NEAR TERM /UNTIL 7 AM SATURDAY MORNING/
715 PM Update:

No significant changes needed with this update.

Forecast looks to be holding up pretty well so far, with a pleasant/tranquil evening ahead. Will mention that we're now seeing quite a bit of hazy skies associated with high-altitude smoke well aloft stemming from the wildfires burning in west- central Canada. This is seen really well in GOES True-Color satellite imagery and recent CEF METAR remarks also indicate smoke above 25,000 ft. Fortunately no adverse impacts from this aside from a potentially more vibrant/redder sunset. 18z HRRR- Smoke model indicates a potential repeat performance for tomorrow under NNWly flow aloft. But again, no adverse impacts are expected with modeled near surface smoke concentrations being nil.

Aside from that, lighter northerly winds expected tonight with dry weather prevailing. Lows in the mid 50s to lower 60s, with low-mid 60s for the cities and Cape Cod/Islands.

Previous discussion:

quiet mid-summer weather across the region. Just some scattered shallow daytime heating cumulus clouds. The slightly gusty northwest winds are diminishing, and this is allowing the sea breeze to develop across eastern coastal areas of Massachusetts.
Temperatures are seasonable, with lots of low to mid 80s. For the rest of today, what you see is what you get. Get out and enjoy -- unless you are a fan of cold and snow...and in that case, it's going to be awhile. Clouds quickly dissipate with sunset so it's setting up to be clear tonight. With afternoon dewpoints in the 50s in most inland areas, that gives us a rough idea of the potential lows temperatures. Given decent radiational cooling expected, did lean toward the cooler of the guidance and blended in the NBM 10th percentile data and the MOS guidance. Could be a touch of fog in typical spots (like parts of the CT River Valley) and around some lakes and ponds.
Not expecting anything widespread however.

SHORT TERM /7 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/
245 pm update...

Synoptically we are under a high pressure "big bubble no trouble" pattern. For the most part, Saturday will look and feel very similar to today. Expect daytime cumulus to develop as well as sea breezes along the coast. With 850 mb temperatures running in the 13-15C range, that would suggest temperatures here on the ground should be in the 28-30C (low to mid 80s) range. Coolest will be in the higher elevations as well as where we will see the sea breezes along the immediate coast and Cape and Islands.
Saturday night should be a near repeat of tonight. Again trended toward some of the cooler temperature guidance, and painted in low temperatures in the mid to upper 50s -- though urban areas should stay in the 60s. Could there be some more patchy fog Saturday night? Sure, why not. But with a generally dry atmosphere, not expecting it to be widespread.

LONG TERM /SUNDAY THROUGH FRIDAY/
245 pm update...

Highlights:

* Dry Sunday with seasonably warm temperatures, though with increasing cloud cover.

* Upper low moving near or over Southern New England Sunday night into Monday brings cloud cover and light rain showers to the region.

* Turns much more humid Tuesday thru Thursday with daily chances for showers and thunderstorms, although won't be raining the whole time. Temperatures around or slightly above normal, but nightime lows will be above normal.

Details:

Sunday into Monday:

Initial ridge of high pressure to be in place over Southern New England on Sunday. However the main weather feature of interest is an upper level low and surface reflection expected to be located somewhere near or just south of 40N/70W on Sunday. This feature is expected to meander NW later Sunday evening into Monday into Southern New England or the lower Hudson Valley, as it merges/phases with a slow-moving mid/upper level trough over the Gt Lakes region.
There remains considerable uncertainty in the initial placement of the upper low and its exact track through the Northeast, and analysis of 12z ensembles don't offer much insight into a preferred track. The ECMWF remains on the western end (more into northeast NJ/lower Hudson Valley); the GFS and Canadian are somewhat similar in low track over the eastern coast of Southern New England. While the details are still quite hazy,

It looks as though Sunday and even into later-Sunday should be dry, though the latter part of Sunday should feature increasing cloud cover expanding northwestward associated with the upper low's landward approach. Thus for Sunday, we should be able to eke out one final nice day before our weather pattern turns cloudier and more unsettled. Dry weather with highs on Sunday in the 80s, on the upper end of that range over interior CT/MA further removed from advancing cloud cover, and in the lower 80s for southeast New England with more of a canopy of cloud cover to temper heating to an extent. Will be turning a touch more humid as well but excessive humidity isn't expected.

Increasing clouds and shower chances then develop soonest over the Cape and Islands Sunday evening, then expanding northwestward into the overnight and into Monday timeframe. Rain shower chances should initially be favored for eastern/coastal areas, then gradually expanding into the interior as we move into Monday. Precipitable water values associated with this upper level low are not expected to be climatologically anomalous, with values around an inch to inch and a half; correspondingly, PWAT standardized anomalies are around 0 sigma. Thus not expecting any significant downpours from any rains which develop, and it is not likely to be raining all of Monday either. Sunday night's lows should be a bit warmer than prior nights, in the mid 60s, with highs on Monday in the upper 70s to mid 80s areawide due to cloud cover and rain chances.

Tuesday through Thursday:

Upper level low from late Sunday/Monday to either phase with or move northward into northern New England early on Tue. However this period features continued mostly cloudy and unsettled weather with daily chances at showers and thunderstorms associated with the slow- moving mid/upper trough over the Gt Lakes. There is a more favorable southerly influx of deeper moisture in this period, with PWAT standardized anomalies around 1 to 2 standard deviations above normal (1.5-2 inch PWAT values). So this will lead to elevated humidity levels (e.g. dewpoints in the upper 60s to mid 70s), but also support potential for downpours in showers or thunderstorms which develop. Couldn't rule out showers or t-storms anywhere in this period of time, and it likely will not be raining the whole time, but interior MA and CT stand a slightly better chance than eastern MA/RI closer to the upper level feature. Couldn't really provide much specificity given uncertainties, so kept a rather broad brush to PoPs close to NBM values for this period.

With still a good amt of cloud cover around, high temperatures should run close to climatology or slightly above (highs mid 80s Tue/Wed, into the mid to upper 80s on Thurs), with above normal low temps in the upper 60s to mid 70s Tue thru Thu nights. Heat indices should reman below heat advisory criteria, although we could have a few locations reach the mid to upper 90s for heat indices late in the workweek.

AVIATION /23Z FRIDAY THROUGH WEDNESDAY/
Forecast Confidence Levels:

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

00Z TAF Update:

Through Saturday Night: High confidence.

VFR through the period with scattered daytime cumulus clouds with bases around 5000ft. Generally clear each night, although a touch of fog in river valleys is not out of the question.
However given a relatively dry airmass, any fog is not expected to be widespread in coverage. Northwest winds today will trend to the north tomorrow and then become light southerly Saturday night. However through the period, winds will generally be 10kt or less. This will allow sea breezes along the coasts to form.

KBOS TAF...High confidence in TAF. VFR through the period. ESE seabreeze developed late today and expect that to flip back to NW/WNW by 01z Sat. Seabreezes again expected on Sat, but following climatology a bit closer (start time ~ 15z, turning light southerly by 01z Sun).

KBDL TAF...High confidence in TAF. VFR thru the period. Light north winds.

Outlook /Sunday through Wednesday/...

Sunday: VFR.

Sunday Night through Monday: VFR. Slight chance SHRA.

Monday Night through Tuesday: Mainly VFR, with local MVFR possible. Slight chance SHRA, isolated TSRA.

Tuesday Night: VFR. Slight chance SHRA, isolated TSRA.

Wednesday: Chance SHRA, isolated TSRA.

MARINE
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

230 pm update...

Overall high confidence through the weekend.

Ridge of high pressure will be across the region through Saturday night. Thus winds should be 15kt or less, and in fact barely over 10kts in many areas. There will be local onshore sea breezes on Saturday. With the light winds and no significant swell energy coming into the region, wave heights will remain 3 feet or less.

Outlook /Sunday through Wednesday/...

Sunday: Winds less than 25 kt.

Sunday Night: Winds less than 25 kt. Chance of rain showers.

Monday: Winds less than 25 kt. Slight chance of rain showers.

Monday Night through Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers, isolated thunderstorms.

Tuesday Night: Winds less than 25 kt. Slight chance of rain showers.

Wednesday: Winds less than 25 kt. Slight chance of rain showers, isolated thunderstorms.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...None.