396
FXUS61 KBOX 071855
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
255 PM EDT Mon Apr 7 2025

.SYNOPSIS...

A wave of low pressure will continue to bring periods of light rain
occasionally mixed with wet snow/sleet persist tonight with the
focus for the light precipitation shifting towards the I-95
corridor. A strong cold front sweeps through the region Tuesday
morning with a few brief rain/snow showers possible...followed by
dry but windy and unseasonably chilly temperatures Tuesday afternoon
and night. It will remain dry and chilly on Wednesday...but with
less wind. Warming up toward the end of the week, but turning
unsettled again with showers at times, which will likely linger
through next weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...

Key Messages...

* Focus for the periods of light rain occasionally mixed with wet
  snow/sleet will shift towards the I-95 corridor tonight

* Chilly/Raw tonight with overnight lows mainly in the 30s

* Cold front may bring a few rain/snow showers and even a localized
  heavier snow squall or two Tue toward daybreak

A wave of low pressure lifting northeast will pass just southeast of
the Benchmark tonight. This will continue to generate enough forcing
for periods of light precipitation and fog...but the main focus for
additional precipitation will shift towards the I-95 corridor
tonight and especially the Cape/Islands where better forcing exists.
Thermal profiles may be cold enough near and northwest of the I-95
corridor at times for wet snow/sleet mixed in at times.
However...temps generally above freezing coupled with limited
intensity will result in no impact with wet roadways.

The other issue will be toward morning when a strong shortwave/cold
front approaches from the west. Enough moisture seems to be
available along with a dynamic shortwave to trigger a few rain/snow
showers that cross the region toward daybreak. In fact...we may even
have a localized heavier snow squall or two in the high terrain
given there is even a bit of MUCape depicted in the guidance.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...

Key Messages...

* Strong cold front may bring a few rain/snow showers and even a
  localized heavier snow squall or two in the high terrain Tue AM

* Westerly wind gusts of 35-50 mph & unseasonably chilly Tue with
  high mainly in the upper 30s to the middle 40s

* Windy and unseasonably cold Tue night with lows mainly in the 20s
  and wind chills dropping into the teens in many locations

Details...

Tuesday and Tuesday night...

A strong cold front crosses the region Tue morning with a few brief
rain/snow showers possible. As we mentioned in the prior
section...ingredients are favorable for the risk of a localized
heavier snow squall or two in the high terrain so that is something
will need to watch. Otherwise...the main story will be the
unseasonably chilly temps and windy conditions that will develop by
mid afternoon Tuesday behind the strong cold front. While we expect
partial sunshine to develop...850T drop to between -10C and -12C by
mid afternoon behind this cold front. Highs will be mainly in the
upper 30s to the middle 40s with the help of a very well mixed
atmosphere and april sun angle. Nonetheless...it will feel chillier
given the strong WNW winds by mid afternoon.

That brings us to the main concern Tuesday afternoon and
evening...which will be for strong WNW wind gusts. A modest LLJ
between 40 and 50 knots develops Tue afternoon across the region
with steep low level lapse rates resulting in excellent mixing.
Given the April sun angle and tendency for mixing to exceed what
guidance is advertising this time of year...we opted to issue a Wind
Advisory for western/central and northeast MA. This is where we have
the best chance to see gusts between 40 and 50 mph. Across the rest
of the region...expect gusts on the order of 35 to 45 mph.

These strong winds will continue into Tuesday evening...gradually
diminishing overnight although it will remain be quite breezy. The
strong cold advection and 850T between -10C and -12C will result in
unseasonably cold Tue night low temps mainly in the 20s. Wind chills
will be down in the teens to the lower 20s!

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...

Key Messages:

* Continued cool, breezy, and dry weather for Wednesday.

* Warming trend Thursday and Friday with a return to wet conditions.

* Wet and unsettled weather continues into next weekend, but details
  remain uncertain this far out.

Wednesday through Friday...

High pressure builds in Wednesday, allowing for some drying out and
socking in colder temps. Looking to stay in the low 40s across the
interior to upper 40s along the coastal plain. The wind chill index
will make it feel like the 30s in the afternoon. Winds become calm
after sunset on Wednesday, setting up for good radiational cooling
conditions and another night of lows in the 20s.

Winds turn southerly on Thursday in response to an approaching warm
front and surface low over the Great Lakes. Temps rebound into the
low 50s, but cloudy and wet conditions return. Rain chances don`t
increase until Thursday evening into Friday as an upper-level trough
and surface low start to form over the Great Lakes.

Saturday and Sunday...

Guidance remains in good agreement heading into the weekend as a
deep trough stretching from the Great Lakes to the Florida Panhandle
reaches the East Coast. Most ensembles are indicating a low pushing
up the coast Saturday and exiting southern New England Sunday;
however, the exact track is quite variable this far out. The trough
and low will bring continued wet and unsettled weather to the region
next weekend. However, with this system being a week out, details
remain uncertain, as the pattern could easily change between now and
then.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...

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

18z TAF Update...

This afternoon into tonight...Moderate Confidence

Mainly IFR-LIFR conditions will persist across much of the
region this afternoon and tonight. Periods of light rain/drizzle
and fog expected into this evening with some light snow/sleet
at times especially across the interior high terrain...but
runways will remain wet with no impacts. The pockets of light
precipitation will tend to shift focus towards the south coast
as the night wears along. Light NNE winds shifting to the NW
toward daybreak.

Tuesday...High Confidence.

A strong cold front may bring a few brief rain/snow showers to
parts of the region Tue morning. Otherwise...MVFR-IFR conditions
early Tuesday morning will improve to VFR from west to east by
early afternoon. The main story though will be WNW wind gusts
of 30-40 knots developing by mid afternoon.

Tuesday night...High Confidence.

VFR. WNW wind gusts of 30-40 knots during the evening will
gradually diminish to between 15-30 knots toward daybreak.

BOS TAF...Moderate confidence in TAF. Light rain may be mixed
with wet snow at times into this evening...but no accumulations
or impacts.

BDL TAF...Moderate confidence in TAF.

Outlook /Tuesday Night through Saturday/...

Tuesday Night: VFR. Strong winds with gusts up to 40 kt.

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

Wednesday Night: VFR.

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

Thursday Night through Friday: Mainly MVFR, with local IFR
possible. Chance SHRA.

Friday Night through Saturday: Mainly MVFR, with areas IFR
possible. Breezy. SHRA likely.

&&

.MARINE...

Forecaster Confidence Levels:

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

* Gale Warning all waters Tue afternoon and night

Tonight through Tuesday night...High Confidence.

Areas of light rain, drizzle and fog will be the main story across
the waters tonight. Otherwise...a strong cold front crosses the
region Tue morning bringing WNW wind gusts of 30-40 knots Tue
afternoon and night. Gale Warnings are now in effect for all
waters.

Outlook /Tuesday Night through Saturday/...

Tuesday Night: Low risk for gale force winds with gusts up to
40 kt. Areas of rough seas.

Wednesday: Low risk for Small Craft Advisory winds with gusts
up to 30 kt. Local rough seas.

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

Thursday: Winds less than 25 kt.

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

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

Friday Night: Winds less than 25 kt. Seas up to 5 ft. Rain
showers likely.

Saturday: Winds less than 25 kt. Areas of rough seas. Rain
showers likely.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Wind Advisory from 10 AM to 11 PM EDT Tuesday for MAZ002>016-
     026.
RI...None.
MARINE...Gale Warning from 11 AM Tuesday to 5 AM EDT Wednesday for
     ANZ230>237-250-251-254>256.

&&

$$

SYNOPSIS...Frank/McMinn
NEAR TERM...Frank
SHORT TERM...Frank
LONG TERM...McMinn
AVIATION...Frank/McMinn
MARINE...Frank/McMinn