C-19 Chat Post – November 23 2021

Welcome to the long-winded but hopefully useful discussion and forecast that is my outlook for the 2021-2022 winter (December through March). Basically, I combine meteorological winter (December, January, February) and astronomical winter (December 21-March 20) to come up with this, so you can basically think of this forecast as being valid December 1-March 20). Does that mean I’m going to give you a day-by-day detailed 110 day forecast with high temps, low temps, wind speed & direction, exact rainfall & snowfall amounts down to the nearest hundreths and tenths of inches! Sure, I could do that, and it might be a “good” forecast out for the first 3 days, and then basically fiction from there on. You all know that’s not how long range forecasting works, and I’m not going to pretend to know more than I do about it. What I and my colleagues attempt to do when preparing these outlooks is take everything we have learned so far, everything we know now, and link it with our best educated guess about the future weather trends, garnered by a close look at numerous “puzzle pieces” consisting of long term, medium term, and even some shorter term behavior of ocean and atmosphere. You’ve already seen several of these outlooks from various media outlets. What follows here is my own version. Will it be similar to others? Read on…

OVERVIEW

The usual players will be on the field as we assess their potential and observe their performance going into winter. ENSO: We are in a La Nina now, and will likely remain in one at least through February, after which we may see it weaken toward a little more neutral as we get into March. The QBO (Quasi-biennial Oscillation), stratospheric winds in the tropical regions, in their easterly phase at this time with this likely to continue through the winter as well. The PDO (Pacific Decadal Oscillation) is and will likely continue to be in a negative phase (cool water off the US West Coast and warmer water toward the central North Pacific). This index may play a little havoc with the forecast if it goes more neutral later in the winter, which it may do. The MJO (Madden-Julian Oscillation), which is a measure of movement of regions of enhanced and suppressed tropical rainfall, has been an aggravation for long range forecasting the last couple winters due to its almost non-factor but the unknown of when it could “wake up” and be more of a factor. As we approach the end of November, the MJO is currently in a weak phase and not a huge factor (where have we heard that before?), however the ensemble forecasts from our major medium range guidance have indicated at least somewhat of an upswing in the index’s influence on the global pattern as we head into early December, with it being borderline between indicating enhanced snow threats and just a more benign milder regime, so at the moment, the MJO is of not much help in discerning much, and I suspect for another winter it will behave much like it has the last couple winters, like the prankster lurking around the corner, waiting for the right moment to throw a water balloon at you. And don’t forget our good old friends, the AO (Arctic Oscillation), NAO (North Atlantic Oscillation), and perhaps the villain of the story, the PV (Polar Vortex). I’ve often seen too many forecasts go bad in a quick way when too much dependence is placed on the behavior of the PV without taking into account the remaining factors. When the AO is in its positive phase, the PV is generally tighter to the polar regions, and stable, which is generally a milder pattern for the mid latitudes with more zonal flow. This is often a fairly mild and sometimes tranquil weather pattern for the US in winter (though there can be storminess from other factors, like an active southern jet stream, especially during El Nino years, which this is not). When the AO is in its negative phase, the PV is disrupted and usually breaks into several lobes which extend much further southward from the polar regions, resulting in a much less stable weather pattern, but where these lobes go and whether or not they are fairly stable in one area or progressive (moving west to east) or retrogressive (moving east to west) has to be taken into account in determining the finer details of the pattern for any area. First, a PV disruption is often linked directly to cold/snowy weather for the Northeast. This is not always the case. A PV lobe could just as easily take up residence in the central or western US and leave the eastern areas mild. When the QBO is in its easterly phase, this has been linked to the initiation of PV disruption more often, so we look at that as a factor in a potential early-season disruption. Some of the long range (weekly and monthly) forecast models have also hinted at potential PV disruption in the orientation that colder weather would visit the northeastern US earlier in the winter (December to early January) with a then more stable PV following that for later January and February. A fair amount of La Nina winters have featured the coldest core of air, relative to normal, from the upper Midwest to the Northwest, with milder weather a little more dominant in the Northeast with occasional intrusions of colder air. This tends to be more the case with a stable PV, so in that case, we could make an argument for the chance of colder weather, relative to normal, being more likely during the first third of the winter (December – early January), with the trend for milder weather, relative normal from mid January through February, leaving March vulnerable due to the wildcard factors of strength of La Nina by late winter, and the unpredictability of both the AO and MJO that far in advance, and to a lesser degree the magnitude of the expected continued negative PDO. Another factor is somewhat below normal arctic sea ice, which is a factor in initiating PV disruption, a better advance of snowcover in parts of the northern hemisphere than we saw last year, which can help build cold air masses and get them started heading southward in the case of an unstable PV. And lastly, the solar cycle, still climbing away from a recent minimum and toward the next maximum but not nearly there yet. Solar minima are sometimes correlated to colder winters with solar maxima correlated to more mild winters, but this is not necessarily a huge factor, only a contributing one, that can be overshadowed by the many other indices. So based on that, I don’t see the solar cycle playing a huge part in this particular winter’s weather pattern. A bit of amusement and maybe poking fun at myself in the process: So often you hear me on the blog during the year talking about not being a fan of winter forecasts that are issued before a careful observation and analysis of the pattern of October and at least the first half of November, so I put that practice in play as I always do, and I honestly didn’t get much out of it this time. I don’t have a strong feel for the “October/November predicting the winter pattern” thing this time. And lastly, analog winters. I’ve always been so-so on this. Yes, there are definitely clues to what an upcoming season can hold when you can identify similarities to indices leading up to that season in other years. In fact, one of the analogs leading into this winter is that we have a lot of similarities to 2011’s autumn (weather pattern, current and expected indices being similar, including La Nina and negative PDO). Boston only recorded 9.4 inches of snowfall that winter, and for many suburban locations the “biggest snowstorm of the winter” actually occurred in late October. So there may be similarities but definitely no mirror image. This doesn’t mean that Boston’s snowfall will end up that far below normal. Too many other things go into that result. So that is why analogs can be used as a tool but should never sway a forecaster too much… So there are all the edge pieces and a few of the middle pieces of the puzzle we can fit together to form a reasonably adequate educated guess. The pieces we have not fit into place represent the uncertainty that is always present in forecasting, especially long range efforts.But based on what I do know, let’s move on to the month-by-month breakdown followed by a temperature / precipitation / snowfall forecast for the winter as a whole…

DECEMBER
In theory, this should be the easiest portion of the forecast to make, since it is the shortest-range portion. However, a little doubt was cast into this section from the most recent runs of the weekly and monthly model forecasts, previously looking colder than they look now. That said, I’ve also spoken recently of how poorly the guidance has performed, at one point painting a major winter storm for the Northeast just a day before Thanksgiving, and as we know, we’ll be under the influence of high pressure with chilly but dry weather that day (just one example of several). So that’s a good reason not to let any kind of run with a big change in it (regardless of whether its looking out just a couple weeks or several months) influence my overall thinking. For December, we’ll look for La Nina conditions, an easterly QBO helping to lead to a slightly better than 50% chance we see a PV disruption in progress or initiating, one or two periods of negative NAO (high latitude blocking in the North Atlantic), and continued negative PDO. Arctic sea ice will increase but remain below normal, another factor in possibly helping to initiate a PV disruption. A tendency for a little more high latitude blocking in the North Atlantic would bend the air flow southeastward as it gets into the eastern part of North America, and the lack of early-appearance of a Southeast Ridge would help allow more frequent intrusions of cold air into the northeastern US, including New England. Digging disturbances in this pattern would be the shots at snowfall and as we get deeper into the month a determining factor in whether or not places like Boston get a white Christmas. Temperature: Near to below normal. Precipitation: Near normal, most active in the middle 20 days. Snowfall: Near to slightly above normal.

JANUARY
If we are going to have a period of classic winter weather, the first half of the first month of 2022 would be the time to look for it, as the pattern of December helps us build some cold, and the transitional period out of a negative to neutral to eventually positive AO would likely be accompanied by an active Pacific jet stream with disturbances interacting with cold air in place. We’ll continue La Nina, easterly QBO, and negative PDO, with wildcards MJO and NAO helping to determine more detailed outcomes. Temperature: Near to above normal, coldest early followed by a thaw. Precipitation: Near to above normal. Snow: Near to slightly below normal, but may start out snowy with above normal for the first half of the month.

FEBRUARY
La Nina continues, easterly QBO dominates, PV is stronger and AO positive, NAO largely positive (not much if any blocking), PDO continues negative. The La Nina-driven Southeast ridge likely makes its most prominent appearance at this time driving the primary storm track from northwestern US through the Great Lakes into southeastern Canada, with the majority of lows passing north and west of New England. While mountain areas can be cold enough for snow at times in this pattern, the majority of precipitation events tend to be more rain for southern New England. However, with it being just at and barely beyond the coldest time of the year, from a climatology standpoint, a pattern like this can result in some icing events, including southern New England areas, and we will need to watch for this. Temperature: Above normal. Precipitation: Near normal. Snow: Below normal.

MARCH (FIRST 20 DAYS)
Oh March, the month that can bring anything from extreme cold and major snowstorms to the first hints of summer (we have been over 80 several times). What March is most remembered for in New England: Late-season snow and cold, ice, mud, wind, and people asking “will winter ever end?” This particular March outlook is a tough one. It’s hard to believe that a pattern of milder weather (as is expected in February and assuming it verifies) would continue right through March. I mean, something has to go wrong, doesn’t it? Our MJO and PV/AO wildcards will very probably still be in place. We’ll still likely be in negative PDO but maybe not as strongly so, and we also may be seeing the weakening of La Nina heading more toward neutral ENSO by then. An easterly QBO is likely to still be present, remaining a factor in helping to initiate another disruption of the PV. Should this occur, we may be able to expect one more blast of winter’s cold and some snow, before we finally bid it goodbye. As I have stated previously, late season snow, occurring with a steadily climbing sun angle, tends to disappear nearly as fast as it appears, so if you’re tired of winter, at least you won’t have to look at it for all that long. The higher sun angle also counteracts some of the March cold, as we get a more direct sun for more hours than we had back in the low sun / short days of early winter. Temperature: Near to below normal. Precipitation: Near normal. Snow: Near normal.

WINTER SEASON OVERALL
Temperature: Slightly above normal (departure +1F to +2F).
Precipitation: Slightly above normal (departure about +1 inch).
Snow: Below normal.
-Boston 30-40 inches
-Worcester 40-50 inches
-Providence 20-30 inches
-Hartford 30-40 inches

DAYS 1-5 (NOVEMBER 22-26)

The holiday week is underway and there are no big changes to the outlook. First though, a little more potent were the showers and even a few isolated thunderstorms associated with the warm frontal passage overnight. Here at the WHW headquarters in Woburn I heard thunder off to my south and southeast in the 2 a.m. hour, and that cluster resulted in a short-lived tornado warning for Essex County MA as low level rotation was detected by radar, strong enough for a warning, according to the NWS. However, at this time I have not seen any reports of damage and I don’t believe that we will see any. Otherwise, today will start out on the wet side for most of the region ahead of a cold front that is bringing one final band of rain, mainly during this morning. The front itself will pass through the region from west to east during midday and afternoon, but the clouds will hang tough during the day, with only a few breaks possible. The front will introduce a much colder air mass to the region tonight into midweek. This colder air will come along with a gusty wind Tuesday between strengthening low pressure in eastern Canada and high pressure to our west. For the first time this season we will be talking about noticeable wind chill. The wind will settle down as high pressure noses closer to the region during Tuesday night and Wednesday, but that will be a slow process. But other than the wet weather early today, the next three days bring generally favorable pre-Thanksgiving travel weather, and even the holiday itself looks great for local and regional travel, visiting, and high school football games and other outdoor activities, as high pressure sinking off to the south will bring fair weather and a slight warm-up. When we get to Friday, low pressure will move quickly down the St. Lawrence Valley and will drag a warm front / cold front combo across the region. The timing on this system looks quick, with impact mainly during the morning for any rainfall threat, followed by windy and colder weather with perhaps a passing snow shower before the day is over. Keep that in mind if you plan on doing any traditional in-store Black Friday shopping – not a major impact but plan for some wet weather to start and a windy/cold finish.

TODAY: Cloudy. Rain tapering off from west to east during the morning. Highs 52-59 this morning, cooling into the 40s west to east this afternoon. Wind S-SW 5-15 MPH with gusts 20-25 MPH mainly Cape Cod / South Coast, shifting to W this afternoon.

TONIGHT: Partly cloudy. Lows 28-35. Wind NW 10-20 MPH.

TUESDAY: Sun and passing clouds. Highs 36-43. Wind N 10-20 MPH, higher gusts. Wind chill below freezing at times.

TUESDAY NIGHT: Mostly clear except Cape Cod clouds and a few snow showers possible. Lows 18-25. Wind N-NW 5-15 MPH, higher gusts. Wind chill below 20 at times.

WEDNESDAY: Mostly sunny. Highs 39-46. Wind NW-W 5-15 MPH, higher gusts.

WEDNESDAY NIGHT: Mostly clear. Lows 25-32. Wind W-SW up to 10 MPH.

THURSDAY (THANKSGIVING): Mostly sunny to partly cloudy. Highs 46-53. Wind SW 5-15 MPH.

THURSDAY NIGHT: Increasing clouds. Lows 33-40. Wind variable up to 10 MPH.

FRIDAY: Mostly cloudy with a brief period of light rain in the morning followed by few midday rain showers, then variably cloudy afternoon with a slight chance of a passing rain or snow shower. Highs 41-48 morning, falling into the 30s afternoon. Wind variable 5-15 MPH morning, WNW 10-20 MPH and gusty afternoon.

DAYS 6-10 (NOVEMBER 27 – DECEMBER 1)

The November 27-28 weekend looks mostly dry, perhaps a passing insignificant snow flurry or sprinkle of rain, but breezy and rather chilly. Overnight lows drop to the 20s, maybe even a few upper 10s possible. Daytime highs recover to the lower 40s, maybe some upper 30s hills. Watching the period November 29-30 for the potential impact by low pressure, but right now the overall idea is that any system may be pushed to the south of the region by a much larger low pressure circulation to our north and northeast. Fair and seasonable weather looking out to December 1.

DAYS 11-15 (DECEMBER 2-6)

Indications are for below normal precipitation and near to slightly below normal temperatures for the early days of December with high pressure the main controller in a west northwesterly air flow.

C-19 Chat Post – November 22 2021

DAYS 1-5 (NOVEMBER 21-25)

A quick discussion for this Sunday update. No big changes to the outlook. Warm front moves through today / tonight with lots of clouds, although there will be some intervals of sun today between heavier cloud areas. Across Cape Cod, however, there will be a feed of low level moisture enough to produce some rain showers, so a bit more of an unsettle day there. Overnight through midday Monday comes the wet weather period for the remainder of the region as well, with rain showers as a cold front approaches from the west, though it will be mild post-warm front and pre-cold front. That cold front will sweep across the area during Monday, which ends drier as the temperature starts to go down. As we have leaned all along, the front gets offshore for enough so that new storminess on it occurs far enough east for no significant impact, in fact so far east that it will only serve to enhance a chilly wind across the region Tuesday, which will then relax Wednesday as high pressure moves in from the west. So all-in-all other than a relatively minor bump in the road Monday, we’re looking at good local and regional travel weather leading up to Thanksgiving. The holiday itself will also feature nice weather courtesy high pressure, but the center of it shifting to the east a bit will allow for a milder day than we see Wednesday.

TODAY: Lots of clouds / partial sunshine. Scattered rain showers Cape Cod. Highs 46-53. Wind variable to S up to 10 MPH except 5-15 MPH Cape Cod.

TONIGHT: Mostly cloudy. Numerous to widespread rain showers arriving west to east late evening and overnight. Lows 39-46 evening then rising temperatures overnight. Wind S 5-15 MPH.

MONDAY: Cloudy. Widespread rain showers morning and midday. Highs 51-58. Wind S 5-15 MPH with higher gusts, shifting to NW.

MONDAY NIGHT: Variably cloudy. Lows 30-37. Wind NW 10-20 MPH.

TUESDAY: Partly sunny. Highs 38-45. Wind N 10-20 MPH, higher gusts.

TUESDAY NIGHT: Partly cloudy. Lows 22-29. Wind NW 5-15 MPH, higher gusts.

WEDNESDAY: Partly cloudy. Highs 41-48. Wind W 5-15 MPH, higher gusts.

WEDNESDAY NIGHT: Mostly clear. Lows 28-35. Wind W up to 10 MPH.

THURSDAY (THANKSGIVING): Mostly sunny. Highs 46-53. Wind SW 5-15 MPH.

DAYS 6-10 (NOVEMBER 26-30)

A weak frontal boundary from low pressure passing north of the region may bring a few rain showers November 26 (Black Friday) but no significant problems for shopping trips, maybe minor inconvenience if you have outdoor decorating plans. Dry, cool, breezy weather November 27-28 weekend. Still watching the November 29-30 period for the potential impact of low pressure, but most indications this far out indicate it may miss the region to the south.

DAYS 11-15 (DECEMBER 1-5)

The early days of December look mostly dry with one or two minor precipitation threats and some up-and-down temperatures. Can’t get a real feel for specific trend at this point, really just looks like more of the same.

C-19 Chat Post – November 21 2021

DAYS 1-5 (NOVEMBER 20-24)

The fine-tuning has been ongoing for the period of time leading up to Thanksgiving, and that’s what the next 5 days are through Wednesday. We start with a not-so-bad weekend that features plenty of sunshine under high pressure’s control today and more cloudiness as a warm front approaches on Sunday. There may be some light rainfall not too far away Sunday morning and midday as the thickest band of cloudiness with the warm front moves through, and a little low level moisture may cause a shower to cross the Cape Cod area sometime during the day as well, otherwise expect an essentially rain-free Sunday. It is the cold front crossing the region Monday that will produce widespread rain showers for our region, but most of these will occur during the morning and midday hours before a drying trend takes over. It will be mild on Monday, but once the front goes by, in comes a new cold air mass for Monday night through Wednesday. Tuesday and Wednesday will be dry days as it stands now with the evolution of low pressure on the frontal boundary taking place far enough to the east and northeast of our region not to have impact more than just enhancing the northerly air flow and chilly air flowing into the region. So general weather for pre-Thanksgiving travel, other than for several hours Monday, will not be that bad at all.

TODAY: Sunny. Highs 40-47. Wind NW up to 10 MPH becoming variable.

TONIGHT: Partly cloudy. Lows 21-28. Wind variable under 10 MPH.

SUNDAY: Variably cloudy – least sun morning, a bit more sun afternoon. Possible rain shower Cape Cod. Highs 46-53. Wind variable to S up to 10 MPH.

SUNDAY NIGHT: Mostly cloudy. Rain showers arriving late evening or overnight. Lows 39-46 evening then rising temperatures overnight. Wind S 5-15 MPH.

MONDAY: Cloudy. Widespread rain showers morning and midday. Highs 51-58. Wind S 5-15 MPH with higher gusts, shifting to NW.

MONDAY NIGHT: Variably cloudy. Lows 30-37. Wind NW 10-20 MPH.

TUESDAY: Partly sunny. Highs 38-45. Wind N 10-20 MPH, higher gusts.

TUESDAY NIGHT: Partly cloudy. Lows 22-29. Wind N 5-15 MPH, higher gusts.

WEDNESDAY: Partly cloudy. Highs 41-48. Wind NW 5-15 MPH, higher gusts.

DAYS 6-10 (NOVEMBER 25-29)

Thanksgiving Day (November 25) looks dry and tranquil and a little milder than the couple days leading up to it as high pressure sits over the area. High pressure shifts offshore and a low pressure system passes north of the region while weakening November 26, bringing some cloudiness and perhaps some rain shower activity to the region. This leads to a dry, breezy, and seasonably chilly weekend November 27-28. We’ll have to watch a wave of low pressure taking a more southerly track as it approaches the region at the end of the period. If it were to get into the region some frozen precipitation would be possible, but it also may be forced too far south to have much of an impact. At day 10, this is a low confidence outlook.

DAYS 11-15 (NOVEMBER 30 – DECEMBER 4)

One or two precipitation threats are possible between the final day of November through the first several days of December with a bit of a rollercoaster temperature pattern.

C-19 Chat Post – November 20 2021

DAYS 1-5 (NOVEMBER 19-23)

A strong cold front moved through from west to east overnight, putting a quick end to our brief warm treat. The cloudiness also blocked a fair amount of the lunar eclipse that was ongoing, but the clearing line did move in quickly enough from the west, combined with the moon lowering in the western sky, to allow many areas from the I-95 belt westward to view the last hour or so of the event (myself included here in Woburn). The moon in my area and others as well was then re-obscured by advancing stratocumulus clouds, which mark the arrival of colder air. We’ll see these clouds mixing with the sun today and later a few of them may grow enough to produce a brief shower of rain, graupel, or snow, with no impact from them where they occur. After high temperatures in the middle 60s to lower 70s yesterday, today will be a “back-to-reality” day with high temperatures from the middle 40s to around 50 this morning before they hold steady or fall during the afternoon along with a gusty breeze. High pressure will move right over the region tonight into Saturday with winds dropping off. After a cold night and early morning, it recovers back to the 40s Saturday, which by then will feel nice because of the lack of wind. A warm front approaching on Sunday will bring more cloudiness to the region, but the day will be rain-free. We get into the warm sector for a while into Monday, but that will be a wet day as a cold front approaches from the west, parented by low pressure passing north of the region. Once the front goes by, it gets far enough offshore for drying out here, but low pressure will form on the front east of New England then get captured by upper level low pressure and do a loop to our northeast (Canadian Maritimes back to northern Maine) Tuesday. This will enhance a chilly wind here, and perhaps a few rain and/or snow showers may wheel southwestward back into our region, but not looking at any significantly stormy weather here.

TODAY: Sun/cloud mix. Chance of a passing rain/graupel/snow shower. Highs 45-52 in the morning, falling slowly through the 40s during the afternoon. Wind NW increasing to 15-25 MPH.

TONIGHT: Partly cloudy evening. Clear overnight. Lows 23-30. Wind NW 10-20 MPH with higher gusts evening, diminishing overnight.

SATURDAY: Sunny. Highs 40-47. Wind NW up to 10 MPH becoming variable.

SATURDAY NIGHT: Partly cloudy. Lows 21-28. Wind variable under 10 MPH.

SUNDAY: Variably cloudy. Highs 46-53. Wind variable to S up to 10 MPH.

SUNDAY NIGHT: Mostly cloudy. Rain showers arriving late evening or overnight. Lows 39-46. Wind S up to 10 MPH.

MONDAY: Cloudy. Widespread rain showers. Highs 51-58. Wind S 10-20 MPH.

MONDAY NIGHT: Variably cloudy. Lows 33-40. Wind NW 10-20 MPH.

TUESDAY: Variably cloudy. Chance of a passing rain or snow shower. Highs 40-47. Wind N 10-20 MPH, higher gusts.

DAYS 6-10 (NOVEMBER 24-28)

Low pressure offshore and high pressure approaching from the west means a breezy and cold start to November 24, but the day before Thanksgiving is expected to be dry with wind settling down during the day and good conditions for travel both local and into and out of the region. High pressure will bring fair and slightly milder weather for Thanksgiving Day (Nov 25). A weakening frontal boundary brings the risk of a rain shower later next Friday (Nov 26) and right now the weekend of November 27-28 looks generally dry and seasonably chilly.

DAYS 11-15 (NOVEMBER 29 – DECEMBER 3)

Watching the chance for a precipitation event in the November 29-30 window of time followed by drier weather the first few days of December, based on current anticipated timing of weather systems many days ahead.

C-19 Chat Post – November 19 2021

DAYS 1-5 (NOVEMBER 18-22)

Many times this autumn, the “pick of the week” has been Thursday (coincidence), and this week is no exception if you like warm conditions. Yes, it’s mid November, and we’ve felt the chill of the season recently, but today will be a big exception. A warm front moved through the region last night and after low temperatures in the 40s during the evening, it warmed into the 50s overnight, along with the dew points as you probably noticed by the “wet ground but it didn’t rain” look early this morning. Those dew points will be left behind in the 50s today but the temperature will continue its climb on a freshening southwesterly breeze ahead of an approaching cold front, and it will be a battle between warm advection and length of daylight to determine who makes it to 70 today. At least 60s for all though! I’ve seen commentary out on social media about how “crazy” this is for November. Not really. Although a day in the 60s to 70 is not overly common for November, we usually get at least one instance of it every year, and sometimes more. It just tends to be very fleeting at this time of year in most cases (last year being an exception when we had an extended stretch of November warmth). Well, this one won’t be hanging around. The aforementioned cold front will be charging across the region from west to east tonight, with a band of rain showers. Some of the shorter range guidance has depicted strips of snowfall on the back side of the rain area as the temperature plummets directly behind the sharp front, and to some degree (no pun intended), this is likely a true representation, but even though the flakes may fly in portions of central MA and southwestern NH, they won’t last and they won’t stick, because the ground will simply be too warm. For most of us, the rain will come to an end, and the temperature will drop fast as the wind shifts. Of interest to sky watchers is the timing of the clearing, which should take place very quickly behind the precipitation. There is a partial lunar eclipse (not far from total) that starts in the 2 a.m. hour and lasts into the 5 a.m. hour, and hopefully we will get enough clearing in the WHW forecast area to see the last part of this event. After a slight recovery in temperature first thing in the morning, we won’t see them go up any further, but down gradually from there, and Friday will be one of those days that features a gusty wind and passing clouds, a few of which may release a brief rain or snow shower, though most of these will stack in the mountains to our west and north. Friday night, as high pressure from Canada moves closer via the Great Lakes, the wind will drop off and the temperature will follow suit, under a clear sky. Most areas will find themselves in the 20s by dawn Saturday. But Saturday will be a very nice day with lots of sunshine and light wind so the cold of the morning and the recovery to the 40s won’t be too tough to take if you are outside. Plymouth Massachusetts has its annual Thanksgiving parade that day, which the weather will be great for! As we get to the back half of the weekend, it’s time for more changes. A warm front approaches on Sunday with more cloudiness but a rain-free day. Low pressure will pass northwest and north of our region Monday, dragging a cold front and a ribbon of rainfall through our area, though it will be fairly mild for a good parts of the day as the frontal boundary will still be west of us until sometime Monday evening.

TODAY: Mostly sunny. Highs 64-71. Wind SW 10-15 MPH, gusts 20-25 MPH.

TONIGHT: Mostly cloudy. Widespread rain showers arriving west to east evening, ending west to east overnight. Lows 37-44. Wind SW 10-20 MPH shifting to NW, higher gusts possible.

FRIDAY: Sun/cloud mix. Chance of a passing rain and/or snow shower. Highs 45-52 in the morning, falling slowly through the 40s during the afternoon. Wind NW 15-25 MPH.

FRIDAY NIGHT: Partly cloudy evening. Clear overnight. Lows 23-30. Wind NW 10-20 MPH with higher gusts evening, diminishing overnight.

SATURDAY: Sunny. Highs 40-47. Wind NW up to 10 MPH becoming variable.

SATURDAY NIGHT: Partly cloudy. Lows 21-28. Wind variable under 10 MPH.

SUNDAY: Variably cloudy. Highs 46-53. Wind variable to S up to 10 MPH.

SUNDAY NIGHT: Mostly cloudy. Rain showers arriving late evening or overnight. Lows 39-46. Wind S up to 10 MPH.

MONDAY: Cloudy. Widespread rain showers. Highs 51-58. Wind S 10-20 MPH.

DAYS 6-10 (NOVEMBER 23-27)

Still working on the details of what happens once the frontal boundary clears the coast. A low pressure area likely does form on it to our east Tuesday and do a loop to our east through early Wednesday, far enough away to not bring stormy weather but close enough so that some showers of rain/mix/snow may occur during this time frame, along with windy and colder weather. A more tranquil period of weather later Wednesday (Nov 24) through Thanksgiving Day (Nov 25) as a small area of high pressure moves in. We will watch for a weak system coming through from the west with a minor precipitation later Nov 26 or Nov 27.

DAYS 11-15 (NOVEMBER 28 – DECEMBER 2)

The pattern does look a little more active in this time frame with a couple rain and/or snow threats from a more active Pacific jet stream resulting in near to slightly above normal precipitation and temperature for the period overall.

C-19 Chat Post – November 18 2021

DAYS 1-5 (NOVEMBER 17-21)

West-to-east zonal flow will dominate our weather for the next several days. This will bring some quick changes to our region as nothing lingers for long. High pressure sitting over us early this morning has allowed a decent early morning of radiational cooling with many areas having fallen to the 20s. Coastal and urban temperatures are a little less cold, partly due to some lingering nighttime cloud cover and a little more wind in those locations. We’ll have a decent day today, but you’ll notice more clouds arriving as the day goes on, this in response to a warm front moving into and across the area. This front will not produce any precipitation for our area, however. We’ll be in the “warm sector” behind that front and ahead of an approaching cold front tonight and Thursday, with Thursday’s high temperatures soaring by November standards well into the 60s for most of the region – and not out of the question that a couple locations achieve a 70. The records for the date are above that and will remain as they are. Enjoy the warmth because it will not be hanging around. A strong cold front will move across the region Thursday night and early Friday, accompanied by a band of rain showers. As its parent low moves across southeastern Canada and strengthens, and high pressure moves into the Great Lakes from central Canada, we’ll find ourselves in a blustery, colder northwesterly air flow on Friday with temperatures having fallen to the 40s just behind the front, then pretty much sitting there during the day (may reach the lower 50s some areas). High pressure will move closer and winds will start to drop off gradually Friday night and then this high will move over the region giving us a very nice but chilly day Saturday. But as noted above, nothing will be hanging around, and the high will move offshore Sunday and an approaching warm front will bring more cloudiness to the region.

TODAY: Sunny start, then variably cloudy. Highs 50-57. Wind variable to S up to 10 MPH.

TONIGHT: Variably cloudy evening. Mostly clear with patchy ground fog overnight. Lows 42-49. Wind S to SW up to 10 MPH.

THURSDAY: Mostly sunny morning. Increasing clouds afternoon. Highs 63-70. Wind increasing to SW 10-20 MPH.

THURSDAY NIGHT: Mostly cloudy. Widespread rain showers arriving west to east evening, ending west to east overnight. Lows 37-44. Wind SW 10-20 MPH shifting to NW, higher gusts possible.

FRIDAY: Sun/cloudy mix. Chance of a passing rain and/or snow shower. Highs 45-52 in the morning, falling slowly through the 40s during the afternoon. Wind NW 15-25 MPH.

FRIDAY NIGHT: Partly cloudy evening. Clear overnight. Lows 23-30. Wind NW 10-20 MPH with higher gusts evening, diminishing overnight.

SATURDAY: Sunny. Highs 40-47. Wind NW up to 10 MPH becoming variable.

SATURDAY NIGHT: Clear. Lows 21-28. Wind variable under 10 MPH.

SUNDAY: Variably cloudy. Highs 46-53. Wind variable to S up to 10 MPH.

DAYS 6-10 (NOVEMBER 22-26)

Thanksgiving Week, a big travel, shopping, and gathering time for many. Perhaps no other week during the year faces such weather focus. What’s going to happen here? My thoughts have not really changed on this. The warm front that I spoke of above (for Sunday) will have passed by and we’ll find ourselves with a mild and wet Monday ahead of a cold front which will bring rain showers. As this front passes through we’ll likely see low pressure form on it in response to a vigorous upper level disturbanace. Model guidance has been all over the place with details on timing/movement of this feature with a wide variety of computer-predicted outcomes. No surprise there. My (and other forecaster’s) aim is to try to sort through it all and come up with the most likely scenario for our forecast. My having gone through that process yet again leads me to believe we’ll get colder air in fairly quickly behind that cold front but after the main precipitation is to our east. The low’s development will be rather rapid and it will likely intensify and do at least a partial and maybe complete cyclonic loop east and north of our region. The weather that results here would be unsettled, but not overly stormy in terms of heavy precipitation. It would be a blustery set up with rain and snow showers that could occur in the Tuesday to early Wednesday time frame. I still expect the system to have completed its tantrum and pulled off to the east enough so that we have calmer weather later Wednesday and for Thanksgiving Day on Thursday. A weak low pressure system may approach and move into the region by Friday (Nov 26) with a minor precipitation threat (favoring rain over snow but either possible). I’ll continue to fine-tune this forecast as we go.

DAYS 11-15 (NOVEMBER 27 – DECEMBER 1)

The pattern does look a little more active in this time frame with a couple rain and/or snow threats from a more active Pacific jet stream. Similar to yesterday, a summary of the period would be precipitation near to above normal, but I’m not as sold on the colder side of the pattern right now so near to slightly above normal for overall temperatures.

C-19 Chat Post – November 17 2021

DAYS 1-5 (NOVEMBER 16-20)

Our overall weather pattern will feature a west to east flow the next 5 days. But the fairly zonal pattern does not mean we’ll be without weather changes. No systems hang around long, so there are plenty of changes to be had. We start with a bright but blustery and chilly day today as a fresh westerly breeze blows between low pressure in eastern Canada and high pressure approaching from the Great Lakes. The wind will drop off as the high pressure center moves over our area tonight, but this will set up a fairly cold night due to radiational cooling, a process in which a clear sky and light wind allows temperatures to fall rapidly. This could be the night that Logan Airport reaches or drops below 32 for the first time. This can be made more difficult if the breeze stays too strong for too long, or a component of the wind blows over some of the water that around the airport before reaching the temperature sensor. So it’s not abnormal to have pretty much every area having dropped to at least several degrees lower than what the airport reading will be. This is yet another example of why Boston’s reported official temperature from the airport is not always representative of the rest of the city and its immediate surroundings. Anyway, 32 or not at Logan, a chilly night is ahead followed by a decent rebound Wednesday after the cold start. We will not see the day stay as bright Wednesday as it will be today though, because an approaching warm front will help to generate a fair amount of high and some mid level clouds. Precipitation is not going to occur in our region with this warm frontal passage, however, with any of that staying to our north in northern New England and southern Canada, closer to the warm front’s parent low. What will happen is a spike of unseasonably warm weather for Thursday ahead of the low’s approaching cold front. It appears that we’ll get through the daylight hours with a fair amount of sun before clouds eventually increase, but not before temperatures soar to the 60s throughout the region. The cold front will march through the region from west to east Thursday night and early Friday with a fairly solid band of rain showers accompanying it. Current indications are that the precipitation along the front will exit before nearly enough cold air arrives to end it as a mix or snow anywhere in our region. But the daytime hours of Friday will see the temperature turn out about 20 degrees colder than Thursday was, as any attempted diurnal warming is thwarted by strong cold air advection behind the cold front. This will come along with a fair amount of wind too. Cold air aloft will also help trigger some clouds which may produce a rain or snow shower in a few locations, though that will be a minor threat with no real impact of any kind. High pressure moves in with fair weather Saturday, starting cold but feeling nicer than Friday as while we’ll be cool during the day, it will be with much less wind.

TODAY: Mostly sunny. Highs 41-48. Wind W 10-15 MPH, gusts 20-25 MPH.

TONIGHT: Clear. Lows 24-29 except 30-35 urban centers and immediate shoreline. Wind W diminishing to under 10 MPH.

WEDNESDAY: Sunny start, then variably cloudy. Highs 50-57. Wind variable to S up to 10 MPH.

WEDNESDAY NIGHT: Partly cloudy evening. Mostly clear with patchy ground fog overnight. Lows 42-49. Wind S to SW up to 10 MPH.

THURSDAY: Mostly sunny morning. Increasing clouds afternoon. Highs 62-69. Wind SW 10-20 MPH.

THURSDAY NIGHT: Mostly cloudy. Widespread rain showers arriving west to east evening, ending west to east overnight. Lows 37-44. Wind SW 10-20 MPH shifting to NW, higher gusts possible.

FRIDAY: Sun/cloudy mix. Chance of a passing rain and/or snow shower. Highs 45-52 in the morning, falling through the 40s during the afternoon. Wind NW 15-25 MPH.

FRIDAY NIGHT: Partly cloudy evening. Clear overnight. Lows 23-30. Wind NW 10-20 MPH with higher gusts evening, diminishing overnight.

SATURDAY: Sunny. Highs 40-47. Wind NW up to 10 MPH becoming variable.

DAYS 6-10 (NOVEMBER 21-25)

This period, from the end of the coming weekend (November 21) to Thanksgiving Day (November 25) is a busy period of time for errands and travel both locally as well as into and out of the region, so it’s always heavily dependent on weather, and we will have a storm threat in here. The transition begins Sunday (Nov 21) as we have a warm front cross the region with some cloudiness but only a minor threat of any light rainfall occurring. The parent low of this front, like its predecessor, is expected to move from the Great Lakes into eastern Canada, and a trailing cold front arrives Monday with a band of rain showers along it. What we will be seeing is at upper levels a trough of low pressure will become more amplified in the eastern US so that a new low pressure area develops along that frontal boundary. Right now, it looks like this will take place late Monday into Tuesday (Nov 22-23) but with us on the milder side of the low, with a rain and wind event for the WHW forecast area to start out, and then once the frontal boundary is pulled offshore we see stronger cold advection along with wind, but with the main precipitation gone, leaving us with rain and snow showers – exact timing and details on these 2 days TBD. Enough overall west to east flow in the atmosphere should help to push this system away from the region with more tranquil weather returning for the middle of next week Wednesday and Thanksgiving Day, but we’re looking pretty far ahead here so there can always be some adjustment needed to that part of the outlook.

DAYS 11-15 (NOVEMBER 26-30)

Earliest indications for the final days of November are for a bit more of an active pattern with a couple of rain and even potential snow threats materializing. Don’t panic in thinking we suddenly go into full fledged winter mode here. We won’t be quite there yet, but it’s also not impossible that some of us may need to reach for our shovels for the first time. If I had to summarize the last 5 days of November in terms of precipitation, near to above normal, and temperature, near to below normal.