8:37PM

The transitional pattern continues…

Short term: Low pressure offshore to the east of southern New England has taken its time getting out of here, and one lobe of moisture may bring some rain showers to the South Shore of MA and parts of Cape Cod tonight.

Thursday & Friday split pair: Narrow high pressure will bring a slice of nice weather Thursday, though a bit cool. Low pressure will track northeastward from the Midwest into NY then down the St. Lawrence Valley Friday, redeveloping Friday night just east of New England. Ahead of the initial storm will come a period of rain which may be mixed with snow in some interior areas as cold air hangs on in the early stages of the storm Friday morning. By Friday noontime the warm sector will have enveloped all of southern New England. During this time a period of strong southeast to south winds will take place with the potential for some wind damage. As a cold front charges eastward across southern New England on Friday afternoon, a band of heavier rain and possible thunderstorms will take place, and may result in some additional wind damage and local flooding. Once this is by, a rush of drier and colder air will come in from the west Friday night.

Weekend: This colder air will make it possible for some wrap around moisture to produce snow showers Saturday. Weak high pressure should bring dry conditions and chilly air to the region on Sunday.

Christmas Eve & Christmas Day: It is far away, but the previous dry/cold outlook has to be replaced with a threat of a period of snow as a wave of low pressure passing just to the south of the region may be enough to throw some moisture into some cold air in place for a period of snow in some areas. Will this be enough for a white Christmas (defined as 1 inch or more of snow on the ground)? We’ll see.

In the mean time, the updated forecast for eastern MA, southern NH, and RI…

TONIGHT: Variably cloudy. A few rain showers along the South Shore of MA and over Cape Cod early. Lows 35-40. Wind W 5-15 MPH.

THURSDAY: Mostly sunny. Highs around 40. Wind W 5-15 MPH, diminishing.

THURSDAY NIGHT: Clouding over. Light rain and snow possible before dawn. Lows 30-35. Wind light variable to E.

FRIDAY: Mostly cloudy. A touch of light rain/snow early, a few rain showers later morning-midday, then a band of rain and possible thunderstorms pushing west to east through the region in the afternoon. Highs from the middle 40s well to the northwest to the middle 50s over Cape Cod. Wind E 10-20 MPH with higher gusts, shifting to south and increasing to 15-35 MPH with gusts over 40 MPH especially late morning through early afternoon, then shifting to SW 10-20 MPH in the afternoon, then W 15-25 MPH by sunset.

SATURDAY: Mostly cloudy with rain and snow showers. Low 30. High 40.

SUNDAY: Mostly sunny. Low 22. High 36.

MONDAY – CHRISTMAS EVE: Partly sunny. Chance of snow at night. Low 18. High 34.

TUESDAY – CHRISTMAS DAY: Mostly cloudy. Chance of snow in the morning. Low 20. High 33.

WEDNESDAY: Cloudy. Chance of snow or rain. Low 27. High 37.

10:34PM

The transitional pattern will continue for the next 7 days, through Christmas Day. Computer model solutions will likely be somewhat unstable during this time. My best guess at the pattern is that we will see drier and cooler air move in through early Thursday. Another low pressure area will traverse the region Thursday night and Friday. Some of the chilly air may be hard to scour out and make precipitation type issues for the forecast. Right now the thinking is that we may see some areas, especially north and west of Boston, start out as some snow late Thursday night into Friday before the warm sector blasts into the region and everyone ends up mild and wet. But as the low pressure area passes, colder air will wrap back in from the north and west. A race between the cold and the end of the precipitation makes it uncertain as to whether or not a period of snow will occur Friday night. Either way, we may see additional periods of snow on Saturday as an upper low pressure area comes across the region in a newly arrived cold air mass, with a surface low sitting just offshore. This should clear out on Sunday, and early next week (Christmas Eve & Christmas Day) should also be cold and mainly dry, though we will need to watch the orientation of the wind field as an ocean wind may set up and bring in ocean effect snow showers. There are many days to fine tune this.

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

TONIGHT: Mostly cloudy. Scattered rain showers except rain or snow showers in areas well north and west of Boston. Lows 33-38. Wind W increasing to 10-15 MPH.

WEDNESDAY: Partly to mostly sunny. Isolated rain or snow showers. Highs 40-45. Wind NW 10-20 MPH with gusts around 25 MPH.

WEDNESDAY NIGHT: Mostly clear. Lows from the upper 10s inland valleys to middle 20s coast. Wind NW to N decreasing to around 10 MPH.

THURSDAY: Sunny. Highs around 40. Wind light variable.

FRIDAY: Cloudy with mix to rain morning. Mostly cloudy with rain showers afternoon. Variably cloudy with rain showers changing to snow showers at night. Low 32. High 50.

SATURDAY: Cloudy. Periods of snow. Low 24. High 33.

SUNDAY: Partly sunny. Chance of light snow showers. Low 22. High 35.

MONDAY – CHRISTMAS EVE: Partly cloudy. Low 18. High 37.

TUESDAY – CHRISTMAS DAY: Partly sunny. Low 17. High 33.

10:44PM

A week of transition is underway from the mild pattern of December so far to a colder/dry pattern coming in the days ahead. This will take place with the passage of low pressure systems late Tuesday and late Thursday to early Friday. Both of these systems should be largely mild systems with rain for the forecast area. Looking ahead to the end of the week, it looks like it will be colder & mostly dry, but we may have to watch for a couple disturbances that may produce some snow showers.

Forecast for eastern MA, RI, and southern NH…

OVERNIGHT: Overcast. Areas of fog. Periods of rain and drizzle except some freezing rain and sleet in the 495 belt north of the Mass Pike up through southern NH. Lows 30-40 from north to south. Wind NE-E up to 10 MPH.

MONDAY: Overcast. Areas of fog. Periods of rain and drizzle. Highs 40-45. Wind E 5-15 MPH.

MONDAY NIGHT: Overcast. Periods of rain. Lows 35-40. Wind E 5-15 MPH.

TUESDAY: Overcast with periods of rain in the morning. Mostly cloudy with lingering rain showers in the afternoon. Highs 45-50. Wind SE 5-15 MPH in the morning shifting to W in the afternoon.

WEDNESDAY: Mostly cloudy and windy. Isolated rain and snow showers. Low 30. High 40.

THURSDAY: Mostly sunny. Low 25. High 42.

FRIDAY: AM cloudy with rain. PM variably cloudy with rain or snow showers. Low 35. High 43.

SATURDAY: Partly sunny. Low 25. High 38.

SUNDAY: Partly sunny. Low 20. High 36.

12:17PM

Short discussion now, full discussion next update…

The next several days will be a transition period between the mild pattern and the return to the pattern of November. It will feature the passage of 3 low pressure systems during the transition. None of these at the moment look like they have a great chance of putting down snow that will hang around for Christmas, but since that day itself is still 10 days away, we absolutely cannot discount the possibility of a White Christmas in southern New England, though I would say the percentage chance lies around that of climatology, at best.

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

THIS AFTERNOON: Mostly sunny. Highs around 40. Wind N around 10 MPH.

TONIGHT: Increasing cloudiness. Lows in the 20s. Wind NE under 10 MPH.

SUNDAY:  Cloudy. Snow and sleet developing except some rain near the South Coast. Precipitation changing to rain from south to north late in the day and at night. Minor accumulation of up to 1 or 2 inches may occur especially higher elevations north of the Mass Pike. Highs 35-40. Wind NE to E 10-15 MPH.

MONDAY: Cloudy. Drizzle and patchy fog. Chance of light rain. Low 35. High 45.

TUESDAY: Cloudy. AM rain. PM rain showers. Low 40. High 49.

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

THURSDAY: Partly sunny. Low 25. High 43.

FRIDAY: Mostly cloudy with rain AM. Variably cloudy with snow showers PM. Temperatures falling from the 40s through the 30s.

9:39PM

The headline deals with tonight through Saturday, in which high pressure will dominate (other than a quiet cold frontal passage Friday night). The mostly clear sky tonight allows a good view of the peak night of the Geminid Meteor Shower.

Beyond Saturday, things get more complicated, as we will find ourselves near a boundary of mild air to the south and a feed of cold air trying to press down from Canada. A series of storms will fire up along this boundary and bring some chances of precipitation from later in the weekend into the middle of next week. The details of these events remain elusive mainly due to the fact they are far enough out in time to not be able to tell the details, and also because computer guidance has been flip-floppy about the events. Given this, I’ll spare details in the forecast and stay generalized for now, fine tuning as they draw closer.

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

TONIGHT: Mostly clear. Lows in the 20s. Wind W under 10 MPH.

FRIDAY: Mostly sunny. Highs 44-49. Wind W 10-15 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 27-32. Wind W 10-15 MPH gusting around 20 MPH, shifting to N late.

SATURDAY: Mostly sunny. Highs 37-42. Wind N 5-15 MPH.

SATURDAY NIGHT: Increasing clouds. Lows 22-27. Wind NE under 10 MPH.

SUNDAY: Cloudy. Light snow by afternoon except rain or snow RI and southern MA. Light snow accumulation possible. Highs 32-37. Wind NE to E 5-15 MPH.

MONDAY: Mostly cloudy. Chance of light rain. Low 32. High 42.

TUESDAY: Partly sunny. Isolated snow showers. Low 30. High 40.

WEDNESDAY: Variably cloudy. Chance of snow showers. Low 22. High 35.

THURSDAY: Partly sunny. Chance of snow showers. Low 18. High 33.

12:25AM

“Halcyon Days” are defined as a stretch of chilly & quiet weather in late Autumn or early Winter. With high pressure dominating this will be the case for the next 5 days. It won’t be completely clear though as some high clouds fan across the southern sky and a few low clouds cross Cape Cod today from the influence of a wave of low pressure on the recently passed frontal system offshore. Another reinforcing cold front dropping down from the north late Friday night or early Saturday may also bring a few clouds with it, otherwise it’s quiet for a while.

There are increasing signs of a change in the weather pattern back to that of November, that is, chilly and dry. But let me caveat this by saying “dry” does not mean zero precipitation. It means below average precipitation. In fact, there is a chance of precipitation Sunday, and it may very well be snow for a good portion of the area. At this far-away stage it does not, however, look like a big storm. Just some snow that may be put down as we enter the final 10 days before Christmas. Stay tuned as this comes into focus in the days ahead.

For now, the updated forecast for eastern MA, RI, and southern NH goes something like this…

OVERNIGHT: High clouds southeastern MA & RI, clear elsewhere. Lows from around 20 inland valleys to near 30 immediate coast. Wind NW under 10 MPH.

WEDNESDAY: High clouds filter the sun at times especially southern MA and RI with brighter sun elsewhere. Also a few low clouds crossing Cape Cod from north to south. Highs around 40. Wind N 5-15 MPH.

WEDNESDAY  NIGHT: Mostly clear. Lows in the 20s. Wind N under 10 MPH.

THURSDAY: Sunny. Highs 40-45. Wind NW 5-15 MPH.

FRIDAY: Sunny. Low 30. High 47.

SATURDAY: Partly cloudy. Low 22. High 40.

SUNDAY: Cloudy. Chance of snow and rain. Low 30. High 38.

MONDAY: Mostly cloudy. Chance of snow showers. Low 28. High 37.

TUESDAY: Partly sunny. Chance of snow showers. Low 21. High 34.

12:56AM

The unseasonably mild air mass that flooded the region and produce downpours and even some thunder for parts of the region Monday is on the way out as high pressure pushes in and brings colder and drier weather through the middle of the week. Moderating air returns Friday but another cold air mass will be lurking just to the north of New England and may play a part by later in the coming weekend in bringing some rain/snow to the region as low pressure comes along.

Forecast for eastern MA, RI, and southern NH…

TODAY: Any lingering rain showers eastern areas especially Cape Cod ending by mid morning, otherwise clearing with increasing sun NW to SE. Highs 45-50. Wind NW 10-15 MPH.

TONIGHT: Clear. Lows 22-27. Wind NW 10-15 MPH gusting around 20 MPH.

WEDNESDAY: Sunny. Highs 35-40. Wind WNW 5-15 MPH.

THURSDAY: Sunny. Low 20. High 41.

FRIDAY: Sunny. Low 24. High 46.

SATURDAY: Partly cloudy. Low 29. High 43.

SUNDAY: Cloudy. PM snow/rain. Low 28. High 40.

MONDAY: Mostly cloudy. AM rain/snow showers. Low 32. High 38.

7:03AM

A very mild Monday as a warm front lifts north of the region first thing in the morning and a cold front approaches from the west. It will be unsettled though with clouds dominating and showers, some heavy, especially early in the day. Another round of showers Monday evening with a cold front passing west to east across the region will set the stage for a return to chilly weather Tuesday through midweek. Clouds may be stubborn to leave and there may even be a touch of light rain in southeastern areas Tuesday and a near-miss of snow in the same areas later Wednesday as a couple of waves of low pressure travel along the front which will slow down just offshore. High pressure will dominate with fair weather later in the week into the early part of the weekend with the next threat of unsettled weather coming later in the weekend, based on current timing of systems.

Forecast for eastern MA, RI, and southern NH…

TODAY: Cloudy. Numerous rain showers, a few heavy, moving southwest to northeast across the region during the morning, then scattered to just isolated light rain showers rest of day. Highs 55-60. Wind S to SW increasing to 10-20 MPH.

TONIGHT:  Cloudy. Another round of rain showers crossing the region from west to east. Lows 40-45. Wind SW 10-20 MPH shifting to W.

TUESDAY: Mostly cloudy start with a threat of a little light rain southeastern MA, then increasing sun northwest to southeast. Temperatures steady 40-45. Wind NW 5-15 MPH.

WEDNESDAY: Increasing clouds. Low 25. High 40.

THURSDAY: Mostly sunny. Low 22. High 42.

FRIDAY: Mostly sunny. Low 25. High 45.

SATURDAY: Partly sunny. Low 27. High 45.

SUNDAY: Mostly cloudy. Rain and snow showers. Low 30. High 40.

8:49PM

Just an update to the eastern MA, southern NH, and RI forecast. Full discussion Sunday!

OVERNIGHT: Breaking clouds above patchy fog. Lows 34-39. Wind W under 10 MPH.

SUNDAY: Sunshine in some clouds into afternoon then clouds increase by late in the day. Highs 43-48. Wind NW 5-15 MPH.

SUNDAY NIGHT: Clouds thicken and rain moves in. Temperatures steady in the 40s. Wind E 5-15 MPH.

MONDAY: Mostly cloudy. Any rain ends in the morning, maybe a shower in the afternoon. Highs 60-65 occurring late in the day. Wind SE shifting to SW increasing to 10-20 MPH.

TUESDAY: Clouds linger, maybe a period of light rain day and a few snow showers night. Low 40. High 45.

WEDNESDAY: Partly cloudy. Low 25. High 43.

THURSDAY: Mostly sunny. Low 22. High 43.

FRIDAY: Mostly sunny. Low 25. High 44.

SATURDAY: Partly cloudy. Low 25. High 47.

2:18AM

Ok, we had our chilly day, and now it’s time for another wave of mildness. This will get underway today as a warm front moves in from the southwest, bringing clouds and eventually some light rain later today and tonight. Low pressure will travel northwest of New England by Saturday and we’ll spend a bit of time in the warm sector, but with a chance of rain showers as a cold front crosses the region. This will set up a nicer day on Sunday, though not perfect as many clouds will be around. Another low pressure area will travel up the St. Lawrence Valley just to the north of New England later Monday and early Tuesday with a similar wave of unsettled and mild weather. High pressure should deliver drier and chilly air to the region by the middle of next week.

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

TODAY: Increasing clouds. Highs 45-50. Wind S to SW 5-15 MPH.

TONIGHT: Cloudy. A few periods of light rain. Lows 40-45. Wind SW 5-15 MPH.

SATURDAY: Mostly cloudy. Scattered rain showers, mainly morning through midday. Highs 50-55. Wind SW to W 5-10 MPH.

SATURDAY NIGHT: Partly cloudy. Patchy fog. Lows 35-40. Wind W under 10 MPH.

SUNDAY: Partly sunny. Highs 45-50. Wind NW 5-15 MPH.

MONDAY: Mostly cloudy. Rain showers likely. Low 41. High 56.

TUESDAY: Variably cloudy. Scattered rain showers day and snow showers night. Low 36. High 46.

WEDNESDAY: Partly cloudy. Low 23. High 41.

THURSDAY: Mostly sunny. Low 22. High 42.

11:46PM

The cold front went through, the cold air has come in and will be with us through Thursday night as high pressure moves across the region. A warm front will approach Friday, bringing clouds back. This front may produce some light rain late Friday before the warm sector visits for Saturday, along with a chance of rain showers. A little parcel of drier air will make Sunday the better of the 2 weekend days before another round of unsettled weather takes place early next week.

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

OVERNIGHT: Clear. Lows in the 20s. Wind NW 10-20 MPH.

THURSDAY: Sunny. Highs around 40. Wind NW 10-15 MPH.

THURSDAY NIGHT: Increasing high clouds. Lows 25-30. Wind W under 10 MPH.

FRIDAY: Thickening overcast. Chance of light rain late. Highs 45-50. Wind S 5-15 MPH.

SATURDAY: Mostly cloudy. Chance of rain showers. Low 40. High 53.

SUNDAY: Partly sunny. Low 33. High 48.

MONDAY: Cloudy. Chance of rain showers. Low 42. High 61.

TUESDAY: Mostly cloudy. Low 36. High 44.

WEDNESDAY: Partly sunny. Low 22. High 44.

4:45PM

Apologize for the lack of update since Sunday evening.

Other than a cloudier, cooler day today than I had forecast, there are no real surprises, and the pattern we are in now will continue through the forecast period in southern New England. This pattern was described in the previous post but is basically a milder pattern with a low pressure track north and west of New England and only brief shots of chilly air from time to time. One such chilly shot will occur Thursday. A more extended unsettled period will get underway this weekend into early next week but at this time I am still not expecting a tremendous amount of precipitation as the overall pattern remains a dry one.

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

TONIGHT: Mostly cloudy. Rain showers late. Lows in the 40s. Wind SW 5-15 MPH.

WEDNESDAY: Mostly cloudy. Rain showers in the morning. Highs 50-55 in the morning then  falling through the 40s in the afternoon. Wind shifting to NW 10-15 MPH and gusty.

WEDNESDAY NIGHT: Clearing. Lows in the 20s. Wind NW 5-15 MPH.

THURSDAY: Mostly sunny. Highs around 40. Wind NW 10-20 MPH.

FRIDAY: Partly cloudy. Low 20. High 46.

SATURDAY THROUGH TUESDAY: Mostly cloudy with episodes of rain showers. Possible break with partly sunny conditions Sunday. Overnight lows upper 30s to lower 40s. Daytime highs upper 40s to lower 50s. Sunday may be slightly cooler.

9:20PM

A respite from the cold pattern of November is what we’ll see this first full week of December as the overall pattern is mild and rather uneventful. A storm track north of the region will bring frontal passages early Monday morning, Wednesday, and sometime over the weekend.

Forecast for eastern MA, RI, and southern NH…

OVERNIGHT: Mostly cloudy with episodes of rain showers pushing from west to east. Lows 41-46. Wind SW 5-15 MPH.

MONDAY: Partly cloudy. Any showers exiting via Cape Cod & the Islands early morning. Highs 50-55. Wind NW 5-15 MPH.

MONDAY NIGHT: Mostly clear. Lows 35-40. Wind W 5-10 MPH.

TUESDAY: Partly cloudy. Highs 55-60. Wind SW 10-15 MPH.

TUESDAY NIGHT: Mostly cloudy. Chance of rain showers late. Lows 45-50. Wind SW 10-15 MPH.

WEDNESDAY: Mostly cloudy with scattered rain showers in the morning. Partly sunny with  isolated snow showers in the afternoon. Highs 50-55 early then dropping through the 40s. Wind SW 10-15 MPH shifting to NW 15-20 MPH.

THURSDAY: Mostly sunny. Low 28. High 41.

FRIDAY: Partly sunny. Low 22. High 47.

SATURDAY: Mostly cloudy. PM rain showers. Low 38. High 45.

SUNDAY: Partly sunny. AM rain showers. Low 35. High 45.

3:11AM

Warm front slowly pushing northeastward will finally win out and the mild air will continue to scour out the cold and melt the newly fallen light snow during the day today.

Very weak cold front crosses the region tonight with a band of rain showers, followed by fair weather but only a tiny cool-down Monday as a small bubble of high pressure visits.

A stronger cold front approaches from the west Tuesday with a very mild push of air ahead of it, then passes through Wednesday with rain showers possibly ending as snow showers.

High pressure brings fair and chilly weather for the end of the coming work week.

Forecast for eastern MA, RI, and southern NH…

TODAY: Mostly cloudy. Early morning patches of fog, drizzle and pockets of freezing drizzle with a few icy spots remaining. Highs 52-57. Wind SE to SW 5-15 MPH.

TONIGHT: Mostly cloudy. Rain showers crossing the region west to east. Lows 42-47. Wind SW 5-15 MPH shifting to W.

MONDAY: Mostly cloudy east coastal areas and Cape Cod early, otherwise mostly sunny. Highs 49-54. Wind NW 5-15 MPH.

TUESDAY: Partly cloudy. Low 39. High 60.

WEDNESDAY: Mostly cloudy with rain showers AM. Partly cloudy with snow showers PM. Low 46. High 50 early then falling.

THURSDAY: Partly cloudy. Low 26. High 40.

FRIDAY: Mostly sunny. Low 22. High 44.

8:20AM

A cold front passed by overnight, quietly in southern New England, but not before putting down several inches of snow in some of the northern New England ski areas! It’s also been cold enough up there to be making snow, so a bit of an early start to the season for some.

The cold front will come to a halt just south of New England today and mild air to the southwest and west of the region will ride up over it, creating lots of clouds today and Saturday. Some light precipitation may break out on Saturday but not looking for a heavy event. By Sunday, the front will have returned northward as a warm front and will introduce a thaw that will last a few days, until a cold front brings us back to the chill around the middle of next week.

Forecast for RI, eastern MA, and southern NH…

TODAY: Mostly cloudy. Highs 33-38. Wind N  up to 10 MPH.

TONIGHT: Cloudy. Lows 24-29. Wind NE under 10 MPH.

SATURDAY: Cloudy. A few periods of light snow (no significant accumulation) and rain. Highs 35-40. Wind E up to 10 MPH.

SATURDAY NIGHT: Mostly cloudy. Chance of rain showers early. Patchy fog late. Temperatures steady 35-40. Wind SE under 10 MPH.

SUNDAY: Mostly cloudy. Highs 50-55. Wind S 5-15 MPH.

MONDAY: Mostly sunny. Low 43. High 55.

TUESDAY: Partly sunny. Low 44. High 60.

WEDNESDAY: Mostly cloudy. AM rain showers. PM snow showers. Low 40. High 50.

THURSDAY: Partly cloudy. Low 23. High 40.