816
FXUS61 KBOX 060118
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
918 PM EDT Sat Oct 5 2024

.SYNOPSIS...
A cold front moves through Southern New England late Sunday
night into Monday, bringing a period of rain showers. This cold
front will usher in a cooler, fall-like weather pattern for the
rest of the work week.

&&

.NEAR TERM /THROUGH SUNDAY/...

930 PM Update...

Radiational cooling has sprung into action after sunset with
temperatures falling into the upper 40s and low 50s at our
typically radiative sites. Urban heat islands, like Boston and
Hartford, were grasping the the last 60s of the evening at the
top of the hour ob, but expecting they too will fall below that
mark in the next hour or so. With dewpoints in the upper 30s to
low 40s across the interior, temps have a ways to fall under
clear skies tonight.

Previous Update...
Daytime cu is expected to linger before clearing out tonight.
Radiational cooling with dew points reaching the lower 40s will help
bring lows down to the 40s, particularly towards the interior. Lows
along the coast and within the urban heat islands of Providence
and Boston could reach the lower 50s, but not below that just
yet.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...

Weak high pressure provides relatively tranquil weather to
start Sunday, which then continues into first part of Sunday
night.

Then looking at the combination of a cold front and a mid level
shortwave to provide our next chance for showers late Sunday night
into Monday. This front should still be lingering near the east
coast of MA by Monday evening, so thinking unsettled conditions will
be more the rule Monday. Moisture is quite a bit deeper than the
past few systems that have come trough southern New England. This
should be a greater chance for rainfall than we have had in a while.

There is a low risk for isolated thunderstorms late Sunday Night
into Monday. Not the best environment expected, with meager mid level
and poor low level lapse rates. Will need to monitor this potential
with later forecasts, but severe weather is not anticipated.

Near to slightly below normal temperatures expected during this
portion of the forecast.

&&

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

* Dry and cooler weather is expected for much of next week.

* Cold overnights may lead to areas of frost, mainly across northern
  Massachusetts Tuesday night. With frost possibly more widespread
  on Wednesday.

There are no significant changes to the extended section of the
forecast. The coming week features dry and noticeably lower
temperatures. The only active weather is Monday night through
predawn Tuesday with the passage of a cold front, during this time
scattered showers are still possible across Rhode Island and eastern
Massachusetts. Given this is 48 to 60 hours out, timing could sway
by a few hours.

Behind the departing front, surface high builds to the northwest of
southern New England on Tuesday though Friday. This provides quiet
weather conditions for the rest of the work week. Aloft, there is an
anomolous mid-level low pressure system sitting to our north and
ushers cooler airmass through northwest flow into southern New
England. True taste of fall with daily highs Tuesday through Friday
between the upper 50s and lower 60s, as for nighttime lows, 30s and
lower 40s Tuesday night through Thursday night. Did adjust minimum
temperatures by blending in the cooler 25th percentile of the NMB on
those nights because of the potential for effective radiation
cooling, clear sky and light winds. These conditions could lead to
the first frost of the season for some areas in northern
Massachusetts.

It is worth noting, average first frost for northern Massachusetts
is around the 1st of October, since we are past is date, there would
be no headlines issued. Though, areas outside of the east slopes of
the Berkshires and northern Worcester Hills, our frost and freeze
program remains active through the 11th of October. Potentially
could have lows the morning of October 10th around the mid-30s.
Either way, if you have fall mums sitting outside, be mindful
of the cooler weather that is upon us this week.

As previously mentioned, expect a mainly dry week ahead. While there
will be shortwave energy pivoting around the mid-level low to our
north, PWATs are VERY low, mainly below 0.5", but at times less than
0.25". Given lack of sensible moisture, not expecting any rainfall.

As for an early look at the upcoming holiday weekend, Saturday is
dry with seasonable high temperatures in the upper 60s to 70F. The
second-half of the weekend there remains uncertainty amongst model
guidance, but as that is more than 7 days out, there is still time
for things to change.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Forecast Confidence Levels:

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

Tonight...High Confidence.

VFR for most, with MVFR at Nantucket, along with some very
localized ground fog possible late. North winds 5 to 8 knots.

Sunday...High Confidence.

VFR. Winds shift from the N/NE to the SE first across the interior
around 17Z, and eventually across coastal terminals by 22z; except
outer Cape terminals. Some MVFR possible for the outer Cape with
lingering onshore flow during the afternoon.

Sunday Night...High Confidence in trends. Moderate confidence in
timing.

VFR, trending to MVFR late across the higher terrain. Scattered
SHRA, with a low risk for TSRA late.

Monday...Moderate Confidence.

VFR, with areas MVFR in scattered -SHRA. Low risk for TSRA.

KBOS TAF...High confidence in TAF.

VFR. Light winds this evening, becoming north after 03z/04z. A
sea-breeze 8-11 knots develops around 15z from the NE, then E
by 18z/20z. The sea-breeze moves out as wind becomes S less than
5 knots.

KBDL TAF... High Confidence in TAF.

VFR. Outlook /Monday Night through Thursday/...

Tuesday Night through Wednesday: VFR.

Wednesday Night through Thursday Night: VFR. Breezy.

Friday: Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

Saturday...High Confidence

Scattered showers possible early Saturday morning into Saturday
mid-day, though showers may linger across the eastern outer
waters into Saturday evening. Winds shift behind passing front
to the NW Saturday morning; winds less than 25 kts. Waves 2-4
ft.

Saturday Night...High Confidence

Winds 10-20 kts with higher winds confined to the outer waters.
Seas grow to 5-6ft overnight tonight, prompting the issuance of
a SCA from 06Z and beyond.

Sunday... High Confidence

Winds less than 25kt but seas across the outer waters continue
to range from 4-6ft. SCA continues for the outer waters through
the day Sunday, and beyond.

Outlook /Monday Night through Thursday/...

Tuesday Night: Winds less than 25 kt. Areas of seas approaching
5 ft.

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

Thursday through Thursday Night: Winds less than 25 kt. Areas
of seas approaching 5 ft.

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 2 AM Sunday to 8 AM EDT Tuesday for
     ANZ250-254-255.
     Small Craft Advisory from 4 AM Monday to 8 AM EDT Tuesday for
     ANZ256.

&&

$$

SYNOPSIS...Belk/Dooley/Hrencecin
NEAR TERM...Hrencecin/KS
SHORT TERM...Belk
LONG TERM...Dooley
AVIATION...Belk/Dooley/Hrencecin
MARINE...Belk/Dooley/Hrencecin