931
FXUS61 KBOX 301923
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
323 PM EDT Thu May 30 2024

.SYNOPSIS...
High pressure builds across Great Lakes through Friday night
bringing dry conditions with seasonable daytime temperatures
but chilly nights. Dry weather with a warming trend this
weekend, although a few showers are possible Sunday afternoon
and evening in the west. Mainly dry and warm weather is
expected through mid to late next week as high pressure is in
control.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Last of the comma head showers impacting portions of eastern MA
will end during the next hour or 2. Partial clearing has
developed across central/W MA and northern CT and this will push
eastward across rest of SNE through late afternoon as drier air
moves in from the west. However, low risk for a pop-up shower
later this afternoon/evening as upper level trough approaches
from the west. This trough will be moving across SNE tonight but
drying in the column will result in clearing skies and a chilly
night for late May as winds become light. Lows will be mostly
in the 40s. Some patchy radiation fog is possible in the typical
prone locations.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Friday...

Mid level trough axis east of New Eng moves offshore as
amplified ridge builds across the Gt Lakes. Large scale
subsidence will result in a dry day, but do expect some cloud
cover as area of mid level moisture moves southward across SNE.
Generally partly to mostly sunny skies expected. Seasonable
temps with highs mostly in the mid 70s, but developing sea-
breezes will keep the immediate coast a bit cooler. It will also
be quite dry as deep BL mixing results in dewpoints dropping
into the upper 30s to lower 40s.

Friday night...

High pres builds to the west with mainly clear skies and light N
winds. Another night of decent radiational cooling with lows
dropping into the mid-upper 40s in the colder locations in western
MA, NE CT and interior E MA, with 50s elsewhere.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Key Points...

* Temperatures will be increasing steadily each day through
  early next week into the 80s.

* An extended stretch of mostly dry weather is expected through
  Wednesday but there is a chance for some scattered showers late
  Sunday then isolated showers each afternoon thereafter.

Details...

Quiet weather continues for the weekend and well into next week
thanks to a broad ridge of high pressure in the mid levels and high
pressure at the surface. This means mostly dry and sunny/partly
sunny conditions for the weekend and even through the middle of next
week. The one period to watch for the potential of some unsettled
weather would be later Sunday into Monday as global guidance shows a
weak shortwave dampening the ridge; however, some of the guidance
shows this being suppressed too far south to impact SNE so
confidence is low at this time that we`ll see any wet weather.
Ensemble guidance places the odds of measurable rainfall during this
period at 40-60% for western MA/CT and less further east. Either
way, not expecting a washout. As for Monday through Wednesday, each
day will feature the chance for a few diurnally driven showers in
the afternoon, especially away from the coasts but most should stay
dry.

Temperature-wise we`ll kick off the weekend seasonable to slightly
above seasonable for the start of June, with highs in the 70s to low
80s (CT valley). As the ridge builds in the airmass will continue to
warm each day into Monday when highs will reach into the mid 80s
inland and low to mid 70s along the coasts. This will continue to be
the case through mid week before our next shortwave approaches
bringing the chance for cooler temps and wet weather toward the end
of next week.

&&

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

* Seasonably warm and dry on Saturday and Sunday

* Low chance for some afternoon showers across western MA/CT Sunday
  afternoon

* High pressure supports warm/dry weather through mid to late next
  week

Through Next Thursday

Northwest flow east of an upper-ridge axis will supports a
dry/sunny day on Saturday with highs in the upper 70s to low
80s. On Sunday, a plume of moisture advects in from the west
ahead of a subtle short- wave disturbance aloft. Latest model
guidance suggests that the aforementioned ridge axis which will
be centered over southern New England on Sunday will steer this
feature to the south and east. This will prevent any widespread
precipitation as this energy traverses through the region, but
there will be a chance for some showers across western MA/CT on
Sunday afternoon as this disturbance moves overhead. By the
beginning of next week a broad upper ridge aloft and associated
surface high pressure will support warm/dry conditions through
late week. Rain chances return sometime Thursday or Friday as
high pressure shifts east allowing for south/southwest flow to
advect moisture into the Northeast. Throughout the extended
daily highs/low will generally be in the upper 70s/low 80s and
upper 50s/low 70s respectively.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
Forecast Confidence Levels:

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

Through 00z...

Areas of MVFR cigs with IFR Cape/Islands will gradually improve
to VFR through the afternoon. Showers across NE MA will end by
20z. N wind gusts to 20-25 kt over Cape/Islands.

Tonight... High confidence.

Areas of MVFR outer Cape/Islands early, otherwise VFR. Light N
winds.

Friday and Friday night... High confidence.

VFR. NW 5-10 kt Fri but sea-breezes developing along the
immediate coast. Light wind Fri night.

KBOS TAF... High confidence. Brief MVFR cigs until 19-20z,
otherwise VFR. Sea-breeze develops around 15z Fri.

KBDL TAF... High confidence.

Outlook /Saturday through Tuesday/...

Saturday through Saturday Night: VFR.

Sunday through Sunday Night: VFR. Slight chance SHRA.

Monday through Tuesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels:

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

Tonight...

N wind gusts to 25 kt will be common across waters adjacent and
SE of Cape Cod from a modest low level jet. SCA will continue
into the evening before winds diminish overnight.

Friday and Friday night...

Light N winds will become S-SW during the afternoon as a weak
surface trough develops to the west, then winds turn northerly
overnight Fri night as the trough moves to the east.

Outlook /Saturday through Tuesday/...

Saturday through Sunday: Winds less than 25 kt.

Sunday Night: Winds less than 25 kt. Slight chance of rain
showers.

Monday through Tuesday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ231-
     232-254-255.
     Small Craft Advisory until 8 PM EDT this evening for ANZ250.
     Small Craft Advisory until 4 PM EDT this afternoon for ANZ251.

&&

$$

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