Lexington, Massachusetts, USA
000
FXUS61 KBOX 240531
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
131 AM EDT Wed Jun 24 2026
.WHAT HAS CHANGED...
No changes to the forecast at this time.
&&
.KEY MESSAGES...
- Showers and unsettled weather taper off tonight. This will be
followed by dry and seasonable conditions through Wednesday
night.
- Scattered showers and a few thunderstorms possible at times
Thu night into Fri. We will need to watch the risk for a few
severe t-storms Fri PM...But only if enough instability develops.
- A few showers may linger into Sat...otherwise dry weather
dominates into early next week but will need to watch for MCS
potential given northwest flow aloft. Warming trend as well,
but thinking the worst of the heat may remain to our southwest.
&&
.DISCUSSION...
KEY MESSAGE 1... Showers and unsettled weather taper off tonight.
This will be followed by dry and seasonable conditions through
Wednesday night.
Convergence along a frontal boundary extending southwest to
northeast across Rhode Island and southeast MA will continue to
support wet/unsettled weather through this afternoon. No widespread
shower or thunderstorm activity expected, but rather some fog, low
clouds, and spotty showers. May see some breaks of sunshine across
interior MA and CT as some drier air works its way in behind the
front. Expect the front to move offshore by tomorrow morning. This
will be followed by a beautiful Wednesday with seasonable
temperatures in the upper 70s to low 80s, mostly sunny skies, and
light winds.
KEY MESSAGE 2...Scattered showers and a few thunderstorms possible
at times Thu night into Fri. We will need to watch the risk for a
few severe t-storms Fri PM...But only if enough instability
develops.
The next shortwave and associated mid level warm front will approach
and cross the region Thu night into early Fri. There is enough
forcing along with some elevated instability for an initial round of
some showers and perhaps a few thunderstorms sometime Thu night into
early Fri. Uncertainty prevails at this time range on the areal
coverage of any of this activity. This will be followed by a
potential second round of scattered showers and a few thunderstorms
Fri afternoon and evening. This potential will be determined by how
much instability we can generate along with forcing along the
approaching pre-frontal/cold front. The SPC SREF is showing some
impressive probabilities of effective shear exceeding 40 knots Fri
afternoon. However...it remains to be seen if we will have enough
instability and favorable time for any severe weather.
Regardless...much of the machine learning guidance indicating some
low probabilities so bears watching.
KEY MESSAGE 3...A few showers may linger into Sat...otherwise dry
weather dominates into early next week but will need to watch for
MCS potential given northwest flow aloft. Warming trend as well, but
thinking the worst of the heat may remain to our southwest.
Still some timing differences on the cold front and if another wave
of low pressure impacts us Sat as the front sags southward. So there
is the possibility for some lingering showers Sat if the front is on
the slower side especially near the south coast. Otherwise...the
main weather story for the first half of next week will be an upper
level ridge of high pressure building across the Ohio Valley. This
will place us in northwest flow aloft...so we will need to watch for
the potential to be impacted by an MCS sometime during the first
half of next week. Whether or not this occurs though will depend on
where exactly the ring of fire sets up. In terms of temperatures...
the GFS is quite aggressive in bringing near record heat to our
region by the middle of next week. While we do expect a warming
trend...thinking the GFS/CMC ensembles are more realistic keeping
the worst of the heat to our southwest given lingering trough to
our east over the Atlantic.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06Z Update
Through 12z...High confidence.
Areas that saw more significant rainfall yesterday can expect a
higher chance of fog developing overnight if it hasn't already.
In areas of patchy fog, IFR possible. Rain lingering over the
Cape and Islands continues to make its exit and should clear out
by 12z at the latest. Higher confidence in these having exited
the region by 09z. Otherwise, VFR with light to calm winds.
12z Today through Thursday...High confidence.
VFR. Clearing skies and light NW winds through today, shifting
more W tonight and going calm for some. NW winds shift SW/S for
Thursday and remain light.
KBOS Terminal...High Confidence.
KBDL Terminal...High Confidence.
Outlook /Thursday through Sunday/...
Thursday: VFR.
Thursday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Friday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA, slight chance TSRA.
Friday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Saturday: VFR. Chance SHRA.
Saturday Night: VFR. Slight chance SHRA.
Sunday: VFR.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Tonight through Tomorrow Night
Some showers and possible a rumble of thunder over the south coastal
waters this evening as an area of low-pressure slowly moves
east/northeast this evening. Winds are generally light through this
period varying in direction with a westerly component. Sustained
speeds and gusts less than 20 through tomorrow night with seas 2-4
feet.Outlook /Thursday through Sunday/...
Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Thursday Night through Friday: Winds less than 25 kt. Chance of
rain showers.
Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers, slight chance of thunderstorms.
Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers.
Saturday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Slight chance of rain showers.
Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
DISCUSSION...Frank/RM
AVIATION...Frank/Hrencecin/RM
MARINE...Frank/RM
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ID: d5065c0d-686c-400d-9813-19ed0c9db23c
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Index:
https://api.weather.gov/products/types/AFD/locations/BOX