Arlington, Massachusetts 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

759
FXUS61 KBOX 051821
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
221 PM EDT Sun Apr 5 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...

- A few showers early this morning, then more widespread
  showers move through SNE this afternoon into early evening
  associated with a cold front.

- Clearing and colder overnight, then blustery Monday.

- Could see a few rain/snow showers Monday night into
  Tuesdaymorning, but otherwise expecting cooler temperatures
  and dry weather for a good portion of next week.

- Second half of next week looks mainly dry with temperatures on
  the rise.

&&

.DISCUSSION...
KEY MESSAGE 1...A few showers this morning, then more
widespread showers move through SNE this afternoon into early
evening associated with a cold front.

The backdoor front which moved through SNE Saturday will return
northward as a warm front later this morning. Modest low level
jet combined with marginal elevated instability will bring a few
showers this morning and possibly a rumble of thunder. Lots of
stratus and fog also expected this morning with abundant low
level moisture trapped within a strong surface inversion. The
fog should lift later this morning and afternoon as SW flow
develops but stratus may linger as low level moisture is
persistent. The surface inversion eventually erodes in the
afternoon but mixed layer is quite shallow. This combined with
cloud cover and showers will limit how mild it gets, expecting
highs reaching upper 50s and lower 60s, but cooler along the
south coast. It will also be breezy over the Cape/Islands with
low level jet across the region, expecting gusts to 35 mph at
times.

We expect a period of widespread rain moving west to east
across SNE during the afternoon as a cold front moves through.
The cold front will be accompanied by a deep moisture plume with
PWATs 1-1.5" and right entrance region of upper jet so a period
of widespread showers is likely. Marginal elevated instability
is also present so can`t rule out an isolated t-storm. The bulk
of the showers should end by late afternoon, but will linger
into the evening across SE MA and Cape/Islands with later timing
of cold front.

KEY MESSAGE 2...Clearing and colder overnight, then blustery
Monday.

Cold front moves across the Cape/Islands in the evening then
offshore overnight. The frontal passage will be followed by
clearing and colder conditions and it will become blustery
overnight in the cold advection pattern. Lows will drop into the
30s. Blustery but dry weather continues Monday with soundings
showing a deepening and well mixed boundary layer supporting
gusts to 35 mph at times. Diurnal cu will develop as upper
trough and cooling temps aloft move through. Highs will range
from the upper 40s to lower 50s which is near or slightly below
normal for early April.

KEY MESSAGE 3...Could see a few rain/snow showers Monday night
into Tuesday morning, but otherwise expecting cooler
temperatures and dry weather for a good portion of next week.

Expecting an upper-level trough to push across the Great Lakes
and into New England early next week, leading to mostly dry
weather and cooler temperatures. Ensemble guidance is indicating
850mb temperatures could get to below -5C and 500mb
temperatures below - 30C Tuesday as a shortwave moves through,
which would support some light snow showers developing and
mixing in with rain showers, especially over the higher
elevation areas, though we`re not expecting any road or travel
impacts. Surface temperatures will likely hover near or possibly
just below freezing Monday night into Tuesday morning, but
they`re expected to make a fast recovery later Tuesday
morning... into the mid 40s. Otherwise, dry weather with high
temps mainly in the middle 40s to the lower 50s and overnight
temperatures ranging from the mid 20s to mid 30s through
Wednesday night.

KEY MESSAGE 4...Second half of next week looks mainly dry with
temperatures on the rise.

A large high pressure system moves into the Mid-Atlantic region
by the second half of next week, bringing predominantly
southwesterly flow and dry conditions back to southern New
England. The warmer airmass advecting into the region will allow
temperatures to recover back into the 50s and 60s by the end of
the week.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...

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

18z TAF Update:

Today: Moderate confidence.

Still IFR/LIFR due to stratus, mist and areas of fog until cold
frontal passage. Cold front has moved into Southern New England
and is bringing widespread rains, with some brief downpours
possible. Expect rains to come to an end from 21-23z west to
east, though could linger until 02z for the Cape and Islands.
Post-frontal, expect lifting of ceilings into the SCT- BKN VFR
range and winds becoming NW and increasing to around 10 kt.

Tonight: High confidence.

Leftover MVFR ceilings should scatter out to VFR all areas
early. NW winds increase to 10-15 kt with developing gusts to 25
kt after midnight.

Monday: High confidence.

Mainly VFR; for the interior higher terrain, wouldn`t rule out
some MVFR bases interior high terrain in the aftn as disturbance
aloft approaches and there could be some hit-or-mostly-miss
sprinkles or flurries. Main concern for aviation is gusty NW
winds, around 12-17 kt with gusts 25-35 kt, highest at ORH.

Monday Night: High confidence overall, though moderate on
possible precip chances.

Disturbance aloft moves through Southern New England Mon night,
which will bring at least SCT-OVC mainly VFR ceilings. Less
clear if we can wring out any precip; if we do, potential for
brief periods of MVFR visby -SHSN. NW winds decrease to 8-12 kt
with gusts in low 20s kt range.

KBOS Terminal...Moderate confidence. IFR, widespread rain at
MVFR visbys continue thru 23z with arrival of cold front.
Clearing to VFR likely into the early evening with NW winds
increasing to around 10-13 kt before midnight, with gusts to 25
kt toward daybreak Mon.

KBDL Terminal...Moderate confidence. IFR/LIFR, widespread rain
at MVFR visbys continue thru 22z with arrival of cold front.
Clearing to VFR likely by sundown, with NW winds increasing to
around 10-15 kt late evening, with gusts to 25 kt toward
daybreak Mon.

Outlook /Monday Night through Friday/...

Monday Night: VFR. Chance SHRA, chance SHSN.

Tuesday: Breezy. Chance SHRA, chance SHSN.

Tuesday Night: Breezy.

Wednesday through Wednesday Night:

Thursday: Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

High confidence.

Gusty pre-frontal SW winds today with gusts to 25-35 kt as LLJ will
be over the waters. Will continue SCA although a few near gale force
gusts possible. The LLJ moves offshore tonight but expect post-
frontal W gusts to 25 kt late tonight and Monday. Areas of fog this
morning with poor vsbys, then showers mid afternoon into this
evening. An isolated t-storm is possible.

Outlook /Monday Night through Friday/...

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

Tuesday: Winds less than 25 kt. Chance of rain showers.

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

Wednesday: Winds less than 25 kt. Areas of seas approaching
5 ft.

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

Thursday: Winds less than 25 kt. Seas up to 5 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
     ANZ230>234-236-251.
     Small Craft Advisory until 2 AM EDT Monday for ANZ235-237.
     Small Craft Advisory until 2 PM EDT Monday for ANZ250.
     Small Craft Advisory until 8 PM EDT Monday for ANZ254>256.

&&

$$

DISCUSSION...KJC/McMinn
AVIATION...Loconto/Hrencecin
MARINE...KJC