909
FXUS61 KBOX 050644
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
244 AM EDT Sat Jul 5 2025

.SYNOPSIS...

Tranquil weather with low humidity continues today. Very warm
temperatures in the upper 80s to lower 90s and rising humidity
levels will lead to high heat indices Sunday and Monday. Unsettled
weather makes a return Monday night, off and on through much of the
week.

&&

.NEAR TERM /THROUGH TONIGHT/...

Key Messages...

* Dry today with more sun than clouds.

Mid level height rises will lead to dry weather as surface high
pressure begins to sink to our south. This placement directs light
SW winds into SNE, though WAA doesn`t kick in in earnest until
Sunday when a trough of low pressure passes in closer proximity. A
weak warm front in the mid levels will lead to increasing high
clouds during the day, but there will be more sun than clouds,
helping push high temperatures up into the mid 80s (lower on the
south coast where onshore flow keeps temps in check). Tonight partly
cloudy skies should keep radiational cooling from being as much of
an issue as Friday night, keeping lows about 10 degrees warmer (in
the mid 60s).


&&

.SHORT TERM /SUNDAY/...

Key Messages...

* Hotter with increasing humidity.

The mid level ridge axis crosses New England on Sunday placing us
beneath increasingly breezy SW flow. Warm air and and moisture is
advected north pumping up both the heat and humidity. So, while it
will be breezier, gusting 20 to 30 mph, it will feel much hotter
than Saturday. Dewpoints increase from the 50s to the upper 60s
while high temperatures make it back into the 90s; highest
temperatures will be in the CT and Merrimack valleys while the
coolest spots are on the south coast, thanks again to onshore flow.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

Key Messages...

* Peak of the heat and humidity Monday.

* Periodic chances of unsettled weather late Monday through the
  week.

Steering flow becomes rather zonal to start the week keeping warm SW
flow around. While no rain is expected during the day, what will be
notable is the 70F+ dewpoints that will make it feel very humid
outside. A weak shortwave moving through the steering flow around
Tuesday with a surface frontal system will bring more clouds heading
into Tuesday along with the chance for scattered showers and
thunderstorms. It remains difficult to nail down when these periodic
bouts of unsettled weather move through, but another trough looks to
move through around Thu/Fri. Temperatures are more seasonable after
Monday.


&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...

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

06z TAF Update:

Today and Tonight: High confidence.

VFR. Winds to become SWly around 5-10 kt. There remains a low
probability of a seabreezes at BOS and PVD but more than likely
that it remains offshore. Light SW winds expected Sat night.
Sunday, SW winds increase a bit 10-15 kts with gusts 20 to 25
kts.

KBOS Terminal...Moderate confidence in TAF. There is the low
probability of a seabreeze, but more likely that it remains
offshore.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday Night through Wednesday/...

Sunday Night: VFR. Breezy.

Monday: VFR. Breezy. Slight chance SHRA.

Monday Night: VFR. Breezy. Chance SHRA, slight chance TSRA.

Tuesday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA, chance TSRA.

Tuesday Night: Mainly VFR, with local IFR possible. Chance
SHRA, slight chance TSRA.

Wednesday: VFR. Slight chance SHRA, slight chance TSRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Sunday: High confidence.

Tranquil boating weather conditions through Saturday night. SW winds
around 10-15 kt today and tonight. Seas 4 ft or less all waters, and
around 1-2 ft nearshore. No obstructions to visibility expected. SW
winds increase on Sunday, gusting 20-25 kts, as high as 30 kts on
eastern waters.

Outlook /Sunday Night through Wednesday/...

Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Seas locally approaching 5 ft.

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

Monday Night through Tuesday Night: Winds less than 25 kt.
Chance of rain showers, slight chance of thunderstorms.

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from 7 AM Sunday to 8 PM EDT Monday for
     CTZ002>004.
MA...Heat Advisory from 7 AM Sunday to 8 PM EDT Monday for
     MAZ003>007-010>019-026.
RI...Heat Advisory from 7 AM Sunday to 8 PM EDT Monday for
     RIZ001>004.
MARINE...None.

&&

$$

SYNOPSIS...BW
NEAR TERM...BW
SHORT TERM...BW
LONG TERM...BW
AVIATION...BW
MARINE...BW