189
FXUS61 KBOX 240253
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1053 PM EDT Thu May 23 2024

.SYNOPSIS...
Much drier air moves in tonight followed by warm and less humid
conditions Friday into Saturday as high pressure builds into the
region. A frontal system may bring a few showers and isolated
thunderstorms Saturday night into Sunday. Turning cooler and
more seasonable early to mid next week, with a better chance of
showers.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A front was stalled across southern new England this evening,
generally from near Beverly, to east of Worcester, to just north
of Hartford. This was most evidenced by dew points in the 50s to
the north, with much more humid air pooled just along the front,
where dew points were in the mid and upper 60s.

Thinking this front makes very slow progress towards the coast
the rest of tonight. it should still linger near the Cape and
islands towards daybreak. Thus, it will take a while for the
humidity to ease across eastern MA and RI. Clearing skies per
satellite data, and no rainfall evident on the radar this
evening. Brought the forecast back in line with observed trends.

Previous Discussion...

Much drier air moves in from the north tonight behind the weak
cold front. Expect a fair amount of cirrus so overall mostly
clear to partly cloudy skies. Exception will be along the
immediate south coast and especially the Cape/Islands where
stratus and fog expected to develop. Lows will be in the 50s,
except around 60 in urban centers.

&&

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

Northern stream trough passes well to the north with attendant
cold front dropping south across northern New Eng. Wedge of dry
air and subsidence will prevail across SNE leading to abundant
sunshine. It will be a warm day with 925 mb temps 19-20C
supporting highs 80-85 with less humidity as dewpoints drop
through the 50s and into the 40s, especially northern MA. It
will become a bit breezy as deep mixing will result in W-SW
gusts to 20-25+ mph developing in the afternoon, especially in
northern MA.

Friday night...

The secondary cold front moves south of the coast with high pres
building in from the north. Clear skies and light winds will
result in good radiational cooling with lows dropping into the
low-mid 50s, with some upper 40s across western MA.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Highlights

* Warm and dry Saturday

* Scattered thunderstorms possible Sunday

* Unsettled for the first half of next week

Saturday and Sunday

A mid-level ridge builds over southern New England on Saturday
supporting dry/sunny conditions across the forecast area. Temps
will be warm across the interior in the upper 70s to low 80s,
but sea- breezes will keep the coastal locations cooler in the
upper 60s to low 70s. As the mid-level ridge shifts east
Saturday night into Sunday, return flow from the south will
support increasing dewpoints/moisture for Sunday afternoon.
Model guidance is resolving a subtle upper-level short-wave/mid-
level low moving over the region early Sunday. With a few
hundred J/kg of CAPE and 30 to 40 knots of deep layer shear,
this disturbance may be enough to trigger a few scattered
thunderstorms on Sunday. With instability values on the modest
side, there is no signal for any potential storms to become
strong to severe at this time. Aside from thunderstorm potential
on Sunday, it looks to be a quiet second half of the weekend
with seasonable temperatures and a mix of sun and clouds.

Next Week

A broad upper-low builds over the eastern US early next week.
This feature is expected to support unsettled weather through
mid to late week with substantial precipitation expected Monday
night into Tuesday. Temps look to be seasonable with daily
highs/lows in the mid 70s and mid 50s respectively. A cold front
may bring another round of precipitation and cooler
temperatures by the end of next week. Details are vague at this
time range so stay tuned for more details.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Forecast Confidence Levels:

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

Tonight...Moderate Confidence.

IFR-LIFR stratus and fog over the outer Cape/Islands, possibly
reaching the immediate south coast. Otherwise VFR. Winds
becoming light W.

Friday and Friday night...High confidence.

VFR. W wind 10-20 kt Fri with 25 kt gusts possible north of the
MA Pike. Diminishing wind Fri night becoming light N-NW.

KBOS TAF...High confidence in TAF.

SW wind 10-15 kt becoming W this evening. W gusts to 20 kt
developing Fri afternoon

KBDL TAF...High confidence in TAF.

Outlook /Saturday through Tuesday/...

Saturday: VFR.

Saturday Night through Sunday: VFR. Slight chance SHRA,
isolated TSRA.

Sunday Night: Mainly VFR, with local MVFR possible.

Memorial Day: Mainly VFR, with areas MVFR possible. Chance
SHRA, isolated TSRA.

Monday Night: MVFR/IFR conditions possible. Chance SHRA,
isolated TSRA.

Tuesday: Mainly VFR, with local IFR possible. Breezy. Chance
SHRA, isolated TSRA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Friday night...High Confidence.

SW winds become light W tonight behind a weak front, then
increasing SW-W wind 15-20 kt during Fri. Winds become light
NW-N Fri night as another front moves through. Seas below Small
Craft Advisory thresholds.

Outlook /Saturday through Tuesday/...

Saturday: Winds less than 25 kt.

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

Sunday Night: Winds less than 25 kt.

Memorial Day: Winds less than 25 kt. Slight chance of rain
showers, isolated thunderstorms.

Monday Night through Tuesday: Winds less than 25 kt. Seas up to
5 ft. Chance of rain showers, isolated thunderstorms.

&&

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

&&

$$

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