Waltham, Massachusetts 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

818
FXUS61 KBOX 151123
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
723 AM EDT Wed Oct 15 2025

.SYNOPSIS...
Cloudy, cool, and blustery conditions today. An unseasonably
cool airmass brings below normal temps and blustery conditions
Thursday with ocean effect cloud cover, periods of rain showers
and stronger northerly breezes across the eastern Massachusetts
coast. Warming trend for Friday into the weekend before turning
more unsettled as we move into early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Key Point

* Cool and blustery today

Shortwave trough and cold front drop out of northern New England
today, bringing blustery cool conditions to much of the region.
Highs today will struggle to reach the upper 50s to low 60s due to
cold air advection.  Winds increase from the NW this afternoon with
gusts of 20-25mph, which will make it feel like the low to mid 50s.
Not anticipating much sunshine today, as even after the low cloud
cover clears, mid to high-level clouds will filter in with the
shortwave.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Key Point

* Cold and blustery tonight

* Cool and windy Thursday

* Minor splash over coastal flooding possible Thursday afternoon
  high tide for north facing beaches.

Temperatures tonight will drop rather quickly into the 40s by 8 pm
and then bottom out in the 30s due to strong cold air advection.
Winds remain blustery overnight with 15-20mph gusts as winds aloft
increase.  Strong cold air advection continues into Thursday, and
with 850mb temps holding at -5C, high temps at the surface will only
top out in the low to mid 50s.  Thursday should feature more sun
than clouds across the interior, which will help promote boundary
layer mixing and gusty winds of 25-35mph.  With the cold air moving
over ocean water temps still in the upper 50s to low 60s, expecting
overcast skies for the Cape and Islands with periods of ocean effect
showers.  Winds near and over the waters will be stronger than
across the interior with gusts of 35-40mph.  There could be some
very minor splash over coastal flooding during the Thursday
afternoon high tide for north-facing coastlines as offshore waves
increase to 7-10 feet.

&&

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

* Dry with a warming trend Fri/Sat. Mid 70s possible Sun.

* Cold front later Sun night and Mon brings a period of rainy
  conditions.

Details:

Thursday Night:

Nighttime lows, while still rather chilly in the upper 30s to the
mid 40s, will be kept up some by at least the continued northerly
winds and also coastal cloudiness.

Friday/Saturday:

Transition period in the pattern toward 500 mb height rises and a
warming trend to temps for late in the week into the early weekend.
Sunny and dry with decreasing northerly winds, with highs on Fri in
the lower 60s, and into the mid 60s to perhaps near 70 on Sat
depending on how well we can mix.

Sunday and Monday:

Main forecast challenge in this period is the timing of a strong
cold front which moves through either Sunday or on Monday. This will
affect the timing of rain chances but also on temperatures for both
Sunday and Monday. Leaned toward a slower frontal timing which would
mean warmer temps on Sunday, which were already forecast to be above
normal in the lower 70s, but mid to even upper 70s could be
conceivable given 925 temps around +10C if cloud cover/rain from the
front can hold off. Thinking rain chances increase Sun night into
Mon, leading to a cloudy day Mon with periods of showers and temps
in the 60s.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...

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

12z TAF Update:

Today: Moderate Confidence

Guidance has improved this morning with the exception of the
lingering fog and low stratus across the South Coast & Cape.
IFR/MVFR cigs improving to MVFR/VFR with the sunrise. Less
certain on afternoon MVFR coverage inland to the I-95 corridor
as guidance generally remains mixed. Further west, CIGS should
be VFR this afternoon, but won`t rule out brief periods of MVFR
with diurnal cumulus. Winds today stay NNW with gusts up to 20
knots in the afternoon.

Tonight: Moderate Confidence

VFR. with MVFR over the Cape and Islands. Steady northwest
winds around 15 knots with 20-25 knot gusts.

Tomorrow: Moderate Confidence

VFR with MVFR over the Cape and Islands and periods of light
showers for the East Coast. Very windy with northerly gusts of
25-30 knots inland, and 30-40 knots near the waters.

KBOS Terminal...Low Confidence

VFR with periods of MVFR possible through much of the day as
strato cumulus form over the waters. Winds remain NNW gusting up
to 20 knots today, and up to 30 knots Thursday.


KBDL Terminal...Moderate Confidence

MVFR this morning becoming VFR by afternoon. Gusty NNW winds up
to 20 knots this afternoon and 25 knots Thursday.

Outlook /Thursday Night through Sunday/...

Thursday Night: VFR. Windy with gusts up to 35 kt. Slight
chance SHRA.

Friday: VFR. Windy with local gusts up to 30 kt.

Friday Night: VFR. Breezy.

Saturday through Saturday Night: VFR.

Sunday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Marine

Tonight through Tomorrow Night

Gusty northerly winds dominate the coastal waters through the end of
the week. Northeast 15-25 knot northeast winds gradually weaken and
become northwest from 10 to 15 knots tonight. The weaker wind speeds
will be short-lived however, is 15-25 knot northwest winds develop
over the coastal waters tomorrow into tomorrow night. Gale force
gusts are forecast to develop on Thursday, thus a Gale Watch has
been raised for the eastern marine zones. Seas remain elevated
generally in the 5 to 8 foot range through the period. Seas a bit
lower over the near-shore south coastal marine zones in the 2 to 5
foot range.


Outlook /Thursday Night through Sunday/...

Thursday Night: Strong winds with gusts up to 35 kt. Rough seas
up to 10 ft. Chance of rain showers.

Friday: Moderate risk for Small Craft Advisory winds with gusts
up to 30 kt. Areas of rough seas. Chance of rain showers.

Friday Night through Saturday: Winds less than 25 kt. Local
rough seas.

Saturday Night through Sunday: Winds less than 25 kt. Seas up
to 5 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Gale Watch from Thursday morning through Friday morning for
     ANZ231-232-250-251-254-255.
     Small Craft Advisory until 8 AM EDT Thursday for ANZ235-237-
     256.
     Small Craft Advisory until 8 PM EDT this evening for ANZ250-
     251-254-255.

&&

$$

SYNOPSIS...Loconto/KP
NEAR TERM...KP
SHORT TERM...KP
LONG TERM...Loconto/KP
AVIATION...McMinn/KP
MARINE...KP