C-19 Chat Post – August 9 2020

8:25AM

DAYS 1-5 (AUGUST 8-12)

A weak disturbance crosses the region today with still some cloudiness in the region, even some showers/thunderstorms crossing the northern reaches of the WHW forecast area in south central NH early this morning. There will be enough solar heating today to create sea breezes and those boundaries, especially the ones near the South Coast, may trigger a few showers to form during the day today as well. High pressure then gains control for Sunday which will feature lots of sun and the feel of summer. This high will sink to the south and the resultant southwesterly air flow will increase the heat and humidity for Monday and Tuesday, both days generally rain-free other than the risk of a pop up afternoon thunderstorm. A cold front approaching Wednesday cutting into the warm/humid air mass will mean a better risk for the development of showers and thunderstorms.

TODAY: Variably cloudy. A shower or thunderstorm threat south central NH into mid morning. Isolated showers favoring the South Coast this afternoon. Highs 77-84, coolest in coastal areas. Wind variable up to 10 MPH with sea breezes developing.

TONIGHT: Clearing. Lows 60-67. Wind variable up to 10 MPH.

SUNDAY: Mostly sunny. Highs 80-87, cooler some coastal areas. Wind variable up to 10 MPH with coastal sea breezes.

SUNDAY NIGHT: Mostly clear. Lows 62-69. Wind SW up to 10 MPH.

MONDAY: Sunny to partly cloudy. Slight risk of an isolated afternoon thunderstorm. Humid. Highs 85-92. Wind SW 5-15 MPH.

MONDAY NIGHT: Partly cloudy. Humid. Lows 66-73. Wind SW up to 10 MPH.

TUESDAY: Partly cloudy. Isolated showers and thunderstorms in the afternoon. Humid. Highs 87-94. Wind SW 5-15 MPH.

TUESDAY NIGHT: Partly cloudy. Humid. Lows 68-75. Wind SW under 10 MPH.

WEDNESDAY: Partly sunny. Scattered showers and thunderstorms, mainly afternoon to early evening. Humid. Highs 85-92. Wind SW 10-20 MPH.

DAYS 6-10 (AUGUST 13-17)

The front that arrives August 12 may still be hanging around in southeastern areas for an additional risk of a shower or thunderstorm into August 13 before a push of drier air later in the day into August 14, but that frontal boundary may never really get that far to the south at all and complete clearing may never take place. The same boundary may result in a lot of cloudiness over the August 15-16 weekend, and with high pressure centered to the north and northeast of the region, this should keep the air moderated, temperature-wise. By the end of the period the high should have pushed a little more to the south allowing the boundary to push more to the north, but this may mean a rare showery day if things come together just so. Can’t say I’m too confident forecasting rainfall on day 10 during a drought.

DAYS 11-15 (AUGUST 18-22)

Typical August weather, humid, warm to hot, a few showers/thunderstorms, but overall rainfall pattern below average.

C-19 Chat Post – August 8 2020

7:17AM

DAYS 1-5 (AUGUST 7-11)

A frontal boundary south of New England and a weak wave of low pressure moving along it will bring lots of cloudiness to the region today. Some showers will occur, and while they are most likely in the South Coast region they can make it anywhere up into the vicinity of I-90. A weak surface trough and upper level disturbance may trigger a few more showers Saturday, favoring areas south and southwest of Boston. High pressure will be in control by Sunday with a return to the full feel of summer, and as the high sinks south of the region early next week the heat and humidity will be back, along with a risk of thunderstorms by Tuesday as a cold front approaches.

TODAY: Mostly cloudy. Scattered showers mid morning on, favoring areas south of I-90. Highs 76-83, coolest coast. Wind E-SE up to 10 MPH.

TONIGHT: Mostly to partly cloudy. A few showers possible near the South Coast early. Lows 61-68. Wind E up to 10 MPH.

SATURDAY: Variably cloudy. Scattered showers favoring northeastern CT, south central MA, and RI. Highs 76-83, coolest coast. Wind E-NE up to 10 MPH.

SATURDAY NIGHT: Clearing. Lows 60-67. Wind variable up to 10 MPH.

SUNDAY: Mostly sunny. Highs 80-87, cooler some coastal areas. Wind variable up to 10 MPH with coastal sea breezes.

SUNDAY NIGHT: Mostly clear. Lows 62-69. Wind SW up to 10 MPH.

MONDAY: Sunny to partly cloudy. Humid. Highs 85-92. Wind SW 5-15 MPH.

MONDAY NIGHT: Partly cloudy. Humid. Lows 66-73. Wind SW up to 10 MPH.

TUESDAY: Partly cloudy. Isolated to scattered showers and thunderstorms in the afternoon. Humid. Highs 86-93. Wind SW 5-15 MPH.

DAYS 6-10 (AUGUST 12-16)

High humidity and a shower/thunderstorm risk August 12 with a cold front slowly passing through the region. Trending drier and cooler August 13-14 as the front pushes to the south and high pressure builds north of the region. August 15-16 weekend may feature a lot of clouds with that frontal boundary nearby to the south and high pressure hanging to the north and northeast of the region, but I’d favor drier over wetter weather.

DAYS 11-15 (AUGUST 17-21)

The possibility of a showery day to start the period marking the transition back to higher humidity and some mid August heat. Low confidence but will watch for this pattern transition.

C-19 Chat Post – August 7 2020

7:22AM

DAYS 1-5 (AUGUST 6-10)

High pressure builds in today, centered north of our area, providing nice weather and air a little cooler and less humid than what we saw yesterday. A frontal boundary to the south will develop a wave of low pressure along it that will bring cloudiness and the risk of some shower activity on Friday, which may persist into Saturday before high pressure regains control and brings drier weather back later Saturday through Sunday as it pushes to the south, then continues drifting southward far enough to allow a southwesterly flow and some heat and humidity back by Monday…

TODAY: Partly cloudy morning. Mostly sunny afternoon. Highs 80-87 except cooling back to the upper 70s some coastal areas. Wind variable up to 10 MPH with developing coastal sea breezes.

TONIGHT: Increasing clouds. Lows 60-67. WindSE-E under 10 MPH.

FRIDAY: Mostly cloudy. Scattered showers, mainly midday and afternoon. Highs 76-83, coolest coast. Wind E-SE up to 10 MPH.

FRIDAY NIGHT: Mostly cloudy. Scattered showers. Lows 61-68. Wind E up to 10 MPH.

SATURDAY: Variably cloudy. Scattered showers. Highs 76-83, coolest coast. Wind E-NE up to 10 MPH.

SATURDAY NIGHT: Clearing. Lows 60-67. Wind variable up to 10 MPH.

SUNDAY: Mostly sunny. Highs 80-87, cooler some coastal areas. Wind variable up to 10 MPH with coastal sea breezes.

SUNDAY NIGHT: Mostly clear. Lows 62-69. Wind SW up to 10 MPH.

MONDAY: Sunny. Humid. Highs 85-92. Wind SW 5-15 MPH.

DAYS 6-10 (AUGUST 11-15)

Hot and humid with a risk of a few afternoon thunderstorms on August 11 with high pressure centered off the East Coast. Warm and humid with scattered showers/thunderstorms August 12 as the high remains offshore and a cold front approaches. Front passes through the region August 13 with a humid start and a risk of showers followed by a drier finish. Cooler/drier August 14-15.

DAYS 11-15 (AUGUST 16-20)

High pressure builds across the region then sinks to the south. This is a mainly dry pattern, starting with seasonable temperatures which then warm to above normal.

C-19 Chat Post – August 6 2020

7:30AM

DAYS 1-5 (AUGUST 5-9)

The impact from TS Isaias speaks for itself today in the power outages and damage (mainly downed trees and tree limbs) to clean up. Largely, the system behaved about as expected, with top wind gusts in the expected range. A good deal of the strongest wind not only came with the main convective line that passed through late in the day, but after it as well, as the storm was rapidly transitioning to post tropical, which expands its wind field. But in terms of sensible weather, that is now beyond us, and we look ahead. Today will be a warm and somewhat humid day and a weak trough moving through from the west may set off a shower or 2, but look for a generally rain-free day. High pressure builds in Thursday, centered north of the region it will provide a broad onshore flow and comfortable air. This high retreats as a low pressure disturbance passes south of the region Friday, but close enough to bring cloudiness and a shower threat. I’ve expected this shower threat to favor the South Coast region, but looking things over this morning make me believe the high may retreat enough that at least a minor shower threat exists anywhere in the region. This will be pushed back out of here Saturday as the high pressure area drifts back to the south, though it may take some time, and even as it dries out, we may set up some sea breeze convergence enough to pop a few afternoon showers on Saturday. High pressure will be in firm control with great August weather on Sunday.

TODAY: Sun and passing clouds. Slight risk of a passing shower. Moderately humid. Highs 82-89. Wind W 5-15 MPH, a few higher gusts.

TONIGHT: Clearing. Lows 62-69. Wind W up to 10 MPH.

THURSDAY: Sunny to partly cloudy. Highs 78-85, coolest coastal areas. Wind variable up to 10 MPH becoming NE-E 5-15 MPH.

THURSDAY NIGHT: Increasing clouds. Lows 60-67. Wind E to SE under 10 MPH.

FRIDAY: Mostly cloudy. Isolated to scattered showers. Highs 76-83, coolest coast. Wind E-SE up to 10 MPH.

FRIDAY NIGHT: Mostly cloudy. Risk of showers, favoring the South Coast. Lows 61-68. Wind SE up to 10 MPH.

SATURDAY: Early clouds and a shower risk South Coast, otherwise partly to mostly sunny but the slight risk of a pop up afternoon shower favoring southern and eastern areas. Highs 78-85, coolest coast. Wind variable up to 10 MPH with developing sea breezes.

SATURDAY NIGHT: Clearing. Lows 60-67. Wind variable up to 10 MPH.

SUNDAY: Mostly sunny. Highs 80-87, cooler some coastal areas. Wind variable up to 10 MPH with coastal sea breezes.

DAYS 6-10 (AUGUST 10-14)

High pressure shifts to the south with an increase in humidity and a risk of showers/t-storms during the August 10-13 period, highest risk around August 12-13 with a frontal boundary in the region. High pressure builds in with drier weather to end the period.

DAYS 11-15 (AUGUST 15-19)

A warm front may push through early in the period with cloudiness and perhaps a shower as high pressure retreats to the northeast. Look for a flat ridge of high pressure mainly south of the region and a jet stream to the north which would be a warm to hot pattern with mainly dry weather here. Will have to watch a frontal boundary to the north.

C-19 Chat Post – August 5 2020

7:42AM

DAYS 1-5 (AUGUST 4-8)

As far as “action” goes, this forecast is front-end-loaded. Today and this evening will be our impacts from Isaias. The thinking has not really changed since yesterday. While the system, according to NHC, returned to hurricane strength before making landfall in SC yesterday and moving up across the eastern Carolinas overnight, it has weakened to a tropical storm and will continue to slowly weaken while at the same time starting to undergo transition to a post-tropical system (or return to a cold core low pressure area) as it tracks north northeastward all the while accelerating. This track will take the center of the low across NJ, southeastern NY, and far western to northwestern New England during this evening. It’s known, but I will remind you, that the wind field around these systems tends to expand as the storm loses tropical characteristics. Another general rule of thumb is that the heaviest rainfall amounts occur west of the center with a more showery/windy eastern side of a northward-moving storm system. All these rules generally apply here. I think it’s important to note that the absolute strongest wind gust potential will be coming as what appears to be a single band of convective rainfall (downpours & possible thunder) sweeps across the region from southwest to northeast early this evening. Yes it will be breezy to windy before it and after it, but those convective cells are what can bring down your strongest winds to the surface, and therefore can be where you find the most significant pockets of wind damage. These systems also bring their own wind sheer along with them and those convective cells can easily rotate, sometimes enough to produce brief and (relatively) weak tornadoes. It goes without saying that even “weak” tornadoes can cause significant localized damage. So we will need to be on the watch for this. But as quickly as the maximum part of this event will be underway for us, it will be gone, and the overnight hours will feature less wind, but still a gusty breeze, and an opportunity to look at the stars and moon as the sky clears. With the low in eastern Canada and moving rapidly away on Wednesday, expect a rather nice summer day here on Wednesday. If there is any damage cleanup to be done it can proceed without any further weather issues. High pressure builds in, centered just to the north of the region, with a nice day, air temperature modified by an easterly wind flow, on Thursday. A frontal boundary not too far to the south will edge northward far enough on Friday for more cloudiness, and maybe a bit of South Coast shower activity. This may linger into early Saturday before high pressure wins the battle and clouds retreat for a nice start to the second weekend of August.

TODAY (THROUGH EARLY AFTERNOON): Mostly cloudy. Passing rain showers possible. Increasingly humid. Highs 76-83. Wind SE-S 5-15 MPH except increasing to 15-25 MPH late afternoon, strongest South Coast.

MID AFTERNOON / EARLY EVENING (ABOUT 3PM TO ABOUT 7PM): A band of showers, some heavy, and a risk of thunder, moving southwest to northeast across the region. Very humid. Temperatures cooling slightly to 70-77. Wind SE-SSW sustained 15-25 MPH interior and 25-35 MPH coast. Maximum wind gust potential generally 45-60 MPH, favoring coastal and higher elevations, but can occur in isolated locations interior with any heavier showers/storms.

TONIGHT: Partly cloudy to mostly clear. Humid. Lows 65-72. Wind SW 10-20 MPH, higher gusts.

WEDNESDAY: Sun and passing clouds. Less humid. Highs 82-89. Wind W 10-20 MPH and gusty early, diminishing to 5-15 MPH.

WEDNESDAY NIGHT: Clear. Lows 62-69. Wind W up to 10 MPH.

THURSDAY: Sunny to partly cloudy. Highs 80-87, but turning cooler in some coastal areas during the afternoon. Wind variable up to 10 MPH with coastal sea breezes.

THURSDAY NIGHT: Increasing clouds. Lows 60-67. Wind E to SE under 10 MPH.

FRIDAY: Mostly cloudy. Slight risk of showers South Coast. Highs 77-84, coolest coast. Wind SE up to 10 MPH.

FRIDAY NIGHT: Mostly cloudy. Risk of showers South Coast. Lows 63-70. Wind SE up to 10 MPH.

SATURDAY: Early clouds and a shower risk South Coast, otherwise partly to mostly sunny. Highs 78-85, coolest coast. Wind NE 5-15 MPH.

DAYS 6-10 (AUGUST 9-13)

High pressure brings fair and warm weather August 9, then shifts to the south with an increase in humidity and a risk of showers/t-storms during the August 10-13 period, highest risk around August 12-13 with a frontal boundary in the region.

DAYS 11-15 (AUGUST 14-18)

This looks like a mostly dry period with high pressure centered north of the region at first, keeping temperatures moderate, then high pressure shifting to the south later as upper level high pressure builds, increasing the chance of hotter weather returning.

C-19 Chat Post – August 4 2020

7:29AM

DAYS 1-5 (AUGUST 3-7)

August in New England. The sun angle may not be as high as it was in June and July, but we’re still in the midst of summer and we get some of our best “summer weather” around this time of year. And some of that will indeed take place during this 5 day period, but there will be a couple of “less-nice” days as well. We start with a hot and day today in a humid southwesterly air flow ahead of a trough, that will pass by and dry the air out a bit with a wind shift to west. Humidity will start to rise again later tonight and Tuesday as another trough approaches from the west – the very trough of low pressure that will steer a weakening Tropical Storm Isaias up (mostly just inland) along the East Coast today and Tuesday, the center passing just west of the WHW forecast area, probably between the Connecticut & Hudson Rivers Tuesday night. This track keeps much of the rainfall in advance of the system light and patchy with only an embedded heavier shower possible during the day, and the main storm impact will be a band or two of showers / downpours (possible thunder) Tuesday evening, also when the strongest wind will occur. We’re not going to see any widespread damaging winds from this – it will be too far west and too weak, but gusts in the 40 to 50 MPH range are definitely possible, favoring the South Coast. This system exits overnight, and by the time the sun comes up it’ll be a memory except for a gusty westerly breeze, transporting some drier air into the region behind it. Wednesday will be a very nice summer day, despite some forecasts you may have seen to the contrary. High pressure builds in for a nice Thursday too, but this high will be centered a bit north of the region and during Friday, a frontal boundary and weak disturbance to the south will be close enough for some cloudiness, but probably no rain except possibly a few South Coast showers.

TODAY: Mostly sunny to partly cloudy. A very slight risk of isolated showers or thunderstorms central MA and southwestern NH. Humid. Highs 80-87 South Coast, 87-94 elsewhere. Wind SW 5-15 MPH, higher gusts.

TONIGHT: Partly to mostly cloudy. Risk of a shower or thunderstorm late evening and overnight, favoring areas southwest and west of Boston. Humid. Lows 67-74. Wind S 5-15 MPH, higher gusts possible.

TUESDAY: Mostly cloudy. Episodes of showers, a few of which may be heavy. Slight risk of a thunderstorm. Humid. Highs 78-85. Wind S 10-20 MPH, gusts 25-40 MPH possible especially by late in the day favoring the South Coast.

TUESDAY NIGHT: Mostly cloudy evening with showers likely, a few downpours probable, and a risk of thunderstorms. Clearing overnight. Humid. Lows 67-74. Wind S 15-25 MPH with gusts 35-45 MPH favoring the South Coast and higher elevations evening, shifting to SW 10-20 MPH with higher gusts overnight.

WEDNESDAY: Sun and passing clouds. Less humid. Highs 81-88. Wind W 10-20 MPH and gusty early, diminishing to 5-15 MPH.

WEDNESDAY NIGHT: Clear. Lows 62-69. Wind W up to 10 MPH.

THURSDAY: Sunny to partly cloudy. Highs 80-87, but turning cooler in some coastal areas during the afternoon. Wind variable up to 10 MPH with coastal sea breezes.

THURSDAY NIGHT: Increasing clouds. Lows 60-67. Wind E to SE under 10 MPH.

FRIDAY: Mostly cloudy. Slight risk of showers South Coast. Highs 77-84, coolest coast. Wind SE up to 10 MPH.

DAYS 6-10 (AUGUST 8-12)

High pressure drifts back to the south providing fair weather for the August 8-9 weekend. High pressure then shifts south of the region with an increase in humidity and a slight risk of showers and thunderstorms August 10-12, maybe highest around the end of the period as a frontal boundary arrives.

DAYS 11-15 (AUGUST 13-17)

Weak blocking pattern – high pressure north and low pressure south, probably with this region influenced more by high pressure with dry weather, but a more persistent northeast to east air flow keeping heat at bay. Still not the highest amount of confidence on this forecast. A high pressure area that shifts to the south, which may happen later in the period, could quickly open the door to a shot of heat.

C-19 Chat Post – August 3 2020

8:34AM

DAYS 1-5 ( AUGUST 2-6)

While today will not be as sunny as yesterday was, we’re still not looking at a bad summer day, with partial sun eventually losing the battle to clouds, and only the minimal risk that a few showers work into areas outside of and around I-495 mid to late afternoon. This will be taking place as a warm front approaches the region. This front will cross the region tonight when there is a better risk of showers and even a few isolated thunderstorms. While our parameters are not ideal for severe weather, it’s important to keep an eye out for any isolated storm that can gets its act together, as they can produce isolated damage. The front will be by the region by Monday, which will be a very warm to hot and humid summer day with a southwesterly air flow. Other than the remote risk for a pop up shower or thunderstorm again mainly outside of I-495 later in the day, Monday should be a rain-free day. Then we can turn our attention toward Isaias, currently a tropical storm, and forecast by NHC to remain one for the duration of its run up the East Coast toward our region. We can discuss the impacts from Florida to the Mid Atlantic in the comments section of this blog over the next couple days. I will focus on its impacts here for the purposes of this discussion. Best guess now is we have a weakening tropical storm, getting ready to transition to post tropical, center passing west of the Boston area, possibly as far west as near the NY border with CT/MA very early Wednesday. Typically, this set-up would produce a couple periods of rain or showers, not too heavy, initially, with that timing most likely during the day Tuesday, and a band or 2 of heavier tropical showers (possibly some thunder), that timing likely Tuesday night into the pre-dawn hours of Wednesday. As always, the right flank of a system like this creates its own wind shear, and that can be enough for a brief weak tornado in some of the convective showers. This will be a very low risk but as you have heard many times, if it’s a non-zero risk it is worth paying attention to. Except for a gusty westerly breeze Wednesday morning, the system will be a memory by then, with a nice day behind the departed system. High pressure will build in with another nice day expected Thursday.

TODAY: Mostly cloudy. Scattered mid to late afternoon showers and possible thunderstorms, mainly west of to around the I-495 belt. More humid. Highs 78-85, coolest coastal areas. Wind SE up to 10 MPH.

TONIGHT: Variably cloudy. Risk of showers. Slight risk of a thunderstorm. Humid. Lows 65-72. Wind S up to 10 MPH.

MONDAY: Mostly sunny to partly cloudy. Isolated showers and thunderstorms possible late-day, mainly outside the I-495 belt. Humid. Highs 86-93, cooler South Coast. Wind S-SW 5-15 MPH.

MONDAY NIGHT: Variably cloudy. Slight risk of a shower or thunderstorm. Humid. Lows 65-72. Wind variable 5-15 MPH.

TUESDAY: Mostly cloudy. A few episodes of rain or showers likely. Humid. Highs 75-82, coolest coastal areas. Wind SE-S 5-15 MPH.

TUESDAY NIGHT: Mostly cloudy. Showers likely. Slight risk of thunderstorms that may contain locally strong wind gusts. Humid. Lows 65-72. Wind SE-S 15-25 MPH, higher gusts coastal areas, especially South Coast.

WEDNESDAY: Mostly sunny to partly cloudy. Moderately humid. Highs 83-90. Wind W-SW 10-20 MPH, higher gusts during the morning then diminishing during the afternoon.

WEDNESDAY NIGHT: Clear. Lows 60-67. Wind SW up to 10 MPH.

THURSDAY: Mostly sunny. Highs 80-87, coolest coast. Wind variable up to 10 MPH with coastal sea breezes.

DAYS 6-10 (AUGUST 7-11)

A frontal boundary to the south will get close enough for some cloudiness Friday but no more than a risk of showers near the South Coast. High pressure should win out for fair weather, seasonable temperatures, coolest coast, and moderate humidity over the August 8-9 weekend. A disturbance brings higher humidity and a risk of showers / thunderstorms August 10-11 but too far away to know any detail.

DAYS 11-15 (AUGUST 12-16)

A weak block may form in the atmosphere (low pressure to south, high pressure to north in upper levels). This promotes surface high pressure to the north with a general maritime air flow (northeast to east) at the surface. With time high pressure would probably drift southward and keep the region dry with a late-period warm-up.

C-19 Chat Post – August 2 2020