072
FXUS61 KBOX 021703
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
103 PM EDT Thu May 2 2024

.SYNOPSIS...
A weak low pressure will bring scattered showers near the coast
Thursday. High pressure north of our region will bring dry and
seasonable weather Friday and most of Saturday with onshore
winds. An approaching front should bring showers late Saturday
into Sunday. Dry and warmer weather is expected early next week.

&&

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

10AM Update

Area of low status continues to move east. While areas of
Eastern MA and RI woke up to Sun this morning, should expect
overcast skies for much of the day with some clearing possible
in the late afternoon. Western MA and CT are starting to break
out of those low clouds now and will see sun the rest of the
day. The short wave trough currently over northern New England
will drop south today bringing a weak cold front with it. hi-
res guidance continues to show light convective showers possible
this afternoon with a low chance at rumble of thunder with
100-300 J/kg of SBCAPE. Thunder chances will likely be driven on
how well the cloud cover holds together over eastern MA as any
added sunshine will increase instability. The best chance for
showers is across northeast MA where the best forcing will be
present.

Areas across interior/western MA where sunshine will be more
abundant can expect a very warm afternoon with 15C temps at 925 hPa
supporting surface temperatures in the mid to upper 70s in the CT
River Valley. Low 70s/upper 60s will be more common east of the
Worcester Hills where the air mass will be cooler and the skies will
be cloudier. Overall a mild/quiet spring afternoon across the
forecast area.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
Tonight

Winds shift to the northeast tonight as a surface low departs to the
southeast of southern New England. Onshore flow will support clouds
filling back in across the region. Overcast skies will prevent
temperatures from falling too far, so we can expect near to slightly
above normal low temperatures in the mid to upper 40s overnight.

Tomorrow

Onshore flow and east/northeasterly winds will support a
cooler/cloudier day tomorrow. Locations along the east coastline
will be much cooler than the interior in the face of onshore winds.
Areas along the coast will struggle to escape the low to mid 50s.
Temperatures will be more mild in the low to mid 60s across the
interior and warmest in The CT River Valley in the upper 60s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Key Points:

 * Scattered showers late Saturday into Sunday
 * Warmup early next week

Upper ridge should maintain dry weather Saturday before it heads
offshore Sat night/Sun and allows scattered showers to reach SNE as
cold front crosses region. Certainly looks cooler over weekend,
especially Sunday with onshore winds once again.

Pattern becomes a little more complicated early next week as closed
low over Rockies becomes blocked by building ridge over Great Lakes.
Broad SW flow aloft will favor warming temperatures but how quickly
ridge flattens will determine when low pressure will reach western
Great Lakes, lifting warm front through SNE in the midweek time
frame. For now it looks dry Mon and Tue with increasing chances of
showers sometime Wed-Thu.

&&

.AVIATION /18Z THURSDAY THROUGH MONDAY/...
Forecast Confidence Levels:

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

Rest of today: Moderate Confidence

Scattering out of the cloud deck is leading to VFR conditions
for all interior terminals the rest of the afternoon. Cape Cod
and the Islands will be stuck in IFR likely the rest of the day
as the cloud deck moves east. There is still a low chance for an
isolated shower and rumble of thunder mainly in NE MA this
afternoon, but confidence was only high enough to include VCSH
in the TAF at this time. Winds may occasionally gust 15-20
knots this afternoon.

Tonight: Moderate Confidence

Winds turn NE overnight advecting in a marine status cloud deck
from over the ocean. This will bring IFR and localized LIFR
overnight for eastern terminals, while western terminals may be
spared with VFR/MVFR. Winds may occasionally gust 15-20 knots
overnight esspically near the coasts.

Tomorrow: Moderate Confidence

Gradual improvements in CIGS back to MVFR in the morning, then
to VFR in the afternoon with the CAPE and Islands seeing IFR
linger longer into the day. Winds turn SSE at 5-10 knots

Tomorrow Night: High Confidence

VFR with light and variable winds.

KBOS TAF...Moderate confidence.

VFR this afternoon with a low chance for an isolated shower and
rumble of thunder. Winds turn NE this evening brining in
IFR/LIFR CIGS after 00z. Gradual improvements to MVFR then VFR
tomorrow.

KBDL TAF...Moderate confidence.

VFR this afternoon. MVFR/IFR possible overnight, but the extent
west of the marine status deck remains uncertain.

Outlook /Friday Night through Monday/...

Friday: Mainly VFR, with local MVFR possible.

Friday Night: VFR. Chance SHRA.

Saturday: Mainly VFR, with local MVFR possible. Chance SHRA.

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

Sunday: MVFR/IFR conditions possible. Chance SHRA.

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

Monday: VFR. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Today through Tomorrow

Conditions remain quiet across the coastal waters through tomorrow
with modest wind speeds and seas generally 3 feet or less. Southwest
winds for the first half of today become northeast as a weak low-
pressure circulation moves over the marine zones. Northeast winds
then persist through tonight and tomorrow.

Outlook /Friday Night through Monday/...

Friday through Friday Night: Winds less than 25 kt.

Saturday: Winds less than 25 kt. Slight chance of rain showers.

Saturday Night: Winds less than 25 kt. Chance of rain showers.

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

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

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

SYNOPSIS...RM/JWD
NEAR TERM...RM/KP
SHORT TERM...RM
LONG TERM...JWD
AVIATION...KP
MARINE...RM/JWD