055
FXUS61 KBOX 061123
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
723 AM EDT Sun Apr 6 2025

.SYNOPSIS...
A cold front moves south across the region this morning with
scattered showers, then drying this afternoon as the front moves
south of New England. The front stalls south of New England tonight
into Monday as low pressure tracks along it, bringing more rain
mixing with snow late tonight into Monday morning, with minor wet
snow accumulations over the higher elevations. Then a strong cold
front passage late Monday night will be followed by blustery and
chilly conditions Tuesday into Wednesday. Warming up, but turning
cloudy and damp again for Thursday and Friday. Continued wet and
unsettled weather heading into next weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
720 AM update...

Next area of showers moving across interior SNE this morning
and will gradually shift south and east to SE New Eng late
morning and early afternoon before moving offshore. Adjusted
PoPs to reflect current radar trends.

Previous discussion...

Key Messages:

* Scattered showers this morning followed by drying during the
  afternoon. Seasonable temperatures

Cluster of showers with isolated t-storms will be exiting the
Cape/Islands by daybreak, but additional showers upstream are lifting
NE from PA assocd with a mid level shortwave. This shortwave and
deep moisture plume moves across the region which will bring
scattered showers this morning, moving off the SE New Eng coast
early this afternoon. Some drying moves in from the north this
afternoon so expect mainly dry weather this afternoon with perhaps a
few breaks of sun away from the south coast. Seasonable temps in the
50s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Key Messages...

* Rain redeveloping late tonight into Monday, with wet snow
  over the higher elevations with minor accumulations possible.

* Rain mixing with snow to near I-95 corridor early Mon morning
  with no accumulation

The cold front stalls south of New Eng as upper trough is hanging
back to the west. A frontal wave along this boundary will track
south of New Eng late tonight into Mon with another plume of deeper
moisture ahead of trough moving back into New Eng with favorable
right entrance region of the upper jet providing forcing for ascent.
Still some uncertainty with how far north steadier precip shield
gets which will have impact snow accum across higher elevations.
Ensembles show highest probs of greater than 0.10" QPF south of the
Pike with decreasing PoPs to the north, and axis of higher 0.50" QPF
probs are south of New Eng. So this is looking like light QPF event,
likely 0.10-0.25", with lesser in northern MA.

The first half of tonight should be dry with rain developing after
midnight. Low level cold air drains southward tonight and precip
will likely be wet snow as it moves into the Berkshires and
Worcester Hills, with rain possibly mixing with or even changing to
snow for a brief time across rest of interior MA late tonight into
early Mon morning. Rain may even mix with some snow or sleet to the
I-95 corridor around daybreak Mon. Marginal surface temps and lack
of heavy precip will confine accum to higher elevations in
Berkshires and Worcester Hills with a coating to an inch, with low
risk for up to 2 inches in the Berkshires if higher QPF amounts are
realized.

Rain and snow Mon morning will gradually taper off and transition to
rain showers before ending in the afternoon as deeper moisture
moves offshore. Chilly day Monday with highs upper 30s to mid
40s.

&&

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

* A strong Cold front will bring blustery, cold, and dry conditions
  on Tuesday and 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.

Tuesday and Wednesday.

A strong cold front moves through the region overnight Monday into
Tuesday, helping kick out the remaining rain/snow showers.  There
could be some snow showers/squalls as the cold front enters western
MA with a strong pressure rise/fall couplet and good low-level
moisture.  However, good low-level lapse rates are lacking due to
diurnal cooling.  The cold front weakens as it moves through the
region. Thus, the threat of snow squalls/showers will diminish
quickly into central and eastern SNE. Strong CAA will bring daytime
high temps on Tuesday and Wednesday into the low to mid-40s, while
the wind chill factor will make it feel like the 30s.  Overnight
lows Tuesday night will be quite chilly, in the low to mid-20s. WNW
winds and diurnal heating will promote mixing up to, if not above,
the 800 mb level, where winds will be around 40-50mph.  With super
adiabatic lapse rates near the surface, would not be surprised to
see gusts of 40-50mph frequently reach the surface during the day
Tuesday.  Dry and sunny conditions expected both days as high
pressure builds in.

Thursday and Friday.

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.  The best chance for
precip looks to be Thursday night and Friday as better forcing
arrives from the shortwave and a reinforcing warm front.

Saturday and Sunday.

Guidance is in surprisingly good agreement heading into next weekend
as a deep cut-off trough exits the SE US and works north up the
eastern coastline.  This would bring continued wet and unsettled
weather to the region for next week.  However, with this system
being a week out, details remain uncertain as the pattern could
easily change between now and then.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

12z update...

Today...High confidence on trends. Low confidence on timing.

IFR improving to VFR 16-20z, but not until evening for
Nantucket. Scattered showers in the interior this morning
will gradually shift to SE New Eng late morning and early
afternoon before exiting Cape/Islands. NW winds 8-15 kts.

Tonight and Monday...Moderate confidence.

VFR this evening, lowering to MVFR late tonight into Monday,
possibly IFR near the south coast as rain redevelops with snow
higher elevations. Rain mixing with and changing to snow
interior through 12z. Rain-snow-sleet mix possible for BOS and
PVD by 12z. Improving conditions Mon afternoon. Minor snow
accum confined to mainly higher elevations.

BOS TAF...Moderate confidence in TAF.

BDL TAF...Moderate confidence in TAF.

Outlook /Monday Night through Thursday/...

Monday Night: Mainly VFR, with areas IFR possible. Breezy.
Chance SHRA, chance SHSN.

Tuesday: VFR. Strong winds with gusts up to 40 kt. Slight
chance SHRA, slight chance SHSN.

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

Wednesday: VFR. Windy with gusts up to 35 kt.

Wednesday Night: VFR.

Thursday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

* SCA in effect late Sat into Sun night.

Through Sunday night...High confidence.

Rain overspreads the waters this afternoon, along with SE winds
increasing to 15-20 kt. A few gusts to 25 kt are possible from
approximately 20z-04z. Tonight, the warm sector enters the MA/RI
waters, with SE winds becoming SW late as warm front lifts
northward. Sunday, winds shift from SW to WNW with frontal passage.
Rain and fog early, then vsby improving with the wind shift. Sunday
night winds switch to NE and increase toward sunrise. Seas remain 2-
5 ft.

Outlook /Monday Night through Thursday/...

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

Tuesday: Low risk for gale force winds with gusts up to 35 kt.
Seas up to 5 ft. Slight chance of rain showers.

Tuesday Night: Moderate 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 through Thursday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ235.
     Small Craft Advisory until 2 PM EDT this afternoon for ANZ250.
     Small Craft Advisory until 8 PM EDT Monday for ANZ254>256.

&&

$$

SYNOPSIS...KJC/KP
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...KP
AVIATION...KJC/KP
MARINE...KJC/KP