Barnstable Town, Massachusetts 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

059
FXUS61 KBOX 241106
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
606 AM EST Sun Nov 24 2024

.SYNOPSIS...
Mostly sunny and dry weather are expected today, although with
continued gusty northwest winds. High pressure builds into the
region Monday with dry and seasonable conditions along with
diminishing winds. A frontal system passing to our northwest on
Tuesday brings another round of rain, then blustery, cooler and
dry weather returns Tuesday night and Wednesday. Monitoring
another storm system that could impact southern New England
Thanksgiving into Friday with rain and wintry precipitation
possible. Blustery and colder next Saturday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4AM Update

Key Messages for Sunday

* Sunny on Sunday but with cool/blustery conditions and another
  round of gusty northwest winds

Today

Deep northwest flow continues to advect a drier air mass over
southern New England this afternoon. As a result we can expect a
mostly sunny day today. 925 hPa temps around 0C will support near-
normal surface temps in the upper 40s/low 50s today. However, with
CAA aloft and efficient boundary layer mixing, we expect blustery
conditions today with more northwest wind gusts of 30 to 40 mph
through at least early afternoon. Gusts will gradually diminish into
the mid-afternoon/evening hours as the atmosphere decouples after
sunset.

&&

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

* Gusty northwest winds gradually diminish tonight into tomorrow

* Clear skies with seasonable temperatures tonight and tomorrow


Tonight and Tomorrow

Generally looking at a quiet end to the weekend/start to the week.
Deep northwest flow persists over southern New England a moderately
strong 30 to 40 knot low-level jet aloft. However, model soundings
suggesting that most of the forecast area will decouple overnight
which will prevent any significant wind gusts mixing to the surface.
Areas closer to the ocean may experience a few stronger gusts with
milder temperatures near the ocean supporting steeper low-level
lapse rates. Still would only expect modest wind gusts over night in
these locations from 20 to 30 mph. Despite the clear skies,
sustained winds should be strong enough to prevent efficient
radiational cooling, thus overnight lows will be close to normal for
this time of year in the low to mid 30s.

Monday will feature clear skies and calm weather as a mid-level
ridge axis builds in from the west. This will support a weakening
pressure gradient that will allow steady northwest winds to
gradually diminish throughout the day. High temps near normal in the
upper 40s to low 50s.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Highlights:

* Another round of beneficial rains with a frontal system moving
  through on Tue.

* Cooler and blustery but dry weather for the Wed holiday
  travel day.

* Monitoring a potential storm that may impact Southern New
  England on Thanksgiving Day and/or into Fri, including the
  potential for some wintry weather. Confidence in the details
  is still low. Stay tuned!

* Drying out for the weekend, but blustery with below normal
  temperatures.

Details:

Monday Night into Tuesday:

Increasing clouds Mon night as a strong shortwave disturbance in
midlevels along with a related sfc low tracks through the St.
Lawrence Valley on Tue. Should see lows early lows in the mid 30s
before beginning to rise some for the 2nd half of the overnight.
Rather mild and moist warm-sector airmass advects into the region
bringing PWATs to around 1" on SWly 35-40 kt low-level jet.
Increasing dynamics will act on this moisture plume with steady
light rains breaking out in western MA/CT by the pre-dawn hrs, then
advancing east across the remainder of SNE during the day. Precip
still looks to come to an end during the early evening. Despite
otherwise favorable dynamics and PWATs around an inch, the
progressive, quick-moving nature of the system should keep QPF amts
in the quarter to half-inch range, which has support through most
global model ensemble QPF probs. Highs mainly in the 50s, mildest
along the south coast where upper 50s are possible, and around the
mid 40s/near 50 for the terrain. Turns colder with increasing WNW
breezes around 10-15 mph for the evening. Lows in the upper 20s to
mid 30s, though the breezes will make it feel like the lower 20s!

Wednesday:

Don`t see any weather-related impediments to holiday travel on
Wednesday. Blustery conditions for Wednesday, although we are
still expecting dry weather. NW winds 10-15 mph with gusts 20-25
mph. Mostly sunny conditions should help take the edge off the
colder airmass, with highs in the 40s, with upper 30s in the
higher terrain. Decreasing winds Wed night should lead to a
pretty chilly night, with lows in the 20s for most, though the
Greater Boston area and the Cape/Islands should stay around
freezing.

Thanksgiving Day into Friday:

Global ensembles are at least coming around to the idea of a
storm system coming out of the mid-MS Valley region into the
Northeast Thurs and/or into a part of Fri. Background conditions
seem to favor the potential for a complex interaction between
southern-branch trough energy coming out of the Rockies with
northern-stream trough energy digging southward from the
Canadian Prairies into the upper Midwest. However there still
remains quite a bit of uncertainty on the exact storm track, and
as is the case, the track of these storms heavily dictates
impacts. A very loose number of ensemble member lows seem to be
becoming clustered near or just inside of 40W/70W, there are
still several other members which depict a stronger cyclone
which would track through the interior, while still others are
offshore which would favor Southern New England seeing mostly
snow in the low pressure area`s cold-conveyor-belt region but
with less QPF.

Potential exists for portions of Southern New England to see
its first appreciable snowfall sometime on Thanksgiving Day
and/or into Friday; although the current (early) thinking is
that the best potential for some snow is in interior Southern
New England, with coastal areas less favored. Some caveats to
keep in mind is that water temps over our coastal waters are
still in the 50s coming out of the summer and fall months, and
with early-season coastal storms, advection of that marine layer
will greatly shape the duration of rain vs snow in the coastal
plain. Thermal profiles also look pretty marginal, and assuming
we get a storm track supportive of some snow, it may be of the
wet/dense type leading to snow to liquid ratios that may be
quite a bit lower than 10:1. But a still-uncertain track and
timing limits predictability beyond that. Because it is a
complex interaction involving multiple streams of energy, expect
there to be additional changes in the model-forecast guidance.
Something we`ll be continuing to monitor, so keep abreast with
the latest forecasts/changes as we move through the next few
days.

Saturday:

We`ll be on the western side of the storm for Sat, which will usher
in a blustery and cold airmass. While we are expecting dry weather
for Sat, below normal temperatures are likely.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
Forecast Confidence Levels:

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

12Z TAF Update:


Today: High confidence.

VFR, with a few stratocu clouds around the higher terrain. NW
wind gusts experience a second increase to 30-35 kt thru the
morning hours, then with decreasing gust speeds to around 20-25
kt thru the afternoon.

Tonight: High confidence.

VFR. NW winds around 10 kt to gradually decrease to under 10
kt.

Monday: High confidence.

VFR; could see mid to high clouds arrive late Mon aftn in
western New England. WNW winds around 5-10 kt shift to SW and
decrease thru the day.

KBOS Terminal...High confidence in TAF. VFR. Gusty NW winds increase
to up to 35 kt during the morning hrs, then gust speeds
steadily decrease. NW winds around 10-14 kt Sunday night to ease
to under 10 kt overnight.

KBDL Terminal...High confidence in TAF. VFR, NW gusts 25-30 kt
thru sunrise, then could increase for a few hrs this morning to
near 35 kt, before decreasing steadily thru the afternoon. NW
winds around 10 kt early tonight decrease to 5 kt by early Mon
AM.

Outlook /Monday Night through Thursday/...

Monday Night: VFR. Chance RA.

Tuesday: Mainly MVFR, with local IFR possible. Breezy. RA.

Tuesday Night: VFR. Breezy. Chance RA.

Wednesday through Wednesday Night: VFR. Breezy.

Thanksgiving Day: Mainly VFR, with local IFR possible. Breezy.
Chance RA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Today through Monday

Gale force wind gusts persist through early afternoon today with
significant wave heights over the outer marine zones continuing to
range from 5 to 10 feet. Gale force wind gusts come down overnight,
but still remain at SCY levels between 25 and 30 knots. Seas come
down as well with highest wave heights between 5 and 7 feet over the
outer marine zones. Conditions improve substantially on Monday with
high pressure building in from the west supporting diminishing
west/northwest winds. Wave heights over the outer marine zones may
continue to reach SCY criteria greater than 4 feet.

Outlook /Monday Night through Thursday/...

Monday Night: Winds less than 25 kt. Chance of rain.

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

Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Local rough seas. Chance of rain.

Wednesday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft.

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

Thanksgiving Day: Winds less than 25 kt. Chance of rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 PM EST this evening for ANZ230-
     236.
     Gale Warning until 1 PM EST this afternoon for ANZ231>235-237-
     250-251-254>256.

&&

$$

SYNOPSIS...Loconto/RM
NEAR TERM...KJC/RM
SHORT TERM...RM
LONG TERM...Loconto
AVIATION...Loconto/RM
MARINE...Loconto/RM