Area Forecast Discussion
Issued by NWS Boston, MA

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
816
FXUS61 KBOX 081731
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
131 PM EDT Fri May 8 2026

.WHAT HAS CHANGED...

No significant changes have been made to the forecast.

&&

.KEY MESSAGES...

- No significant weather concerns are expected today, though a
  few brief afternoon showers are possible.

- Mother`s Day weekend looks split, with widespread showers and
  cooler temperatures Saturday followed by somewhat warmer and
  drier conditions Sunday.

- Another round of unsettled weather is possible Sunday night
  into Monday, followed by a brief drying trend midweek with
  temperatures remaining below normal.

&&

.DISCUSSION...

KEY MESSAGE 1...No significant weather concerns are expected
today, though a few brief afternoon showers are possible.

While high pressure builds offshore of the Carolinas, a surface
trough and fairly strong mid-level shortwave move through SNE
this afternoon. Despite this forcing, the airmass remains
considerably drier in the wake of Thursday morning`s cold front
passage. PWAT values are only around 0.4-0.6 inches per the 00z
HREF, indicating limited moisture availability. As a result,
expect mainly diurnal driven showers this afternoon, with the
greatest coverage across interior MA where PoPs range from 25-40
percent. Elsewhere, PoPs are generally 15-25 percent between
roughly 2-8 PM. Not all locations will see rainfall, and any
showers that do develop should be brief and light. Temperatures
today will be seasonably cool, with highs running a few degrees
below climatological normals in the upper 50s to lower 60s. Dry
weather returns tonight, though clouds will gradually increase
from west to east ahead of a more widespread rainfall event
expected Saturday. Overnight lows fall into the 30s and 40s,
coldest across interior MA where some locations dip into the mid
30s, while coastal areas remain milder in the mid 40s.

KEY MESSAGE 2...Mother`s Day weekend looks split, with
widespread showers and cooler temperatures Saturday followed by
somewhat warmer and drier conditions Sunday.

Guidance continues to support unsettled conditions developing by
late Saturday morning into the afternoon as an elevated warm
front and accompanying 850mb shortwave move through SNE.
Temperatures are somewhat below normal with highs in the upper
50s to lower 60s. Wind direction aloft are SW, this helps to
increase humidity, PWATs too are increasing, 0.8-1.0 inches
per the 00z HREF, which is more or less the climatological
normal for the first half of May, promotes widespread beneficial
rainfall. 00z GEFS indicate a moderate probability of 50 percent
for totals to exceed 0.5 inches. ECMWF ENS show something
similar, with an axis of moderate-high probabilities (60-80
percent) of 0.5 inches across coastal RI and SE MA. This does
align somewhat with HREF, currently thinking widespread amounts
of 0.3-0.6 inches with locally higher amounts possible in any
convective showers. And at this time, there are no concerns with
flooding.

Conditions improve heading into Sunday as subtle mid-level
height rises support quieter and milder condition`s for Mother`s
Day. While SW to WSW flow persists, a notably drier airmass is
not expected to move into SNE. In fact, dew points climb into
the low to mid 50s, making it feel somewhat more humid compared
to the much drier conditions observed Thursday and Friday. Given
the lingering moisture and embedded shortwave energy within the
flow, cannot rule out a passing afternoon shower or thunderstorm
as a few hundred J/kg of CAPE may develop. That said, Sunday
does not appear to be a washout, though those with outdoor plans
should remain weather aware. Afternoon highs rise into the low
to mid 70s.

KEY MESSAGE 3...Another round of unsettled weather is possible
Sunday night into Monday, followed by a brief drying trend
midweek with temperatures remaining below normal.

Attention then turns to Sunday evening into early Monday as
another mid-level trough and embedded shortwave energy moves
through SNE. This likely supports development of weak surface
low pressure south of the region, bringing another round of rain
during this timeframe. While details regarding exact timing and
rainfall amounts remain uncertain, the overall signal for
unsettled conditions is increasing. A brief drying trend is
possible Tuesday into Wednesday as high pressure attempts to
build S and W of the region. Temperatures trend back below
climatological normal early next week, with highs mainly in the
50s Monday and upper 50s to lower 60s Tuesday and Wednesday.

&&

.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...

Through Tonight...High confidence.

VFR conditions persist outside a few spot showers through early
this evening. W wind gusts of 20 to 25 knots should diminish
after sunset.

Saturday and Saturday night...Moderate confidence.

Scattered showers Sat morning will result in low end VFR-MVFR
conditions with the lower cigs mainly across the interior. Widespread
showers with brief heavy rainfall overspread the region from
west to east Sat afternoon into the early evening hours. This
will result in cigs/vsbys lowering to lower end MVFR-IFR
thresholds. There may even be an isolated t-storm or two...But
not expecting anything widespread. The bulk of the showers will
exit the coast by late evening...but a few showers along with
MVFR-IFR conditions will persist overnight. Winds shift to a
SSE direction by Sat afternoon the order of 5-15 knots. Some
20-25 knot gusts are possible towards the south coast late Sat
into Sat evening along with some LLWS too.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday through Wednesday/...

Sunday: VFR. Breezy. Slight chance SHRA.

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

Monday: Mainly VFR, with local IFR possible. SHRA likely.

Monday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA.

Tuesday: VFR. Breezy. Slight chance SHRA.

&&

.MARINE...

Forecaster Confidence Levels...

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

Through Saturday...High confidence.

A weak frontal passage this afternoon produce SW gusts 20 to
25 kt for the nearshore waters off the south coast of MA & RI,
followed by gust less than 15 kt tonight. Seas today into
tonight are 2 to 4 ft.

An area of low pressure tracks well inland on Saturday, a warm
front lifting north during the day and periods of rain and
embedded thunderstorms. A wind shift to the S-SSE and increasing
wind speeds 15 to 20 kt and gust 25+ kt. Seas build from S to N
as well throughout the day 4 to 7 ft. Due to these conditions,
likely will need a Small Craft Advisory come Saturday afternoon.

Outlook /Saturday Night through Wednesday/...

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Rain showers, isolated
thunderstorms, patchy fog.

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

Sunday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers.

Monday: Winds less than 25 kt. Rain showers.

Monday Night: Winds less than 25 kt. Seas locally approaching
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...None.

&&

$$

DISCUSSION...Dooley
AVIATION...Frank
MARINE...Dooley