Office: BOX
FXUS61 KBOX 210620
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
220 AM EDT Tue Oct 21 2025
.SYNOPSIS...
Sunny skies will result in beautiful weather across the region
today. Another frontal system will bring a period of showers late
tonight into Wednesday morning. This will be followed by mainly dry
and cool weather late this week into early next week.
&&
.NEAR TERM /THROUGH TODAY/...
Key Messages...
* Sunny & beautiful today with highs well into the 60s
Details...
A mid level ridge axis briefly builds into the region today. This
will result in a sunny and beautiful day. 850T around +6C/+7C with
good mixing on southwest flow should allow for highs to reach well
into the 60s in most locations. A bit of a southwest breeze gusting
to between 15 and 25 mph at times...but again a very nice day of
weather is on tap for the region.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
Key Messages...
* A round of showers late tonight into Wed AM
* Drying trend by Wed afternoon with highs mainly in the 60s
Details...
Tonight into Wednesday...
Dry weather prevails this evening...but another approaching
shortwave will bring increasing clouds to the region. While the
dynamics/forcing with this shortwave will not be as impressive as
what we saw Monday morning...still enough there to result in a few
hours of fairly widespread showers crossing the region late tonight
into Wednesday morning from west to east. The showers should arrive
across the interior between 10 pm and 4 am...reaching eastern MA/RI
roughly between 4 and 8 am. Pwats briefly spike to near 1 and
Showalter indices near zero do support some brief downpours. There
is a low risk for a rumble of thunder...but not worth including in
the forecast at this point.
This shortwave is fairly progressive...so really just a expect a few
hours of rain at a given location. Mainly dry weather expected by
the midday Wednesday other than perhaps a leftover spot shower. In
fact...expect partial sunshine to develop Wednesday afternoon with
highs back into the 60s in most locations. Bufkit soundings indicate
SW winds will gust up to 25 mph at times.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Key Messages...
* Mainly dry Thu through Mon with temps trending cooler
* Highs in the 50s to near 60 with lows mainly upper 20s & 30s
Details...
Thursday and Friday...
Deep shortwave trough sets up across the northeast Thursday and
Friday. This will probably result in a fair amount of strato-cu at
times...especially across interior southern New England. Given the
shortwave energy...a spot shower or two will be possible Thu & Fri
but for all intensive purposes dry weather will prevail that vast
majority of the time. There will be a bit breeze especially on
Thursday when SW winds will gust between 20 and 30 mph.
Otherwise...typical late fall weather with highs in the middle 50s
to the lower 60s Thu/Fri with Fri the slightly cooler day.
This Weekend through Monday...
Large high pressure centered over Quebec will take control of our
weather this weekend into Monday bringing less cloud cover
compared to Thu and Fri. This should result in generally dry
weather with temperatures running a bit below normal. High temps
will generally be in the 50s with overnight low temps mainly in
the upper 20s and 30s.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06z TAF Update...
Today...High confidence.
VFR. SW wind gusts of 15-20 knots across the interior and 20-25
knots along the coast.
Tonight and Wednesday...High confidence in trends but lower
confidence in timing.
VFR conditions persist for a good portion of this evening. Cluster
of showers overspreads the interior between 03z and 07z...reaching
the coastal plain in the 07z to 11z time frame although perhaps a
tad later towards the Cape and Islands. Brief downpours with a
period of MVFR-IFR conditions with this activity. The showers should
not last more than a few hours in a given location as they will
quickly sweep eastward with the shortwave. Otherwise...the bulk of
the showers will have exited the coastal plain by early Wed
afternoon with VFR conditions returning. SW winds may gust to 20+
knots at times and near 25 knots along the south coast.
KBOS Terminal...High confidence in TAF.
KBDL Terminal...High confidence in TAF.
Outlook /Wednesday Night through Saturday/...
Wednesday Night: VFR. Breezy.
Thursday: VFR. Breezy. Slight chance SHRA.
Thursday Night: VFR. Breezy.
Friday through Saturday: VFR.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Today through Wednesday...High confidence.
Persistent SW winds and long fetch will result in 3 to 6 foot seas
through Wednesday...the highest of those seas will be across the
southern outer-waters. The winds will also gust from the southwest
at 20 to 25 knots at times with the strongest of those across the
southern waters. Therefore...small craft headlines continue for our
southern waters right through Wednesday and later shifts will likely
need to extend these headlines into Thursday.
Outlook /Wednesday Night through Saturday/...
Wednesday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. Slight chance of rain
showers.
Thursday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. Chance of rain showers.
Thursday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain showers.
Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
Friday Night through Saturday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 2 PM EDT this afternoon for ANZ230-
236-250-251.
Small Craft Advisory until 8 PM EDT this evening for ANZ231.
Small Craft Advisory until 8 PM EDT Wednesday for ANZ232>235-
237-254>256.
&&
$$
SYNOPSIS...Frank
NEAR TERM...Frank
SHORT TERM...Frank
LONG TERM...Frank
AVIATION...Frank
MARINE...Frank
