140
FXUS61 KBOX 120227
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1027 PM EDT Wed Sep 11 2024

.SYNOPSIS...
High pressure will continue to dominate our weather through at
least early next week, maintaining dry weather and above average
temperatures for the foreseeable future.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
1020 PM Update:

High pressure offshore of Provincetown is extending a surface
ridge axis SSW through south-coastal MA, CT and RI; it is here
where the strongest cooling rates have been observed over the
last couple hours, with temps in the low to mid 50s, close to
observed dewpoints. Further north, enough of a light SSW flow is
keeping temps here in the mid 50s to lower 60s at this hour.
Won`t be too much change to the position of the high pressure
area through the remainder of the evening.

The more notable fcst changes were in southeast MA, RI and
eastern CT. Adjusted hourly temps downward using bias-
corrected HRRR datasets which shows the lower temps over
southeast New England the best. This resulted in reducing lows
here as well into the upper 40s to lower 50s, and some areas
were already at or below their forecast lows. Because temps were
already near dewpoint temps in these same southeastern New
England areas, I ended up adding a mention of fog too. MOS
guidance doesn`t really show much signal for this, although the
higher-resolution model guidance does; seeing as there is
already an expanding fog layer east of ACK currently, in light
of the observed temp/dewpoint spreads felt it should be added
in. The extent of the fog is in some question with how dry it
has been of late though.

No other fcst changes needed attm for the remainder of Southern
New England.

Previous discussion:

High pressure just offshore. Light S to SW winds for some, with
calm winds for others. Near normal temperatures expected with
overnight lows dipping into the upper 40s to low 50s. Patchy
fog possible late tonight mainly in portions of the CT River
valley.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
Not much change to the overall pattern. High pressure offshore,
but still nearby. It looks like S/SW winds could keep the
seabreeze from developing along the east coast of MA, but would
be more comfortable with that statement if winds were slightly
stronger. Will need to monitor the potential for a seabreeze
with later forecasts.

Near to slightly above normal temperatures expected.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Highlights:

* High pressure remains in control through early next week,
allowing for continued dry weather.

The dry weather pattern continues well into the extended
forecast as guidance agrees that an upper-level blocking ridge
will keep high pressure parked over the region. With clear
skies during the day, high temps will top out in the low to
mid-80s through the middle of next week. Expecting good
radiational cooling each night with light winds and clear skies.
Blended the NBM and consensus MOS for overnight lows through
Tuesday, bringing temps in the mid to upper 50s.

Looking way ahead to late next week, guidance indicates the
upper level ridge will start to break down, with some weak
shortwave energy moving through. This would be the next best
chance for precip, but uncertainty remains high. Stayed with NBM
for POPs for the middle to end of next week, showing 20-40%
precip chances.

We continue to monitor tropical development in the eastern
Atlantic and near the SE Atlantic coast. NHC shows several areas
of possible tropical development, along with the newly formed
Tropical Depression Seven. With the blocking ridge overhead,
this should steer any tropical activity away from our region.
For more information, please visit www.nhc.noaa.gov.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Forecast Confidence Levels:

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

High confidence.

Tonight: High confidence overall, though is moderate on fog
development.

Mainly VFR; higher moisture levels would favor a better chance
for patchy radiation fog across portions of southeast MA and RI
and into portions of eastern CT after 06z. May need to
introduce mention of BR/FG for the Cape airports and perhaps
into PVD too with later TAFs issuances. Light SE to S winds,
calm at times.

Thursday and Thursday Night: High confidence.

Any fog which developed overnight becomes VFR early Thu morning.
S/SW winds around 5-10 kt; looks like eastern MA seabreeze
stays offshore of KBOS.

KBOS TAF...High confidence in TAF.

KBDL TAF...High confidence in TAF.

Outlook /Thursday Night through Monday/...

VFR.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Thursday Night: High confidence.

High pressure remains over the waters for the next several days.
Light winds with daily sea breezes are expected, and seas 2 ft
or less expected.

Outlook /Thursday Night through Monday/...

Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

SYNOPSIS...Belk/KP
NEAR TERM...Belk/Loconto/KP
SHORT TERM...Belk
LONG TERM...KP
AVIATION...Belk/Loconto/KP
MARINE...Belk/Loconto/KP