874
FXUS61 KBOX 091907
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
307 PM EDT Wed Jul 9 2025

.SYNOPSIS...
Temperatures trend cooler Thursday with continued chances for
showers and storms. Warmer and drier conditions return Friday,
continuing through the weekend before summertime heat and
humidity make a return for the start of the week along with
unsettled conditions.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Key Messages:

* Mild and cloudy with scattered showers and thunder possible

Cloudy skies expected to remain across the region with some
scattered showers and thunderstorms popping up heading into the
evening hours. Cloud cover is expected to build back in over the
interior tonight where some clearing has occurred this afternoon.
Patchy fog across southern New England may also develop overnight.
Lows expected to be in the 60s for most, with some spots approaching
70 in the CT Valley and RI.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Key Messages:

* Showers with the potential for heavy downpours throughout the day

A quasi-stationary front makes its way to southern New England then
settles in overhead. Some clearing over western parts of the
interior is possible tomorrow, which could aid in providing some
daytime heating that would favor convective development in the
early afternoon through the evening hours. Highs in western MA
and CT may reach the low 80s while the rest of the region sits
in the low to mid 70s. This area is still in a Marginal risk for
severe weather per SPC, but aside from that, chances for severe
weather remain low. HREF thunder probs are very low across the
region, though a thunderstorm or two cannot be ruled out.
Onshore flow will keep the cooler and cloudier conditions over
eastern MA into RI, which will help limit the convective
potential over this area. Torrential downpours are more likely
as PWATs remain elevated, sitting at around 1.5" to just over
2". It`s worth noting WPC has southern New England under a
Marginal risk for excessive rainfall as we remain under this
moist and warm airmass.

For Thursday night, lows once again sit in the mid 60s with cloudy
skies. Rain clears out heading into Friday as a small low to the
south exits northeast.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Key Messages:

* Trending drier Friday through the weekend
* Summertime heat and humidity return early next week, with highs in
  the upper 80s to low 90s possible Monday through Wednesday
* Daily chances for isolated, non-severe showers and thunderstorms


Friday through Sunday

After a wet and unsettled week, well begin transitioning to drier
weather Friday into the weekend as an area of high pressure settles
over the coastal waters to our east. This will support
east/southeast flow through Sunday, resulting in relatively cooler
temperatures (upper 70s to low 80s) east of I-495 along with sunny
and dry conditions.

Across the interior, temperatures will be near normal, with daily
highs in the mid to upper 80s. Elevated dewpoints in the upper 60s
to low 70s will support diurnal instability west of I-495, leading
to a slight chance of a pop-up afternoon shower or thunderstorm
across the interior this weekend.

At this time, there are no signals indicating a risk for severe
thunderstorms, as weak wind fields should suppress the wind shear
needed to support deep moist convection. Any storms that do develop
should collapse relatively quickly. Minimal, if any, thunderstorm
activity is expected across eastern areas, as onshore flow/marine
air should help stabilize the atmosphere.

Monday through Wednesday

Prevailing southwest flow returns on Monday, which will support
rising temperatures across southern New England. Highs will reach
the mid to upper 80s on Monday. A few scattered thunderstorms may
also develop across the interior, as a pulse of shortwave energy
could move through the Northeast Monday afternoon.

There is still no strong signal for the presence of deep-layer wind
shear needed to support severe weather, but some uncertainty remains
this far out.

By Tuesday, ensemble guidance suggests increasing heat, with a
4050% chance of high temperatures exceeding 90 degrees across
southern New England on both Tuesday and Wednesday. While there is
no clear signal for widespread precipitation during the middle of
next week, the typical slight chance for a diurnal thunderstorm
remains possible.

Stay tuned for further details.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
Forecaster Confidence Levels...

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

18z TAF Update...

Rest of Today...Moderate to high confidence.

Some areas across the interior have seen some improvement to
MVFR and even VFR conditions. There`s a chance some eastern
terminals might see some improvement to MVFR as well before
sunset. An isolated t-storm or scattered shower remains possible
this afternoon. Winds remain light and primarily from the NE
aside from parts of the immediate south coast which will
continue to see light SW winds.

Tonight...Moderate to high confidence.

The cooling boundary layer will result in conditions lowering to
mainly IFR/LIFR levels in most locations...but perhaps some
lower end MVFR conditions much of the night across the distant
interior. A cluster of showers and a few thunderstorms containing
locally heavy rainfall will also be possible tonight, especially
after 08z. Winds becoming calm in some areas.

Thursday...Moderate confidence.

MVFR to IFR conditions. More -SHRA and TSRA possible in the
morning hours, becoming more isolated as the day goes on. E to
ENE wind 5 to 10 knots.

KBOS Terminal...Moderate confidence in timing.

Possible improvement this afternoon to MVFR briefly before
becoming IFR to LIFR tonight after sunset. SHRA timing may start
earlier than 14z, but no earlier than 10z.

KBDL Terminal...Moderate confidence in TAF.

Chance for spot shower this evening. Higher confidence in
improvement to VFR this afternoon based on latest satellite
imagery.

Outlook /Friday through Monday/...

Friday: Mainly VFR, with local IFR possible. Slight chance
SHRA, patchy BR.

Friday Night: Mainly VFR, with areas IFR possible. Patchy FG.

Saturday: Mainly VFR, with local IFR possible. Slight chance
SHRA, slight chance TSRA, patchy FG.

Saturday Night: Mainly VFR, with areas IFR possible. Patchy FG.

Sunday: Mainly VFR, with local IFR possible. Slight chance
SHRA, slight chance TSRA, patchy FG.

Sunday Night: Mainly VFR, with local IFR possible. Slight
chance SHRA, patchy FG.

Monday: Mainly VFR, with local IFR possible. Slight chance
SHRA, slight chance TSRA, patchy FG.

&&

.MARINE...
Forecaster Confidence Levels...

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

Tonight: High confidence.

Winds to just under 10 kts out of the SW on the southern waters
and out of the NE on the eastern waters. Seas 2-4 ft.

Thursday to Thursday Night: Moderate confidence.

Winds 10-15 kts out of the SSE on the southern waters and out of
the E to NE on the eastern waters. Winds closer to the shores
along the south coast may be more NE. Seas 2-4 ft.

Outlook /Friday through Monday/...

Friday: Winds less than 25 kt. Patchy fog, slight chance of
rain showers. Visibility 1 to 3 nm.

Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Patchy fog. Visibility 1 to 3 nm.

Saturday through Monday: Winds less than 25 kt. Patchy fog.
Visibility 1 to 3 nm.

&&

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

&&

$$

SYNOPSIS...Hrencecin/RM
NEAR TERM...Hrencecin
SHORT TERM...Hrencecin
LONG TERM...RM
AVIATION...Frank/Hrencecin/RM
MARINE...Hrencecin/RM