969
FXUS61 KBOX 111129
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
729 AM EDT Fri Apr 11 2025
.SYNOPSIS...
Light rain and interior rain and wet snow ongoing early this
morning will move northeast during the morning. Considerable
cloudiness and increasing northeast winds are expected for the
afternoon. Then low pressure over the coastal mid-Atlantic
brings a soaking, wind-swept rain and raw conditions to lower
elevations in Southern New England, with a wintry mix of wet
snow and rain in interior higher terrain areas. Minor, slushy
accumulations are possible. Additional rains are possible in
eastern New England on Sunday. Milder temperatures are on top
for the first half of next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
400 AM Update:
Key Messages:
* Light precip (interior rain/wet snow mix, lower-elevation
rain) comes to an end by mid morning from SW to NE. Slushy
accumulation on grassy non-paved surfaces possible in
CT/northern MA, but no impacts to transportation.
* Trends toward partly to mostly cloudy by afternoon. Temps in the
mid 40s to near 50.
Details:
A generally light rain or interior rain/wet snow mix event is
underway across most of Southern New England. Temps around 32-34F in
much of northern CT and northern/western MA has allowed for precip
types of wet snow mixed with rain. Webcams and pavement temps at BDL
around the upper 30s suggest wet snow probably is not sticking to
asphalt surfaces, thus likely not leading to adverse impacts, but is
producing visbys in the 1-3 SM range. Temps are just warm enough for
most of the MA/RI coastal plain such that light rain is the dominant
precip-type. This precipitation is expected to lift off toward the
northeast into NH/southern VT, with the back edge of the
precipitation now into the Catskills of NY. Some difficult travel
thru low visbys are possible into the morning commute for areas
north and west of I-95, but slippery travel isn`t expected.
Most of Southern New England to then trend dry by mid-morning,
although we`ll be lift with a still considerable amt of cloudiness
as a surface ridge over coastal ME/NH builds back southward. There
is some optimism that at least eastern MA and perhaps RI break out
into the afternoon to more of a mostly to partly cloudy look per
latest HRRR and RAP solutions, partly from some drier air that
filters in. However interior areas may struggle to shake free of the
overcast. So by afternoon, sky conditions should trend to more
variable cloudiness...with quite a bit more overcast for
central/western MA and much of northern CT, and a mix of clouds with
peeks of sun for eastern MA, RI and the Cape/Islands. Given the
above sky cover expectations, along with increasing northeast winds
keeping coastal areas with a cooler onshore flow, it makes for a
very complex/challenging high temperature forecast. Opted for highs
in the 40s generally areawide, but with lower 40s near the eastern
coast and the interior terrain, and mid/upper 40s to near 50 for
remaining parts of northern CT and RI. If overcast lasts as long as
it looks like it might in interior Southern New England where temps
currently are in the mid 30s, temps here could be too warm, perhaps
by several degrees. Could see downward adjustments later for those
interior locales, pending sky cover trends.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
400 AM Update:
Key Messages:
* Steady precipitation breaks out overnight tonight, continuing into
much of Saturday. Although rain will predominate and be wind-swept
in eastern MA and much of RI, a wintry mess of wet snow/rain
(mixed with sleet at times) is looking more likely for interior
Southern New England.
* Minor accumulation of snow and sleet possible in high terrain (1-
3"/near 4"). Possible need for Advisories given longer duration of
wintry precip for the terrain, but impacts probably limited.
* Raw, cloudy weather Sat with temps in the mid 30s to low 40s.
Details:
Tonight through Saturday:
As has been advertised previously, this is a raw, dreary forecast
period. An organizing low pressure over the northern mid-Atlantic
moves northward for overnight tonight, which sends a slug of
steadier precipitation northward into Southern New England and lasts
right through Saturday. Although eastern/coastal areas of Southern
New England still stand to stay as entirely rain through Saturday,
one of the more significant changes over the last 24 hours is that
the precip is moving into a somewhat drier airmass favorable for
evaporative cooling in interior Southern New England. That now lends
itself to more wintry precipitation types given a borderline thermal
profile across interior Southern New England and the higher terrain.
Forecast accumulations in the terrain agree well with WPC`s Winter
Weather Desk (around 1-3", with up to 4" in the hills in northern
Worcester County/Berkshires, and slushy coatings for lower
elevations), and could support Winter Weather Advisories in later
updates. But it`s also now mid-April, where pavement is milder and
with impacts being limited, it could be more difficult to justify
one. After coordination with surrounding WFOs and WPC, we opted to
hold on Winter Weather Advisories with this package for now, to
allow for later shifts to assess the colder trend in guidance
for another forecast guidance cycle.
Mostly cloudy conditions are expected to begin tonight, with
increasing northeast winds. Latest guidance now shows the leading
edge of precipitation moving into our southern coastal areas toward
midnight, then expanding northward during the overnight. Temps
around 30-34 in interior Southern New England (roughly to I-95)
would favor a mix of wet snow and rain for these locations. It is
possible that sleet pellets could mix in at times given layer of
shallow cold air. Further east and south, temperatures should be
mild enough for rain, but the rain will be wind driven with NE winds
around 10-15 mph. Saturday will continue to see this slug of
precipitation lift northward, with total QPF ranging from a half to
an inch/inch and a quarter. With abundant cloud cover and
precipitation most of Saturday, temperatures could be very slow to
rise if they do at all. Showed highs on Saturday mainly in the mid
30s to low 40s, climbing only a couple degrees from forecast lows.
Thus, the wintry precip in interior Southern New England could
linger for quite a while into Saturday, but impacts should be
limited.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Key Messages:
* Rain lingers over the eastern Massachusetts coast Sunday
* Brief warmup at the start of the week before cooler air returns,
along with the chance for rain
* Drier and cooler to start the back half of the week
Details...
A brief break in rainfall is expected for Saturday night. A second
low passes just to the south of southern New England but is expected
to bring more rain to eastern MA and the Cape and Islands, along
with parts of RI Sunday. This event is expected to have lower
accumulations than Saturday`s event; ensemble mean PWATs sit around
0.6-0.65" for much of eastern MA and RI. Spots on the Cape and
Nantucket with PWATs around 0.75" and 0.8" and could see slightly
higher accumulations, but the possible accumulations right now are
around a tenth of an inch for most and up to 0.25-0.30" on the far
eastern parts of the Cape. The ECMWF ensemble means are running a
little higher on 24 hour QPF, but the rain should be quite light, so
the chances for anything more than a quarter of an inch are low.
With the rain during the day and temperatures expected to be well
above freezing, precip should remain liquid.
The trough fueling this weekend`s unsettled pattern should move
offshore by the start of next week. Ridging and high pressure build
back in Monday ahead of another trough sitting over the Great Lakes
that will bring in another frontal system. Rain chances return going
into Tuesday as the warm front arrives, ushering a warmer airmass
with 925 mb temperatures up to and around +10C. Highs Tuesday will
likely be in the 60s across southern New England as a result.
Showers across the region will be possible with persistent cloud
cover before beginning to clear out going into the overnight hours
as a cold front follows the warm front earlier in the day. 925 mb
temperatures return to values near or below 0C with 850 mb
temperatures close to -10C, so cooler nights are expected Tuesday
and Wednesday. Highs Wednesday will also sink a bit into the 40s and
50s. This colder airmass will sit over the region before starting to
shift out of the area Thursday with the trough`s exit to the
northeast.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
12z TAF Update:
Today: Moderate confidence.
Widespread MVFR bases (perhaps lingering IFR for BAF/BDL/ORH
early) should continue into the morning. It looks ceilings may
improve to VFR/MVFR borderline for eastern airports around
15-17z or even earlier, with better chance at MVFR ceilings
lingering most of the day west of ORH. Some VFR possible out in
western terminals late morning/early afternoon. SE/E winds 4-8
kt continue to back to NE by late- AM/noontime, while increasing
in speed to around 10 kt. Stronger aftn NElys for the Cape and
Islands, around 10-15 kt gusts 20-25 kt.
Tonight through Saturday: Moderate confidence.
Through about 04z Sat, VFR for most, with VFR/borderline MVFR
ceilings for the interior. Conditions to deteriorate from south
to north after 04z-08z Sat, with categories going down to
widespread MVFR- IFR levels as steady precipitation moves
northward from the mid- Atlc/southern waters. There is high
confidence in sub-VFR conditions once precip begins, but
greater uncertainty in precip types. Potential for a wintry mix
of wet snow/rain mixed at times with sleet for airports north
and west of Interstate 95. Wintry p-types could linger well
into Sat with terrain airports having best chance at minor
slushy accums but runways probably should be wet. Stronger
confidence that BOS, PVD and Cape airports stay as a plain,
wind- driven rain at onset and continue into Sat.
NE winds continue to increase to around 10-15 kt tonight into
Sat, with gusts 20-24 kt for most, though around 30 kt for the
Cape and Islands.
KBOS TAF...Moderate confidence. Brief VFR deteriorates to MVFR
bases in light rain 07-12z Fri with winds shifting to SE/E.
Rain ends around 12z-13z with slow rise in bases to BKN VFR
levels around noontime (TEMPO 16-18z for residual MVFR cigs) as
winds become NE 4-8 kt. Should be VFR by Fri aftn but NE winds
increase to around 10-13 kt.
KBDL TAF...Moderate confidence. IFR in -SNRA thru around 09z Fri,
then precip should begin to taper off to the northeast. IFR
ceilings to trend to MVFR. Improvement to BKN VFR ceilings
possible but not as likely as further east. Light winds to trend
NE this morning, increasing in speed to around 5-10 kt this
aftn.
Outlook /Saturday Night through Tuesday/...
Saturday Night: MVFR/IFR conditions possible. Windy with local
gusts up to 30 kt. Chance SHRA.
Sunday: Mainly VFR, with areas IFR possible. Breezy. Chance
SHRA.
Sunday Night: Mainly VFR, with local MVFR possible. Breezy.
Slight chance SHRA.
Monday: VFR.
Monday Night: Mainly VFR, with local IFR possible. Chance SHRA.
Tuesday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Conditions today are sub-SCA with increasing northeast winds
and seas around 2-4 ft. However a slow moving low pressure
moving northward will bring an enhanced NE fetch to Southern New
England tonight into Saturday. This will allow for
building/rough seas up to 10 ft and northeast winds of 30-35
kt, along with periods of windswept rain. Strongest winds are
expected over the southern waters tonight into Saturday, then
increasing more into Saturday for the eastern waters.
Gale Warnings are now posted effect for most of the southern
waters, which take effect late this afternoon and continue into
much of Saturday. As gale force gusts subside, these will need
to be shifted to small craft advisories, which probably will run
through much of the weekend as seas will very slowly subside.
Small Craft Advisories have been hoisted for most of the eastern
waters, with NE winds 25-30 kt developing on Saturday. Although
these gusts will be easing into Sunday, locally rough seas will
linger into early on Monday, and SCAs have been extended into
Monday morning.
Outlook /Saturday Night through Tuesday/...
Saturday Night: Low risk for Small Craft Advisory winds with
local gusts up to 30 kt. Rough seas up to 8 ft. Rain showers
likely.
Sunday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Rough seas up to 8 ft. Chance of rain showers.
Sunday Night: Winds less than 25 kt. Local rough seas. Slight
chance of rain showers.
Monday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Monday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers.
Tuesday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 5 AM Saturday to 2 AM EDT Sunday for
ANZ230.
Small Craft Advisory from 5 AM Saturday to 2 AM EDT Monday for
ANZ231-251.
Gale Warning from 8 PM this evening to 4 PM EDT Saturday for
ANZ232>235-237.
Small Craft Advisory from 9 PM this evening to 4 PM EDT
Saturday for ANZ236.
Small Craft Advisory from 5 AM Saturday to 8 AM EDT Monday for
ANZ250.
Gale Warning from 6 PM this evening to 4 PM EDT Saturday for
ANZ254>256.
&&
$$
SYNOPSIS...Loconto/Hrencecin
NEAR TERM...Loconto
SHORT TERM...Loconto
LONG TERM...Hrencecin
AVIATION...Loconto/Hrencecin
MARINE...Loconto/Hrencecin