592
FXUS61 KBOX 261752
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
152 PM EDT Sat Sep 26 2026

.WHAT HAS CHANGED...
No significant changes in the forecast for the ongoing Nor`easter.

&&

.KEY MESSAGES...

- Strong/long duration Nor`easter will continue to bring
  damaging wind gusts, coastal flooding/beach erosion, and
  periods of heavy rain through the weekend. Rain and gusty
  winds persist into Monday.

- One final day of wet and unsettled weather Tuesday before a
  warming and drying trend arrives next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Strong/long duration Nor`easter will continue to
bring damaging wind gusts, coastal flooding/beach erosion, and
periods of heavy rain through the weekend. Rain and gusty winds
persist into  Monday.

What`s there to be said about the ongoing early season nor`easter
that hasn`t been said already...not much! Things are playing out
largely as expected so far...OPC surface analysis indicates the
996mb surface low spinning well to our south. It`s on its way north,
slowly, before it makes a sharp westward turn into New Jersey
tonight/tomorrow. So far we`ve already seen some minor coastal
flooding on Nantucket where ~2 feet of storm surge pushed water
levels into minor flood stage during the overnight high tide.
The area of most concern continues to be the east coast of MA,
especially south of Boston, where a several factors are at play.
These include the long duration of the winds and long NE fetch,
inability for water to fully recede between high tides, and the
steadily rising astronomical tides. A Coastal Flood Warning
remains in effect for these east facing locations where the
greatest concern will be the Saturday afternoon and overnight
high tides, though we`ll be flirting with minor flooding
through Sunday. A Coastal Flood Advisory is in effect for the
south coast of Massachusetts and Rhode Island where more
sporadic minor coastal flooding is possible due to high surf
just offshore and increasing swells.

Winds have increased as expected, with widespread gusts of 45 to 55
mph observed from Cape Cod and the islands to coastal Rhode
Island while several coastal stations have reported gusts 60+
mph. This occurred as the core of a 65kt LLJ moved overhead
tonight and this continues to lift north and west (weakening)
through Saturday and Sunday. That is why timing of the strongest
wind gusts won`t be identical for everyone...more likely later
Saturday into Sunday for northeast MA for example. Regardless,
northeast winds will be relentlessly gusty through Sunday,
gusting 35-45 mph for most inland locations and as high as 45-55
mph along the coast at times. The timing of this storm before
trees have lost their leaves will exacerbate impacts from broken
limbs and increase the potential for power outages. Strong
winds will continue through Sunday but won`t be as strong as the
storm weakens. Even so, even Monday will be breezy and wet.

This system will dump a lot of rain over the next 72 hours thanks to
the impressive moisture and dynamics...anomalous PWATs and the
previously mentioned 925mb jet along with orographic lift into the
higher terrain. Rainfall totals of 3-5" are expected. The best
chance at these higher amounts is along the coasts and the east
slopes of the CT hills, Worcester hills. Flood risk will be
mitigated by the long duration of the event, though pockets of urban
and poor drainage flooding are possible.

KEY MESSAGE 2...One final day of wet and unsettled weather Tuesday
before a warming and drying trend arrives next week.

The first part of the extended forecast features lingering effects
from our decaying nor`easter as the upper level low will be slow to
exit. Thus, while we won`t see the wind and rain that we saw over
the weekend to start the work week, it will still be wet and
unsettled. By Tuesday afternoon guidance shows gradual clearing from
SW to NE with even some breaks of sunshine possible later in the
afternoon! By Wednesday, the upper air pattern begins to change as a
ridge builds over the eastern CONUS. By Thursday, 500mb heights
build to 582dm and seems to persist through at least the end of the
week across ensemble guidance. Closer to the surface, 850 mb
temperature anomalies soar to +6-10C above climo through late week.
At the surface this translates to a period of late-summer like
warmth with highs in the upper 70s to perhaps low 80s inland.
Outside of Tuesday, the only chance for any  precipitation arrives
later Thursday into Friday as a weakening shortwave approaches the
region from the west.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

18z TAF Update...

Today through Sunday...High confidence in trends, moderate
confidence in timing.

Periods of windswept rain will impact the region through Sunday.
MVFR with IFR ceilings spreading north and west through the
evening. Potential for borderline LIFR ceilings tonight, though
lower in confidence as we do have windy conditions that
typically limit low ceilings. Low risk for a thunderstorm this
afternoon with the higher risk for southern terminals (BDL/PVD).
TEMPOs have been included for a few hours this afternoon for
TSRA although as convective showers shift through. NE wind gusts
of 30 to 50 knots expected with the strongest of those winds
near the coast tonight. Wind gusts will diminish a bit on
Sunday...But still expect NE wind gusts of 25 to 40 knots.

KBOS Terminal...High confidence in trends, moderate confidence
in timing.

Confidence lower in ceiling heights overnight tonight. There is
potential for borderline LIFR conditions. This is lower
confidence as higher winds typically limit the potential for
very low ceilings.

KBDL Terminal...High confidence in trends, moderate confidence
in timing.

Convective showers this afternoon. There is a risk for a brief
thunderstorm or pulse or two of lightning this afternoon which
has resulted in the TEMPO TSRA.

Outlook /Sunday Night through Thursday/...

Monday: MVFR/IFR conditions possible. Windy with local gusts up
to 30 kt. SHRA.

Monday Night: MVFR/IFR conditions possible. Chance SHRA.

Tuesday: Mainly VFR, with local IFR possible.

Tuesday Night through Thursday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through the Weekend...

* Dangerous conditions for Mariners through the weekend with NE wind
  gusts of 45 to 60 knots and seas offshore of 15-25 feet.

The strengthening early season Nor`easter will bring strong NE wind
gusts of 45-60 knots and seas offshore building to between 15 and 25
feet. The strongest of the winds/seas will be early this morning
and peak Sat into Sat night...but seas will remain quite high
Sun into Mon along with NE wind gusts of 25 to 40 knots
persisting. Storm Warnings continue for all the waters.

Outlook /Sunday Night through Thursday/...

Monday: Low risk for Small Craft Advisory winds with gusts up
to 30 kt. Rough seas up to 9 ft. Chance of rain showers.

Monday Night: Winds less than 25 kt. Rough seas up to 8 ft.
Chance of rain showers.

Tuesday: Winds less than 25 kt. Areas of rough seas.

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

Wednesday: Winds less than 25 kt. Areas of seas approaching
5 ft.

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

Thursday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory until noon EDT Sunday for CTZ002>004.
MA...Wind Advisory until noon EDT Sunday for MAZ004>006-011>014-017-
     018-026.
     Wind Advisory until noon EDT Sunday for MAZ002-003-008>010.
     Flood Watch through late Monday night for MAZ004>007-012>024-
     026.
     High Wind Warning until 8 AM EDT Sunday for MAZ007-015-016-
     019>024.
     Coastal Flood Warning until 8 PM EDT Sunday for MAZ007-015-016-
     019-022>024.
     High Surf Advisory until 8 PM EDT Sunday for MAZ007-015-016-
     019-022>024.
     Coastal Flood Advisory until 8 PM EDT Sunday for MAZ020-021.
RI...Wind Advisory until noon EDT Sunday for RIZ001.
     Flood Watch through late Monday night for RIZ001>008.
     High Wind Warning until 8 AM EDT Sunday for RIZ002>008.
     Coastal Flood Advisory until 8 PM EDT Sunday for RIZ002-
     004>008.
MARINE...Storm Warning until 10 AM EDT Sunday for ANZ230>237-250-251-
     254>256-280>283.

&&

$$

DISCUSSION...BW
AVIATION...Mensch/Frank
MARINE...BW