C-19 Chat Post – November 22 2020

DAYS 1-5 (NOVEMBER 21-25)

Discussion…

A cold front will pass by the region today, although the day itself will be pleasant by November standards, just some clouds for a while before sun returns and most areas achieve a high temperature of over 50. As the center of high pressure in southeastern Canada moves eastward it will turn the wind, which is northwest as the front passes, around to the east by Sunday, bringing a maritime air mass into the region with cooler/raw feel being the result. Expect some low clouds to arrive from the ocean as high and mid level clouds stream in from an approaching warm front. For now, I’m expecting the daylight hours of Sunday to remain dry. Things change Sunday night when that warm front gets closer, bringing a threat of rain at the same time areas of drizzle result from the onshore air flow. As previously mentioned, the warm front may have trouble getting northward through the entire area Monday before a cold / occluded front arrives from the west to bring drying but colder air into the region during Monday night. Before that, we’ll have a wet day on Monday with widespread rain showers. Tuesday will be a dry but breezy and colder day with high pressure approaching via the Great Lakes, delivering Canadian cold to our region. While the center of high pressure moves just to our north Tuesday night, a nose of it will extend across the region, so a clear/cold night will result. Wednesday, the high moves quickly off to the east and a southeast to south wind develops here. Expect it to moderate somewhat, temperature-wise, but we’ll also see an increasing cloudiness ahead of the next disturbance. Guidance continues to be very divergent on how quickly this system arrives here, but my best guess for now is that our next rain threat holds off until after the daylight hours of Wednesday.

Details…

TODAY: Variably cloudy morning. Mostly sunny afternoon. Highs 50-57. Wind W 5-15 MPH shifting to N.

TONIGHT: Mostly clear. Lows 28-35. Wind N to NE up to 10 MPH.

SUNDAY: Partly sunny to mostly cloudy. Highs 46-53. Wind NE to E 5-15 MPH.

SUNDAY NIGHT: Cloudy. Periods of rain and drizzle. Areas of fog. Lows 42-49. Wind E to SE 5-15 MPH.

MONDAY: Cloudy with rain showers likely through early afternoon. Areas of fog and drizzle in the morning. Breaking clouds later in the day. Highs 48-55, coolest southern NH and northeastern MA. Wind SE 5-15 MPH in southern NH and northeastern MA, SW 5-15 MPH elsewhere, shifting to W and increasing to 10-20 MPH with higher gusts all areas by late day.

MONDAY NIGHT: Partly cloudy. Lows 27-34. Wind NW 10-20 MPH and gusty.

TUESDAY: Mostly sunny. Highs 37-44. Wind NW 10-20 MPH and gusty.

TUESDAY NIGHT: Clear. Lows 20-27. Wind N under 10 MPH.

WEDNESDAY: Increasing clouds. Rain possible at night. Highs 45-52. Wind SE 5-15 MPH.

DAYS 6-10 (NOVEMBER 26-30)

To give an example of the guidance divergence I have been mentioning, the most recent run (as of the writing of this blog) of the US operational model (GFS) has a dry, breezy, cool Thanksgiving Day while the most recent run of the European operational model (ECMWF) has an overcast and rain day here. My adjusted educated guess for now is a wet morning and drier afternoon for November 26, but I have a feeling further tweaking will be needed. The behavior and timing of that system has an impact on the forecast for the last several days of the month as well. Cautiously optimistic that we have fair and mild weather for November 27-28 and somewhat unsettled weather for the last couple days of the month, but this is very low confidence at this time.

DAYS 11-15 (DECEMBER 1-5)

The first several days of December should see a west-to-east large scale flow aloft, with out area still in that middle ground between a warm US Southeast and a cold Canada. At least one episode of unsettled weather and a couple air mass changes are likely.

C-19 Chat Post – November 21 2020

DAYS 1-5 (NOVEMBER 20-24)

Discussion…

A warm front has passed by the region and while it introduces a mild air mass today it will also open the door for windy conditions as we have a fairly tight pressure gradient between low pressure passing to the north and an elongated area of high pressure to the south. The low to the north is parenting a cold front which will slip southeastward across the region tonight and early Saturday but fairly innocuously other than some clouds. What it will do is shift the wind from southwest to northwest, but it will diminish somewhat as the pressure gradient loosens up as high pressure approaches New England via the Great Lakes. The center of this new high pressure area will slide eastward, passing to our north, and this will turn the wind easterly by Sunday when we’ll have both increasing low level moisture off the ocean and high level moisture from the frontal boundary starting its return as a warm front. That front may or may not make it all the way through the region Sunday night and Monday, and the position of that boundary makes Monday’s high temperature forecast a challenge, but what will be the case during Sunday night and Monday as we’ll have a greater opportunity for wet weather. Finally, as a cold (or occluded front depending on the location of the warm front) passes through during Monday it will shift the wind back to the west again and drier air will return by the end of the day. Along with this will come another shot of chilly air which we will feel Tuesday as high pressure approaches from the west, pushing that cold air right out of Canada and into New England.

Details…

TODAY: Clouds eventually give way to sun. Highs 53-60. Wind SW increasing to 10-20 MPH with gusts 25-35 MPH.

TONIGHT: Partly cloudy. Lows 40-47. Wind W 5-15 MPH.

SATURDAY: Partly to mostly sunny. Highs 50-57. Wind W 5-15 MPH shifting to N.

SATURDAY NIGHT: Mostly clear. Lows 33-40. Wind NE up to 10 MPH.

SUNDAY: Mostly cloudy. Drizzle possible eastern coastal areas. Highs 46-53. Wind NE to E 5-15 MPH.

SUNDAY NIGHT: Cloudy. Periods of rain and drizzle. Areas of fog. Lows 42-49. Wind E to SE 5-15 MPH.

MONDAY: Cloudy with rain showers likely through early afternoon. Areas of fog and drizzle in the morning. Breaking clouds later in the day. Highs 48-55, coolest southern NH and northeastern MA. Wind SE 5-15 MPH in southern NH and northeastern MA, SW 5-15 MPH elsewhere, shifting to W and increasing to 10-20 MPH with higher gusts all areas by late day.

MONDAY NIGHT: Partly cloudy. Lows 27-34. Wind NW 10-20 MPH and gusty.

TUESDAY: Mostly sunny. Highs 37-44. Wind NW 10-20 MPH and gusty.

DAYS 6-10 (NOVEMBER 25-29)

We continue to see divergent and variable guidance which is of limited help. My feel for the situation at this point says this area sees clouds and milder air return November 25 with wet weather late day or at night, a small bubble of high pressure saving Thanksgiving Day from rainfall, so a drier day but with limited sun. Two more systems both with rain chances in an overall mild pattern around November 27 and 29. Again remember that the uncertainty and low confidence level of forecasts this far out leave the door open for significant adjustments.

DAYS 11-15 (NOVEMBER 30 – DECEMBER 4)

The overall pattern will be fast-flowing, zonal (west-to-east), with our region still sitting in the battle zone between cold north and warm south. While none of the disturbances to come through appear they’d have much time to evolve into major storms, we should deal with a couple of episodes of precipitation and frequent air mass changes, but no very large temperature departures from seasonal averages that last any length of time.

C-19 Chat Post – November 20 2020

DAYS 1-5 (NOVEMBER 19-23)

Discussion…

Yesterday’s anomalous cold and last night’s clear sky and lighter wind combined to set up one cold start to this morning, but as high pressure sinks to the south of New England we begin a moderation in short order, but that moderation will be tempered a little today due to a very low launching pad and limited daylight to help warm things up – it’s that time of year! A warm front with some high cloudiness will pass by today as well, and while filtering the sunshine at times today, it will lead to helping accelerate the warm-up on Friday, which will end up much milder. We’ll remain on the mild side of this front into early Saturday, but high pressure in eastern Canada will push the boundary back to the south during Saturday, shifting our wind to north and northeast later Saturday into Sunday, with cooler air (though not as cold as recently) settling in. During Sunday, however, a warm front will approach the region with increasing cloudiness and we may even deal with some wet weather before the day is done. This is more likely to take place Sunday night into Monday as low pressure tracks north of the region, finally pushing its cold front across the region later Monday, at which time any rain threat will end, just in time for the arrival of a new cold air mass from Canada Monday night.

Details…

TODAY: Sun and high clouds. Highs 40-47. Wind SW 5-15 MPH, gusts around 20 MPH.

TONIGHT: Partly cloudy. Lows 38-45. Wind SSW 5-15 MPH, gusts to 20 MPH.

FRIDAY: Partly sunny. Highs 53-60. Wind SW 5-15 MPH, gusts 20-25 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 40-47. Wind W 5-15 MPH.

SATURDAY: Partly to mostly sunny. Highs 50-57. Wind W 5-15 MPH shifting to N.

SATURDAY NIGHT: Mostly clear. Lows 33-40. Wind NE up to 10 MPH.

SUNDAY: Clouding over. Highs 46-53. Wind NE 5-15 MPH.

SUNDAY NIGHT: Cloudy. Chance of rain. Lows 42-49. Wind SE 5-15 MPH.

MONDAY: Cloudy with rain showers likely through early afternoon. Breaking clouds later in the day. Highs 50-57. Wind SW 10-20 MPH, shifting to W late.

DAYS 6-10 (NOVEMBER 24-28)

Guidance all over the place, with different runs of the same model somewhat inconsistent and varying solutions between models, so they’re not a lot of help in general, but what appears to be is that we’ll be in a fairly active pattern, as previously hinted at, being near a battle between cold air in Canada and warmer air to our south. Initially, cold high pressure wins the battle with dry weather and below normal temperatures November 24. The November 25-26 period will likely bring a period of unsettled weather as low pressure moves into the Northeast via the Ohio Valley, with rain favored over any other precipitation type as cold air retreats quickly. Other than that, the detail of timing remains uncertain and will be fine-tuned. Briefly drier about November 27 before the next unsettled system moves through at the end of the period.

DAYS 11-15 (NOVEMBER 29 – DECEMBER 3)

The overall pattern will be fast-flowing, zonal (west-to-east), with our region still sitting in the battle zone between cold north and warm south. While none of the disturbances to come through appear they’d have much time to evolve into major storms, we should deal with a couple of episodes of precipitation and frequent air mass changes, but no very large temperature departures from seasonal averages that last any length of time.

C-19 Chat Post – November 19 2020

DAYS 1-5 (NOVEMBER 18-22)

Discussion…

A solid shot of cold air today accompanied by wind, while making it feel more like mid winter than later autumn, is not indicative of the longer term mild pattern we are in but is a good illustration of the cold shots we still get during a pattern like that, especially when our area will not be far from the boundary between more persistent warmth to the south and plenty of cold air helped a long by a lot of early snowfall in Canada. So we’re in the cold now, and that will be around into tomorrow, although after a very cold start tomorrow morning, we’ll start to moderate during the day as high pressure shifts off to the south and we get a milder west to southwest air flow, which brings in much milder air for Friday, the boundary having slipped north. But it comes back to the south again somewhat over the weekend and we get onto the cooler side again, although only slightly cooler this time as there is not a mechanism to deliver a good shot of cold from Canada. It will be more typical of a pattern we’ve seen many times since summer where high pressure slides across eastern Canada and we get more of a north to northeast air flow, weaker in comparison to the gusty northwest wind we see today.

Details…

TODAY: Mostly sunny. Highs 32-39. Wind NW 10-20 MPH and gusty.

TONIGHT: Clear. Lows 18-25. Wind NW 5-15 MPH.

THURSDAY: Mostly sunny. Highs 42-49. Wind W 5-15 MPH and gusty.

THURSDAY NIGHT: Partly cloudy. Lows 38-45. Wind WSW 5-15 MPH.

FRIDAY: Partly sunny. Highs 53-60. Wind SW 5-15 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 40-47. Wind W 5-15 MPH.

SATURDAY: Partly to mostly sunny. Highs 49-56. Wind N 5-15 MPH.

SATURDAY NIGHT: Mostly clear. Lows 33-40. Wind NE up to 10 MPH.

SUNDAY: Mostly sunny. Highs 47-54. Wind NE 5-15 MPH.

DAYS 6-10 (NOVEMBER 23-27)

As mentioned previously, trying to time systems beyond a few days is difficult at best. Still looking like an unsettled day on November 23 as high pressure shifts offshore and a disturbance and frontal system moves in with a rain or rain shower threat. The front settles to the south after that and timing the next low pressure area is a challenge, with additional unsettled weather possible anywhere from later November 24 through November 25, but not likely for the entire time. High pressure should move in with drier weather later in the period, including Thanksgiving Day (November 26).

DAYS 11-15 (NOVEMBER 28 – DECEMBER 2)

The last days of November to the start of December should see a continued generally westerly (zonal) flow with our area often in the boundary zone between mild air to the south and colder air to the north. Early period is most likely to see some unsettled weather with a front in the vicinity.

C-19 Chat Post – November 18 2020

DAYS 1-5 (NOVEMBER 17-21)

Discussion…

A cold front moves through the region today with some cloudiness and a chance of a passing rain/snow shower, introducing a significant shot of cold air for midweek before high pressure that moves in from the Great Lakes with the cold air slips to the south and we see a warming trend later this week, mildest by Friday, then a slight cool down for Saturday as a weaker cold front slips through the region early in the day.

Details…

TODAY: Variably cloudy. Passing rain and/or snow showers are possible. Highs 40-47. Wind W 5-15 MPH with higher gusts.

TONIGHT: Variably cloudy with a passing snow shower possible, then clearing. Lows 22-29. Wind NW 10-20 MPH.

WEDNESDAY: Mostly sunny. Highs 32-39. Wind NW 10-20 MPH and gusty.

WEDNESDAY NIGHT: Clear. Lows 18-25. Wind NW 5-15 MPH.

THURSDAY: Mostly sunny. Highs 42-49. Wind W 5-15 MPH and gusty.

THURSDAY NIGHT: Partly cloudy. Lows 38-45. Wind WSW 5-15 MPH.

FRIDAY: Partly sunny. Highs 50-57. Wind SW 5-15 MPH.

FRIDAY NIGHT: Partly cloudy. Lows 38-45. Wind W 5-15 MPH.

SATURDAY: Partly to mostly sunny. Highs 47-54. Wind N 5-15 MPH.

DAYS 6-10 (NOVEMBER 22-26)

Current timing of systems in a general west to east air flow brings a warm front through on November 22 with cloudiness but not much of a rain threat. Cold front follows with a rain shower threat November 23. This front may sit just to the south with a wave of low pressure bringing some wet weather later November 24, exiting early November 25 with a shot of cooler but dry weather for the end of the period.

DAYS 11-15 (NOVEMBER 27 – DECEMBER 1)

The last days of November to the start of December should see a continued generally westerly (zonal) flow with our area often in the boundary zone between mild air to the south and colder air to the north. Mid period is most likely to see some unsettled weather with a front in the vicinity.

C-19 Chat Post – November 17 2020

DAYS 1-5 (NOVEMBER 16-20)

Discussion…

A west to northwesterly air flow will dominate the first 3 days of the week, with a colder trend. A few rain/snow showers will accompany a cold front and upper level disturbance passing through the region on Tuesday, bringing air feeling more like winter by Wednesday. A moderating trend gets underway later in the week as high pressure, first to our west helping to deliver the colder air, slips off to the south and helps push in milder air.

Details…

TODAY: Sun and passing clouds. Highs 46-53. Wind W 10-20 MPH and gusty.

TONIGHT: Clear. Lows 28-35. Wind W 5-15 MPH with higher gusts.

TUESDAY: Variably cloudy. Passing rain and/or snow showers are possible. Highs 40-47. Wind W 5-15 MPH with higher gusts.

TUESDAY NIGHT: Variably cloudy with a passing snow shower possible, then clearing. Lows 22-29. Wind NW 10-20 MPH.

WEDNESDAY: Mostly sunny. Highs 32-39. Wind NW 10-20 MPH and gusty.

WEDNESDAY NIGHT: Clear. Lows 18-25. Wind NW 5-15 MPH.

THURSDAY: Mostly sunny. Highs 42-49. Wind W 5-15 MPH and gusty.

THURSDAY NIGHT: Partly cloudy. Lows 38-45. Wind WSW 5-15 MPH.

FRIDAY: Partly sunny. Highs 50-57. Wind SW 5-15 MPH.

DAYS 6-10 (NOVEMBER 21-25)

We’ll be close to a boundary between mild air to our south and Canadian cold, as noted previously. We may find it flip flopping back and forth on us one day to the next which will help determine temperatures. Right now my best guess is we will be on the cooler side of the boundary November 21, 23, and 25, the milder side the other 2 days, and the only chance of significant precipitation (probably rain or rain showers) would come about November 24.

DAYS 11-15 (NOVEMBER 26-30)

The final 5 days of the month look like they will be dominated by a general westerly air flow but still with us not too far from the cold / warm air boundary, so at least once in there we should see air mass changes and at least one opportunity for precipitation, probably around mid period.

C-19 Chat Post – November 16 2020

DAYS 1-5 (NOVEMBER 15-19)

Discussion…

First I would like to mention the minor coastal flooding threat a couple hours either side of the late morning high tide today as we have one of the astronomically higher tides of the year. High pressure hangs on and gives us a bright start to the day, if you were up early enough. Clouds advance quickly today ahead of a warm front which will pass by later today. While the warm front does not have any precipitation with it, it will open the door for a surge of warm and humid air this evening ahead of a strong cold front which will then cross the region late tonight from west to east, as its parent low tracks north of here. This front will produce a fairly solid area of showers/downpours and possibly some thunder. While the heaviest rain will occur in a fairly narrow, quick-moving band, it can result in street flooding, especially where fallen leaves block storm drains. Wet leaves on roads also can be as slippery as snow/ice, not to mention the reduce visibility, so anyone on the road later tonight will need to exercise caution. The other threat is wind. While it will be breezy leading up to and into the time of the showers, there can be some particularly strong wind gusts aided by heavier showers bringing down much stronger winds from above. Isolated wind damage and power outages are possible. The window of greatest risk will be 10PM to 2AM from west to east across the region. Monday’s weather will feature a chilly wind with sun and clouds as a cold Canadian air mass enters via the Great Lakes. A disturbance will come along in the flow on Tuesday with more cloudiness and a rain/snow shower risk, though no significant precipitation will occur. This disturbance will serve to drag even colder air into the region for the middle of next week.

Details…

TODAY: Increasing clouds. Highs 52-59. Wind S 5-15 MPH, higher gusts late.

TONIGHT: Mostly cloudy. Rain showers moving in from west to east evening, including a band of heavier showers and possible thunder during the 10 p.m. to 2 a.m. window but lasting only a short time in any one area, then rain showers exiting from west to east overnight. Temperatures steady or rising slightly evening. Overnight lows 40-47. Wind S 10-20 MPH with higher gusts, shifting to W. During the passage of the heaviest showers wind gusts in excess of 30 MPH at lower elevations and in excess of 45 MPH at higher elevations may occur.

MONDAY: Sun and passing clouds. Highs 47-54 occurring in the morning then falling through the 40s. Wind W 10-20 MPH, gusts 25-35 MPH.

MONDAY NIGHT: Variably cloudy. Lows 30-37. Wind NW 5-15 MPH.

TUESDAY: Mostly cloudy. Chance of rain/snow showers. Highs 38-45. Wind W 10-20 MPH.

TUESDAY NIGHT: Mostly cloudy with a chance of snow showers early, then clearing. Lows 23-30. Wind N 10-20 MPH.

WEDNESDAY: Partly sunny. Slight chance of a passing snow flurry. Highs 35-42. Wind N 10-20 MPH.

WEDNESDAY NIGHT: Clearing. Lows 22-29. Wind NW 5-15 MPH.

THURSDAY: Sunny. Highs 45-52. Wind W 10-20 MPH.

DAYS 6-10 (NOVEMBER 20-24)

We’ll be near the boundary of mild air to the south and Canadian cold air. Currently expecting this region to be on the milder side of the boundary November 20 & 22, the cooler side November 21 & at the end of the period. Despite the boundary nearby, the overall pattern is dry to start with, but the precipitation change may increase toward the end of the period with the possibility of a more significant wave of low pressure entering the region.

DAYS 11-15 (NOVEMBER 25-29)

Indications are that we will remain in that battle zone area between the mild to the south and the cold to the north, with additional opportunities for unsettled weather, with dry interludes, and variable temperatures.

C-19 Chat Post – November 15 2020