pressure area will sweep across the region Thursday evening, bringing the shot at a snow shower or snow squall, except snow and/or rain showers in the milder environment from Boston southward. This front will usher in noticeably colder air for Friday, and along with wind it’ll feel more like mid winter than late autumn.

TODAY: Sunshine except some clouds and a chance of a few passing rain and/or snow showers Outer Cape Cod. Highs 35-42. Wind NW 5-15 MPH, higher gusts.

TONIGHT: Partly cloudy Cape Cod. Mostly clear elsewhere. Lows 20-27. Wind WNW 5-15 MPH.

TUESDAY: Partly cloudy with a passing rain or snow shower possible Cape Cod / Islands. Mostly sunny elsewhere. Highs 36-43. Wind W 5-15 MPH.

TUESDAY NIGHT: Mostly clear. Lows 18-25. Wind W under 10 MPH.

WEDNESDAY: Sun followed by clouds. Highs 37-44. Wind variable to S up to 10 MPH.

WEDNESDAY NIGHT: Cloudy. A period of snow inland with minor accumulation, snow/mix to mix/rain coast with little or no snow accumulation. Lows 31-38 evening, may rise slightly overnight. Wind S up to 10 MPH.

THURSDAY: Cloudy early with a chance of snow/mix inland, rain coast, then a sun/cloud mix with a chance of a late day snow shower inland and rain or snow shower coast. Highs 38-45. Wind SW 5-15 MPH, higher gusts.

THURSDAY NIGHT: Partly cloudy with a chance of snow showers early, then clearing. Lows 17-24. Wind NW 10-20 MPH. Wind chill as low as 10.

FRIDAY: Mostly sunny. Highs 29-36. Wind NW 10-20 MPH, higher gusts. Wind chill as low as 20.

DAYS 6-10 (DECEMBER 7-11)

A fast-moving disturbance brings a snow shower chance later December 7 to early December 8 with below normal temperatures over the weekend. Moderating temperatures early next week including a rain/mix/snow threat late December 9 to early December 10 – doesn’t look like a big storm at this point, but have to watch several areas of moisture and energy before a higher confidence outlook can be made for that system.

DAYS 11-15 (DECEMBER 12-16)

Another low pressure area threatens some precipitation early to mid period, then drier weather. Temperatures near to slightly above normal.