7:28AM

A wave of low pressure riding up a cold front just offshore will toss an area of snow into southeastern New England today, mainly from late morning through mid afternoon. The snow will be most significant along the South Coast with less to the north, with snow probably never really making it to southern NH. Amounts below will reflect this set-up.

Then a dry and very cold stretch of weather will take hold Wednesday through Friday as we finally get a taste of some of the arctic air that has been dominant to the west and north of the region.

The weekend looks unsettled but I’m low confidence on the details of how that will play out, so that will be revisited soon.

Forecast for southeastern New England…

TODAY: Cloudy with a period of snow developing from southwest to northeast this morning and ending late in the day with accumulations less than 1 inch in most areas north of the Mass Pike (isolated 1 inch+ amounts possible) and 1-3 inches from around the Mass Pike southward (isolated greater than 3 inch amounts possible). Temperatures steady in the 30s. Wind NW to W 5-15 MPH.

TONIGHT: Clearing. Lows 15-20. Wind W 5-15 MPH.

WEDNESDAY: Mostly sunny. Highs around 30. Wind W 10-20 MPH and gusty.

THURSDAY AND FRIDAY: Dry. Lows 10-18. Highs in the 20s.

SATURDAY AND SUNDAY: Unsettled with episodes of snow/mix possible. Lows in the 20s. Highs in the 30s.

MONDAY: Dry. Lows in the 10s. Highs in the 20s.

2:39AM

We remain near the boundary between very cold air to the north and west and milder air to the south and east, and that means some unsettled weather today with snow/ice/rain. This system is expected to behave as described in the last blog entry, with a light amount of snow to start the day today, except mix/rain closer to the South Coast and Cape Cod, with the rain area advancing northward to include all of the region by early afternoon. Cold air at the surface means some icing will take place over interior MA and NH for several hours during the morning and midday, with some hazardous travel on untreated surfaces. This system winds down later today and is gone tonight, with lingering clouds and some fog around. As expected, its trailing cold front will linger just offshore and allow a wave of low pressure to move up along it Tuesday, bringing a good chance of a period of mix/snow to RI, eastern MA, and coastal NH, though this should be moving along rather quickly and snow amounts will be limited. Drier and cold weather will dominate from the middle of the week to the start of the weekend, with a few minor disturbances bringing occasional clouds and a slight chance of snow showers. A trough moving into the region at some point over the weekend may increase the chance of some snow, though early indications are that this would not be a big storm.

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

TODAY: Overcast. Areas of snow, except mix/rain southeastern MA and southern RI, changing to rain south to north, with a period of icing interior MA/NH through midday. Morning snow accumulation from a coating to 2 inches, highest amounts from the higher elevations well NW of Boston into interior southern NH. Highs middle 30s to around 40. Wind E 5-15 MPH.

TONIGHT: Mostly cloudy. Areas of fog. Lows 30-35. Wind light NE.

TUESDAY: Mostly cloudy. A period of snow, some mix coast, mainly coastal NH, eastern MA, and RI, with some minor snow accumulation. Highs 35-40. Wind NE 5-15 MPH.

WEDNESDAY: Partly cloudy. Low 15. High 28.

THURSDAY: Partly cloudy. Low 14. High 26.

FRIDAY: Partly cloudy. Isolated snow showers. Low 11. High 24.

SATURDAY: AM sun. PM clouds. Chance of snow at night. Low 10. High 28.

SUNDAY: Mostly cloudy. Snow showers possible. Low 15. High 30.

2:30AM

A bright and cold start and a grey and cold finish can be expected today as high pressure to the north of the region slips away to the east and a low pressure area approaches the Great Lakes and spreads increasing cloudiness across southern New England. This system will attempt to redevelop just south of New England and track just offshore, but will be quite weak and rather fast-moving. With cold air locked at the surface for the early to middle stages of the event Monday morning, most areas will start as snow, but as warm air comes in aloft rather rapidly, a change to rain will take place. This rain will freeze on the surfaces it falls on in areas north and west of Boston for a time Monday morning to midday, with the best chance of some minor icing being mainly near I-495 through the Worcester Hills and into interior southern NH. But even here the ice should melt as temperatures go above freezing during Monday afternoon. Moisture exits the region from south to north by Monday evening but we may be left with some fog. As low pressure finally pulls away by early Tuesday, we’ll see drying and cooling take place, but a frontal system trailing the low will be lingering offshore and a wave of low pressure will ride up along it and bring the chance of a period of light mix/snow to the South Coast and Cape Cod Tuesday morning to early afternoon. The mid to late week will feature dry and cold weather as a northwesterly flow becomes established. A few disturbances moving along the flow may bring some clouds at times and there may also be a few instances where snow showers from the Great Lakes try to sneak into parts of the region, but these will be the exception rather than the rule, and the main story will be the cold along with some windy episodes.

Updated forecast for southeastern New England…

TODAY: Sunshine fading behind increasing cloudiness. Highs in the 30s. Wind light variable.

TONIGHT: Overcast. Light snow developing overnight, except mix/rain South Coast. Lows in the 20s except 30-35 South Coast. Wind light SE.

MONDAY: Overcast. Snow from Boston area north and west, mix/rain to the south early, changing to rain all areas during the morning but a period of freezing rain interior MA and NH. Rain tapering off late. Areas of fog. Highs upper 30s to middle 40s, coolest interior valley areas. Wind SE 5-15 MPH.

TUESDAY: Mostly cloudy. A period of light snow/mix South Coast through Cape Cod through early afternoon. Temperatures in the 30s.

WEDNESDAY-FRIDAY: Partly cloudy periods. Isolated snow showers. Lows 10s to lower 20s. Highs middle 20s to lower 30s.

SATURDAY: Sun to clouds. Lows 10-20. Highs 25-35.

6:42PM

A chilly and mostly dry weekend will be book-ended by the departure of one minor storm and the arrival of another minor to moderate system, both of which will include some snow, and one of which will include some icing.

The first system has been in the area and has been a strung-out area of moisture occurring with mild air, but now that a cold front has passed, colder air is filtering in, and the last plume of moisture sliding northeastward through the region tonight into early Saturday will start as rain and then change to snow as the cold air finally becomes established enough at all levels. But since this is a fast-moving system and it’s coming at the end of a very mild period, the ground is relatively warm, and amounts will be kept down.

Behind this system, brighter and cold weather will dominate for Saturday afternoon through early Sunday, and though it will remain cold through late Sunday as well, we’ll lose the sunshine as cloudiness advances from the next system. This system later Sunday night and Monday will start as snow in most if not all areas (mix/rain South Coast), but warmer air advancing quickly northward first in the upper levels will switch precipitation over to rain during the early morning hours of Monday. However, cold air will be harder to dislodge at the surface over inland areas (especially from around Interstate 495 northwestward and especially north central MA into interior southern NH. These areas will see a period of icing during the morning Monday, which will make travel somewhat hazardous. By later Monday, these areas will have warmed above freezing and the ice will disappear. That system will exit Monday night and Tuesday through midweek will feature a return to dry weather and colder than normal conditions, along with some gusty wind.

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

TONIGHT: Overcast.  Rain develops early from southwest to northeast, but a changeover to snow takes place from northwest to southeast from around 9PM through midnight, then precipitation gradually tapers off during the overnight hours. Snow accumulations will be around a coating to 1 inch away from the coast in eastern MA and southern NH, but 1-3 inches may occur on unpaved surfaces especially in higher elevations of western and northern Middlesex County of MA northwestward from there. Lows around 30. Wind N under 10 MPH.

SATURDAY: Mostly cloudy with spotty light snow possible in the morning. Increasing sun midday through afternoon. Highs in the 30s. Wind NW up to 10 MPH.

SATURDAY NIGHT: Clear. Lows 15-25, coldest inland valleys. Wind light variable.

SUNDAY: Sunshine followed by increasing cloudiness. Highs in the 30s. Wind variable up to 10 MPH.

MONDAY: Early morning hours snow except mix South Coast, changing to rain south to north morning but a period of ice inland eastern MA and southern NH, then rain, tapering off late. Lows in the 20s. Highs upper 30s to lower 40s.

TUESDAY: Partly sunny. Lows around 30. Highs in the 30s.

WEDNESDAY THROUGH FRIDAY: Dry and cold. Lows 10-20. Highs 22-32.

7:21AM

We here in southeastern New England will find ourselves near the border of mild and cold during the next several days, and this means we’re setting up for several periods of unsettled weather. Without delving into the hype-fueled frenzy of dramatic what-if’s and gloom-and-doom scenarios, the remainder of this section of the blog entry will detail the players (weather systems) and the expected plays (resultant weather) during the next several days.

High pressure dominates with a nice day today, but it may start with patchy fog and frosty windows in some locations after a mostly clear and calm overnight allowed radiational cooling and moisture in the air to condense. The daylight hours will feature sunshine which will quickly erase any of the early fog/frost as it turns rather mild. Clouds will begin to increase later in the day ahead of a warm front, which will slog its way into southern New England by early Thursday. This front may have trouble pushing all the way through the region Thursday (watch for this in the temperature forecast), but will produce some light rain activity. A cold front will come along by Friday and send a couple batches of rain or showers into and across the region. Timing is a little uncertain, but it looks like the bulk of the rain will come in 2 batches, one in the early morning hours of Friday, the second on Friday night. As the cold front settles through the region it will hang up near or just off the coast, but allow enough cold air in so that we will see a mix with or change to snow sometime in the Friday night to early Saturday time frame as the final batch of precipitation moves through. The amount of time that snow can occur will be greater to the north and west of Boston and less to the south. The timing will also determine if any accumulation occurs. An early call is for a minor accumulation away from the coast and especially in higher elevations northwest of Boston. Either way, clouds may hang on through Saturday, because the upper level air flow will likely be from the southwest, and with the front barely offshore, that is often a setup for clouds streaming northeastward in the vicinity of the front. Eventually enough of a push of colder air from the northwest will clear things out, especially for the second half of the weekend, so expect a nice but chilly Sunday. This will be short-lived, as the next weather system will be coming along for early next week. With the colder air in place, we’ll have to watch for some potential for some snow/ice to be involved in at least part of the early-next-week storm, but it is far too early to really have any idea of details. The early feeling is that the main storm will be cutting through the Great Lakes, so even though we may have cold air around to start, we’ll likely warm up at some point during the system’s passage. But with the cold air lurking close by, it all needs to be watched. For now, generic wording will be used on the outlook for the start of next week.

Updated forecast for southeastern New England (southern NH, eastern MA, and RI)…

TODAY: Areas of fog and frost early morning (watch for a few icy patches), then sunshine, but fading late in the day behind advancing clouds. Highs 42-50, coolest in higher elevations northwest of Boston and mildest over interior southern NH and eastern MA. Wind W up to 10 MPH.

TONIGHT: Partly to mostly cloudy. Lows around 30. Wind light variable.

THURSDAY: Mostly cloudy. A chance of light rain, mainly morning and midday. Highs around 40 in southern NH to the lower 50s southern MA and RI. Wind light SE in areas to the north, light S to SW in areas to the south.

FRIDAY: Cloudy. Periods of rain, especially in the early morning (pre-dawn) and late day. Low 40. High 50.

SATURDAY: Mostly cloudy. Chance of mix/snow early morning. Low 30. High 40.

SUNDAY: Mostly sunny. Low 20. High 35.

MONDAY: Cloudy. Ice to rain, may start as snow. Low 30. High 40.

TUESDAY: Cloudy. Chance of rain/mix/snow. Low 32. High 40.

5:25PM

Apologies for the lack of “The Week Ahead”. This post takes the place of it for this week. 🙂

It will be a milder week than the previous, with no major weather systems, just sluggish cold front late in the week. An ocean storm will remain far enough offshore to keep its precipitation shield over the water Tuesday and early Wednesday, but it will stir up the waters and that in combination with astronomical high tides may result in minor coastal flooding, especially at the Tuesday morning high tide. The general pattern across the US this week features a trough in the Southwest and a long southwest to northeast jet stream into the eastern US with a ridge of high pressure east of Florida. Very cold air exists in Canada and though it cannot make a full punch into the East at this time, pieces of it will glance the region at times.

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

TONIGHT: Lots of clouds. Patchy fog. Lows 30-35. Wind N under 10 MPH.

TUESDAY: Lots of clouds and patchy fog in the morning. Increasing sun in the afternoon. Highs in the 40s. Wind N to NW up to 10 MPH.

TUESDAY NIGHT: Clear. Lows in the upper 20s valleys to middle 30s coast and urban areas. Wind light NW.

WEDNESDAY: Sunshine followed by increasing cloudiness. Highs around 40. Wind NW up to 10 MPH becoming light variable.

THURSDAY: AM rain showers / PM partial sun. Low 35. High 45.

FRIDAY: Cloudy. Rain showers possible. Low 35. High 47.

SATURDAY: Mostly cloudy. Low 28. High 41.

SUNDAY: Partly cloudy. Low 23. High 38.

MONDAY: Cloudy. Chance of rain. Low 34. High 44.