C-19 Chat Post – September 11 2021

DAYS 1-5 (SEPTEMBER 10-14)

The slow-moving front that brought us our muggy and showery weather yesterday is offshore, and drier air will move in today, but an upper level disturbance combined with the sun’s heating of the ground and lower atmosphere, and leftover moisture there, will cause clouds to pop up, a few of which may build enough to release isolated showers this afternoon. Other than that, it will be a nice day today. However I do need to remind anybody with plans that include being near the coast or in the coastal waters that large ocean swells, rough surf, and rip currents will be an issue today into the start of the weekend as a result of offshore Hurricane Larry. These conditions will improve later in the weekend. The weekend itself will feature great weather as high pressure is in control. After a night of calm wind tonight, Saturday starts off rather cool, but warms nicely during the day, and Sunday ends up the warmer of the 2 days as the high pressure area slides to the south and a west to southwest wind strengthens, transporting warmer air from the Ohio Valley our way. However a cold front will drop out of Canada and cross the region during the early hours of Monday, perhaps with a few showers. There has been some waffling of guidance as to whether or not Monday would clear out or end up unsettled. For now I continue to lean toward the drier more optimistic side with perhaps a morning shower then fair weather returning. An area of high pressure from Canada will not really make a dive into the Northeast, but rather nose its way in but stay mostly to the north. This will allow the front that went by to re-approach as a warm front later Tuesday with an increase in clouds, but the early idea is that any shower threat with this would hold off that day.

TODAY: Sunny start then a sun/cloud mix. Isolated afternoon showers. Highs 70-77. Wind NW 5-15 MPH.

TONIGHT: Clearing. Lows 49-56. Wind NW under 10 MPH then calm.

SATURDAY: Sunny. Highs 72-79. Wind calm then W to SW up to 10 MPH.

SATURDAY NIGHT: Clear. Lows 53-60. Wind SW up to 10 MPH.

SUNDAY: Sunny. Highs 76-83. Wind S 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Chance of a shower overnight. Humid. Lows 60-67. Wind SW 5-15 MPH.

MONDAY: Partly sunny. Chance of a shower in the morning. Highs 70-77. Wind N 5-15 MPH.

MONDAY NIGHT: Mostly clear. Lows 50-57. Wind NE up to 10 MPH.

TUESDAY: Partly sunny. Highs 70-77. Wind E up to 10 MPH.

DAYS 6-10 (SEPTEMBER 15-19)

Low pressure passing north of the region drags a warm front through early on September 15 with a warm and more humid day being the result. Its cold front should move in at night or on September 16 with potential showers and a few thunderstorms followed by drier and cooler air later September 16 into September 17. High pressure that moves in briefly at that time will then slide offshore later in the period and a southerly wind will develop, at which time we may need to be keeping an eye on tropical moisture to the south of New England for a potential run at the region. Low confidence on this part of the forecast but definitely some hints that it can occur on our medium range guidance and from the overall weather pattern expected.

DAYS 11-15 (SEPTEMBER 20-24)

The weather pattern still should feature a mostly west-to-east movement of systems pending on what happens with the moisture to the south to start the period, but eventually a cold front should sweep through with a drier air mass arriving by mid period. A lot of tweaking to come on future updates.

C-19 Chat Post – September 10 2021

DAYS 1-5 (SEPTEMBER 9-13)

A slow-moving cold front moving west to east across the region will be the focus for showers and a few thunderstorms today into tonight, enhanced this afternoon and early evening by a wave of low pressure moving along it. Shower activity will be widespread, and while not every location will see the heaviest downpours, many will see some heavy rainfall for a time, and localized flooding may result – but not to the degree of recent events. Additionally, we have rough surf and large ocean swells (and resultant high rip current risk) from offshore Hurricane Larry ongoing today, which will also linger into the start of the weekend as the storm races by southeastern Canada on its way into the northern Atlantic. Meanwhile, we dry out overnight / early Friday as our low pressure wave and front pull offshore. Drier air moves in Friday as high pressure moves across the Great Lakes and Ohio Valley, but a weak trough moving through at upper levels supplies a pool of chilly air above us, and that results in some atmospheric instability, so when the sun heats the ground on Friday and works on the lingering moisture from today’s rainfall, we’ll see diurnal cloud development to prevent a totally sunny day, and some of those clouds may grow enough to produce a few isolated showers mainly in the afternoon. But with high pressure sliding to the south of the region and the upper levels warming, we have excellent timing for great late summer weather this upcoming weekend, both Saturday and Sunday, with the coolest part of the weekend being Saturday morning and Sunday the warmer of the 2 days. Another bubble of high pressure in eastern Canada will send a frontal boundary through the region early Monday with some clouds accompanying it, but right now it looks like we will miss any shower chance.

TODAY: Mostly cloudy morning with showers/thunderstorms moving out of eastern coastal MA and across Cape Cod through 8AM then numerous to widespread showers returning from southwest to northeast all areas mid morning through afternoon with embedded downpours and possible thunder. Poor drainage area flooding and small stream flooding may occur. Areas of fog. Humid. Highs 69-76. Wind S becoming variable then N 5-15 MPH.

TONIGHT: Cloudy with widespread to numerous showers through evening. Breaking clouds overnight. Areas of fog. Humid. Lows 60-67. Wind N 5-15 MPH.

FRIDAY: Partly sunny. Isolated afternoon showers. Less humid. Highs 70-77. Wind NW 5-15 MPH.

FRIDAY NIGHT: Clearing. Lows 51-58. Wind NW to W under 10 MPH.

SATURDAY: Sunny. Highs 72-79. Wind calm then S to SW up to 10 MPH.

SATURDAY NIGHT: Clear. Lows 53-60. Wind SW up to 10 MPH.

SUNDAY: Sunny. Highs 76-83. Wind S 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 60-67. Wind SW 5-15 MPH.

MONDAY: Partly sunny. Highs 70-77. Wind NW 5-15 MPH.

DAYS 6-10 (SEPTEMBER 14-18)

High pressure brings fair weather to the region September 14 into September 15 with a cooler start then warming up. Next frontal system brings shower chances late September 15 to early September 16 followed by fair, drier and slightly cooler weather into September 17 before it warms up again at the end of the period.

DAYS 11-15 (SEPTEMBER 19-23)

A weaker west to east flow pattern is expected but this may allow low pressure to the south of the region to get a little closer with some cloudiness and possible shower chances early in the period. Another disturbance from the west may bring showers followed by a late period cool-down, but this is lower confidence at this time.

C-19 Chat Post – September 9 2021

DAYS 1-5 (SEPTEMBER 8-12)

High pressure moves offshore today and a southerly air flow develops and strengthens ahead of an approaching trough and frontal system from the west. While we see lots of sun during the day today, you’ll notice more clouds showing up later and those will increase significantly this evening. This time when we get into unsettled weather with some threat of heavier rainfall, it will all take place pretty much during the calendar day Thursday, between the two midnights, as a frontal boundary slowly moves west to east across the region and a wave of low pressure forms on it. This will create waves of showers and a few possible embedded thunderstorms. Downpours are possible but this time we won’t see them as intense and widespread for longer time like we saw with a couple recent systems. We’ve had a little time to dry out since Ida’s remains came through last week, so while some localized flooding is possible, it should not be a major issue. It’s back to fair weather Friday as Canadian high pressure approaches with a drying northwesterly breeze, and then a spectacular weekend follows with high pressure in control, coolest early Saturday as the high center will be moving overhead, warmest Sunday afternoon as the high slides offshore.

TODAY: Mostly sunny to partly cloudy. Highs 76-83. Wind S 5-15 MPH, gusts above 20 MPH.

TONIGHT: Clouding up. Showers arriving from west to east. Downpours and embedded thunderstorms possible. Humid. Lows 62-69. Wind S 5-15 MPH, gusts above 20 MPH.

THURSDAY: Cloudy. Numerous to widespread showers with embedded thunderstorms possible. Humid. Highs 71-78. Wind S 5-15 MPH with higher gusts, becoming variable.

THURSDAY NIGHT: Mostly cloudy with lingering showers and patches of fog in the evening. Clearing overnight. Humid evening, less humid overnight. Lows 56-63. Wind variable 5-15 MPH becoming NW.

FRIDAY: Mostly sunny to partly cloudy. Highs 70-77. Wind NW 5-15 MPH.

FRIDAY NIGHT: Clear. Lows 51-58. Wind NW under 10 MPH becoming calm.

SATURDAY: Sunny. Highs 72-79. Wind calm then SW up to 10 MPH.

SATURDAY NIGHT: Clear. Lows 53-60. Wind SW up to 10 MPH.

SUNDAY: Sunny. Highs 77-84. Wind S 5-15 MPH.

DAYS 6-10 (SEPTEMBER 13-17)

A weak low and frontal system will move through the region on September 13 with some cloudiness and a risk of a few passing showers, otherwise dry. High pressure brings fair weather to the region September 14 into September 15 with a cooler start then warming up. Next frontal system brings shower chances late September 15 to early September 16 followed by fair, cooler/drier weather later in the period.

DAYS 11-15 (SEPTEMBER 18-22)

A generally zonal (west-to-east) flow pattern is expected. Current medium range timing suggests the best shower threat comes in the middle of the period with fair/mild weather to start, fair and briefly cooler thereafter.

C-19 Chat Post – September 8 2021

DAYS 1-5 (SEPTEMBER 7-11)

It’s been a while since a forecast outlook has been filled with many fair weather days, but this one is filled with 4 out of 5. The slower timing of the next frontal system makes it pretty much a Thursday system, with two fair-weather days on either side of it. First, high pressure moves over us today with a top 10 kind of day, then the high slides offshore for a warmer and slightly more humid day on Wednesday before a slow-moving cold front crosses the region taking nearly all 24 hours of Thursday, possibly delayed by a wave of low pressure on the front that may also enhance rainfall. But despite it’s slow movement, the front will clear the coast by Friday and we end up with two great days with dry weather and lower humidity to end the week and start the weekend Friday and Saturday as Canadian high pressure arrives. Also, still need to mention the large swells, rough surf, and rip current risk for coastal areas late this week due to offshore Hurricane Larry. Keep that in mind if you have any beach/boating plans.

TODAY: Sunny. Highs 71-78. Wind W up to 10 MPH.

TONIGHT: Clear. Lows 56-63. Wind SW under 10 MPH.

WEDNESDAY: Mostly sunny. Highs 76-83. Wind SW 5-15 MPH.

WEDNESDAY NIGHT: Clouding up. Showers arriving from west to east. More humid. Lows 61-68. Wind S 5-15 MPH.

THURSDAY: Cloudy. Widespread showers with embedded thunderstorms possible. Humid. Highs 71-78. Wind S 5-15 MPH becoming variable.

THURSDAY NIGHT: Clearing. Lows 55-62. Wind W up to 10 MPH.

FRIDAY: Sunny to partly cloudy. Highs 70-77. Wind NW 5-15 MPH.

FRIDAY NIGHT: Clear. Lows 51-58. Wind NW under 10 MPH.

SATURDAY: Sunny. Highs 72-79. Wind SW up to 10 MPH.

DAYS 6-10 (SEPTEMBER 12-16)

High pressure moves offshore with fair and warmer weather September 12. Right now it appears the next frontal boundary comes through quietly early September 13 with fair weather continuing through mid period with only a slight cool-down. Next round of unsettled weather comes September 15 and/or 16 with the approach and arrival of a trough and frontal system from the west.

DAYS 11-15 (SEPTEMBER 17-21)

A generally zonal (west-to-east) flow pattern is expected with limited rainfall chances and a couple air mass changes keeping temperatures variable, but not that far from normal overall.

C-19 Chat Post – September 7 2021

DAYS 1-5 (SEPTEMBER 6-10)

We start Labor Day with a lot of clouds. It’s a rainy early morning across the southern coast of Cape Cod as well as over Nantucket and Martha’s Vineyard, but this rainfall will depart soon and the region will experience an increase in sunshine later this morning into midday. However, we still have a trough of low pressure to cross the region and this may kick off a few isolated showers and possible thunderstorms, favoring areas north and west of Boston, during this afternoon to very early evening. Much of the region will be rain-free today, with decent travel conditions for those returning home from what is considered the closing weekend of summer. High pressure builds in tonight and Tuesday with slightly cooler, dry air. High pressure slips off to the east on Wednesday and we warm up as well as seeing an increase in humidity as a warm front passes through the region. Following this is a cold front which now looks slow enough to allow our region to escape with rain-free weather into Wednesday evening before we get a couple rounds of showers and possibly a thunderstorm later Wednesday night into Thursday, before drier air finally arrives late Thursday. High pressure builds in with more fair weather for Friday. Additionally, as we get to later this week (Thursday-Friday) our coastline will see larger swells, rough surf, and rip currents associated with Hurricane Larry, which will be well offshore but as a strong storm.

TODAY – LABOR DAY: Mostly cloudy early into mid morning including rain parts of Cape Cod, Nantucket, and Martha’s Vineyard. Sun/cloud mix remainder of day with isolated showers and a possible thunderstorm mainly west and north of Boston this afternoon. Highs 75-82. Wind W 5-15 MPH.

TONIGHT: Mostly clear. Lows 51-58. Wind W under 10 MPH.

TUESDAY: Mostly sunny. Highs 71-78. Wind W up to 10 MPH.

TUESDAY NIGHT: Mostly clear. Lows 55-62. Wind S under 10 MPH.

WEDNESDAY: Increasing clouds. Highs 73-80. Wind S 10-20 MPH.

WEDNESDAY NIGHT: Mostly cloudy. Chance of showers. Patchy fog. Humid. Lows 61-68. Wind SW 5-15 MPH.

THURSDAY: Mostly cloudy with a chance of showers during the morning. Partly sunny midday with a chance of a shower or thunderstorm. Mostly sunny later in the day. Highs 71-78. Wind SW shifting to W 5-15 MPH.

THURSDAY NIGHT: Clear. Lows 50-57. Wind NW up to 10 MPH.

FRIDAY: Sunny to partly cloudy. Highs 70-77. Wind NW 5-15 MPH.

DAYS 6-10 (SEPTEMBER 11-15)

Offshore Hurricane Larry may continue to result in increased swells, heavy surf, and rip currents along the coast into the beginning of next weekend before subsiding. Keep that in mind if planning any beach or boating. Weather-wise, high pressure is expected to bring fair weather for the September 11-12 weekend with a cool/dry start and warm/humid finish. Low pressure systems bring potential wet weather September 13 and again at the very end of the period, based on current timing in a west-to-east flow.

DAYS 11-15 (SEPTEMBER 16-20)

Expecting the west-to-east flow pattern to continue with limited shower chances around air mass changes, some up and down temperatures, but averaging slightly warmer than normal for the period overall.

C-19 Chat Post – September 6 2021

DAYS 1-5 (SEPTEMBER 5-9)

The middle day of the Labor Day Weekend will be the “least fair” but also could be much worse. We’ll have a cloud-dominated day as a warm front approaches, but any shower activity will be fairly limited during the day with the better chance of passing shower activity occurring during tonight. Humidity levels come up today and into early Monday but not to oppressive levels, until a cold front, which may kick off a shower or thunderstorm, passes by during the day Monday from west to east across the region. Overall, Labor Day itself will be a fairly nice day with more sun than today. High pressure brings fair weather Tuesday but a warm front which approach later Tuesday with more clouds arriving, putting us into a warmer and more humid air mass into Wednesday when a cold front will approach with the chance of showers and thunderstorms. Another drier air mass is expected to arrive during Thursday behind that system.

TODAY: Mostly cloudy. A shower possible. Highs 70-77. Wind S increasing to 5-15 MPH with higher gusts.

TONIGHT: Variably cloudy. A few showers possible. More humid. Lows 58-65. Wind SW 5-15 MPH.

MONDAY – LABOR DAY: Partly sunny. A shower possible early. A shower or thunderstorm possible in the afternoon. Humid. Highs 73-80. Wind SW 5-15 MPH wit higher gusts, shifting to W.

MONDAY NIGHT: Partly cloudy. Lows 50-57. Wind W 5-15 MPH.

TUESDAY: Sunny start, cloudy finish. Highs 70-77. Wind W up to 10 MPH shifting to S.

TUESDAY NIGHT: Mostly cloudy. Chance of showers. Lows 60-67. Wind S 5-15 MPH.

WEDNESDAY: Variably cloudy. Chance of showers and thunderstorms. Humid. Highs 72-79. Wind SW 10-20 MPH.

WEDNESDAY NIGHT: Variably cloudy. Chance of showers. Patchy fog. Humid. Lows 60-67. Wind SW to W 5-15 MPH.

THURSDAY: Early clouds then mostly sunny. Highs 70-77. Wind W 5-15 MPH.

DAYS 6-10 (SEPTEMBER 10-14)

Hurricane Larry expected to be far offshore but as a strong storm will result in large ocean swells, rough surf, and enhanced rip current activity along the coast. West to east upper level air flow pattern expected. Best guess on timing of disturbances is late September 10 to early September 11, and again late September 12 to early September 13. Temperatures will vary but will not stray too far from normal during this period.

DAYS 11-15 (SEPTEMBER 14-18)

Likely to see a continued west-to-east flow pattern with limited shower chances around air mass changes which result in some up and down temperatures but with warmer than normal in control the majority of the time. Having just passed the peak of the hurricane season and with conditions somewhat favorable for additional activity in the western portion of the Atlantic Basin we will continue the need to be vigilant in regard to this.

C-19 Chat Post – September 5 2021

DAYS 1-5 (SEPTEMBER 4-8)

It’s a 2 1/2 out of 3 kind of holiday weekend, and honestly all 3 days will have very nice weather. Today is the sunniest day with lowest humidity as high pressure moves from over the region to just offshore. Humidity comes up a little bit on Sunday as a trough approaches from the west, bringing more clouds, but still a fair amount of sun, and then a trough crosses the region later Sunday night into Monday (Labor Day) when our best chance of showers comes, but we likely salvage many rain-free hours on Monday too. When you compare the three “warm season” holiday weekends this year, this one wins. Looking into next week a little, the next trough approaches later Tuesday bringing a warm front toward the region, then a cold front swings through Wednesday. I’m favoring faster timing of this feature in a quick west-to-east flow and a minor and fairly brief shower threat with the passages of the fronts.

TODAY: Mostly sunny. Highs 71-78. Wind W up to 10 MPH.

TONIGHT: Partly cloudy. Lows 55-62. Wind variable under 10 MPH.

SUNDAY: Partly sunny. Highs 72-79. Wind SW 5-15 MPH.

SUNDAY NIGHT: Variably cloudy. A passing shower possible. Lows 58-65. Wind SW 5-15 MPH shifting to W.

MONDAY – LABOR DAY: Variably cloudy. A few showers possible. Highs 73-80. Wind WSW 5-15 MPH.

MONDAY NIGHT: Partly cloudy. Lows 50-57. Wind NW 5-15 MPH.

TUESDAY: Sunny start, cloudy finish. Highs 70-77. Wind W up to 10 MPH shifting to S.

TUESDAY NIGHT: Mostly cloudy. Chance of showers. Lows 60-67. Wind S 5-15 MPH.

WEDNESDAY: Mostly cloudy with a chance of showers followed by clearing. Highs 70-77. Wind S 5-15 MPH shifting to W.

DAYS 6-10 (SEPTEMBER 9-13)

West-to-east flow aloft. Best guess timing of weak disturbances / fronts with shower threats is September 10 & 12. Much of the period is likely to be dry. Offshore Hurricane Larry produces a period of large ocean swells, rough surf, and enhanced rip current risks.

DAYS 11-15 (SEPTEMBER 14-18)

Likely to see a continue west-to-east flow pattern with limited shower chances around air mass changes which result in some up and down temperatures but with warmer than normal in control the majority of the time. Having just passed the peak of the hurricane season and with conditions somewhat favorable for additional activity in the western portion of the Atlantic Basin we will also need to be vigilant in regard to this as well.

C-19 Chat Post – September 4 2021