Category Archives: Weather

A Slip-Up, Then A Trip Up

7:25AM

First a slippery morning today as temperatures have stayed below freezing in most areas of southeastern New England except Cape Cod and the Islands where it has made it into the middle 30s with a few areas of spotty light rain and drizzle there. Elsewhere, spotty light snow, frozen drizzle (tiny ice pellets) and freezing drizzle (liquid drizzle freezing on surfaces) has been occurring and will continue through dawn. This will continue to make untreated surfaces slippery, so use caution if outside into the mid morning hours. By late morning onward, temperatures in most locations should rise above freezing, though they may stay close to the freezing mark over some interior valleys. Precipitation will be over in all locations though by the middle of the morning and the balance of the day will be precipitation-free. However, as the warm front responsible for the unsettled weather finally begins a push northward, some additional light rain/drizzle may develop Tuesday evening, and there may be a few pockets of freezing rain/drizzle over interior valleys. But finally the warm air will win out, and the temperature will take a trip up – all the way into the 50s to around 60 by Wednesday. A band of rain showers and possible thunderstorms will mark the end of the very brief warm up Wednesday evening through early Thursday morning from west to east across the region, as the first of 2 cold fronts moves through. Windy and drier weather will arrive during the day Thursday but it will not get too cold right away. A sharper cold front will arrive Thursday night or Friday morning and introduce a shot of much colder weather for the end of the week. I’m still watching the weekend period to see if any additional storminess forms nearby, bringing some snow.

Updated forecast for southeastern New England…

THROUGH MID MORNING: Overcast with spotty  light snow, frozen drizzle, and freezing drizzle except liquid drizzle/very light rain Cape Cod & the Islands. Cloudy thereafter. Temperatures 30-35. Wind light variable.

LATE MORNING THROUGH AFTERNOON: Cloudy. Highs 35-40. Wind light E-SE.

TONIGHT: Cloudy. Periods of light rain and drizzle with some freezing rain/drizzle possible far northwest of  Boston. Lows 32-38 early then temperatures rising into the 40s overnight. Wind light SE shifting to S and increasing to 5-15 MPH.

WEDNESDAY: Mostly cloudy. Highs 55-60. Wind SSW 10-15 MPH with higher gusts.

WEDNESDAY NIGHT: Cloudy with a band of rain showers and possible thunderstorms moving across the region west to east. Some heavy rain possible. Lows 50-55. Wind SW 15-25 MPH gusting 35-50 MPH shifting to W overnight.

THURSDAY: Mostly cloudy to partly sunny. Rain showers possible in southeastern MA in the morning. Temperatures falling slowly through the 40s. Wind W 15-25 MPH gusting over 30 MPH.

FRIDAY: Partly cloudy. Low 20. High 33.

SATURDAY: Mostly cloudy. PM snow. Low 18. High 28.

SUNDAY: AM snow. PM clearing. Low 18. High 28.

MONDAY: Mostly sunny. Low 16. High 32.

The Week Ahead (Update)

This is largely the same post as the previous one, but edited to update for time periods, add a threat of some freezing rain to Monday evening, and lower Tuesday’s temperatures a bit. A few minor changes are made in the discussion below……………………………..

12:43AM

An active week of weather leads off with a warm front moving into the region Monday, the mild air behind it overrunning the cold air in place, resulting in a period of snow and mixed precipitation developing from southwest to northeast during the day Monday lasting into the evening. Though snow amounts will be generally light (mostly under 3 inches), some slippery travel is possible for the Monday afternoon / evening commute and for a few more hours into the night, especially across interior RI up through eastern MA into southern NH. Some freezing rain may take place along the changeover line mainly south and west of Boston during the evening hours, so be aware that a coating of glaze may take place in some areas.

The warm front responsible for the wintry precipitation Monday will slog slowly northward during Tuesday, which will become slightly milder from south to north. The front’s movement will be very slow, so the mild air is going to struggle to reach areas north of the Mass Pike. I’m not expecting much additional precipitation on Tuesday at this point, but with the front not too far away, it’s always possible a few areas of light rain and drizzle (as it will be milder aloft) may occur. So expect clouds to rule more than anything. If a few areas of rain/drizzle take place, they would be most likely to occur during the early nighttime hours.

By Wednesday, as a strong cold front approaches from the west but doesn’t quite make it into the region during the day, expect a stronger push of warmer air from the south and southwest. It’s not impossible that some areas may approach or reach 60, and much of the day should be rain-free, as it looks like the cold front’s timing would bring most of the wet weather, possibly a ribbon of heavy rain including thunderstorms, through from west to east during the evening and nighttime hours.

The cold front should be moving offshore during Thursday, which will transition back to colder weather via a strong west wind and possibly a few lingering rain or snow showers.

The first 3 days of February (Friday-Sunday) look cold and there is a shot of a winter weather event in there as well. There are far too many variations on medium range computer guidance to even attempt any detail here yet, but will make a best-guess for now and then fine-tune as it gets closer.

Forecast for southeastern New England (southern NH, eastern MA, RI)…

MONDAY: Thickening overcast. Snow developing from west to east during the afternoon through dusk except mixed snow/rain South Coast and rain on the Islands. Highs 30-35 except some upper 30s on the Islands. Wind light variable eventually becoming SE to E up to 10 MPH.

MONDAY NIGHT: Overcast. Snow, sleet, and some freezing rain, especially south and west of Boston, with liquid rain outer Cape Cod through the Islands, all ending from west to east around midnight. Snow accumulation in mix areas of less than 1 inch, 1-2 inches elsewhere. Temperatures rising slowly through the 30s. Wind light SE shifting to S.

TUESDAY: Mostly cloudy. Chance of drizzle and light rain at times mainly northern MA and southern NH, especially late day/evening. Highs 35-45 north to south. Wind light S.

WEDNESDAY: Mostly cloudy. A line of showers and possible thunderstorms west to east at night. Low 40. High 60.

THURSDAY: Variably cloudy. Chance of rain and snow showers. Temperatures falling through the 50s overnight and the 40s during the day to the 30s at night.

FRIDAY: Mostly sunny. Low 20. High 29.

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

SUNDAY: Clearing. Low 18. High 31.

The Week Ahead

1:50PM

Starting the outlook for the coming 7 days a bit early, as there is not much to talk about on this bright and cold Sunday afternoon. The tranquil chill is a bit of a rest-up ahead of what will be an active and changing weather week in southeastern New England.

This will lead off with a warm front moving into the region Monday, the mild air behind it overrunning the cold air in place, resulting in a period of snow and mixed precipitation developing from southwest to northeast during the day Monday lasting into the evening. Though snow amounts will be generally light (mostly under 3 inches), some slippery travel is possible for the Monday afternoon / evening commute and for a few more hours into the night, especially across interior RI up through eastern MA into southern NH.

The warm front responsible for the wintry precipitation Monday will slog slowly northward during Tuesday, which will become milder from south to north. I’m not expecting much additional precipitation on Tuesday at this point, but with the front not too far away, it’s always possible a few areas of light rain and drizzle (as it will be milder aloft) may occur. So expect clouds to rule more than anything.

By Wednesday, as a strong cold front approaches from the west but doesn’t quite make it into the region during the day, expect a stronger push of warmer air from the south and southwest. It’s not impossible that some areas may approach or reach 60, and much of the day should be rain-free, as it looks like the cold front’s timing would bring most of the wet weather, possibly a ribbon of heavy rain including thunderstorms, through from west to east during the evening and nighttime hours.

The cold front should be moving offshore during Thursday, which will transition back to colder weather via a strong west wind and possibly a few lingering rain or snow showers.

The first 3 days of February (Friday-Sunday) look cold and there is a shot of a winter weather event in there as well. There are far too many variations on medium range computer guidance to even attempt any detail here yet, but will make a best-guess for now and then fine-tune as it gets closer.

Forecast for southeastern New England (southern NH, eastern MA, RI)…

REMAINDER OF AFTERNOON: Sunshine. Highs 23-28. Wind NW 10-15 MPH gusting 20-25 MPH.

TONIGHT: Clear start, increasing high clouds west to east late. Low from near 5 interior valleys to 10-15 coastal and urban areas. Diminishing NW wind.

MONDAY: Thickening overcast. Snow developing from southwest to northeast from mid afternoon through dusk except mixed snow/rain South Coast and rain on the Islands. Highs 30-35. Wind light variable eventually becoming SE to E up to 10 MPH.

MONDAY NIGHT: Overcast. Snow inland, mix coast especially south of Boston and rain outer Cape Cod & Islands. Precipitation ending from west to east before midnight. Snow accumulation in mix areas of less than 1 inch, 1-3 inches elsewhere. Temperatures rising slowly through the 30s. Wind light SE shifting to S.

TUESDAY: Mostly cloudy. Chance of drizzle and light rain at times mainly northern MA and southern NH. Highs around 40. Wind light S.

WEDNESDAY: Variably cloudy. Rain showers & possible thunderstorms arriving at night. Low 40. High 60.

THURSDAY: Variably cloudy. Chance of rain and snow showers. Temperatures falling through the 50s overnight and the 40s during the day to the 30s at night.

FRIDAY: Mostly sunny. Low 25. High 35.

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

SUNDAY: Clearing. Low 18. High 28.

Snow-Between

10:12AM

A cold weekend with high pressure in control will progress to a milder Tuesday and Wednesday, but getting from cold to mild will be accomplished with a period of snow later Monday with the passage of a warm front. This does not look like a significant event in terms of amounts, however we will have to watch for timing of the event which may result in a slick evening commute Monday and continued slippery untreated roads Monday evening. More on this later. A cold front will put an end to the brief mild party by Thursday as a return to colder weather commences. Looking ahead, the first days of February look cold, and we may have to also watch for potential storminess.

Forecast for eastern MA, RI, and southern NH…

TODAY: Mostly sunny morning except clouds and snow showers with 1/2 inch to 1 inch accumulation on Outer Cape Cod. Partly cloudy afternoon. Highs 23-28. Wind NW increasing to 10-20 MPH.

TONIGHT: Mostly cloudy evening. Partly cloudy overnight. Lows 5-10. Wind NW 10-20 MPH with higher gusts in the evening, diminishing overnight. Wind chill near to below zero at times.

SUNDAY: Mostly sunny. Highs 22-27. Wind NW 10-20 MPH with higher gusts.

MONDAY: Cloudy. Afternoon & evening light snow. Low 16. High 31.

TUESDAY: Mostly cloudy. Morning sleet and rain showers. Low 31. High 41.

WEDNESDAY: Variably cloudy. Afternoon rain showers. Low 41. High 51.

THURSDAY: Partly sunny. Scattered rain to snow showers. Temps falling 40s to 30s.

Cold Ease

2:02AM

It will still be cold through the weekend, but it will ease up from the levels of the last 2 days. A small clipper low pressure system will drop down from Canada via the Great Lakes tonight bringing some light snow to MA and RI. It will be too dry for anything more than flakes in the air in southern NH. There will be some additional moisture passing to the south, but the lack of phasing of the northern energy with the southern energy will prevent a significant snowfall in this area. More cold and dry weather will return for the weekend.

A moderating trend will get underway Monday and last into the middle of next week, but will be rather short-lived, as it looks like cold air will charge back as the month comes to an end. Some unsettled weather will take place during this time, and this may include some variety of precipitation.

Forecast for southern NH, eastern MA, and RI…

TODAY: Increasing cloudiness. Highs 20-25. Wind NW 10-15 MPH gusting 20-25 MPH in the morning, shifting to N and diminishing to 5-10 MPH in the afternoon.

TONIGHT: Cloudy. A period of light snow, especially MA & RI, with accumulations of a dusting to 1 inch, except  locally around 2 inches over Cape Cod and the Islands. Lows 15-20. Wind N 5-10 MPH.

SATURDAY: Variably cloudy. Highs 25-30. Wind NW 10-15 MPH with higher gusts.

SATURDAY NIGHT: Mostly clear. Lows 10-15. Wind NW 5-15 MPH.

SUNDAY: Mostly sunny. Highs 25-30. Wind NW 10-20 MPH.

MONDAY: Partly cloudy. Low 16. High 35.

TUESDAY: Mostly cloudy. Chance of light snow, sleet, and rain. Low 29. High 40.

WEDNESDAY: Mostly cloudy. Chance of rain showers. Low 35. High 50.

THURSDAY: Variably cloudy. Chance of snow showers. Low 30. High 40.

Bitter Winds

12:28AM

With many focusing on whether or not we’ll have a snowstorm late Friday, it should not be lost that we’re in the middle of a very cold outbreak that will continue through early Friday. One disturbance is moving south of the region during the next 24 hours then blowing up a storm that will remain well offshore. A second disturbance will come along late Friday through early Saturday but should be far enough south of the region to limit the snowfall. Another shot of cold air is expected through the end of the weekend, but not as cold as what is currently occurring. A period of moderating temperatures is still expected next week for the final days of January.

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

OVERNIGHT: Mostly clear. Lows around 0. Wind W 5-15 MPH gusting over 20 MPH. Wind chill near to below 0.

THURSDAY: Mostly sunny. Highs 15-20. Wind NW 15-25 MPH and gusty. Wind chill near 0.

THURSDAY NIGHT: Mostly clear. Lows 0-5 inland, 5-10 coast. Wind N 5-15 MPH.

FRIDAY: Increasing cloudiness. Highs 20-25. Wind N to NE 5-10 MPH.

FRIDAY NIGHT: Cloudy. Snow developing, accumulating from a coating to 5 inches from northwest of Boston to Cape Cod and the Islands. Lows 15-20. Wind NE 5-15 MPH.

SATURDAY: Clearing. Highs 25-30. Wind N to NW 10-20 MPH with higher gusts.

SUNDAY: Sunny. Low 8. High 27.

MONDAY: Variably cloudy. Low 20. High 35.

TUESDAY: Partly sunny. Low 25. High 40.

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

Arctic Chill

12:42AM

Here it is – the well-advertised arctic cold outbreak that it seems like took longer to get here than an excited 6-year-old’s birthday party. Some number of days ago, before the “Case Of The Mysterious Norlun” distracted us, I had mentioned that this cold outbreak, though significant, would not be memorable. We’re not going to set any temperature records in this one, but nevertheless it will be the coldest it has been around here in 2 years from today through Friday morning, along with some bitterly cold wind chills. Use caution if you will be outside for any length of time. There will be a sneaky disturbance sliding across the sky just south of us early Thursday, responsible for some clouds, but nothing more.

Looking ahead a little to the storm threat for the end of the week, there is still some uncertainty as to how it will play out. A look at most guidance will show that the type of pattern we’re in will push the developing storm more east than north, lessening its impact potential in southern New England. But it would not take that much of a slightly more amplified jet stream than what these models indicate to bring that storm a little closer and increase the snow threat, and there are, in fact, a few models that indicate this possibility. With this uncertainty in place, I’ll play the cheap-way-out  middle of the road generic forecast wording for now, until I start to get a better feel for what will happen.

Beyond that event, which in whatever form it comes will be late Friday to early Saturday, expect a return to fair but cold weather Sunday, and then a moderation for the beginning of next week as the jet stream relaxes and lifts northward into southeastern Canada above a flat ridge of high pressure building across the east central United States. This will probably be a fairly short-lived moderation as there are already signs of another cold outbreak around the start of February.

Detailing the next 7 days for southern NH, eastern MA, and RI…

TODAY: Mostly sunny. Highs 14-19. Wind W 10-20 MPH with higher gusts. Wind chill below 10.

TONIGHT: Partly cloudy. Lows 0-5. Wind W 10-15 MPH gusting over 20 MPH. Wind chill -5 to -10, briefly colder at times.

THURSDAY: Mostly sunny.  Highs 12-17. Wind NW 10-20 MPH gusting to 30 MPH. Wind chill near to often below zero.

FRIDAY: Increasing cloudiness. Snow at night. Low 0. High 25.

SATURDAY: Clearing. Snow early morning. Low 15. High 26.

SUNDAY: Sunny. Low 10. High 27.

MONDAY: Variably cloudy. Low 20. High 35.

TUESDAY: Partly sunny. Low 25. High 39.

Has Anyone Seen My Norlun Trough?

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.

Not So Fast (Snow Update)

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.

Here We Snow! (There We Don’t!)

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.

The Week Ahead

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.

Weekend Update #2 (Sunday Morning)

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.

Weekend Update

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.

Cold Preview

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.

PV Time

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.