7:21AM

Has anybody seen my Norlun trough? Oh there it is! Sitting offshore, NOT doing what I expected it was going to do. Well, it is doing it, just not WHERE I expected. Oh well, chalk up another forecast bust and move on, right? That’s all I can do here, folks. So here we go.

This one is short and sweet, and a little bitter…cold that is. A few snow showers today as reinforcing arctic cold moves in and hangs around through the middle of the week. The coldest days will be Wednesday and Thursday.

A winter storm threat looms for the end of the week, something we’ve been seeing in the cards for a while. At this still-early stage it looks like low pressure will make a run up just off the East Coast late Friday and Saturday bringing the chance of significant snow to the area. It should be gone by Sunday which would be a cold day. A moderation in temperature may take place by the start of next week, probably temporary, as the longer term pattern still looks colder.

Updated forecast for eastern MA, RI, and southern NH…

TODAY: Variably cloudy. Scattered snow showers. Highs 24-29. Wind W 10-15 MPH gusting 20-25 MPH.

TONIGHT: Mostly clear. Low around 0 inland to 5-10 urban centers and Cape Cod. Wind NW 5-15 MPH.

WEDNESDAY: Mostly sunny. Highs 15-20. Wind NW 10-20 MPH with higher gusts.

WEDNESDAY NIGHT: Partly cloudy. Lows 0-5. Wind NW 5-15 MPH.

THURSDAY: Mostly sunny. Highs 14-19. Wind NW 10-20 MPH with higher gusts.

FRIDAY: Increasing clouds. Snow at night. Low 8. High 25.

SATURDAY: Cloudy. Snow to flurries. Low 18. High 26.

SUNDAY: Partly sunny. Low 11. High 27.

MONDAY: Partly cloudy. Low 17. High 35.

11:14PM

I am beginning to hate the phrase “high bust potential” but I am glad I used it, because a shift of just a number of miles in the development of things means a big change in snow amounts for the ongoing (or not too ongoing) event. Instead of getting into the details of why things are going the way they are, we’ll just outline the newly expected snow amounts, nothing that there is a jackpot area of over 4 inches in southern RI which occurred Monday evening.

There will indeed be a trough development but the latest info suggests it will be just a little further offshore, keeping the heaviest snow out over the water and only brushing the remainder of eastern MA and only giving a moderate (at most) amount to coastal northeastern MA to NH. The dusting to inch or so that has fallen in areas from just west of Boston westward is about it. The few to several inches that have occurred over southeastern MA may be added to a little more, especially over Cape Cod where the new expected amount is 3-6 inches. There is still uncertainty from  Boston northward along the coast, and especially from Cape Ann to NH Seacoast where a 3-6 inch burst is still possible overnight and early Tuesday.

The remainder of the discussion is unchanged from the previous post…

Midweek Arctic cold: Still expecting a nice dose of pure Arctic air for Wednesday & Thursday. A weak disturbance will pass south of the region and bring nothing more than a period of high and middle clouds early Thursday, otherwise it will be dry and very cold.

Late week storm threat: Yes it’s still there. And it’s still too early to provide details, but my best guess is that it will be a Friday night / Saturday threat (still some timing issues to be worked out), and threaten the region with a significant snowfall. A few snow showers may linger Sunday depending on the speed of an upper level trough moving through the region. It will be cold, regardless, right through the weekend, though not as cold as at midweek.

Updated forecast for eastern MA, RI, and southern NH…

OVERNIGHT: Areas of snow, favoring coastal MA and NH. See updated amounts above. Lows 14-19. Wind E to NE up to 10 MPH.

TUESDAY: Cloudy to partly sunny. Any snow mainly coastal areas north of Boston tapering off, with some additional snow showers crossing Cape Cod. Highs 20-25. Wind NE to NW 10-20 MPH and gusty.

TUESDAY NIGHT: Clearing. Lows 0-5 except 5-10 urban centers and Cape Cod. Wind NW to W 10-15 MPH gusting 20-25 MPH. Wind chill below 0 at times.

WEDNESDAY: Mostly sunny. Highs 15-20. Wind W 5-15 MPH.

THURSDAY: AM clouds / PM sun. Low 2. High 20.

FRIDAY: Increasing clouds. Low 10. High 27.

SATURDAY: Cloudy. Chance of snow. Low 18. High 28.

SUNDAY: Variably cloudy. Chance of snow showers. Low 12. High 27.

4:34PM

The snow event for tonight and Tuesday morning is going to behave about as expected. What was not known was the details, and even at this point some of them are still unknown. What we do know is that a very low water content (about 20:1 snow to water ratio) snowfall will occur tonight and Tuesday morning. This will be the result of a small low pressure area from the west redeveloping just south of New England and intensifying as it moves northeastward into the waters east of New England. As mentioned previously, an inverted trough, or Norlun trough, extending back behind the low pressure area will serve as a belt of instability to enhance the snowfall over far eastern MA and coastal NH, adding to the totals there. The dry/fluffy nature of the snow will also allow it to add up quickly. The upside of this type of snow is that it is very lightweight and easy to move. Snow accumulations through Tuesday morning are expected to be 2-4 inches from northern RI up through the I-495 belt of MA into south central NH, 4-8 inches east of there through much of eastern MA, but 8-12 inches over outer Cape Cod, eastern Essex County MA including Cape Ann, and the NH Seacoast. In this 8-12 inch area, isolated amounts of 12-15 inches cannot be ruled out. All this should wind down by Tuesday afternoon and clouds will probably break before the day is over.

Midweek Arctic cold: Still expecting a nice dose of pure Arctic air for Wednesday & Thursday. A weak disturbance will pass south of the region and bring nothing more than a period of high and middle clouds early Thursday, otherwise it will be dry and very cold.

Late week storm threat: Yes it’s still there. And it’s still too early to provide details, but my best guess is that it will be a Friday night / Saturday threat (still some timing issues to be worked out), and threaten the region with a significant snowfall. A few snow showers may linger Sunday depending on the speed of an upper level trough moving through the region. It will be cold, regardless, right through the weekend, though not as cold as at midweek.

Updated forecast for eastern MA, RI, and southern NH…

TONIGHT: Snow developing and becoming widespread, with embedded heavier snow bands especially in coastal MA and coastal NH. Lows 14-19. Wind E to NE up to 10 MPH.

TUESDAY: Cloudy with snow tapering to snow showers then departing northwest to southeast during the morning. Mostly cloudy but a few breaks of sun in the afternoon. Blowing and drifting snow. Highs 20-25. Wind NE to NW 10-20 MPH and gusty.

TUESDAY NIGHT: Clearing. Lows 0-5 except 5-10 urban centers and Cape Cod. Wind NW to W 10-15 MPH gusting 20-25 MPH. Wind chill below 0 at times.

WEDNESDAY: Mostly sunny. Highs 15-20. Wind W 5-15 MPH.

THURSDAY: AM clouds / PM sun. Low 2. High 20.

FRIDAY: Increasing clouds. Low 10. High 27.

SATURDAY: Cloudy. Chance of snow. Low 18. High 28.

SUNDAY: Variably cloudy. Chance of snow showers. Low 12. High 27.

7:31AM

This is the forecast portion only! Discussion will be posted this afternoon.

Forecast for eastern MA, southern NH, and RI…

TODAY – MLK JR DAY: Increasing clouds. A few light snow showers possible late. Highs 24-49. Wind light variable, mostly N to NNE under 10 MPH.

TONIGHT: Overcast. Widespread snow developing, with embedded heavier snow showers developing overnight especially coastal NH and eastern MA including Cape Cod. Lows 13-18. Wind NE to N 5-15 MPH.

TUESDAY: Overcast with snow and snow showers in the morning, with a few areas bands of heavier snow very possible especially coastal NH and eastern MA – accumulation a general 2 to 6 inches in areas without enhancement and 6 or more inches in areas that see enhanced snowfall. Mostly cloudy with any snow and snow showers ending northwest to southeast in the afternoon. Highs 18-23. Wind N to NW increasing to 10-20 MPH. Some blowing snow.

WEDNESDAY: AM sun / PM clouds. Low 0. High 15.

THURSDAY: AM clouds / PM sun. Low 3. High 20.

FRIDAY: Cloudy. Chance of snow. Low 10. High 25.

SATURDAY: Cloudy. Chance of snow. Low 18. High 28.

SUNDAY: Sunny. Low 10. High 27.

9:30AM

This is an update on the previous entry, adjustments needed for this update include an increase in the wind forecast for today and tonight, and a posting of forecast snowfall amounts for Monday night & Tuesday. Otherwise, there are no major changes, and this will all be updated again this evening with the posting of The Week Ahead.

Today / Tonight … The transition from very mild air (for January), with temperatures probably reaching 50 during the day, to arctic cold, with temperatures falling into the teens overnight. This will be announced by big winds (gusting as high as 45 to 50 MPH) shifting from WSW to WNW (not a huge shift but you’ll notice a huge difference in temperature between noon today and midnight tonight – up to a 30-degree drop and even a few more by the time the lows are reached early Monday morning. With a line of snow squalls moving into Vermont early this morning, including thunder, one would think we’d be seeing a heavy shower or thunderstorm (rain due to the mild air) ahead of this front some time today, but that activity is likely to weaken considerably and only a few showers may survive the trip across southern NH and eastern MA early or mid afternoon. There is even a more remote chance of an isolated snow shower coming along with a secondary trough line that has to push through here early this evening around the time of the kick off of the NFL AFC Championship game between the New England Patriots and Baltimore Ravens at Foxboro MA. Expect the temperature to be in the middle 40s during the afternoon tailgate, dropping to the middle 30s by kick off time, and the upper or even middle 20s by the end of the game. The big story will be the strong westerly winds which will gust beyond 40 MPH, playing havoc with tailgate activities (beware of flying paper and plastic cups and plates and maybe a few burger rolls!). The wind will also likely have an impact on the game itself as it swirls around the stadium.

Monday / Tuesday … The winds will have dropped off by Monday but the cold air will be in, not yet in full force (see Wednesday / Thursday), but enough that you will sure notice a big difference from what we had this weekend. Of more importance is a disturbance coming out of the Great Lakes region that is going to transfer its energy to a new low pressure area just south of New England, which will then strengthen as it tracks northeastward into the waters just east of New England. Even though this low track is close enough to throw snow into the region, in most cases it would be a light snowfall, but there are 3 things working to enhance the snowfall in some locations, especially closer to the eastern coastal areas of NH & MA and probably the southern coastal areas of MA & RI. These are 1) very cold temperatures which will lead to snow to water ratios on the order of 20 or more to 1, allowing very fluffy snow to pile up easily, 2) ocean enhancement where wind comes off the ocean water and picks up additional moisture (this would be most likely on the outer part of Cape Ann and across Cape Cod in areas exposed to a northerly wind), and 3) an inverted trough, or Norlun trough setup, in which an elongated or stretched out low pressure trough extends back from the main low pressure area, in this case into southeastern New England, and results in added convergence or instability in the atmosphere. NOTE that the forecast snowfall amounts below are trickier than usual with these factors in place, and can potentially bust quite easily, so please check back in the comments section below as the day and evening goes on for any changes before the full update later tonight. For the timing of the snow, though flakes may begin in some areas late Monday afternoon, the majority of the snow will fall late Monday night into Tuesday morning before tapering off in the afternoon and pulling away to the southeast.

Wednesday / Thursday … Still looking at a pure arctic outbreak, the coldest in 2 years. Not expecting any big record low temperatures though. A weak upper level disturbance may bring some clouds later Wednesday to early Thursday but dry weather is expected.

Friday / Saturday … Not a whole lot to add yet about the winter storm potential here. Starting to see hints that it may be a double-barrel system with a shot of snow Friday with one wave of low pressure, and another low moving up the coast or just offshore on Saturday, being a secondary hit or a close call. It’s still far away, so all I can say still is that there is the potential for another significant snowfall.

Updated forecast for eastern MA, southern NH, and RI…

TODAY: Sunshine & high clouds this morning. Variably cloudy this afternoon with a slight chance of a passing rain shower. Highs around 50. Wind WSW to W 15-30 MPH with gusts 40-50 MPH.

TONIGHT: Variably cloudy with a very slight chance of a passing snow shower early. Partly to mostly clear later. Lows 14-19. Wind W to WNW 15-30 MPH gusting over 40 MPH early, shifting to NW then slowly diminishing later.

MONDAY – MLK JR DAY: Increasing clouds. A few light snow showers possible late. Highs 24-49. Wind light variable, mostly N to NNE under 10 MPH.

MONDAY NIGHT: Overcast. Widespread snow developing, with embedded heavier snow showers developing overnight especially coastal NH and eastern MA including Cape Cod. Lows 13-18. Wind NE to N 5-15 MPH.

TUESDAY: Overcast with snow and snow showers in the morning, with a few areas bands of heavier snow very possible especially coastal NH and eastern MA – accumulation a general 2 to 6 inches in areas without enhancement and 6 to 12 inches in areas that see enhanced snowfall. Mostly cloudy with any snow and snow showers ending northwest to southeast in the afternoon. Highs 18-23. Wind N to NW increasing to 10-20 MPH. Some blowing snow.

WEDNESDAY: AM sun / PM clouds. Low 0. High 15.

THURSDAY: AM clouds / PM sun. Low 3. High 20.

FRIDAY: Cloudy. Chance of snow. Low 10. High 25.

SATURDAY: Cloudy. Chance of snow. Low 18. High 28.

9:21AM

Lots going on in the coming days! Let’s break it down then follow it with an updated detailed forecast for eastern MA, southern NH, and RI…

Saturday / Sunday … Warm front pushes through the region first thing Saturday putting the region in a slice of mild but windy weather into Sunday until an arctic cold front arrives from the west and introduces the coldest air of the season so far. However, this air will not plunge in all at once, but we will see the temperature fall off steadily later in the day after a mild early and middle part of the day. Still not sure if we see any rain/snow showers with the front and a small trough coming along right behind it, but I will toss them into the forecast just in case.

Monday / Tuesday … As the arctic air becomes established, a southward extension of the Polar Vortex (ask me if you missed the definition of the PV previously) will kick off a storm just south to southeast of New England. An inverted trough, or extension of elongated low pressure northwest of the low center, will create instability and this should be enough to get snow to develop over the region Monday night into Tuesday. Though not expected to become a major snowstorm, accumulation is likely, and may be enhanced by onshore winds in many coastal areas.

Wednesday / Thursday … The coldest air mass many of us have seen in 2 years will be here as the arctic comes for a visit (in modified form of course, but still quite cold for southern New England).

End of week … Uncertain about this, but watching the potential for a winter storm. Just simply too early to be sure how this will play out. Plenty of time to chase this potential down.

Forecast details …

TODAY: Variably cloudy. Highs 43-48. Wind SW 15-25 MPH gusting over 30 MPH.

TONIGHT: Variably cloudy. Lows 33-38. Wind SW 10-20 MPH gusting over 25 MPH.

SUNDAY: Variably cloudy through early afternoon with a slight chance of rain showers. Partly cloudy to mostly sunny remainder of day with a very slight chance of snow showers. Highs 42-47 by midday then falling into the 30s. Wind SW 15-30 MPH shifting to W.

MONDAY: Partly to mostly cloudy. Snow showers especially later afternoon and night. Low 15. High 27.

TUESDAY: Mostly cloudy. Snow or snow showers likely especially during the morning. Low 12. High 22.

WEDNESDAY: Mostly sunny. Low 1. High 16.

THURSDAY: Mostly sunny. Low 0. High 20.

FRIDAY: Mostly cloudy. Chance of snow. Low 10. High 26.

3:28AM

As a wave of low pressure sent snow over the top of southeastern New England during the night, dry air pushing down from the north has prevented the snow from reaching the ground in much of the region except  parts of Cape Cod and the Islands. After a brief shot of ocean-effect snow showers over the Outer Cape, any snow activity will push out to sea early today, leaving the region dry and much colder. A low pressure area pivoting around the southern edge of the Polar Vortex will pass north of New England, dragging milder air in with it Saturday into early Sunday, but a strong arctic cold front will pass through during the day Sunday, initiating a temperature fall which will be underway in earnest during the Patriots/Ravens game on Sunday evening. This will lead to about 4 days of very cold weather as arctic air dominates the region. A storm threat being watched for Monday night and Tuesday is increasingly looking like it will materialize too far out to sea to bring significant snow, but a period of snow especially in southeastern areas is possible. This system will serve to bring down even stronger wind and more intense cold during the middle of the week. Despite some model forecasts of a quick warm-up late in the week I am reluctant to buy into this and believe, though we may moderate, that the pattern will remain chilly, and we may even need to eye a potential winter storm of some type during the January 25-27 time-frame. Plenty of time to watch for this possibility.

Updated forecast for eastern MA, RI, and southern NH…

OVERNIGHT: Mostly cloudy. Snow over Cape Cod and the Islands with up to an inch or  2 accumulation. A few snow flakes in the air toward Plymouth County but no accumulation. Lows drop to the 10s north to 20s south. Wind N 5-15 MPH.

FRIDAY: Any morning clouds and lingering snow over Cape Cod pushing out to sea, otherwise mostly sunny. Highs around 30. Wind N to NW 10-20 MPH and gusty.

FRIDAY NIGHT: Partly cloudy. Lows 15-20.  Wind NW to W 10-15 MPH and gusty.

SATURDAY: Partly cloudy. Highs in the 40s. Wind W to SW 10-20 MPH and gusty.

SATURDAY NIGHT: Partly cloudy. Lows around 30. Wind SW 10-20 MPH and gusty.

SUNDAY: Variably cloudy with a passing rain or snow shower morning through early afternoon. Slight chance of a heavier snow squall. Partly cloudy to sunny rest of day. Highs 40-45 in the morning, falling through the 30s in the afternoon. Wind SW 15-25 MPH and gusty, shifting to NW. Foxboro MA outlook for the AFC Championship Game between the Patriots and Ravens: Mostly clear, gusty NW wind, kick-off temperature in the upper 20s, end-of-game temperature in the lower 20s with wind chill closing in on zero at times.

MONDAY – MLK JR DAY: Sunny. Low 6. High 21.

TUESDAY: Partly sunny with a chance of snow showers. Low 3. High 20.

WEDNESDAY: Partly cloudy and windy. Low 1. High 17.

THURSDAY: Mostly sunny. Low 0. High 20.

FRIDAY: Partly sunny. Low 4. High 27.

2:26AM

We will be under the influence of the circulation around the Polar Vortex (PV) as a general rule for the next week plus. Although the PV is normally associated with very cold weather, it will not be continuously very cold here in southern New England, especially at the outset, as the PV will become elongated and send a strong westerly flow across New England, still grabbing pieces of milder air from the south and mixing them with intrusions of Arctic air from Canada. We will be in the milder air today, colder air Friday, milder air again Saturday into Sunday, and then plunge into much colder air by the tail end of the weekend into the first half of next week. At this time, it looks like the circulation of the PV will be strong enough to deflect most storm development out to sea. One such occurrence will be tonight, with another sometime early next week. In between these, another disturbance will pass north of the area on Sunday. It is this disturbance that will send an Arctic cold front through the region, introducing the coldest air of the season so far by the start of next week.

Updated forecast for eastern MA, RI, and southern NH…

TODAY: Mostly to partly sunny – filtered sun in RI & southern MA and a few lower clouds moving down from the north into southern NH & northern MA during the afternoon. Slight chance of an isolated rain or snow shower NH & northern MA end of the afternoon. Highs around 40. Wind W increasing to 10-20 MPH, a few higher gusts possible.

TONIGHT: Partly to mostly cloudy. A period of snow Cape Cod and the Islands with up to 1 inch accumulation possible over the Islands and Outer Cape. Lows around 20. Wind shifting to N 5-15 MPH.

FRIDAY: Mostly to partly cloudy southeastern MA into mid morning with any snow on the Outer Cape ending, otherwise partly cloudy too mostly sunny. Highs 30-35. Wind N 10-20 MPH with higher gusts.

FRIDAY NIGHT: Partly cloudy. Lows 15-20. Wind W 10-20 MPH.

SATURDAY: Partly to mostly sunny. Highs 40-45. Wind WSW 15-25 MPH.

SATURDAY NIGHT: Mostly clear. Lows 20-25. Wind WSW 10-20 MPH.

SUNDAY: Mostly sunny to partly cloudy. Slight chance of a few passing snow showers. Highs around 40 by early afternoon then dropping to the 20s by late in the day. Wind WSW 10-20 MPH and gusty shifting to NW 15-25 MPH and gusty by late in the day.

MONDAY – MLK JR DAY: Mostly sunny. Low 6. High 24.

TUESDAY: Mostly cloudy. Low 8. High 22.

WEDNESDAY: Partly sunny. Chance of snow showers early. Low 1. High 19.

7:21PM

The messy midweek storm is about done with only lingering drizzle & rain over southeastern and eastern MA as well as RI and spotty mixed precipitation to the north and west, all set to wind down and end overnight. If you have slush and/or snow out there that has not been moved yet, it will be wise to have it moved tonight as it will freeze up overnight and even more-so tomorrow night as we see the a preview push of very cold air from an Arctic reservoir of air in Canada, otherwise known as the Polar Vortex. This will be dominating the weather pattern in the next week or so, with several shots of cold to very cold air. A milder interlude after Friday’s cold shot will take place Saturday into Sunday, but by later Sunday the first in a series of much colder shots of air will get here, just in time for the Patriots / Ravens NFL AFC Championship game at Foxboro!

In terms of snow threats, low pressure will be developing off the Mid Atlantic Coast and intensifying as it passes south of Cape Cod Thursday night through early Friday.  This looks like it will scrape Cape Cod with some accumulating snow but should largely be a miss for the majority of the region. Another storm offshore around next Tuesday looks like it will stay mainly out to sea at this time. Another threat looms later next week but is much too far away to really have any idea what may happen with that one.

Updated forecast for eastern MA, RI, and southern NH…

TONIGHT: Overcast with areas of fog and a few periods of light snow & rain to start, then breaking clouds and eventual clearing west to east. Watch for the formation of icy spots on untreated surfaces. Lows 25-30. Wind light variable becoming W up to 10 MPH.

THURSDAY: Sunshine mixed with clouds. An isolated rain or snow shower over northern MA and southern NH. Highs 37-42. Wind W around 10 MPH.

THURSDAY NIGHT: Mostly cloudy. A period of snow with up to 1-3 inches possible over Cape Cod and the Islands and perhaps far southern RI, and a little light snow with under 1 inch near the Cape Cod Canal, with nothing to the north. Lows 20-25. Wind variable becoming NE for a while in southeastern MA and RI up to 10-15 MPH.

FRIDAY: Partly cloudy to mostly sunny. Highs around 30. Wind NW 10-20 MPH and gusty.

SATURDAY: Partly cloudy. Low 20. High 43.

SUNDAY: Partly cloudy. Chance of snow showers. Low 28. High 40 midday then falling.

MONDAY – MLK JR DAY: Mostly sunny. Low 8. High 21.

TUESDAY: Cloudy. Low 11. High 22.

WEDNESDAY: Clearing. Low 1. High 16.

7:49PM

A frontal boundary just southeast of New England will act as a running board for a wave of low pressure, which will move up and across extreme southeastern New England (center probably passing just south of Cape Cod) during Wednesday afternoon. This will send a shield of light to moderate precipitation across southeastern New England on Wednesday. Milder ocean air will become involved with this system especially since we are really not that deep into the cold air mass which is just trying to push into the region at this time.

Precipitation time-table and type: Expect the edge of the precipitation to be moving across the region from southwest to northeast during the overnight hours (midnight to 6AM). Snow will break out in most areas except mixed rain and snow over Cape Cod and the Islands. During the morning hours up through noon or shortly after will be when the steadiest precipitation occurs. This will be in the form of mix to mainly rain Cape Cod and Islands into southern RI and the South Shore of MA, but as you move inland mix will become snow and it may stay all snow or at least mostly snow mainly north of the Mass Pike and from just west of I-95 west and north. Enough mild air may finally reach into some of these areas during the afternoon for it to become too warm for snow, but by then the vast majority of the precipitation will have fallen and there will be only spotty mix/mist left. All precipitation will be over by early evening.

Snow Accumulation: Nothing over Cape Cod and the Islands, slushy coatings at most then melting in coastal RI and the MA South Shore, building rapidly up to 2-6 inches elsewhere with the highest amounts in the highest elevations of north central MA.

Beyond the Wednesday event…

Cold front slices through the region Thursday with nothing more than a rain or snow shower, but introduces a short-lived shot of cold air for Friday (a hint of things to come). Moderating temperatures Saturday into Sunday as the Polar Vortex wobbles about and pulls back slightly, allowing surface low pressure to cut northwest of New England. This low will drag an arctic cold front across New England Sunday, which may be accompanied by a few snow showers/squalls. This will introduce what is expected to be the first in a series of very cold blasts of air, the first arriving Sunday night (during the Patriots/Ravens game) through Monday (MLK Jr. Day). More of these will follow next week as a very cold pattern settles in.

Storminess next week? It remains to be seen how things will work out, but this looks like a largely cold/dry pattern coming. However, with pieces of energy rotating around a wobbly Polar Vortex, we cannot rule out a few threats of snow (watching Tuesday & Friday of next week as potential threat days, of course timing subject to change).

Reeling things back in, details for the next 7 days for eastern MA, RI, and southern NH…

OVERNIGHT: Clouds thicken. Snow/mix/rain (details above) developing southwest to northeast from around midnight to dawn. Lows from the upper 20s south central NH to lower 30s most other areas, some middle 30s Cape Cod. Wind near calm.

WEDNESDAY: Overcast. Snow north and west, mix/rain southeast (details above), steadiest in the morning, with a slight shift northwestward of the rain/snow line before precipitation tapers in the afternoon. For accumulations, see details above. Highs from around 32 north and west of Boston to the lower 40s Cape Cod and the Islands. Wind E to NE up to 10 MPH.

WEDNESDAY NIGHT: Clearing west to east before midnight then some clouds returning after midnight. Lows in the 20s to around 30, mildest Cape Cod. Wind shifting to W up to 10 MPH. Watch for icy spots on untreated surfaces!

THURSDAY: Mostly cloudy to partly sunny. Chance of passing rain or snow showers. Highs around 40. Wind W 10-20 MPH with higher gusts, shifting to NW by late day.

THURSDAY NIGHT: Mostly clear. Lows around 10. Wind NW 10-20 MPH and gusty. Wind chill around zero at times.

FRIDAY: Mostly sunny. Highs around 30. Wind NW 10-20 MPH and gusty.

SATURDAY: Partly cloudy. Low 17. High 40.

SUNDAY: Variably cloudy. Chance of snow showers. Low 20. High 38 then falling late.

MONDAY – MLK JR DAY: Mostly sunny. Low 5. High 20.

7:04PM

60 degrees was reached in many areas Monday afternoon as the sun came out. This was 5 to 10 degrees warmer than I had anticipated for the region. Well, that’s gone. As discussed on the last entry, we are in the process of changing the pattern, but it is going to take all week. There are a couple change to the previous forecast coming up, otherwise the overall idea is largely unchanged.

The frontal boundary sitting near the coast Tuesday-Wednesday will ripple just a bit further northward than I thought previously. The first wave of low pressure will stay mostly offshore through early Tuesday but will be close enough to throw a period of rain and some sleet across RI and southeastern MA. The second, however, will come closer and throw its precipitation shield over southeastern New England Wednesday. This will be good for some accumulating snow, especially away from the immediate coast. It will not be a big storm, but it may have some impacts on travel. Milder air near the ocean should keep this system as mix to rain with no accumulation in these locations.

The cold front that I expected to come through without precipitation on Thursday may in fact carry some rain and snow showers with it. The cold shot for Thursday night and Friday is still on track. A slight temperature recovery over the weekend is still expected to be followed by the first in a series of Arctic blasts by the start of next week.

Updated forecast for eastern MA, southern NH, and RI…

TONIGHT: Mostly cloudy with a period of rain and some mixed sleet/rain over southeastern MA and RI. Lows in the 30s. Wind N 5-15 MPH.

TUESDAY: Partly sunny – least sun Cape Cod, most sun north central MA/southern NH. Highs around 40. Wind NE 5-15 MPH.

TUESDAY NIGHT: Clouding over. Lows around 30. Wind light NE.

WEDNESDAY: Cloudy through mid afternoon with a period of snow, except mix/rain immediate coast, southeastern MA, and southern RI. Snow accumulation of nothing to a coating near the coast to 1-3 inches from the I-95 Belt north and west, highest amounts in the higher elevations. Breaking clouds west to east late. Highs in the 30s to around 40, mildest immediate coast. Wind NE to E 5-15 MPH.

THURSDAY: Variably cloudy. Chance of snow and rain showers. Low 26. High 40.

FRIDAY: Mostly sunny. Low 16. High 31.

SATURDAY: Mostly sunny. Low 13. High 38.

SUNDAY: Partly cloudy. Chance of snow showers. Low 19. High 38.

MONDAY – MLK JR DAY: Mostly sunny. Low 10. High 23.

5:21PM

Today I’m going to do something a little different and go a little further than normal. Almost like TV Guide occasionally puts out 2 weeks of listings, I’m going to talk about the upcoming 2 weeks of weather, or how I think they are going to unfold. A detailed forecast will be provided only for the first week, as going into the 2nd week would be simply foolish to attempt, but we will discuss the pattern.

Week 1 (January 14-20): This week will feature a dip in temperature as a colder pattern begins to be slowly introduced, like dipping your toes into the chilly ocean before getting the courage to dive fully in. This will take place with the passage of 3 cold fronts. The first of these fronts will come through on Monday and will be the one pushing the murky air of the weekend out of here. The irony is, in the few hours before this front gets here, the mild air that could have dominated the weekend will finally have made it into southern New England fully, and the high temperature for the day will likely top 50 in most locations before starting to drop off. As this front slows offshore thanks to a the jet stream still flowing southwest-to-northeast over the area, a couple waves of low pressure will form and move northeastward along it. With cooler air coming into play, I cannot rule out the risk of a period or two of snow or mixed precipitation near the New England South Coast between Tuesday and Wednesday. It does not look like a major deal, and I don’t expect it to creep northward toward Boston but will keep an eye on it, just in case. The second in the series of cold fronts will arrive sometime Thursday and will do so with no precipitation, just some clouds. If anything did happen, it would be an isolated snow shower. Leaving this out of the detailed forecast for now. A sliver of high pressure will move in for Friday and Saturday before a third cold front moves through Sunday, getting us one step closer to some more serious cold air to cold. Can’t rule out a snow shower/squall with the 3rd front but it’s too far away to worry about any details with this. The reason we’re seeing just a slow change to colder with a series of fronts is because the Polar Vortex (a strong upper level low pressure area associated with very cold air often located north of the Arctic Circle) is making a push southeastward into eastern Canada, but will wobble around irregularly and elongate. The southern edge of this Polar Vortex (PV), instead of driving into the US Northeast, will flatten out into a bowl-like shape. This will keep the core of the coldest air just to the north of New England (though northern Maine would likely get into it) through this week. We will just see small pieces of colder air coming southward behind each cold front.

Skip to beyond the detailed forecast for week 1 for eastern MA, RI, and southern NH for a discussion of week 2…

TONIGHT: Mostly cloudy. Areas of fog. Chance of drizzle then a chance of rain showers. Temperatures holding in the 40s. Wind SW up to 10 MPH.

MONDAY: Mostly cloudy with isolated to scattered rain showers during the morning. Clearing west to east midday through afternoon. Highs 50-55 in the morning. Temperatures falling into the 40s in the afternoon. Wind SW 5-15 MPH gusting around 20 MPH in the morning, shifting to NW 10-20 MPH gusting around 30 MPH in the afternoon.

MONDAY NIGHT: Clouds return from southwest to northeast, thickest over RI and southeastern MA. Lows 25-30 except some lower 20s in sheltered inland areas far northwest of  Boston. Wind NW diminishing to 5-15 MPH.

TUESDAY: Partly sunny overall with most sun northwest and least sun southeast. Slight chance of a period of light snow/mix near the South Coast. Highs around 40. Wind NW to N 5-15 MPH.

WEDNESDAY: Variably cloudy. Brief mix far southeast? Low 25. High 40.

THURSDAY: Partly cloudy. Low 25. High 40.

FRIDAY: Mostly sunny. Low 18. High 35.

SATURDAY: Partly cloudy. Snow shower at night? Low 15. High 39.

SUNDAY: Partly cloudy. Snow shower/squall? Low 19. High 36.

Week 2 (January 21-27): Using the ECMWF (or European) model for guidance, believing that it has a better handle on the pattern than the less-stable GFS (American model), and a little bit of non-model meteorology, I am becoming increasingly confident that we will be diving into a cold pattern, seeing between 1 and 3 pushes of pure arctic air during this week. The timing and number of pushes or reinforcements will depend on development and movement of small disturbances coming around the base of the trough, or the southern end of the Polar Vortex, which appears that it will take up residence near or just east of Hudson Bay Canada and extend southward into the Great Lakes and Northeast. This is a very cold pattern for this area. The center of this vortex tends to wobble around when it is this far to the south, but the general position may be held in place for a while due to high pressure ridging solidly in place to its north and east, and also over western North America. So in summary, it is with a reasonable amount of confidence that I expect a very cold week with a few potential and most likely light snow or snow shower events, but largely dry weather. How big a story will the cold become? Time will tell.

9:41AM

The weather is in a lazy mood. Not just this weekend’s weather, but the overall pattern impacting southern New England. What potentially could have been a windy and record warm weekend with sun and clouds will instead be a mainly overcast, foggy, and at times drizzly weekend (though Sunday will still improve a little over today), as we bring the warmest air up over some stubborn cooler marine air stuck near the ground. Again, the worst of that will be today as we will finally start to break out of it during the day Sunday, but just in time for the arrival of a cold front from the west.

How will the cold front, which will mark the start of a new weather pattern, be lazy? Well, the front will barely get itself by us before running out of steam offshore. The jet stream is not helping, as it will be slow to change its configuration as an area of low pressure in the upper levels coming out of Canada will be pushing against a strong high pressure ridge holding on over the western Atlantic. So the front will have to wait for reinforcing pushes later in the week, and even this will get done somewhat lazily as the polar vortex (or strong low pressure area in the upper levels with lots of cold air reflected at the surface) never really makes a hard push southeastward into the USA but rather elongates across southeastern Canada. When this happens, the coldest air doesn’t come in as hard as it may under another pattern. So yes, it is going to get colder, perhaps very cold at times, but the coming cold snap which has been prematurely (in my opinion) advertised as a possible record arctic outbreak, will probably not turn out to be all too memorable when we look back on it.

A memorable Arctic outbreak will be remembered as one that set numerous record low temperatures, and record low-high temperatures, during its run. Such an outbreak occurred in 2 shots in January 1982 (“The Ten Days That Rewrote The Weather Record Books”), with another memorable one in January 1994. I’m not so sure what is coming up, at least initially, will fall into the same category that these events did. If things come together just right, down the road a bit at the end of January or sometime in February, we may be talking about something more substantial in terms of cold. Big snow, in my opinion, is now going to be even harder to come by, since it seems like the PNA/NAO do not want to work together to set things up just right. It’ll be like trying to roll dice several times and only see a major snowstorm if you roll a double-six. Welcome to Weather Vegas!

It will be interesting to see how this all works itself out in the atmosphere in the coming days and weeks. One thing that has been sure, other than the bump in the road slightly wetter than normal December, we remain in an overall dry pattern and regardless of whether you love or hate snow and cold, we may be setting up for some drought issues down the road if we enter Spring/Summer in the same dry regime we are in now.

In the much shorter term, we also have to look out for some coastal flooding issues at high tide times midday and late tonight due to astronomically very high tides. Thankfully, no major storm condition exists with onshore winds or we’d be seeing more serious problems. Minor flooding is indeed possible along the East Coast from Plymouth County northward.

The updated forecast for eastern MA, RI, and southern NH…

TODAY: Overcast. Areas of fog and drizzle. Highs in the 40s. Wind light variable.

TONIGHT: Cloudy. Areas of fog and drizzle. Lows around 40. Wind light variable.

SUNDAY: Mostly cloudy. Areas of fog and drizzle still possible in the morning. Breaks of sun possible in the afternoon. Highs push into the 50s. Wind light and variable eventually becoming SW 5-15 MPH.

MONDAY: Mostly cloudy. Rain showers likely. Low 40. High 49.

TUESDAY: Variably cloudy. Snow showers possible. Low 25. High 40.

WEDNESDAY: Partly sunny. Low 20. High 35.

THURSDAY: Partly cloudy. Low 16. High 32.

FRIDAY: Mostly sunny. Low 10. High 29.

10:55PM

And so begins a week-long pattern transition, much of it without a whole lot of sunshine.  The mild stretch of weather will be coming to an end but that will take time. We’ll go through some unsettled weather to get from it to the onset of another stretch of cold weather.

A low pressure area will pass west of New England late Friday with a warm front moving into the region. This front will slow down and briefly stall for a while on Saturday with a little wave of low pressure along it. Some wet weather will move in late Friday and linger to early Saturday. The clouds will dominate the weekend, even when the warm air finally moves in full force on Sunday.

A transition to colder weather will take place during the Monday-Wednesday period, which will be unsettled, as a series of cold fronts moves through the region slowly, along with waves of low pressure moving up along it. Most of the precipitation will likely fall is rain but some mix/snow may also occur, depending on the regional temperature profile.

By late in the week, mainly dry and much colder weather will be in control as the jet stream finally shifts enough to let some very cold air out of Canada and into New England.

Detailed forecast for eastern MA, RI, and southern NH…

OVERNIGHT: Mostly clear. Lows from the lower 20s inland valleys to lower 30s coast. Wind W shifting to N under 10 MPH.

FRIDAY: Increasing cloudiness. Highs 38-43. Wind NE up to 10 MPH shifting to SE late.

FRIDAY NIGHT: Cloudy. Periods of light rain, but freezing rain pockets are possible over portions of northwestern Middlesex County MA and south central NH early. Areas of fog developing. Lows 32-37. Wind SE to E up to 10 MPH.

SATURDAY: Mainly cloudy. Areas of fog  and a chance of drizzle especially in the morning. Highs from near 40 Merrimack Valley near the MA/NH border to near 50 in southern MA and RI. Wind up to 10 MPH from the E in southern NH and northeastern MA and from the SE to S elsewhere.

SATURDAY NIGHT: Mostly cloudy. Patchy fog. Temperatures steady in the 40s. Wind SE to S 5-15 MPH.

SUNDAY: Mostly cloudy. Highs 50-55. Wind S to SW 10-20 MPH.

MONDAY: Mostly cloudy. Chance of rain showers. Low 40. High 50.

TUESDAY: Cloudy. Chance of rain or mix. Low 33. High 43.

WEDNESDAY: Mostly cloudy. Chance of rain or snow showers. Low 30. High 40.

THURSDAY: Partly cloudy. Isolated snow showers. Low 20. High 33.

3:50PM
Forecast update for eastern MA, RI, and southern NH (discussion and full forecast later)…

THIS AFTERNOON: Sunny. Highs 43-48. Wind W 15-25 MPH.

TONIGHT: Clear. Lows 24-29 except 30-35 coast and urban areas. Wind W 5-15 MPH diminishing and shifting to N.

FRIDAY: Increasing clouds. Highs 40-45. Wind NE up to 10 MPH shifting to SE.

SATURDAY: Mostly cloudy. AM drizzle. Low 35. High 45.

SUNDAY: Partly sunny. Late day rain shower. Low 35. High 53.