761
FXUS61 KBOX 070730
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
Issued by National Weather Service Gray ME
330 AM EDT Wed May 7 2025

.SYNOPSIS...

Trending warmer and drier today and tomorrow except for
scattered showers with isolated thunderstorms. Another
windswept rain event with below-normal temperatures develops for
Friday into Saturday. Clearing out and trending drier on Sunday
with a steady warming trend into early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

Today:

Key Point

 * Scattered showers and isolated thunderstorms possible this
   afternoon.

Even with the weakening upper-level Shortwave moving through
today, it will be much drier and possibly even some peaks of
sunshine after the low clouds and fog from tonight burn off. The
core of the 500mb cold pool passes to our north today, but with
SBCAPE building to 500-700J/kg around 6C/km, there will likely
be scattered showers and thunderstorms, especially North of the
MA Pike. Guidance has somewhat surprisingly increased the amount
of 0-6km shear available tomorrow up to 25-30 knots, but it may
not arrive before showers and storms dissipate. With the cold
pool aloft, it wont take much for graupel or small hail to reach
the ground, but if the shear and storms line up, its not out of
the question that some larger hailstones become possible.
Despite the cold temps aloft, temps at the surface will be quite
mild in the low 70s.


&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...

Key Points

 * Patchy Fog possible tonight

 * More scattered showers and isolated thunderstorms possible
   Thursday

Tonight:

Flow aloft becomes briefly zonal with light rising heights
aloft. With drier mid-level air and some light subsidence, this
should help clear the skies overnight. Winds at the surface turn
light westerly or calm overnight. With dewpoints still in the
50s, patchy fog will likely develop in low-lying areas but could
become more widespread and dense, especially near the south
coast, where winds will take longer to turn west. Overnight lows
stay mild and bound by the dewpoints in the low 50s.

Thursday:

Another shortwave begins to approach from the Great Lakes,
causing light height falls over SNE. Increasing mid-level
moisture and SBCAPE building to near 500 J/kg could lead to
late-day showers and perhaps a rumble or two of thunder.
Guidance has trended warmer for Thursday, with highs reaching
the mid to upper 70s. Light wind will lead to localized sea
breezes to develop, keeping coastal areas cooler in the 60s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Key Points:

* Growing confidence in onshore flow and windswept rain and high
  temps well below normal as low pressure moves through or east
  of Southern New England. Need to watch rivers for possible
  rises at or above flood stage.

* Drying out Sunday and continuing into early next week, with a
  steady warming trend.

Details:


Friday and Saturday:

It is looking like we are unfortunately heading into another
soggy Friday and possibly into Saturday as well, as a upper
level trough closes off into an upper level low over the
northern mid-Atlantic. This will induce a sub-1000 mb low
pressure to trek somewhere over or just southeast of Southern
New England. Expect the latter part of the workweek and
potentially into Saturday with another cool, wind-swept rain
event. This could be enough to raise possible river flood/hydro
concerns for interior basins in Southern New England, which
have received quite a bit of rain and/or are still experiencing
rises. Temps to trend cooler than normal, perhaps significantly
below normal (high temps some 15-20 degs below normal).

Sunday into Early Next Week:

Looks like Sunday is trending more optimistically as the late-
week/Sat system pulls away. Although temperature profiles aloft
still are on the cooler side, we should see a sustained period
of drier weather and a gradual warming trend to temps as we move
into early next week.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

06z TAF Update:

Rest of Tonight: Low Confidence

IFR with pockets of LIFR should gradually lift to MVFR, however,
fog may fill in behind low cloud cover, keeping low lying
terminals in LIFR conditions until after sunrise. Rain has now
moved off shore, so any remaining precipitation should be light
mist or drizzle

Wednesday: Moderate confidence.

Any fog that formed overnight should burn off by 15z giving away
to VFR conditions with pockets of MVFR possible with diurnal
strato cu forming. Low chance for an isolated shower mainly
north of Rt-2. Winds remain southerly at 10-15 knots

Wednesday Night: Low Confidence

Clear skies may allow for Fog formation given the leftover
moisutre from the rains the last couple days. Confidence on fog
is generally low right now and may depend on how light the winds
can become overnight.

Thursday: Moderate Confidence

VFR with pockets of MVFR due to strato cumulus again. Low chance
for isolated showers possible across the interior.


KBOS TAF...Moderate confidence.

IFR/MVFR tonight turning VFR this morning. Low chance for an
isolated shower this afternoon.

KBDL TAF...Moderate confidence

IFR lifting to MVFR/VFR this morning. Showers are possible in
the afternoon.

Outlook /Thursday Night through Sunday/...

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

Friday: Mainly VFR, with local IFR possible. SHRA likely,
slight chance TSRA.

Friday Night: SHRA likely.

Saturday: Breezy. Chance SHRA.

Saturday Night through Sunday:

&&

.MARINE...
Forecaster Confidence Levels:

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

Today through Thursday: High Confidence.

Winds remain southerly today at 10-20 knots. Scattered showers
and thunderstorms may move out over the waters this afternoon.
Seas still around 3-5 feet in the southern waters. Winds become
light overnight, tuning more westerly. Light and variable winds
Thursday.

Outlook /Thursday Night through Sunday/...

Thursday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain showers. Local visibility 1 nm
or less.

Friday: Winds less than 25 kt. Seas up to 5 ft. Rain showers
likely.

Friday Night through Saturday: Winds less than 25 kt. Seas up
to 5 ft. Chance of rain showers.

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

Sunday: 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
     ANZ254>256.

&&

$$

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