169
FXUS61 KBOX 200737
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
337 AM EDT Sun Apr 20 2025

.SYNOPSIS...
Drier and mild behind a cold front today with gusty northwest
winds. Low pressure should pass by to our north Tuesday. High
pressure then expected to linger nearby into Friday with above
normal temperatures.

&&

.NEAR TERM /THROUGH TODAY/...
Key Messages

* Gusty northwest winds (25-35 mph) and low relative humidity
  (15-30%) tomorrow may support elevated fire weather conditions
  across southern New England

A cold front will move offshore early this morning. Drier
weather with gusty northwest winds will result. Most guidance is
typically too high with surface dew points in this scenario, so
trended dew points closer to the 10th percentile of the
NationalBlend.

Despite a cold front passing by, the dryness of the air and more
sunshine today expected to still result in slightly above normal
temperatures today.

925 mb jet of 30-45 kt this morning should move offshore by
early afternoon. Wind gusts of 25-35 mph expected today.
Considered a Wind Advisory for the higher terrain of central and
western MA, but thinking most gusts should just come under the
threshold by the time the mixing deepens enough to more fully
tap into that jet. This will need to be monitored through today.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
Key Messages:

* Gusty winds diminish tonight as high pressure builds in from
  the west to start the upcoming week
* Low risk for late day showers across western MA

High pressure moves across New England tonight, then moves
offshore Monday. Dry conditions continue with near to slightly
above normal temperatures. An approaching warm front may
trigger some showers late in the day towards western MA, but
this will hinge on how quickly the high pressure moves east. Dry
weather most likely to prevail. Gusty winds finally diminish
tonight into Monday.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Key Messages:

* Showers Monday night into Tuesday.

* Mainly dry Wednesday and Thursday with temperatures slightly
  above normal.

* Pattern becomes more unsettled Friday through the weekend with
  periodic chances for precipitation.


Monday Night through Tuesday:

A round of showers move through Monday night into Tuesday with
light rainfall amounts expected. Tuesday likely stays unsettled
for the morning with the remaining batch of showers exiting to
the east by mid-afternoon. Weak warm advection will bring 850 mb
temperatures in the 6-10C range Tuesday. This will support above
normal temperatures in the 60s and low 70s with the exception of
the Cape/Islands in the 50s.

Tuesday Night through Weekend:

A cold front moves through Tuesday night into early Wednesday
morning. This will bring a slightly cooler airmass in for
Wednesday, but still slightly above normal with highs in the 60s
in most places.

A similar pattern stays in place through the end of the week
with zonal flow and 850mb temperature anomalies signaling at
slightly above normal temperatures. Ensemble guidance shows a
transition to a more unsettled pattern Friday into the weekend
with potential for periodic chances for precipitation.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Today...High confidence.

VFR. NW winds with gusts of 20-30 kt. Gust up to 35 kt possible
across the higher terrain this morning. Gusts diminish towards
sunset.

Tonight and Monday...High Confidence.

VFR. Northwest winds gradually become light and variable by 12Z.
Winds become light south by late morning, with seabreezes
expected along the east coast of MA between 14-16Z.


KBOS TAF...High confidence in TAF.

KBDL TAF...High confidence in TAF.

Outlook /Monday Night through Thursday/...

Monday Night: MVFR/IFR conditions possible. Breezy. Chance
SHRA.

Tuesday: Mainly VFR, with local IFR possible. Breezy. Chance
SHRA.

Tuesday Night: VFR. Breezy.

Wednesday through Thursday: VFR.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Monday...High Confidence.

Small Craft Advisory conditions across most eastern waters, as
well as across the southern outer coastal waters. Winds diminish
late today, but seas will take a little longer to subside below
5 feet. Adjusted the end timing accordingly.

Outlook /Monday Night through Thursday/...

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

Tuesday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain
showers.

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

Wednesday through Thursday: Winds less than 25 kt.

&&

.FIRE WEATHER...
Special Weather Statement for elevated fire weather concerns
issued for southern New England. A drier air mass filters into
our region behind a cold front. Gusty northwest winds with gusts
up to 35 mph, combined with low relative humidities between 15
and 30 percent could result in fast spread of any fires.
Exercise caution handling any potential ignition sources.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 7 AM this morning to 1 PM EDT this
     afternoon for ANZ230-231-251.
     Small Craft Advisory until 7 AM EDT this morning for ANZ233-
     236.
     Small Craft Advisory until 1 PM EDT this afternoon for ANZ235-
     237.
     Small Craft Advisory until 7 PM EDT this evening for ANZ250-
     256.
     Small Craft Advisory until 11 PM EDT this evening for ANZ254-
     255.

&&

$$

SYNOPSIS...Belk/Mensch
NEAR TERM...Belk
SHORT TERM...Belk
LONG TERM...Mensch
AVIATION...Belk/Mensch
MARINE...Belk/Mensch
FIRE WEATHER...Belk/RM