196
FXUS61 KBOX 061819
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
219 PM EDT Sat Jun 6 2026

.WHAT HAS CHANGED...
No significant changes to the current forecast.

&&

.KEY MESSAGES...

- A cluster of showers & thunderstorms works across the region
  between 5 and 11 pm this evening. A few storms may become
  severe and produce damaging wind gusts, dangerous cloud to
  ground lightning and brief torrential rainfall.

- Scattered showers and perhaps a few embedded t-storms develop
  Sunday afternoon/early evening with the focus across eastern
  New England Drier and much cooler weather follows Sunday night.

- Cooler Monday with onshore breezes, but drier weather prevails.

- Potential multi-day stretch of 90+ degree temperatures mid to
  late next week, with some potential for showers and
  thunderstorms later in the week.

&&

.DISCUSSION...
KEY MESSAGE 1...A cluster of showers & thunderstorms works across
the region between 5 and 11 pm this evening. A few storms may become
severe and produce damaging wind gusts, dangerous cloud to ground
lightning, and brief torrential rainfall.

Breaks in the mid-high level cloudiness has allowed for partial
sunshine to develop. This will continue to push highs well into the
80s to near 90 in many locations by late afternoon. Low level
moisture is limited and will probably keep surface Capes on the
order 1000 to 1500 J/KG. This is on the marginal side...But bulk
effective shear increasing to between 30 and 40 knots will try to
offset that.

Given the above parameters...we expect a cluster of showers and
thunderstorms to develop and enter western MA and CT after 5-6 pm.
This potential will likely not reach the BOS-PVD corridor until
after 7-8 pm. A few of the storms may become severe and produce
damaging wind gusts. While this potential exists across most of our
region...the greatest risk will be across interior MA & CT given
better instability/more favorable timing.

We will have to see if the bulk effective shear is enough to
overcome the limited instability...but mid level lapse rates are
decent for our standards on the order of 6/6.5 C/KM. Main severe
weather risk will be localized damaging wind gusts given decent T/Td
spread. Much of the machine learning guidance supports this as well
indicating localized damaging wind gusts the main severe weather
threat. They also indicating this potential across most of our
region...But show the greatest threat across interior MA & CT.

So in a nutshell...a few severe thunderstorms possible between 5 and
11 pm this evening. Greatest risk will be after 5-6 pm across
interior southern New England...But can not rule out the risk
approaching the I-95 corridor after 7-8 pm this evening. In
addition...brief heavy rain and dangerous cloud to ground lightning
are possible too. Bulk of any activity will probably exit the region
by midnight followed by mainly dry weather. It will remain mild and
a bit muggy compared to what we have experienced lately...low temps
will only drop into the 60s.

KEY MESSAGE 2...Scattered showers and perhaps a few embedded t-
storms develop Sunday afternoon/early evening with the focus across
eastern New England.

Dry weather is on tap Sunday morning...but a strong shortwave/cold
pool aloft and associated cold front will be dropping south Sunday
afternoon. This will combined with diurnal heating and trigger the
development of afternoon scattered showers and a perhaps a few
embedded thunderstorms. While a few showers will be possible across
the entire region...areal coverage should be the greatest in
central/eastern MA and RI given better instability. Not expecting
severe weather...But a few thunderstorms possible especially towards
the I-95 corridor. Given 500T dropping to between -14C to -16C we
can not rule out some small hail if a thunderstorm two is able to
develop. Highs will mainly be in the upper 70s to the lower 80s.

Showers may linger into the evening across parts of eastern MA/RI
into the evening. Otherwise...drier and much cooler air works into
the region overnight. Lows by daybreak Monday will be in the middle
to upper 40s in the outlying locations and lower to middle 50s in
the urban centers.

KEY MESSAGE 3...Cooler Monday with onshore breezes, but drier
weather prevails.

An enhanced NE onshore flow develops into Monday in the wake of the
upper low/cold front Sunday night, with 925 mb temps running around
8-10C. Although mostly sunny conditions are expected, expect a
cooler and breezy day for most of central and eastern portions of
Southern New England, with highs only in the 60s to lower 70s. NE
gusts could punch as high as 30 mph out over the Cape, but should
clock in around 20-25 mph further inland to central MA and RI. Highs
should reach well into the 70s to low 80s in western MA and most of
CT away from the onshore breezes.

KEY MESSAGE 4...Potential multi-day stretch of 90+ degree
temperatures mid to late next week, with some potential for
showers and thunderstorms later in the week.

The main story in the medium-range is a steady warming trend to
temperatures, which begins on Tuesday with temps running around or
slightly above mid-June normals. However we are looking at a
potential multi-day stretch of 90+ degree temperatures Wed into
early next weekend, as 850 mb temps are in the mid to upper teens C
range as a pronounced upper level ridge over the Gt Lakes flattens
and advects east. Humidity levels could also be on the rise and
could drive higher heat indices. There is time to assess this in
forthcoming guidance but potential for heat headlines could be
needed in portions of this period.

Shower/t-storm chances are more uncertain, but the potential could
stand to increase late in the week as the upper ridge axis
flattens and introduces a stronger belt of westerlies into
Southern New England. Too early at this time to determine if
storms develop if they`ll be strong/severe or not, but the
degree of heat and humidity could certainly provide fuel for at
least some thunderstorms.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

18z TAF Update...

Through tonight...Moderate confidence.

The main issue will be for scattered showers and thunderstorms that
will likely enter western MA/CT after 21z/22z and approach the
coastal plain after 00z/01z. Brief MVFR/IFR conditions are possible
with this activity along with localized strong wind gusts. Greatest
risk for this is across interior southern New England...But there is
the risk for this right to the I-95 corridor. The bulk of this
activity should exit the southeast New England coast near 05z-06z.
Outside this activity...VFR conditions will dominate tonight. The
exception might be towards the Cape/Islands...where low clouds and
fog patches may develop overnight with the best chance across
Nantucket.

Sunday and Sunday night...High confidence.

Any lower clouds/fog patches that form towards the Cape/Islands
should burn off Sunday morning. Otherwise...VFR conditions dominate
outside of scattered showers that are expected to develop Sunday
afternoon. A few embedded t-storms are possible too...but areal
coverage and intensity is expected to be significantly less than
this evening. Winds shift to the NW on Sun and gust to between 20
and 25 knots. Winds then turn N Sun night at speeds of 5 to 15 knots
but may temporarily decouple for a few hours in the typically prone
locations late Sun night.

KBOS Terminal...Moderate confidence in TAF. The main concern for
thunderstorms crossing the terminal will be between 00z and 04z.

KBDL Terminal...Moderate confidence in TAF. The main concern for
thunderstorms crossing the terminal will be between 23z and 03z.

Outlook /Monday through Thursday/...

Monday: VFR. Breezy.

Monday Night: VFR.

Tuesday: VFR. Breezy.

Tuesday Night: VFR.

Wednesday: VFR. Breezy. Slight chance SHRA.

Wednesday Night: Mainly VFR, with local MVFR possible. Chance
SHRA, slight chance TSRA.

Thursday: VFR. Chance SHRA, slight chance TSRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Tonight through Sunday night...High confidence.

We will continue marginal near shore small craft advisories into
early-mid evening for marginal SW wind gusts near 25 knots.
Otherwise...marginal 5 foot seas will flirt with the southern waters
into Sunday while the rest of the region will be below small craft
advisory criteria. However...a surge of northerly small craft wind
gusts is expected Sunday night behind the cold front especially in
our eastern waters. New small craft headlines will eventually be
needed once most of current headlines expire.

Lastly...a cluster of strong t-storms may approach our waters after
7-8 pm this evening. They eventually should weaken and clear the
southeast waters after 6z-7z or so.

Outlook /Monday through Thursday/...

Monday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft.

Monday Night: Winds less than 25 kt. Seas locally approaching
5 ft.

Tuesday through Wednesday: Winds less than 25 kt.

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

Thursday: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Air Quality Alert until 11 PM EDT this evening for MAZ013-
     016>024.
RI...Air Quality Alert until 11 PM EDT this evening for RIZ001>008.
MARINE...Small Craft Advisory until 9 PM EDT this evening for
     ANZ231>235-237.
     Small Craft Advisory until 11 PM EDT this evening for ANZ250.
     Small Craft Advisory until 8 AM EDT Monday for ANZ254>256.

&&

$$

DISCUSSION...Frank/Loconto
AVIATION...Frank/Loconto
MARINE...Frank/Loconto