637
FXUS61 KBOX 150800
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
300 AM EST Fri Nov 15 2024

.SYNOPSIS...
Dry and somewhat blustery conditions will prevail through the
weekend with temperatures warming to above normal levels. A weak
cold front moves through on Monday which may bring a chance for
scattered light showers followed by dry and seasonable conditions
Tuesday and Wednesday as high pressure builds in from the west.
An approaching frontal system will bring a chance of more
widespread showers Wednesday night into Thursday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SNE will be in between systems as low pres to the south moves off
the NC coast and another low over the north Atlantic retrogrades
into the Maritimes. Subsidence and a wedge of very dry air will be
in place across SNE with PWATs below 0.2" and dewpoints down into
the low and mid teens away from the Cape/Islands. Area of deeper
moisture approaches from the north and east during the afternoon but
will remain to the east today. Lots of cirrus across the region will
linger into the morning which may limit sunshine a bit to start the
day but the high clouds will erode leading to increasing sunshine by
late in the morning and a sunny afternoon. It will be a milder day
as 925 mb temps recover to near 6C this afternoon allowing highs to
reach the mid 50s, with a few locations into the upper 50s. Temps
will be a bit cooler over the higher terrain and Cape Cod. Light
winds to start the day will increase to 10-20 mph from the NW as
pressure gradient increases.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Low pres will remain quasi-stationary over the Maritimes tonight and
Saturday with deeper moisture locked in across Maine which is where
the most cloud cover will be along with the risk of showers. Some of
this moisture tries to spill into eastern MA which will only have
the effect of a few extra clouds, otherwise a mostly clear night
tonight and mostly sunny skies on Saturday. NW winds will increase
on Saturday following the passage of a shortwave within the NW flow
aloft. Gusts to 20-25 mph will develop on Saturday.

Temps: Looks like there will be enough wind tonight to limit
radiational cooling so we stayed away from colder MOS and followed
the NBM with lows tonight mostly in the 30s with some upper 20s
possible in the coldest locations. Further moderation occurs on Sat
with 925 mb 6-7C which should allow highs to reach the upper 50s to
lower 60s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Key Points:

* Warmer temperatures this weekend in mid 50s-low 60s. Cooler next
  week.

* Next chance for showers on Monday, but likely light in
  accumulations (if any).

* Potential for a late work week system to bring rainfall for
  southern New England. Confidence low in the details at this time.

Sunday:

A mid-level ridge pushes in from the west Sunday with the offshore
upper low pushing back east. The pressure gradient relaxes from
Saturday resulting in lighter winds. Highs range in the mid 50s to
near 60.

Monday through mid-week:

After a brief mid-level ridge, the mid/upper level pattern trends
more zonal early next week. A quick moving shortwave trough pushes
through the region Monday with a weak cold front. Moisture and
overall forcing will be fairly limited keeping chances for
widespread substantial rainfall low with this system. A couple light
showers are possible along with increased cloud cover. Breezy NW
flow will also likely accompany the passage of the system.

High pressure builds back in for Tuesday with ridging aloft
promoting dry conditions. Breezy NW winds continue. High range in
the 50s in the afternoon.

Mid-week and beyond:

Ensemble means show indications of a pattern change with an upper
level ridge across the western CONUS and trough moving into the
northeast late week. Deterministic and ensemble guidance continue to
show a broad consensus for a storm system that may bring (hopefully)
our next shot at rainfall sometime in the late Wednesday- Friday
timeframe. As you can already take from the large timeframe given,
confidence in the details is low at this time (timing, track,
strength). This is all a result of differences among individual
model solutions right now. Not uncommon for a storm system this far
out. Overall, ensembles indicate a signal for the system paired with
above normal moisture. This could mean potential for a solid
rainfall if the storm system pans out. Details on timing and amounts
will become more clear as we get closer.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
Forecast Confidence Levels:

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

06z TAF Update...

High confidence through Saturday.

VFR through the period. NW wind around 10 kt with gusts to 20
kt today, NW 5-10 kt tonight, then NW 10-15 kt with gusts to
20-25 kt Sat.

KBOS TAF...High Confidence in TAF.

KBDL TAF...High Confidence in TAF.

Outlook /Saturday Night through Tuesday/...

Saturday Night through Sunday: VFR. Breezy.

Sunday Night: VFR.

Monday through Tuesday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Saturday...High confidence.

Persistent NW flow continues through Saturday with occasional gusts
up to 25 kt, especially across eastern MA waters through tonight.
Mainly 20 kt gusts on Sat. Highest seas up to 8 ft will be east of
Cape Cod today but gradually subsiding. Small Craft Advisories will
continue over the eastern waters and southern outer waters.

Outlook /Saturday Night through Tuesday/...

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 20 kt. Seas up to 5 ft.

Sunday: Winds less than 25 kt. Local rough seas.

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

Monday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain.

Monday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft.

Tuesday: Winds less than 25 kt. Local rough seas.

&&

.FIRE WEATHER...
Red Flag warning remains in effect for today, through 6 pm.

Very dry airmass today with RH values lowering to 15-25 percent,
except 30-40 percent over the outer Cape and Nantucket. NW winds
will increase with occasional gusts to 20 mph developing.

On Saturday, winds will be a bit stronger with gusts 20-30 mph
developing. It will still be quite dry with RH values 20-30 percent
in the afternoon. We will coordinate with our CT, MA and RI
state fire partners, but current indications are that Saturday
may see another round of warnings being issued.

Less breezy on Sunday with dry conditions. Next chance for any
rainfall will be with Monday`s system; however, wetting rain
chances are low. Breezy NW flow will likely accompany the
system.

&&

.TIDES/COASTAL FLOODING...
Pockets of very minor coastal flooding is expected during the high
tide this morning.

This morning...

Astronomical high tides reach 11.8 ft MLLW at Boston this morning.
With an expected surge near or just below 1 ft combined with swell
energy from the NE, expect pockets of very minor coastal flooding,
especially along N to NE facing beaches (Cape Ann, Scituate,
Sandwich to Dennis on Cape Cod and Nantucket Harbor).

Astronomical high tide is 5.9 ft MLLW at Providence. Latest ETSS
guidance indicates a surge slightly above 1 ft along the south coast
which may result in splashover at Providence, Newport, Fall River
and New Bedford.

Saturday morning...

Astronomical tides peak during the morning high tides on Saturday
and reaching near 12 ft MLLW at Boston. Latest surge guidance is a
bit less, averaging 0.5 ft to less than 1 ft which would still be
enough for another round of very minor nuisance coastal flooding at
high tide along N and NE facing beaches.

Astronomical tides Sat morning along the south coast are similar to
this morning. However, surge forecasts are a bit lower so worst case
scenario would be pockets of splashover at high tide if surge values
reach 1 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Red Flag Warning from 7 AM this morning to 6 PM EST this
     evening for CTZ002>004.
MA...Red Flag Warning from 7 AM this morning to 6 PM EST this
     evening for MAZ002>024-026.
RI...Red Flag Warning from 7 AM this morning to 6 PM EST this
     evening for RIZ001>008.
MARINE...Small Craft Advisory until 1 AM EST Saturday for ANZ231-232-
     251-256.
     Small Craft Advisory until 7 PM EST Saturday for ANZ250-254-
     255.

&&

$$

SYNOPSIS...KJC/Mensch
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...Mensch
AVIATION...KJC/Mensch
MARINE...KJC/Mensch
FIRE WEATHER...KJC/Mensch
TIDES/COASTAL FLOODING...KJC