C-19 Chat Post – January 27 2021

DAYS 1-5 (JANUARY 26-30)

Three low pressure systems will impact our area during this 5-day period. Low pressure area #1 heads from the Ohio Valley to the eastern Great Lakes through tonight and meets its demise as a surface system over New York by tomorrow, while low #2 is a redevelopment of #1 a few hundred miles south of New England as an elongated system which will help turn our wind to northeast and east, off the Atlantic. It is the synoptic snow, generated at mid levels, that will move into our area from west to east by this evening, when most of the accumulation we are to expect will take place. Low #2 takes over offshore, absorbing the energy of #1 and keeping a northeasterly flow going during Wednesday, and while the synoptic-driven snow fades away due to drier air aloft, we’ll see some ocean-effect snow showers generated. I’m not expecting much snow accumulation during the day Wednesday from these due to their spotty nature and marginal surface temperatures. Low #3, meanwhile, will emerge off the Mid Atlantic and chase #2 away, becoming quite a powerhouse as it passes well to the south, keeping its own precipitation shield offshore, but helping to keep the northeasterly to northerly air flow going through Thursday, with additional ocean-effect snow showers. One more surge of minor accumulation should take place Wednesday night. Low #3 will become quite the large circulation offshore to the east of New England through Friday and the northerly air flow behind it will keep a snow shower threat going over Cape Cod, and one lobe of snow showers may make it as far back as the rest of coastal eastern MA sometime that day as well with a little trough extending out from the offshore storm. This will also pull the coldest air of the season so far out of Canada and into New England with some areas failing to reach 20 that day. Only a modest recovery is expected Saturday although it will be easier to take as the wind diminishes while high pressure moves into the region with sunshine.

TODAY: Increasing clouds. Highs 28-35. Wind N up to 10 MPH.

TONIGHT: Cloudy. Snow of a coating to 2 inches except up to 3 inches possible in higher elevations of north central MA and southwestern NH. Lows 22-29. Wind N-NE 5-15 MPH.

WEDNESDAY: Cloudy early to mid morning with snow tapering off. Mostly cloudy with a chance of snow showers thereafter but little additional accumulation. Highs 30-37. Wind NE 5-15 MPH.

WEDNESDAY NIGHT: Mostly cloudy with snow showers likely, accumulating an additional coating to 1 inch. Lows 23-30. Wind NE 5-15 MPH.

THURSDAY: Mostly cloudy with snow showers likely in the morning. Partly sunny with scattered snow showers favoring Cape Cod during the afternoon. Highs 30-37 by midday but temperatures falling sharply later. Wind NE to N increasing to 15-25 MPH.

THURSDAY NIGHT: Partly cloudy with snow showers Cape Cod. Clear elsewhere. Lows 8-15. Wind N 15-25 MPH, higher gusts especially eastern coastal areas. Wind chill below zero at times.

FRIDAY: Mostly sunny to partly cloudy with most clouds eastern MA coastal areas especially Cape Cod. Additional snow showers possible mainly Cape Cod but brief snow showers possible NH Seacoast to eastern coastal MA too. Highs 16-23. Wind N 15-25 MPH, higher gusts. Wind chill near zero at times.

FRIDAY NIGHT: Clear. Lows 6-13. Wind NW 5-15 MPH.

SATURDAY: Sunny. Highs 20-27. Wind NW 5-15 MPH.

DAYS 6-10 (JANUARY 31 – FEBRUARY 4)

Dry and cold as high pressure hangs on through January 31. Favoring a slower timing for the threat of the next system, focusing on February 1 to early February 2 for this, but too early to determine what specific impacts a low pressure system moving into the region from the southwest will have. Fair, seasonably cold weather should follow this.

DAYS 11-15 (FEBRUARY 5-9)

Best window of opportunity for additional unsettled weather is February 6-7 but low to moderate confidence. Can’t say much more about anything this far out as the status of the large scale pattern (blocking, etc.) is still somewhat uncertain.

C-19 Chat Post – January 26 2021

DAYS 1-5 (JANUARY 25-29)

A quiet & cold start to the week today as high pressure slides eastward into the region, centered to the north, and low pressure in the Canadian Maritime Provinces drifts further away, allowing winds to slacken. A more active period of weather will then be with us for the rest of this period, starting as low pressure makes a run at New England via the Midwest Tuesday. The blocking pattern in place will force a redevelopment of this system in the form of a fairly weak, elongated low pressure area well south of New England later Tuesday into Wednesday, which will then head out to sea, but while this is happening, the energy left from the original dissipating surface low will come across the region at the same time the wind turns northeasterly here. All of this will combine for periods of snow Tuesday night and Wednesday, which will lead to some minor accumulations. Some of this snowfall Tuesday night to early Wednesday, which may be mixed with rain initially over Cape Cod and the South Coast region, will be from the old storm’s energy, while some of it will be ocean-effect. It won’t be a big storm, but since snow has been relatively absent recently, it’ll be important to keep in mind that even small amounts of snow falling on travel ways that are not treated can lead to slippery conditions. As we get to Thursday, a second low pressure area will be passing south of New England, and this one will blow up into a powerful ocean storm, not making a direct hit at all, but serving to keep the northeasterly air flow going with some additional ocean-effect snow showers, especially in eastern and southeastern portions of the region. What this storm will do as it turns northeastward toward the Maritimes of Canada is pull down another piece of Arctic air and we will turn quite cold for the end of the week, with a few additional ocean-effect snow showers due to a northerly air flow over Cape Cod during Friday, which will easily be the coldest day of the next 5.

TODAY: Sunshine & a few high clouds. Highs 29-36. Wind NW 5-15 MPH, gusts 20-25 MPH possible.

TONIGHT: Lots of high clouds. Lows 18-25. Wind N 5-15 MPH.

TUESDAY: Thickening high to mid level clouds. Highs 28-35. Wind N up to 10 MPH.

TUESDAY NIGHT: Cloudy. Periods of snow, except possibly mixed with rain South Coast. Snow accumulation of a coating to around 1 inch possible. Lows 25-32. Wind NE 5-15 MPH.

WEDNESDAY: Mostly cloudy. Periods of snow except possible rain/snow mix South Coast morning with additional snow accumulation of a coating to around 1 inch possible. Snow showers possible in the afternoon. Highs 30-37. Wind NE 5-15 MPH.

WEDNESDAY NIGHT: Mostly cloudy. Snow showers possible, favoring southeastern NH, eastern MA, and RI. Lows 23-30. Wind NE 5-15 MPH.

THURSDAY: Mostly cloudy to partly sunny. Additional snow showers possible favoring Cape Cod. Highs 25-32. Wind NE to N 15-25 MPH.

THURSDAY NIGHT: Partly cloudy. Snow showers possible mainly Cape Cod. Lows 10-17. Wind N 15-25 MPH, higher gusts possible on Cape Cod.

FRIDAY: Sunny except clouds and snow showers possible Outer Cape Cod. Highs 18-25. Wind N to NW 15-25 MPH, higher gusts possible especially eastern coastal areas.

DAYS 6-10 (JANUARY 30 – FEBRUARY 3)

The blocking pattern is likely to still be in place but may be weakening. Fair and cold but more tranquil weather as high pressure moves in January 30. Watching later January 31 to early February 2 period for the next potential impact from low pressure. Fair, chilly ending to this period.

DAYS 11-15 (FEBRUARY 4-8)

Expecting a continued slow weakening of the blocking pattern and we will have to watch for additional opportunities for unsettled weather as a result of a storm track that allows low pressure systems more direct access to the Northeast.

C-19 Chat Post – January 25 2021

DAYS 1-5 (JANUARY 24-28)

It may not be pure arctic air, but after a mild January up until a couple days ago, it feels pretty cold this weekend, and the wind is making it feel more harsh. At least we’ll have a day of bright sunshine today, sun that you are probably starting to notice rising a touch earlier, setting a little later, and climbing just a little higher into the sky each noontime. The weather lore says “as the days lengthen, the cold strengthens”. This refers to the coldest part of winter, on average, being from later January to the start of February, as we are noticing the sun’s higher angle after the dark days of December and early January are behind us. Well, that weather proverb is not always 100% true, but it often holds a good deal of truth, and this winter it does. We’ll continue to see colder than normal temperatures the next 5 days. But what about snow? This short answer is: no. Although that answer may not be completely accurate either. First, we continue to have high pressure centered to the west of New England and a large low pressure circulation in the Canadian Maritime Provinces as part of the ongoing blocking pattern. This keeps us dry/cold/windy today. The low edges away and the high center shifts a bit to the north Monday allowing the wind to relax. At the same time, low pressure is going to be making a run at the Northeast via the Midwest, but it’s going to run into resistance because the large scale pattern is not going to change enough to allow it to make an unimpeded trip into and through the Northeast. Instead, it gets stretched out and forced south of New England. While computer guidance will give you the idea that a solid area of snow tries to make it into the area, this is very likely an over-representation of what will happen, and we’ll probably see a solid area of cloudiness move in, while the snow falling out of it will be largely evaporating before reaching the ground, but we can’t yet rule out a little bit of that synoptic snow working its way down to the ground level sometime Tuesday night. This would be most likely in southern portions of our area. In addition, we should see enough of a northeast wind by then between high pressure to the north and the low passing to the south into Wednesday that some ocean-effect snow showers may develop and work in from the Gulf of Maine, at least into eastern areas. As we get to Thursday, a follow-up area of low pressure will emerge off the Mid Atlantic Coast. This storm is likely to become much stronger than the one before it, but also be tighter and a little further south, so we will probably never hear from its precipitation shield, but the circulation around this storm working with high pressure to the north may continue the ocean-effect snow shower chance and more wind is likely across the entire region. So while we may not be getting buried in snow any time soon, the feel of winter is definitely here to stay for a while.

TODAY: Sunny morning. A few patchy clouds but still plenty of sun afternoon. Highs 24-31. Wind N-NW 10-20 MPH with higher gusts.

TONIGHT: Mostly clear. Lows 12-19. Wind N-NW 5-15 MPH.

MONDAY: Sun & high clouds. Highs 27-34. Wind NW 5-15 MPH.

MONDAY NIGHT: Variably cloudy. Lows 18-25. Wind N 5-15 MPH.

TUESDAY: Partly sunny morning. Cloudy afternoon. Highs 26-33. Wind N up to 10 MPH.

TUESDAY NIGHT: Mostly cloudy. Some very light to light snow possible favoring southern MA southward. Snow showers possible near eastern coastal areas. Lows 17-24. Wind NE 5-15 MPH.

WEDNESDAY: Mostly cloudy. Snow showers possible, favoring southeastern NH, eastern MA, and RI. Highs 27-34. Wind NE 10-20 MPH.

WEDNESDAY NIGHT: Mostly cloudy. Snow showers possible, favoring southeastern NH, eastern MA, and RI. Lows 17-24. Wind NE 5-15 MPH, higher gusts.

THURSDAY: Mostly cloudy to partly sunny. Additional snow showers possible favoring Cape Cod. Highs 25-32. Wind NE to N 15-25 MPH.

DAYS 6-10 (JANUARY 29 – FEBRUARY 2)

Low pressure to the east & high pressure to the west results in dry/windy/cold weather January 29 then high pressure moves in with dry but more tranquil weather January 30. Next window to watch for potential low pressure impact is January 31-February 2. A shifting of upper level features may allow a better chance that the next system gets into the region instead of being forced to the south.

DAYS 11-15 (FEBRUARY 3-7)

Expecting a weakening of the blocking pattern and as a result somewhat more active weather here with another potential low pressure impact by the middle of this period.

C-19 Chat Post – January 24 2021

DAYS 1-5 (JANUARY 23-27)

An arctic cold front is dropping southward through the region early this morning and will take until mid to late morning to completely push through. Snow showers accompanying this front have whitened the ground in some locations north of Boston and briefly moderate snow showers may coat the ground along this boundary as it moves to the south. Its bigger impact will be to introduce the coldest air mass we’ve seen in quite some time, after a long stretch of milder-than-normal weather (other than one below normal day on Thursday). But now we’re putting together a string of colder-than-normal days which will last well into next week, starting with a dry (after the snow showers) and bright weekend between a large area of low pressure in the Canadian Maritime Provinces and high pressure in eastern Canada and the Great Lakes. I am continuing to lean toward mainly a miss for the storm system passing south of the region between late Monday and early Wednesday. I think the synoptic snowfall from this system may get into the NYC and southwestern CT area Monday night and Tuesday but the dry air will be too much to overcome for any of that snow to make it into the southern portion of the WHW forecast area. However, the direction of the wind at the surface may create some snow showers as the wind will be coming off the Atlantic from the northeast between high pressure to the north and low pressure to the south.

TODAY: Clouds and scattered snow showers with coatings of snow possible especially eastern MA through mid morning, otherwise sun & passing clouds. Highs 25-32 occurring early morning, steady or slowly falling thereafter. Wind NNW 10-20 MPH with higher gusts.

TONIGHT: Clear. Lows 10-17. Wind N 5-15 MPH.

SUNDAY: Sunny. Highs 25-32. Wind N 10-20 MPH with higher gusts.

SUNDAY NIGHT: Clear. Lows 10-17. Wind N 5-15 MPH.

MONDAY: Sun & high clouds. Highs 25-32. Wind N 5-15 MPH.

MONDAY NIGHT: Mostly cloudy. Lows 18-25. Wind N 5-15 MPH.

TUESDAY: Mostly cloudy to partly sunny. Snow showers possible, favoring coastal areas. Highs 24-31. Wind NE 10-20 MPH.

TUESDAY NIGHT: Variably cloudy. Snow showers possible, favoring coastal areas. Lows 17-24. Wind NE 10-20 MPH.

WEDNESDAY: Mostly cloudy. Snow showers possible, favoring coastal areas. Wind NE 10-20 MPH.

DAYS 6-10 (JANUARY 28 – FEBRUARY 1)

The large scale blocking pattern continues with another storm likely passing south of the region January 28 to early January 29, but this system, in combination with high pressure in eastern Canada, may help continue the coastal snow shower threat at least to start the period before the air flow turns more northerly. High pressure should control weather weather into the January 30-31 weekend but we will need to keep an eye on the next storm threat as early as January 31 and more likely February 1. That’s out at days 9 & 10 so no detail but just general idea on timing of the threat window.

DAYS 11-15 (FEBRUARY 2-6)

Cautiously and with low confidence forecasting a slight weakening of blocking resulting in a readjustment of large scale features and opening the door for a little more unsettled weather as we move through the early days of February. Greatest chance for storminess here would come during the middle to end of this period.

C-19 Chat Post – January 23 2021

DAYS 1-5 (JANUARY 22-26)

Low pressure passing north of our area today will drag a cold front through the region by later in the day. The air will be relatively mild ahead of this front, probably the last 40+ degree day for much of the region for a while. Although Boston broke their second longest stretch on record of days with above normal temperatures yesterday with a below normal day, there will be one more above normal day today before we head into a stretch of below normal for the remainder of this five-day forecast period (and probably beyond). This is a result of a continued blocking pattern in the northern hemisphere which has now adjusted itself to grab a piece of the arctic air that has been residing on the other side of the hemisphere and deliver it to the northeastern US. Granted, we won’t see anything like the cold that has been experienced in parts of Europe & Asia, but in a relative sense, it will feel quite cold compared to what we have experienced this winter so far. As that cold air arrives, the frontal boundary leading it in will produce a few showers and with marginal temperatures and a little bit of convective action in the atmosphere, these may fall as rain, snow, or even graupel depending on their location. This type of set-up often makes for picturesque skies as well, so a little show is to be put on by the atmosphere to mark the change, and then it’s onto a cold & dry weekend with air coming from Canada on a gusty northwest to north wind. While we’ll have plenty of sunshine both Saturday & Sunday, for the first time in quite a while it may fail to reach freezing throughout most of the region with a few possible exceptions on Sunday. The cold remains in place early next week. That much is certain. What there is continued uncertainty about is a snow threat. Low pressure will be passing south of New England between late Monday and Tuesday, and we continue to see some differences across the various computer guidance we look at, some of them bringing a light to even moderate snowfall into at least southern areas, while others indicate a complete miss. At this point, I continue to lean toward the miss scenario, but with the door open for at least some light snow to reach southern areas, especially the South Coast. But at day 5, that leaves plenty of time to figure this part of the forecast out.

TODAY: Variably cloudy. Passing showers of rain, snow, and/or graupel possible mainly mid to late afternoon and favoring areas west and north of Boston. Highs 37-44. Wind SW 10-20 MPH with higher gusts, shifting to NW late in the day.

TONIGHT: Partly cloudy with passing snow showers possible in the evening. Clear overnight. Lows 18-25. Wind NW 10-20 MPH with higher gusts.

SATURDAY: Sun and passing clouds. Highs 24-31. Wind NNW 10-20 MPH with higher gusts.

SATURDAY NIGHT: Clear. Lows 10-17. Wind N 5-15 MPH.

SUNDAY: Sunny. Highs 25-32. Wind N 10-20 MPH with higher gusts.

SUNDAY NIGHT: Clear. Lows 10-17. Wind N 5-15 MPH.

MONDAY: Sun & high clouds. Highs 25-32. Wind N 5-15 MPH.

MONDAY NIGHT: Mostly cloudy. Some light snow possible near the South Coast. Lows 18-25. Wind N 5-15 MPH.

TUESDAY: Mostly cloudy with some South Coast light snow possible morning. Clearing afternoon. Highs 24-31. Wind N 5-15 MPH.

DAYS 6-10 (JANUARY 27-31)

As we move through the final 5 days of January we should see the blocking pattern continue and the storm track suppressed to the south with another system likely moving out south of the region around the middle of the period, but it may become quite a large ocean storm and bend the air flow around enough that some ocean effect snow showers may reach some coastal areas somewhere in the January 29-31 time frame.

DAYS 11-15 (FEBRUARY 1-5)

Still uncertainty regarding the blocking pattern’s status. With low confidence I believe it holds but weakens during the first several days of February. As far as sensible weather for us, probably still on the drier side overall but any shift in the blocking pattern’s strength or position could open the door for some unsettled weather, which we’ll have to monitor.