DAYS 1-5 (JULY 2-6)

This holiday weekend (Independence Day) won’t be just like the previous holiday weekend (Memorial Day). Only about half of it will…….. oops. Ok, yes, it could be worse, but we are definitely not going to be looking outside or be outside and think thoughts of beautiful summer weather, unless your idea of it is overcast, wet, and much cooler than normal. But hey, if you were one of the many complaining about it being too hot for several days earlier this week, your complaints have been answered by Mother Nature. Happy now? 😉 So enough sarcasm and on to the actual reason our weather has turned 180. First off, it’s not really unusual. It’s not unusual to be hotter than normal and it’s not unusual to be cooler than normal, even in summer. The averages we go by are made up of these above-normal and below-normal episodes. This just happens to be a case where a strong version of each take place over a short period of time, and the timing is pretty bad if you were looking for some nice summertime weather for your outdoor plans. But not all is lost here. If today and Saturday held a lot of your plans, then it’s not good. If your outside stuff is more Sunday and/or Monday, things are not looking quite as dim. We have to deal first with a wave of low pressure passing by a frontal boundary that is sitting just to the southeast of New England now, and this brought in some significant rainfall last night, which has continued, especially in eastern areas, into this morning, but will taper to more of a showery / drizzly situation during the day today. But we still have to deal with an upper level low pressure area crossing the region, and it’s going to take all day Saturday and even until early Sunday to complete its journey. With a northeasterly air flow for much of the region Saturday, and still a lot of low level and mid level moisture around, this doesn’t bode well for what was previously a more optimistic forecast I had made. I can’t be optimistic about Saturday any longer, so expect an overcast day with occasionally wet and continually very cool conditions. Finally, on Sunday, the wind goes around to a drier northwesterly direction behind departing low pressure, but just enough cold air lingers aloft that when the air tries to warm a little bit, we can still see some showers pop up. These are not going to be widespread, and will probably be limited more to inland locations. The air will still be cooler than normal Sunday, though. Just without the more persistent dampness and frequent wet weather of the two days that precede it. With Monday being the observed holiday for many, the opportunity will be there to salvage one very nice summer day, as high pressure moves in, centered to the south, and although it will be a weak high it will be enough to push in a warmer southwesterly air flow and supply a good deal of sunshine, although that sun may start to filter out later in the day as the leading edge of hot and humid air mass starts to approach. The warm front marking the leading edge of this air will cross the region Monday night with clouds and a risk of a shower or thunderstorm, though most of that activity may end up passing to the north, and we’ll find ourselves briefly back in heat and humidity for Tuesday between that warm front and an approaching cold front, which may bring a chance of showers and thunderstorms by late Tuesday or Tuesday night, depending on its timing…

TODAY: Cloudy. Widespread showers morning. Numerous to scattered showers this afternoon. Areas of drizzle and fog. Highs 65-72. Dew point lower to middle 60s. Wind NE 5-15 MPH, gusts 20-25 MPH especially coast.

TONIGHT: Cloudy. Areas of fog and drizzle. Scattered showers. Lows 55-62. Dew point middle to upper 50s. Wind NE 5-15 MPH.

SATURDAY: Cloudy. Areas of fog and drizzle. Scattered to numerous showers, especially afternoon. Highs 60-67. Dew point upper 50s to lower 60s. Wind NE 5-15 MPH.

SATURDAY NIGHT: Cloudy. Areas of fog and drizzle. Showers likely evening, diminishing overnight. Lows 55-62. Dew point middle to upper 50s. Wind NE to N 5-15 MPH.

SUNDAY: Clouds break for partial sun. Chance of a shower early in the day. Scattered afternoon showers possible mainly interior higher elevations. Highs 68-75. Dew point upper to middle 50s. Wind N to NW 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 58-65. Dew point middle 50s. Wind W up to 10 MPH.

MONDAY: Mostly sunny to partly cloudy. Highs 75-82. Dew point middle to upper 50s. Wind SW 5-15 MPH.

MONDAY NIGHT: Partly to mostly cloudy. A shower or thunderstorm possible overnight. Lows 62-69. Dew point near 60. Wind SW 5-15 MPH.

TUESDAY: Partly sunny. Chance of late-day or evening showers and thunderstorms. Highs 85-92. Dew point rising to upper 60s. Wind SW 10-20 MPH.

DAYS 6-10 (JULY 7-11)

Frontal boundary sits nearby July 7-9 with opportunities for showers and thunderstorms, with potentially enhanced rainfall by the middle of the period depending on the future track of TS Elsa (forecast to reach the Florida area) and its remains (which may move northward across the eastern US and exit via New England). Drier weather arriving later in the period.

DAYS 11-15 (JULY 12-16)

Another period of higher humidity and shower/thunderstorm chances followed by drier weather again.

C-19 Chat Post – July 2 2021

DAYS 1-5 (JULY 1-5)

Some folks like to start their long weekends on Thursdays, a fair amount start them on Friday, and with Independence Day falling on a Sunday, the holiday will be observed on Monday for many, so we’ll just call this 5-day forecast period the outlook for the holiday weekend. It won’t be a repeat of Memorial Day Weekend, but it is not going to be a stellar period of weather either. The front that moved down into the region yesterday with thunderstorms, breaking our heatwave, sits nearby today and while it dissipates another front will move down from the north and continue to send cooler and less humid air into the region. But less humid is only relative in this case, because the air will actually be quite humid, just have lower dew points, and lower temperatures. We’re going to see a period of showery weather especially tonight into Friday as moisture travels northeastward along these frontal boundaries and upper level low pressure moves into the region. This upper low will take its time exiting during Saturday and Sunday, but the surface air flow which starts out northeasterly on Saturday will turn more westerly by Sunday. This will result in improving weather during those days, but not absent of a little drizzle or a few showers Saturday, and maybe a few pop up showers Sunday. If you want a day to feel like full summer again, that’ll be Monday, when we’re into a westerly air flow and a much warmer air mass arrives.

TODAY: Lots of clouds, partial sun at times. Isolated showers until mid afternoon. Scattered showers and thunderstorms mid afternoon on. Highs 75-82. Dew point near 70 falling to middle 60s. Wind W 5-15 MPH.

TONIGHT: Cloudy. Numerous showers. Chance of thunderstorms. Areas of fog. Lows 60-67. Dew point falling to near 60. Wind variable 5-15 MPH becoming N to NE.

FRIDAY: Cloudy. Widespread showers in the morning, becoming more scattered during the afternoon. Areas of fog. Highs 65-72, coolest coast. Dew point middle to lower 60s. Wind NE 5-15 MPH.

FRIDAY NIGHT: Mostly cloudy. Isolated showers. Patchy fog. Lows 55-62. Dew point upper to middle 50s. Wind NE 5-15 MPH.

SATURDAY: Mostly cloudy to partly sunny. Scattered showers possible, favoring central MA, eastern CT, and RI. Areas of fog and drizzle especially eastern coastal areas in the morning. Highs 65-70 coast, 70-75 inland. Dew point lower to middle 50s. Wind NE 5-15 MPH.

SATURDAY NIGHT: Mostly to partly cloudy. Lows 56-63. Dew point lower 50s. Wind NE up to 10 MPH becoming variable.

SUNDAY: Partly sunny. Isolated afternoon showers possible, mainly southwestern NH and central MA. Highs 70-77, coolest coast. Dew point upper 50s. Wind variable to W 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 60-67. Dew point upper 50s. Wind SW under 10 MPH.

MONDAY: Mostly sunny. Highs 78-85. Dew point near 60. Wind SW 5-15 MPH.

DAYS 6-10 (JULY 6-10)

Briefly hotter with a chance of showers and thunderstorms from an approaching cold front July 6. Front settles just to the south July 7 with additional clouds and possible showers favoring southern areas. Seasonably warm and drier weather July 8-9 before clouds and showers return at the end of the period with a disturbance moving into the region.

DAYS 11-15 (JULY 11-15)

Near to above normal temperatures and an increase in humidity but with a slightly better chance of showers and thunderstorms as a frontal boundary hangs out in the region.

C-19 Chat Post – July 1 2021

DAYS 1-5 (JUNE 30 – JULY 4)

On this final day of June we will also experience the final day of high heat and humidity in this early summer stretch of it. Unlike the last 2 days, today carries a risk of more regional thunderstorm activity as a cold front approaches. The timing looks a little later on this today, with the primary threat for the WHW forecast area coming in the 4PM through 9PM time frame from northwest to southeast. There can be a couple isolated shower or storms popping up ahead of that threat window, as early as 2PM or so. The greatest threat for severe weather is damaging wind with the storms. Small hail is a potential, along with the usuals: heavy downpours, lightning. If a storm cluster forms and trains over the same area for a while, which is possible, then flash flooding would become a threat, so we’ll have to watch for this as well. If you plan to be outside today into this evening, obviously plan for both the high heat and humidity and watch for approaching or developing storms – and have a plan! Once we get by this threat tonight, the cold front that delivers it will also deliver slightly cooler and less humid air, but only down a little bit, and as the front washes out over far southern New England Thursday we’ll still feel a bit of humidity and it will be a warm day, but we’ll be dealing with a lot more high and mid level cloudiness than we’ve seen during the last few days. An influx of moisture will head northeastward toward our region Thursday night while a second frontal boundary pushes through from the north. This front may trigger a few more showers and thunderstorms in the region Thursday afternoon, and the combination of it and the moisture arriving from the southwest is expected to bring more widespread showers to the region later Thursday night into a portion of Friday, before we see a drying trend north to south, along with much cooler air this time. High pressure from Canada will push the unsettled weather further south as we reach the holiday weekend, but upper level low pressure will still be stretched out across the region and will take a good deal of time to depart, so at this point I cannot rule out some scattered shower activity Saturday and isolated showers for Sunday. As far as the actual weekend goes, humidity levels will be quite manageable, and Saturday will be the cooler of the two days with a general northeasterly flow. The wind should be variable then eventually more westerly on Sunday allowing for a bit of a warm up to get underway.

TODAY: Early clouds north central MA and southern NH otherwise mostly sunny through midday. Partly to variably cloudy this afternoon and evening with isolated showers and thunderstorms possible by mid afternoon, then scattered to numerous showers and thunderstorms from northwest to southeast later afternoon and evening. Thunderstorms can become severe. Highs 88-95, cooler South Coast.. Dew point upper 60s to lower 70s. Wind SW 5-15 MPH, higher gusts.

TONIGHT: Variably cloudy evening with showers and thunderstorms favoring eastern and southern areas. Partly cloudy with patchy ground fog forming overnight. Lows 67-74. Dew point upper to middle 60s. Wind variable up to 10 MPH.

THURSDAY: Variably cloudy but some sunshine. Highs 75-80 South Coast, 80-85 elsewhere. Dew point middle 60s. Wind variable 5-15 MPH.

THURSDAY NIGHT: Cloudy. Numerous showers. Chance of thunderstorms. Areas of fog. Lows 60-67. Dew point falling to near 60. Wind variable 5-15 MPH becoming N to NE.

FRIDAY: Mostly cloudy. Chance of showers, especially CT, RI, southern MA. Highs 68-75. Dew point near 60. Wind NE 5-15 MPH

FRIDAY NIGHT: Mostly cloudy. Lows 55-62.Wind NE 5-15 MPH.

SATURDAY: Partly sunny. Scattered showers possible, favoring central MA, eastern CT, and RI. Highs 65-70 coast, 70-75 inland. Wind NE 5-15 MPH.

SATURDAY NIGHT: Partly cloudy. Lows 56-63. Wind NE up to 10 MPH becoming variable.

SUNDAY: Partly sunny. Isolated afternoon showers possible, mainly southwestern NH and central MA. Highs 75-82. Wind variable to W 5-15 MPH.

DAYS 6-10 (JULY 5-9)

Warmer slightly more humid with a chance of a few showers and thunderstorms later July 5 and again July 6 with a couple disturbances passing by. Mostly fair and seasonable weather mid to late period with weak high pressure in control, but this remains a low confidence forecast.

DAYS 11-15 (JULY 10-14)

Near to above normal temperatures and an increase in humidity but with a slightly better chance of showers and thunderstorms as a frontal boundary hangs out in the region.

C-19 Chat Post – June 30 2021

DAYS 1-5 (JUNE 29 – JULY 3)

The next 5 days will be a good example of the range of temperatures we can see in the summertime, with a hot spell peaking today, backing off ever-so-slightly tomorrow, then ending as July arrives landing us on the cooler end of the spectrum by the end of the work week / start of the holiday weekend. Our Bermuda High continues to pump the heat and humidity into the region today. The atmosphere this afternoon will be very slightly more unstable than it was yesterday, so there is a slightly better chance that some isolated shower and thunderstorm activity will occur in the WHW forecast area this afternoon, where it stayed well west and north of the area yesterday. Most locations see nothing of the kind, but those who do can experience a torrential downpour and of course lightning as the cell peaks. These tend to last a short-time before raining themselves out. So while they are not highly likely, be on the look-out if you are out and about this afternoon. And most importantly, remember your heat precautions and safety measures! A cold front will be getting closer to the region later Wednesday, which will still be a hot and humid day, but with a better chance of at least scattered to possibly linear or segmented lines of showers and thunderstorms developing and arriving in the region later in the day. A slightly slower front would keep this activity mostly to the west and north – something to watch. The initial frontal boundary does get into the area Thursday, but in a dissipating state, and that day will still be humid though not as hot, with a pop up shower or thunderstorm possible with some solar heating. Later in the day expect more substantial cloud cover to take over as we start to see another front coming down from the northwest while some overrunning of tropical moisture starts to take place over the air mass boundaries. Some of this moisture will be from what was called a tropical storm as it quickly formed and made landfall in the US Southeast Monday. This could help produce a period of widespread and potentially heavy shower activity Thursday night and part of Friday, before it pulls away and we’re just left with some lingering showers favoring southern areas Friday, and much cooler air. High pressure from Canada is expected to have enough push to dry the region out but keep it on the cool side for the start of the holiday weekend on Saturday. There is still some medium range guidance that highly disagrees with this scenario, keeping the weather wet.

TODAY: Mostly sunny to partly cloudy. Isolated showers and thunderstorms possible from mid afternoon to early evening. Highs 90-97, cooler South Coast. Dew point near 70, may fall to middle 60s. Wind SW to W 5-15 MPH, higher gusts.

TONIGHT: Partly cloudy to mostly clear. Lows 68-75. Dew point upper 60s. Wind WSW 5-15 MPH.

WEDNESDAY: Partly sunny. Chance of afternoon showers and thunderstorms. Highs 87-94, cooler South Coast.. Dew point upper 60s to 70. Wind SW 5-15 MPH, higher gusts.

WEDNESDAY NIGHT: Partly cloudy. Chance of evening showers. Patchy fog. Lows 67-74. Dew point upper 60s. Wind variable up to 10 MPH.

THURSDAY: Partly sunny. Chance of showers and thunderstorms. Highs 82-89, cooler South Coast.. Dew point upper to middle 60s. Wind variable 5-15 MPH.

THURSDAY NIGHT: Cloudy. Numerous showers. Chance of thunderstorms. Areas of fog. Lows 60-67. Dew point falling to near 60. Wind variable 5-15 MPH becoming N to NE.

FRIDAY: Mostly cloudy. Chance of showers, especially CT, RI, southern MA. Highs 68-75. Dew point near 60. Wind NE 5-15 MPH

FRIDAY NIGHT: Mostly cloudy. Lows 55-62.Wind NE 5-15 MPH.

SATURDAY: Partly sunny. Highs 65-70 coast, 70-75 inland. Wind NE 5-15 MPH.

DAYS 6-10 (JULY 4-8)

The idea of high pressure from Canada coming down over the weekend remains, and if it’s correct we should see mostly fair weather and slight warming for July 4, but some upper level low pressure not far away can trigger some afternoon showers and thunderstorms. A shot of heat and a little higher humidity for July 5 which is counting as the holiday for some, along with a chance of showers and thunderstorms later as a front approaches from the west. If the timing of that system is slower, we’d get by that day without a real storm threat and the next day (July 6) would be more unsettled, followed by a drying trend by the middle of next week. Confidence on this time period is lower than average, so check updates.

DAYS 11-15 (JULY 9-13)

Near to above normal temperatures and an increase in humidity but with somewhat limited shower and thunderstorm chances. to start then increased later in the period as a frontal boundary to the north starts to drift southward into the region. Impossible for daily details this far out.

C-19 Chat Post – June 29 2021

DAYS 1-5 (JUNE 28 – JULY 2)

The story will be the hot and humid weather for the first 3 days of this week, which are also the final 3 days of June. Please keep in mind as we get to the end of this month and you start hearing data via media for Boston, that the thermometer where official records are kept has been reading 2 degrees too high for the entire month, so the average will also be skewed by 2 degrees in that direction. It’ll be billed as the hottest June on record there, yet likely wasn’t. A warm June? Yes, most certainly. But we also had some cool days in there too. Bottom line: Not a brutal June, but a hot stretch early in the month and another hot stretch to end it. The Bermuda High will continue to do its thing into Wednesday and our only chance of seeing any rainfall before then will be from isolated air mass showers and thunderstorms that have a remote chance of popping up in a couple locations mainly well west of Boston today and a very slightly better chance of doing it tomorrow anywhere, but mostly west and north of a Boston-Providence line. These will be the vast exception and far from the rule, but if one does occur where you are, you can experience a torrential downpour along with briefly gusty wind and of course lightning and thunder, so if you are out and about, just know that even though quite low the chance, it’s not a 0% chance. On Wednesday, the shower and thunderstorm chance will increase, and the timing and placement of activity is going to be highly dependent on the location and movement of a cold front moving in from the northwest. It will take a couple days to nail down the timing and the day-of to start focusing on specific threats. Either way, Wednesday will still be a hot and humid day before any activity moves in. There’s been a difference of opinion between myself and much of the guidance for how the second half of this week plays out, but here are my current ideas on it. The cold front that approaches later Wednesday gets into southern New England by Thursday but starts to wash-out or fall apart and a second front drops down from the northwest later Thursday through early Friday. This brings the opportunity for a couple rounds of showers and thunderstorms Thursday, with still very warm and humid air in place, and as a little wave of low pressure moves along the front as it sits just to the south on Friday, some additional showers may occur, along with temperatures that will then be much cooler than they were for the first few days of the week. Before Friday is over, we may see a distinct dry-out and end to the shower threat from north to south. This has weekend implications, but we’ll get to that in the next sections. First, the details for the next 5…

TODAY: Mostly sunny to partly cloudy. Very slight risk of a late-day shower or thunderstorm well west of Boston. Highs 88-95. Dew point upper 60s to 70. Wind SW 5-15 MPH, higher gusts.

MONDAY NIGHT: Partly cloudy to mostly clear. Lows 68-75. Dew point upper 60s. Wind SW up to 10 MPH.

TUESDAY: Mostly sunny to partly cloudy. Slight chance of isolated late-day showers and thunderstorms mainly northwest of a Boston-Providence line. Highs 90-97, cooler South Coast. Dew point falling to middle 60s. Wind WSW 5-15 MPH, higher gusts.

TUESDAY NIGHT: Partly cloudy to mostly clear. Lows 68-75. Dew point middle 60s. Wind WSW 5-15 MPH.

WEDNESDAY: Partly sunny. Chance of afternoon showers and thunderstorms. Highs 87-94, cooler South Coast.. Dew point upper 60s to 70. Wind SW 5-15 MPH, higher gusts.

WEDNESDAY NIGHT: Partly cloudy. Chance of evening showers. Patchy fog. Lows 67-74. Dew point upper 60s. Wind variable up to 10 MPH.

THURSDAY: Partly sunny. Chance of showers and thunderstorms. Highs 82-89, cooler South Coast.. Dew point upper to middle 60s. Wind variable 5-15 MPH.

THURSDAY NIGHT: Mostly cloudy. Chance of showers. Areas of fog forming. Lows 60-67. Dew point falling to near 60. Wind variable 5-15 MPH becoming N to NE.

FRIDAY: Mostly cloudy. Chance of showers, especially CT, RI, southern MA. Highs 68-75. Dew point near 60. Wind NE 5-15 MPH

DAYS 6-10 (JULY 3-7)

There’s been a disagreement between the guidance and myself about the weekend of July 3-4, with many runs painting a far more gloomy & doomy scenario than I believe we are going to see. Call it a meteorological hunch, but the performance of said guidance about 5 and 6 days out for the weekend we just had was less than stellar, with models foretelling of a front moving in with showers and thunderstorms, when in reality we saw the build-in of summer heat and humidity with no such shower & storm activity. This time, I feel that Canadian high pressure is still being under-forecast by the guidance in general, and that we’ll see a stronger push from it resulting in a generally dry Saturday-Sunday period, coolest Saturday with a northeasterly air flow, milder Sunday with more of variable wind evolving into a regional land breeze from the west as the high pressure area sinks to the south. Am I highly confident of this play-out? No, not yet. So please follow the updates through the week, because it’s entirely possible that the guidance can make my hunch look like a joke. Time will tell… Looking into early next week (July 5-7), expect the return of summer warmth and some humidity, along with the chance of a few showers and thunderstorms especially later in the period as a disturbance moves in.

DAYS 11-15 (JULY 8-12)

A “weaker” version of our current pattern tries to set-up with high pressure to the south, another high residing somewhere in eastern Canada, and a boundary between. It’s many days away but my general idea is that we’re on the warm/muggy side of the boundary through mid period and then the boundary moves into or even south of the region again by late in the period. Once again plenty of time to evaluate the weather during this time, as it’s often harder to pick out distinctive medium range patterns in summer than it is during the other seasons.

C-19 Chat Post – June 28 2021

DAYS 1-5 (JUNE 27 – JULY 1)

Heat continues to build in as we close out the weekend and we’ll peak our hot days Monday and Tuesday. As we get to mid week a frontal boundary will get into the region and increase the chance for showers and thunderstorms.

TODAY: Lots of clouds early to mid morning, then partly to mostly sunny. Fog patches South Coast early morning. Highs 85-92, cooler Cape Cod. Dew point middle to upper 60s. Wind WSW 5-15 MPH with gusts over 20 MPH.

TONIGHT: Partly cloudy. Fog patches in sheltered locations. Lows 66-73. Dew point middle to upper 60s. Wind SW diminishing to under 10 MPH.

MONDAY: Mostly sunny. Slight chance of isolated afternoon thunderstorms. Highs 88-95, cooler South Coast. Dew point upper 60s. Wind SW 5-15 MPH, higher gusts.

MONDAY NIGHT: Mostly clear. Lows 68-75. Dew point upper 60s. Wind SW up to 10 MPH.

TUESDAY: Mostly sunny. Highs 90-97, cooler Cape Cod. Dew point falling to lower 60s. Wind W 5-15 MPH, higher gusts.

TUESDAY NIGHT: Mostly clear. Lows 68-75. Dew point lower to middle 60s. Wind WSW 5-15 MPH.

WEDNESDAY: Partly sunny. Chance of afternoon showers and thunderstorms. Highs 86-93. Dew point upper 60s. Wind SW 5-15 MPH.

WEDNESDAY NIGHT: Partly cloudy. Chance of evening showers. Patchy fog. Lows 67-74. Dew point upper 60s. Wind variable up to 10 MPH.

THURSDAY: Partly sunny. Chance of showers and thunderstorms. Highs 84-91. Dew point upper to middle 60s. Wind variable 5-15 MPH.

DAYS 6-10 (JULY 2-6)

A frontal boundary should be in the region to start the period with a higher shower and thunderstorm threat and less heat but still somewhat high humidity, and then high pressure from eastern Canada may sneak down and dry the region out but keep it on the warm side for July 3-4, before that high slips to the south, it stays warm but turns more humid later in the period. The confidence on this scenario is not particularly high still.

DAYS 11-15 (JULY 7-11)

No significant changes to the medium range outlook of a typical summertime pattern with weak jet stream to the north and a regional pattern of moderate humidity, warm air, and limited shower and thunderstorm opportunities.

C-19 Chat Post – June 27 2021

DAYS 1-5 (JUNE 26-30)

Classic summertime in New England pattern over the next five days….. During the weekend we climb the ladder into the heat and humidity. Saturday starts out on the cloudy side with both low level moisture producing low cloudiness and higher level moisture and warming air producing a lot of high cloudiness above that, but the limited or no sun start will progress to partial sun as the day goes on, though South Coast areas may never really break out into much if any sun at all during the day. Cloudiness of both high and low but especially the low variety dominates again tonight. When we get to Sunday, the ability to break those clouds up improves and the amount of high cloudiness coming across the sky from the west will also lessen. Net result: More sunshine Sunday than Saturday. Also, Sunday’s heat and humidity will be more noticeable than Saturday’s. Then it’s the full heat for Monday through Wednesday to finish off June. Monday will have only the minimal chance of isolated air mass showers or thunderstorms, and I think this even remote chance will be absent Tuesday with some potential drying of the air mass and a more westerly wind, not always well-forecast by guidance. Wednesday, a frontal boundary from the northwest that will be held back for several days finally tries to make a run into this area, and while it will likely fail in its effort to fully get into and across the region, in its weakening form it can still be a better trigger for showers and thunderstorms, so those will be in Wednesday’s forecast, with room for adjustment as we get closer to it…

TODAY: Mostly cloudy to partly sunny. Fog patches at times South Coast. Highs 77-82 South Coast, 83-88 elsewhere. Dew point middle to upper 60s. Wind SSW 10-20 MPH.

TONIGHT: Partly to mostly cloudy. Areas of fog South Coast. Lows 63-70. Dew point middle to upper 60s. Wind SW 5-15 MPH.

SUNDAY: Partly to mostly sunny. Fog patches South Coast early morning. Highs 85-92, cooler Cape Cod. Dew point middle to upper 60s. Wind WSW 5-15 MPH with gusts over 20 MPH.

SUNDAY NIGHT: Partly cloudy. Fog patches in sheltered locations. Lows 66-73. Dew point middle to upper 60s. Wind SW diminishing to under 10 MPH.

MONDAY: Mostly sunny. Slight chance of isolated afternoon thunderstorms. Highs 88-95, cooler South Coast. Dew point upper 60s. Wind SW 5-15 MPH, higher gusts.

MONDAY NIGHT: Mostly clear. Lows 68-75. Dew point upper 60s. Wind SW up to 10 MPH.

TUESDAY: Mostly sunny. Highs 90-97, cooler Cape Cod. Dew point falling to lower 60s. Wind W 5-15 MPH, higher gusts.

TUESDAY NIGHT: Mostly clear. Lows 68-75. Dew point lower to middle 60s. Wind WSW 5-15 MPH.

WEDNESDAY: Partly sunny. Chance of afternoon showers and thunderstorms. Highs 86-93. Dew point upper 60s. Wind SW 5-15 MPH.

DAYS 6-10 (JULY 1-5)

Using guidance loosely and applying anticipated model error for early July outlook. Frontal boundary that approaches the region on the final day of June washes out over the region July 1 & 2 with each day running the chance of a couple showers and thunderstorms forming in the region, hottest day July 1, not as hot July 2, humidity high to moderate levels. Stronger front pushes through early July 3 from a not-well-forecast stronger high from Canada which clears the region for the balance of the holiday weekend with lower humidity but still warm for the balance of July 3-4. Heat comes back a little bit July 5 as high pressure shifts to the south. Confidence is not high on this outlook.

DAYS 11-15 (JULY 6-10)

Still a low confidence forecast here too but overall idea is typical summertime pattern with weak jet stream to the north and a regional pattern of moderate humidity, warm air, and limited shower and thunderstorm opportunities.

C-19 Chat Post – June 26 2021

DAYS 1-5 (JUNE 25-29)

It’s “warm front Friday”! While you were (probably) sleeping, clouds came up from the south during the night with areas of showers and drizzle. This will continue through midday today before we start to see some breaks in the clouds from south to north across the region as the front edges northward. This is the surface announcement of the door opening to a classic summer pattern, and rather early in the summer too. A Bermuda High will anchor itself off the US East Coast this weekend into next week and we’ll find ourselves in the classic hot & humid set-up starting Saturday and going at least through the beginning of next week. Initially, when this weekend and early next week were several days away, the medium range guidance was trying to bring a front into the region. This is not going to happen during this period, so the guidance was over-forecasting the ability of that front to get close to and get into the region – a reminder not to put too much stock in model forecast details more than a few days in advance. If we do see any rainfall after today, it would be from air mass pop-up showers and thunderstorms, though the risk of that in any one area during the period from Saturday through Tuesday is fairly low.

TODAY: Mostly cloudy. Areas of fog and drizzle with scattered showers this morning. Highs 75-82, cooler in some coastal locations. Dew point rising into lower 60s. Wind E up to 10 MPH shifting to S.

TONIGHT: Partly to mostly cloudy. Areas of fog. Lows 61-68. Dew point lower to middle 60s. Wind S up to 10 MPH.

SATURDAY: Clouds gradually break for more sun. Areas of fog until mid morning. Highs 83-90, cooler South Coast / Cape Cod. Dew point middle 60s. Wind S to SW 5-15 MPH.

SATURDAY NIGHT: Partly cloudy. Patchy fog interior lower elevations. Lows 65-72, warmest urban areas. Dew point lower to middle 60s. Wind SW up to 10 MPH.

SUNDAY: Mostly sunny to partly cloudy. Slight chance of isolated afternoon showers or thunderstorms. Highs 85-92, cooler South Coast. Dew point middle 60s. Wind SW 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Patches of fog forming interior lower elevations. Lows 65-72. Dew point middle to upper 60s. Wind SW under 10 MPH.

MONDAY: Sunny to partly cloudy. Slight chance of isolated showers and thunderstorms in the afternoon. Highs 87-94, cooler South Coast. Dew point upper 60s. Wind SW 5-15 MPH.

MONDAY NIGHT: Mostly clear. Patchy fog lower elevations. Lows 66-73. Dew point upper 60s. Wind SW under 10 MPH.

TUESDAY: Partly cloudy. Isolated afternoon showers and thunderstorms. Highs 88-95, cooler South Coast. Dew point upper 60s to 70. Wind SW 5-15 MPH.

DAYS 6-10 (JUNE 30– JULY 4)

There are conflicts between various medium range models at this time. Example: One model tends to keep a more of the same regime going with a gradual step-down in the heat as a weakening front brings some showers/storms to the region as it slowly moves through the dissipates. Another model keeps the heat around through July 1 then brings a stronger front through followed by Canadian high pressure with still warm but not nearly as hot and humid weather for the Independence Day Weekend. Given previous “misguided guidance”, we’ll split the difference for now and basically go with the heat hanging around at first, then lessening somewhat, but at least some chance of isolated to scattered showers/storms into mid period before a weekend drying trend for July 3-4. Tweaks will be needed.

DAYS 11-15 (JULY 5-9)

Low confidence forecast. Looking for a weak jet stream to the north and a regional pattern of moderate humidity, warm air, and limited shower and thunderstorm opportunities.