610
FXUS61 KBOX 271726
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1226 PM EST Thu Feb 27 2025

.SYNOPSIS...
A frontal system brings periods of rain today, with snow changing to
rain in northern MA this morning. Dry blustery and cooler conditions
follow behind this system on Friday. A quick moving clipper tracking
to the north will bring another period of snow to northern MA Friday
night, with a few showers and milder temperatures Saturday ahead of
a cold front. Blustery and cold weather follows behind the front for
Sunday and Monday. Milder air returns by the middle of next week
along with another chance of rain.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10AM update...

Mainly all rain across the region, a small pocket of -SN in
northwest Franklin County and perhaps pockets of -FZRA in
northern Worcester County. As temperatures continue to warm
above freezing, opt`d to not extend the SPS. Snowfall reports
have been limited to northern Mass of 1-2 inches of snow.

Forecast on track.

Previous discussion...

Key Messages:

* Minor travel impacts in northern MA for the morning commute
  with snow and pockets of freezing rain changing to rain

* Gusty SW winds developing across portions of RI, SE MA and
  Cape/Islands

Light precip on radar moving into SNE with steadier precip at
the nose of the low level jet approaching from the west. The
steadier precip will move across SNE through daybreak with focus
across northern MA. Ptype will be mostly rain south of the MA
Pike, but soundings support snow or a snow-rain mix to the north
before the column warms with snow transitioning to rain between
6 and 9 am in northern MA. Snow accum will generally be a
coating to an inch north of the MA Pike, but up to 2 inches over
the Berkshires. Still have to watch for the potential for some
freezing rain during the ptype transition. Soundings not
especially supportive for ice with near isothermal profiles as
the column is warning. However, low level cold air will be slow
to erode so there may be pockets of freezing rain for a few
hours over the higher elevations in the Berkshires and northern
Worcester Hills before temps rise above freezing. Just minor
impacts to the morning commute are expected, mainly over higher
elevations. Will issue a SPS to address the minor travel
impacts.

Model guidance is focusing the steady precip across northern MA
this morning into early afternoon within the mid level jet axis
and proximity to the mid level shortwave. Closer to the south
coast, any rain is expected to be spotty with dry periods, then
band of showers ahead of an approaching cold front will move
eastward across SNE this afternoon reaching the Cape/Islands
late today and early evening. There may even be a rumble of
thunder over the Cape/Islands as soundings indicate marginal
instability above the frontal inversion.

Fairly impressive 925 mb jet 60-70 kt develops to the south and
lifts across the Cape/Islands this afternoon. The jet is above
a strong low level inversion so will not mix these winds down to
the surface. General rule of thumb for potential gusts with
strong inversions is to take 50 percent of the low level jet
which translates to 30-40 mph gusts for the Cape/Islands.

Temps: Warm front lifts northward across SNE which will allow
temps to rise into the 50s this afternoon across RI and SE MA
with mid- upper 40s in the interior, but cooler NW MA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
Tonight...

Focus for scattered showers this evening will be across the
Cape/Islands as the front moves through, otherwise excellent
drying moves in behind the front as PWATs drop sharply. Expect
clearing skies overnight, but upslope clouds may spill into the
Berkshires and can`t rule out a few flurries here as mid level
trough axis and cold pool approaches. Lows will be in the low-
mid 30s, with upper 20s over higher elevations.

Friday...

Weak shortwave ridging and subsidence moves into the region behind
the departing mid level trough. Expect lots of sunshine mixed with
developing CU and mid-high clouds will be moving in from the west
late in the day ahead of the next system. It will be somewhat
breezy as well mixed boundary layer supports W-NW gusts to 20-30
mph. Near seasonable temps with highs upper 30s to mid 40s, but
lower 30s Berkshires.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Key Messages:

* Another round of snow changing to rain expected Friday night
  into Saturday
* Cold and blustery conditions settle in behind a cold front
  Saturday night, and continue into early next week
* Above normal temperatures towards mid week
* Another rain storm expected to approach Wednesday


Latest guidance suite continued the trend of rather good
agreement with the overall synoptic picture. Still some timing
and intensity differences, but these appeared to be minor. Still
have above average confidence for this portion of the forecast.

Another low pressure should pass over northern New England
Saturday. Have greater confidence in showers across northern MA
that towards the south coast. Should be mostly a rain event,
with the possibility of some light snowfall towards the end
sometime Saturday afternoon into Saturday night. Not a lot of
moisture to work with here, so any precipitation is expected
to be light.

High pressure then expected to return drier and colder
conditions Sunday into Monday. Still dry but likely warmer
Tuesday.

Anticipating temperatures to not be as much above normal Friday,
before a brief surge of warmth Saturday. A large high pressure
moving southeast from central Canada trends temperatures below
normal Sunday into Monday. Thinking it will be a little warmer
Tuesday as this high pressure moves offshore.

The timing for another low pressure towards mid week is not as
certain. Could see a risk for some rainfall as early as late
Tuesday night. However, it is more likely that heavier rainfall
holds off until later in the day Wednesday.

&&

.AVIATION /18Z THURSDAY THROUGH MONDAY/...
Forecast Confidence Levels:

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

18z TAF update...

Moderate confidence, mainly due to timing of changing
conditions.

Mixture of MVFR and low-end VFR with period of -RA through this
afternoon/early evening ahead of the cold front. Improvement to
VFR from W to E 00-06z, but a few hours later Cape/Islands. VFR
Friday.

Winds are S/SW and increase this afternoon with 25-35 kt gusts
towards the coast. LLWS expected near coast as well with 020
winds S/SW 50-60kt, strongest near Cape Cod. W-NW wind gusts
20-25 kt Fri.

KBOS TAF...High confidence in TAF trends. Lower confidence in
timing and specific details.

KBDL TAF...High confidence in TAF trends. Lower confidence in
timing and specific details.

Outlook /Friday Night through Monday/...

Friday Night: Mainly VFR, with local IFR possible. Breezy.
Chance SN, chance RA.

Saturday: Mainly VFR, with local MVFR possible. Breezy. Chance
RA.

Saturday Night: VFR. Breezy. Slight chance RA, slight chance
SN.

Sunday through Monday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

Today...High confidence.

Increasing S winds today turning SW this afternoon with gusts
25-30 kt developing. A few gale force gusts to 35 kt possible
this afternoon over the waters adjacent to Cape Cod. Seas build
to 7-10 kt over outer waters. Scattered showers with perhaps an
isolated t-storm late today over waters around Cape Cod and
Islands.

Tonight and Friday...High confidence.

Winds shift to W tonight with diminishing speeds below 20 kt, then
ramp up again from the W-NW Fri with gusts 20-30 kt.

Outlook /Friday Night through Monday/...

Friday Night: Winds less than 25 kt. Seas up to 5 ft. Chance of
rain.

Saturday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of rough seas. Chance of rain.

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas. Slight chance of rain.

Sunday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of rough seas. Chance of freezing spray.

Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Chance of freezing spray.

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 PM EST this evening for ANZ230.
     Small Craft Advisory until 10 PM EST this evening for ANZ231-
     236-251.
     Small Craft Advisory until 7 AM EST Friday for ANZ232>235-237-
     250-254>256.

&&

$$

SYNOPSIS...Belk/KJC
NEAR TERM...KJC/Dooley
SHORT TERM...KJC
LONG TERM...Belk
AVIATION...Belk/KJC/Dooley
MARINE...Belk/KJC