-- Discussion containing changed information from previous version are highlighted. --
435
FXUS61 KBOX 251751
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
151 PM EDT Wed Jun 25 2025

.SYNOPSIS...
Another day of hot and humid conditions with widely scattered
thunderstorms this afternoon as a cold front moves down from the
north. Turning cooler Thursday through Saturday, then warming Sunday
into early next week, with daily chances of showers and
thunderstorms.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Key Messages:

* Less hot today, though feels like temperatures are 95F to 100F. It
  will be a "little" cooler along the eastern coast of Massachusetts
  today as a sea breeze develops.

* Widely scattered thunderstorms are possible this afternoon, not
  every town of city experiences one.

Yet another hot and humid day is on tap, but not expected to be as
severe as it was yesterday. In fact, a sea breeze develops along the
eastern coast of Massachusetts, providing albeit minor relief, with
air temperatures between 85F-90F. Elsewhere it is still plenty hot!
925mb temperatures settled from +22C to +25C, this yields highs from
the upper 80s to mid-90s. A forecast challenge for today, will dew
point temperatures mix out and lower during the afternoon. Opt`d to
blend in the 10th percentile of the NBM to show that possibility,
still,  with dew points lowering into the upper 60s will have a heat
index ranging from 95F to 100F. Thus no changes were made to the
Heat Advisory issued by the previous forecasters.

Today`s Record Highs, June 25th:

* BOS: 97F, set in 1943
* ORH: 92F, set in 1943
* PVD: 98F, set in 1943
* BDL: 95F, set in 1943

A cold front sags south this afternoon and with mean SBCAPE from 800
to 1200 J/kg, pop-up showers and thunderstorms are possible, though
will be widely scattered. Meaning, not every town sees rain this
afternoon. Timing is tricky, CAMs are a bit over the place, but feel
a degree of confidence these storms occur during the early afternoon
to early evening. Localized gusty winds and heavy downpours would be
the main concerns with any of these storms that develop. Remember, a
non severe storms can produce lightning, and if you can hear thunder
you are close enough to be struck by lightning. When thunder roars,
head indoors.

Lastly, the Rhode Island Department of Environmental Management has
issued an Air Quality Action Day for Ground Level Ozone, from 11 AM
to 11 PM EDT today. An Air Quality Action day means that Ground
Level Ozone concentrations within the region may approach or exceed
unhealthy standards.

For additional information, please visit the Rhode Island Department
of Environmental Management website at: https:/dem.ri.gov/

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Key Messages:

* Trending much cooler on Thursday with hit-or-miss showers.

Overnight have clouds and spotty showers in the vicinity of the
stalled cold front, over the southern waters. Best chance for any
showers overnight will be the immediate south coast of Rhode Island
and Massachusetts, which includes the Cape and Islands. Look for
overnight temperatures in the middle to upper 60s.

Thursday will have widespread relief from the heat as high pressure
moves off the coast of eastern Canada, bringing northeast flow off
the North Atlantic Ocean. High temperatures are mainly in the low to
middle 70s, with the Connecticut River Valley in the middle to upper
70s. And with the mid-level becoming more zonal, will have shortwave
energy passing through which brings chances for hit-or-miss
showers.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Key Messages:

* Cooler Friday and Saturday. Warming back up into the 80s Sunday
  through Tuesday.

* Daily chances of rain and/or thunderstorms through Tuesday, with
  the greatest chance of widespread rain Friday night into Saturday.

As discussed prior, the mid-level ridge flattens and flow becomes
nearly zonal. Surface high pressure slowly moves further off shore
during the weekend, but will provide cooler easterly flow Friday
into Saturday, followed a Bermuda High building Monday and Tuesday
which shifts the wind out of the south, then southwest. The onshore
flow provides cooler temperatures Friday and Saturday, highs in the
upper 60s to lower 70s on Friday, then low to middle 70s Saturday. A
warm up follows Sunday through Tuesday, summer temperatures return
with highs in the low-80s on Sunday. Early next week highs return to
the middle and upper 80s, along with dew points nearing 70F.

As for any precipitation, at this time, there are no major systems
on the horizon. With the nearly zonal flow, there will be area of
shortwave energy that traverse through southern New England, leading
to marginally unsettled conditions Friday through Tuesday. At this
time the best chance for widespread rain comes Friday night into
Saturday with a robust 850mb shortwave, think those in northern
Massachusetts have the greatest chance for the rain, given the
greatest forcing is displaced to the north in Vermont/New Hampshire.

&&

.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Forecaster Confidence Levels...

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

18z Update

Today: Moderate Confidence.

VFR. Sea breeze has made it to BOS and much of coastal
Massachusetts. Wind speeds are between 8 and 12 knots. Opted to
downgrade the probs to -SHRA as convection that has formed has
been shallow and is producing weak returns.

Tonight: High Confidence.

VFR. Shower chances are highest across the southern coastal
waters. Wind shifts to the northeast, less than 10 knots across
the interior and 10 to 15 knots across eastern Massachusetts and
Rhode Island.

Thursday: Moderate Confidence.

VFR to MVFR. Periods of showers are possible, though confidence
is lower in exact location and timing. Northeast to east winds
around 10 knots.

KBOS Terminal...Moderate confidence in TAF.

VFR with winds turning ENE this morning and staying there for
much the TAF period. Chance for thunderstorms this afternoon
between 17-23z.

KBDL Terminal...Moderate confidence in TAF.

VFR with light winds today. Chance for thunderstorms this
afternoon between 17z-23z.

Outlook /Thursday Night through Sunday/...

Thursday Night: Mainly VFR, with areas MVFR possible. Slight
chance SHRA.

Friday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.

Friday Night: Mainly VFR, with local IFR possible. Chance SHRA,
isolated TSRA.

Saturday: MVFR/IFR conditions possible. Chance SHRA, isolated
TSRA.

Saturday Night: Mainly VFR, with areas IFR possible. Chance
SHRA, isolated TSRA.

Sunday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
-- End Changed Discussion --

&&

.MARINE...
Forecaster Confidence Levels...

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

Today and Thursday: High Confidence.

Weak cold front approaches from the north, increasing clouds and a
few pop-up showers and thunderstorms. Northern waters have northerly
winds while the southerly waters have a southerly wind. Wind becomes
northeast for all waters Wednesday night and increase to 10 to 15
knots. Seas are less than 2 feet. Cold front settles south of the
southern outer waters with east/northeast winds 10 to 15 knots and
gusting to 20 knots. Seas building from the south 3 to 4 feet.
Outlook /Thursday Night through Sunday/...

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

Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain showers.

Friday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers.

Saturday through Saturday Night: Winds less than 25 kt. Seas up
to 5 ft. Chance of rain showers, isolated thunderstorms.

Sunday: Winds less than 25 kt. Seas up to 5 ft. Slight chance
of rain showers, isolated thunderstorms.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Heat Advisory until 7 PM EDT this evening for CTZ002>004.
MA...Heat Advisory until 7 PM EDT this evening for MAZ003-005-006-
     010>014-017-018-020-021-026.
RI...Heat Advisory until 7 PM EDT this evening for RIZ001>007.
     Air Quality Alert until 11 PM EDT this evening for RIZ006>008.
MARINE...None.
-- End Changed Discussion --

&&

$$

SYNOPSIS...Dooley
NEAR TERM...Dooley
SHORT TERM...Dooley
LONG TERM...Dooley
AVIATION...FT
MARINE...Dooley