-- Discussion containing changed information from previous version are highlighted. --
446
FXUS61 KBOX 150536
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
136 AM EDT Sat Jun 15 2024

.SYNOPSIS...
Second round of strong to severe thunderstorms expected through
early tonight ahead of a dry and pleasant Father`s Day weekend.
Several days of excessive heat and humidity are likely starting
Tuesday and lasting through next Friday.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
-- Changed Discussion --
1 AM Update:

Still a couple of lingering thunderstorms out there this morning
in eastern MA. Those should quickly wane and just become rain
over the next our. Rain will continue for a few more hours
across eastern MA and RI, before tapering off before sunrise.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
Departing cold front/deep digging shortwave will allow very, at
least for June, dry air to filter into the region on NW/N flow
tomorrow. PWATs are expected to drop to around 0.4" by 18/21Z
Saturday, yielding a gorgeous, comfortable start to Father`s day
weekend. Little cloud cover is expected, with dewpoints dropping
into the low and mid 40s by early evening. 850mb temperatures
between 8-10C will support highs in the mid 70s to low 80s.

Radiational cooling will be in play Saturday night. With very dry
airmass in place and mainly clear skies overhead, as well as
slackening winds, it is quite possible that low temperatures drop
into the low to mid 40s across northwestern MA by daybreak on
Sunday. Urban heat islands, like Boston and Hartford, will remain
our most mild localities, with lows around 60F expected.
Temperatures across the coastal plain will fall back into the
50s. This is our last shot of cool air for quite some time as
mid level ridging starts to build in to end the weekend.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Key Point:

 * Several days of dangerous heat/humidity Tue-Fri

Big story for next week continues to be likelihood of dangerous heat
and humidity starting Tue and peaking Wed-Fri. Ensembles are in very
good agreement on building strong upper ridge over eastern U.S.
through most of next week which lends increasing confidence. In
fact, 500 mb heights nearing 600 dm is something rarely seen in the
Northeast and is a very strong signal for record heat. This aligns
with EPS and NAEFS Situational Awareness Tables which show several
parameters outside of model climatology relating to temperature,
signaling potential for a highly unusual event.

We`re also seeing fairly high chances of afternoon highs well into
90s Tue-Fri, if not near 100 in some spots. More importantly,
daytime heat indices may reach as high as 105 degrees and there will
be little relief at night with nighttime heat indices in 70s.

Upper ridge also favors dry weather for much of next week, but it`s
possible we see widely scattered showers/storms, especially in Thu-
Fri timeframe as cold front approaches from Great Lakes.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Forecast Confidence Levels:

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

Today:

Rain ends for eastern terminals before sunrise. VFR with
northerly winds at 10-15 knots. MVFR cloud deck could linger for
the Cape and Islands into the late morning.

Tonight:

VFR. Winds remain northerly at 5-10 knots. Fog and low status
possible across the islands.

Tomorrow:

VFR. Winds turn light southerly with localized sea breezes
possible.


KBOS TAF...High confidence in TAF

Rain ends before sunrise this morning, then VFR with gusty
northerly winds today at 10-15 knots.

KBDL TAF...High confidence in TAF

VFR. increasing northerly winds today at 10-15 knots.

Outlook /Sunday Night through Wednesday/...

Sunday through Sunday Night: VFR.

Monday: VFR. Breezy.

Monday Night through Juneteenth: VFR.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
Forecaster Confidence Levels:

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

Tonight:

Steady light to moderate rain with embedded thunder possible.
Winds shift WNW and decrease to 5-10 knots overnight. Seas 2-3
feet.

Tomorrow:

Rain tapers off in the morning with clearing conditions in the
afternoon. Winds turn north and gust 15 to 20mph. Seas 2-4 feet.

Tomorrow Night:

Clear conditions and generally light winds. Seas around 2-4
feet.

Outlook /Sunday Night through Wednesday/...

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

Sunday Night through Monday: Winds less than 25 kt.

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

Tuesday through Juneteenth: Winds less than 25 kt.
-- End Changed Discussion --

&&

.CLIMATE...
Daily Record High Temperatures...

Tuesday, June 18th

BOS - 94F (1929)
BDL - 95F (1994)
PVD - 94F (1929)
ORH - 93F (1929)

Wednesday, June 19th

BOS - 96F (1923)
BDL - 95F (1995)
PVD - 94F (1923)
ORH - 93F (1923)

Thursday, June 20th

BOS - 98F (1953)
BDL - 97F (2012)
PVD - 95F (1941)
ORH - 93F (1953)

Last Day of 100F (or greater)

BOS - 100F (07/24/2022)
BDL - 100F (07/21/2019)
PVD - 100F (07/28/2020)
ORH - 102F (07/04/1911)

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
MA...None.
RI...None.
MARINE...None.
-- End Changed Discussion --

&&

$$

SYNOPSIS...KS/JWD
NEAR TERM...KP/KS/JWD
SHORT TERM...KS
LONG TERM...JWD
AVIATION...KP
MARINE...KS/JWD
CLIMATE...Dooley