-- Discussion containing changed information from previous version are highlighted. --
354
FXUS61 KBOX 151910
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
310 PM EDT Sat Jun 15 2024

.SYNOPSIS...
High pressure will bring dry and pleasant Father`s Day weekend. Dangerous
heat and humidity begin to arrive on Tuesday and peak in the
Wednesday through Friday time frame. Near record high
temperatures are possible with afternoon Heat Indices between 95
and 105 degrees.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

-- Changed Discussion --
As low pressure continues to exit offshore of Nova Scotia high
pressure builds in further this evening and overnight bringing
continued clear skies and dry weather. Humidity is much more
comfortable for much of the region where (outside of Cape Cod)
dewpoints have dropped into the low 40s. This will make for quite a
cold night relative to last night (nearly 20 degrees colder in some
spots) thanks to radiational cooling. Thus, leaning on the MOS
guidance for the low temperature forcast with handles these
situations well. Lows will dip into the mid 40s to mid 50s (urban
centers).
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...

-- Changed Discussion --
High pressure becomes centered over New England on Sunday as mid
level heights continue to rise. This means another dry and
comfortable day with highs in the 70s and dewpoints in the 40s
(though more humidity will be moving in from the south late in the
day on light southerly winds). Expect a mix of sun and high clouds
as a weak shortwave rounds the ridge, but nothing in the way of
precipitation. Overnight increased cloudcover and higher dewpoints
will limit low temperatures to the mid/upper 50s.
-- End Changed Discussion --

&&

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

* Dangerous Heat & Humidity Tue through Fri
* Near Record highs with Heat Indices 95-105 degrees
* Mainly dry weather next week outside widely scattered t-storm risk

Details...

The main story continues to be the expected dangerous heat and
humidity in store for much of the region next week. Ensembles
continue to be in excellent agreement in an anomalous upper level
ridge building across New England. Guidance shows 500 mb height
fields approaching 600 dm in our region...which is rarely seen in
our part of the country and a strong signal for the potential of
record heat. This is also supported by the NAEFS & EPS Situational
Awareness tables...which indicates several parameters outside the
models climatology. That is a strong indication for the potential of
a rare/highly unusual weather event...in this case being heat and
humidity.

The dangerous heat and humidity arrive Tue across the interior, but
appears localized sea breezes/onshore flow may limit the initial
risk on the immediate coast. The heat & humidity should peak in the
Wed through Fri time frame with the only possible relief along the
immediate coast during times of localized sea breezes. Otherwise,
ensemble guidance data supports near record highs well into the
90s...perhaps touching 100 degrees in spots. If that were to
occur...we would challenge all time record highs for the month of
June in spots. Either way though the main story will be several days
of dangerous heat & humidity. Afternoon Heat Indices will reach into
the 95 to 105 degree range. There will not be much relief at night
with heat indices remaining in the 70s.

Upper level ridging will keep the vast majority of the upcoming work
week dry. That being said...near record high temperatures with
modest instability will result in a widely scattered t-storm threat.
This risk may increase towards the end of the work week as a cold
front approaches the region.

So in a nutshell...dangerous heat and humidity is the
concern for much of next week perhaps even challenging all time June
high temperature records in spots!

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
Forecast Confidence Levels:

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

18z TAF Update...

This afternoon...High Confidence.

VFR. N winds 10 to 15 knots with a few gusts to 20 knots early this
afternoon.

Tonight...High Confidence.

VFR. Light N winds.

Sunday...

VFR. Light winds turn southerly with localized sea breezes.

Sunday night...

VFR. Light S winds.

KBOS TAF...High confidence in TAF.

KBDL TAF...High confidence in TAF.

Outlook /Monday through Thursday/...

Monday through Monday Night: VFR. Breezy.

Tuesday through Tuesday Night: VFR.

Juneteenth: VFR. Slight chance SHRA, isolated TSRA.

Wednesday Night: VFR.

Thursday: VFR. Breezy. Slight chance SHRA, isolated TSRA.
-- 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:

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

Sunday and Sunday night:

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

Outlook /Monday through Thursday/...

Monday: Winds less than 25 kt.

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

Tuesday through Wednesday Night: Winds less than 25 kt.

Thursday: Winds less than 25 kt. Slight chance of rain showers,
isolated thunderstorms.
-- 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...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

SYNOPSIS...Frank/BW
NEAR TERM...BW
SHORT TERM...BW
LONG TERM...Frank
AVIATION...Frank/BW
MARINE...Frank/BW
CLIMATE...Dooley