Area Forecast Discussion
Issued by NWS Boston, MA

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789
FXUS61 KBOX 240819
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
419 AM EDT Sun Aug 24 2025

.SYNOPSIS...
The risk for dangerous rip currents will remain elevated
through Sunday in the wake of Erin. Scattered showers/thunderstorms
are possible on Monday ahead of a cold front. Dry conditions
favored with surface high pressure in place through the end of
the week while also trending cooler with temperatures slightly
below normal.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Key Messages:

* Elevated risk for dangerous rip currents today.

An upper level trough and cold front track across the Great Lakes
region today resulting in southwesterly flow aloft across southern
New England. Conditions will be mainly dry today with high pressure
in place. However, weak moisture shifting eastward well ahead of the
approaching front may be enough to support a few isolated showers
late afternoon-evening in western MA. Model soundings show a well-
mixed boundary layer this afternoon which will result in breezy
conditions in the afternoon with occasional gust 20-25 mph.
Temperatures will be a little cooler than Saturday with highs in the
upper 70s to low 80s. The subtle uptick in moisture will also
support more cloud cover in the afternoon.

There will still be an elevated risk for rip currents today.


&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Key Messages:

* Chance for scattered showers/thunderstorms Monday afternoon.

Main story for tonight will be a weak low system passing offshore
overnight into early Monday morning. This will bring increased
chances for showers across the Cape and for the immediate coast of
eastern MA. Increased cloud cover will keep temperatures a little
warmer tonight with low mainly in the mid 60s.

For Monday, a trough/cold front will slowly approach the region,
eventually pushing through Monday night. This will provide some weak
synoptic lift and combined with diurnal heating and marginal
moisture/instability, should be enough to support some shower/storm
development in the afternoon. MLCAPE values range around 50-1000
J/kg. Mid-level lapse rates are fairly weak with steeper low level
lapse rates. 0-6km shear will be sufficient given a jet present
aloft. Coverage should be limited (scattered) as models still bring
the cold front in on the later side, well after peak heating. Clouds
increase through the day with highs in the upper 70s to near 80.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Key Messages:

* Mainly dry conditions for remainder of week with slightly below
  normal temperatures.

Behind Monday`s cold front, a cooler airmass settles across
southern New England Tuesday through the remainder of the week.
850mb temperatures range from +7 to +10C yielding high
temperatures mainly in the mid 70s to near 80. High pressure
will bring dry conditions and mainly clear conditions which will
provide several nights of good radiational cooling. This will
bring overnight lows into the 50s, potentially into the upper
40s for interior southern New England by Wednesday night.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

06z Update...

Today...High confidence.

Light S/SW winds in the morning increasing to around 10-12 kts,
with occasional gusts up to 20 kts for the afternoon. SCT- BKN
mid-level clouds. Low chance for an isolated shower in western
MA in the afternoon.

Sunday Night...High Confidence.

VFR. S/SE winds 5-10 kts. Potential for MVFR cigs developing
after 06z. Showers possible for the Cape/Islands terminals
overnight.

Monday...High Confidence in trends.

Any MVFR cigs from overnight, improve to VFR in the morning.
Showers and thunderstorms possible in afternoon. SW winds.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Monday Night through Thursday/...

Monday Night: VFR.

Tuesday: VFR. Breezy.

Tuesday Night through Wednesday Night: VFR.

Thursday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Sunday...High confidence.

Risk for dangerous rip currents is still elevated with the
larger surf in Erin`s wake. Rip current statements will be in
effect today.

Small Craft Advisories in effect for the lingering high seas
will gradually end this weekend, taking longest across the outer
coastal waters.

Outlook /Monday Night through Thursday/...

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

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

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

Wednesday Night through Thursday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Risk for Rip Currents from 8 AM EDT this morning through this
     evening for MAZ007-019>024.
RI...High Risk for Rip Currents from 8 AM EDT this morning through this
     evening for RIZ006>008.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ250-
     254>256.
     Small Craft Advisory until 7 AM EDT this morning for ANZ251.

&&

$$

SYNOPSIS...Mensch
NEAR TERM...Mensch
SHORT TERM...Mensch
LONG TERM...Mensch
AVIATION...Mensch
MARINE...Mensch