Shrewsbury, Massachusetts 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

765
FXUS61 KBOX 111711
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
111 PM EDT Fri Apr 11 2025

.SYNOPSIS...

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/...

Key Messages...

* Rather cloudy with a few peeks of sunshine at times
* Highs mainly in the 40s to around 50

Details...

The shortwave that brought the earlier rain and wet snow to the
region has departed. High pressure over eastern Canada will
maintain dry weather through the afternoon. However...easterly
flow and lingering low level moisture will keep skies rather
cloudy but we may see a few peeks of sunshine at times.
Otherwise...mostly cloudy and a rather cool day with highs in
the 40s to around 50 with the mildest temps likely in the lower
CT River Valley. Coolest temps will be found along the eastern
MA coast and high terrain.

&&

.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 /18Z FRIDAY THROUGH TUESDAY/...

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

18z TAF Update...

This afternoon...High Confidence.

Lingering MVFR ceilings mainly northwest of I-95 will trend
towards VFR given diurnal heating...but skies will remain mostly
cloudy. ENE winds 5-10 knots.

Tonight into Saturday...High Confidence.

VFR dominates this evening...but lower end MVFR-IFR redevelop
after midnight and persist into Saturday with some localized
LIFR conditions. This a result of the next round of
precipitation overspreading the region from south to north.
Ptype will generally be rain southeast of I-95...but expect some
wet snow and sleet into Sat morning northwest of I-95. Runways
in the lower elevations should generally remain wet...but above
1000 feet they may become snow covered for a few hours Sat
morning. Precipitation tapers off and changes to mainly to
light rain/drizzle Sat afternoon. NE winds will gust to between
20 and 30 knots along the coast and around 35 knots or so for a
time across Nantucket.

Saturday night...High Confidence.

Low end MVFR-IFR conditions with localized LIFR conditions continue
in areas of rain/drizzle and fog with the focus for that across
the coastal plain. NNE winds 5-15 knots.

KBOS TAF...High Confidence. Some wet snow/sleet may be mixed
with the rain in the 10z to 16z time frame...but runways will
remain wet.

KBDL TAF...High Confidence. A period of wet snow/sleet in the 8z
to 14z time frame...but runways should remain generally wet.

Outlook /Sunday through Tuesday/...

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...Frank
SHORT TERM...Loconto
LONG TERM...Hrencecin
AVIATION...Frank/Hrencecin
MARINE...Loconto/Hrencecin