820 
FXUS61 KBOX 171732
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
132 PM EDT Fri Oct 17 2025

.SYNOPSIS...
High pressure takes a hold of the weather pattern this weekend 
bringing less wind and warmer afternoon temperatures.  A Strong 
Frontal system begins to approach the region on Sunday, bringing 
gusty southerly winds with above-normal temperatures. The frontal 
system arrives sometime Monday morning, bringing rain and a chance 
for thunderstorms.  The pattern remains unsettled as we head into 
the middle of next week.
&&

.NEAR TERM /UNTIL 6 AM SATURDAY /... 

This afternoon:

The core of the mid-level cool pool moves east of the area this 
afternoon as surface high pressure builds in overhead. Initially 
gusty winds will gradually relax throughout the afternoon as the 
pressure gradient wanes. Elevated winds may persist a bit longer 
into the afternoon on the Cape and Islands before winding down this 
evening. Still expecting a mild day in the temperature department 
with highs rising into the lower 60s for most of us except closer to 
the coast where temps will likely fall just shy of 60 degrees. 

Overnight:

Surface ridge crests over New England tonight, bringing calm winds 
and clear skies. The calm, clear conditions set the stage for 
efficient radiational cooling overnight with just about everyone 
dropping into the 30s. Coldest conditions will be found in northern 
and central Mass where lows likely fall below freezing. Slightly 
warmer temperatures for the Cape and Islands and urban areas. As a 
result, have opted to blend in some cooler guidance such as the 
CONSMOS to account for this. 

&&

.SHORT TERM /UNTIL 6AM SUNDAY /... 

Pleasant mid-October day on tap for Saturday as the mid-level ridge 
axis moves overhead while the surface high pressure begins to move 
offshore. Despite the retreating high, winds remain calm during the 
day under 5mph. High temperatures warm slightly into the mid to 
upper 60s as 850 mb temps warm to +8C. Skies will start sunny, but 
mid-level moisture streaming behind the ridge axis will bring mid to 
high-level clouds and filtered sunshine to end the day. Slightly 
warmer Saturday night as mid and high level clouds increase. Lows 
will be in the 40s for most areas, with upper 30s possible across 
northern Massachusetts. 


&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Key Messages:

* Dry weekend with moderating temps..highs may approach 70 on Sun in 
  valley locations
* Looking unsettled next week as multiple shortwaves move through 
  the region. 

Details...

This Weekend...

Guidance shows a 576dm ridge building over the northeast CONUS by 
Saturday afternoon. This ridging will result in continued dry 
weather with moderating temperatures. 850mb temps increase to +7-
+11C through the weekend. Model soundings show modest mixing so 
temperatures will be somewhat mild, rising into the upper 60s 
to lower 70s, especially in interior river valleys on Sunday. 

Next Week...

Still seeing good agreement amongst global models in a relatively 
deep shortwave trough moving in from the Great Lakes to start the 
week. Main disagreement between the GFS and ECMWF is the shape and 
orientation of the trough. GFS has a much more progressive, 
postively-tiled trough while the EURO wants to cut it off from the 
mean zonal flow. In terms of sensible weather impacts, the GFS 
solution would result in more of a quick-hitting area of showers and 
perhaps a low-topped thunderstorm or two along the cold front Monday 
afternoon before things quickly cleared out. A more prolonged rain 
event would be possible if the EURO solution panned out, but details 
will be ironed out in future forecast updates. Regardless, the NBM 
has increasing POPs Monday morning, peaking during the afternoon 
before decreasing in the evening. Looking at the large-scale pattern 
for Tues and Weds, a much more significant trough begins to dig over 
the Great Lakes Tuesday night and Wednesday. Although it is still 
fairly early, ensemble guidance suggests the trough becomes 
negatively-tilted as heights build over the western CONUS. 
Temperatures next week should be somewhat cooler with more in the 
way of cloud cover with highs in the lower 60s.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...

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

18z TAF Update...

Today...High Confidence.

VFR with pockets of MVFR lingering over the Cape and Islands for
the next few hours. Winds quickly diminish inland except near
the waters where they will gust to near 30 knots thru 22z. 
Gusts expected to diminish for everyone this evening as strong winds
aloft start to move more offshore.

Tonight...High Confidence.

VFR. Light NW winds around 5 kts or less for much of southern
New England; around 10 kts over the Cape and Islands. Exception
over ACK where wind gusts may take longer to cease based on the
latest forecast soundings; gusts around 20 kts remain possible 
there this evening.

Saturday...High Confidence.

VFR. Light and variable winds.

KBOS Terminal...High Confidence in TAF.

KBDL Terminal...High Confidence in TAF.

Outlook /Sunday Night through Tuesday/... 

Sunday: VFR. Breezy. 

Sunday Night: Mainly VFR, with local IFR possible. Breezy.
Chance SHRA.

Monday: Mainly MVFR, with local IFR possible. Windy with local
gusts up to 30 kt. Chance SHRA, isolated TSRA.

Monday Night through Tuesday: VFR. Breezy. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Saturday...High confidence.

Winds and seas gradually decrease today as high pressure begins
to build in. Winds drop below 15 knots tonight but seas remain
elevated at 5-8 ft from ACK east. Winds remain light on 
Saturday and seas gradually decrease to 3-6 feet.

Outlook /Sunday Night through Tuesday/... 

Sunday: Winds less than 25 kt. Seas up to 5 ft. 

Sunday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Chance of rain showers.

Monday: Strong winds with areas of gusts up to 30 kt. Rough
seas up to 8 ft. Chance of rain showers, isolated
thunderstorms. Local visibility 1 to 3 nm.

Monday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Chance of rain showers. 

Tuesday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain showers. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 2 PM EDT this afternoon for ANZ230-
     233>237.
     Small Craft Advisory until 8 PM EDT this evening for ANZ231-
     232-256.
     Small Craft Advisory until 8 AM EDT Sunday for ANZ250-251-254-
     255.

&&

$$

SYNOPSIS...FT
NEAR TERM...FT
SHORT TERM...FT
LONG TERM...KP/FT
AVIATION...Hrencecin/FT
MARINE...KP