739
FXUS61 KBOX 041101
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
701 AM EDT Tue Jun 4 2024

.SYNOPSIS...
Weak high pressure will bring mainly dry conditions through
Wednesday, with cooler temperatures near the coast. Our weather
pattern then changes to a cloudy and more unsettled outlook by
Thursday and into the weekend. Thursday looks to be the wettest
day with showers and storms capable of localized downpours,
with more hit or miss showers or thunderstorms for Friday into
the weekend. Temperatures trend a little cooler than normal.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Best chance for some early morning stratus will be across the
Cape/Islands. Any low clouds will lift/erode quickly after
sunrise as high June sun angle goes to work. Expect lots of
sunshine this morning with high clouds increasing during the
afternoon. Weak high pres over Gulf of Maine builds south today
which will keep cooler low level temps across eastern New Eng
where onshore flow will prevail. Highs will be limited to upper
60s and lower 70s along the immediate eastern MA coast, but
warming well into the 70s a bit further inland, and into the
low-mid 80s in the CT valley furthest removed from marine
influence.

Mainly dry today as height rises are indicating large scale
subsidence, but all the CAMs are showing a few convective showers
developing this afternoon in western MA where marginal instability
develops with decent low level lapse rates. A closer look at the
forecast soundings show environment is mostly uncapped in the
Berkshires where there is a low risk for an isolated t-storm. But
further east, the presence of a mid level cap will limit updraft
strength.

&&

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

Mainly dry conditions but can`t rule out an isolated shower spilling
south across northern MA as a weak mid level shortwave rotates south
along the east side of the ridge leading to weak height falls.
Otherwise, partly cloudy skies with some stratus possible over
Cape/Islands and portions of south coast. Lows will be mostly in the
50s.

Wednesday...

High pres south of New Eng will drift further south with increasing
SW flow developing. Partial sunshine and warming low level temps
will lead to highs reaching well into the 80s, but 70s closer to the
south coast where SW winds will keep it cooler. Looks mainly dry
again as best moisture and instability will be across northern New
Eng where convection chances are higher.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Thursday through Monday

A broad cyclonic flow pattern settles over The Northeast by late
week beginning an extended period of unsettled weather in southern
New England. Thursday will feature widespread persistent
precipitation and possibly a few thunderstorms as a frontal wave
moves over the region. Rather robust PWATs on the order of 1.75
inches should allow for 0.5 to 1 inches of rainfall across most of
southern New England during the day Thursday. As the associated
surface cold front shifts east on Friday, the region drys out for a
brief period, but persistent broad cyclonic flow and a cold pool
aloft will support daily showers chances through early next week.
Temperatures will be near normal with daily highs/lows in the mid to
upper 70s and upper 50s/low 60s respectively. Expect more clouds
than sun during this time period.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Forecast Confidence Levels:

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

12Z TAFs:

Today...High confidence.

VFR, with sct-bkn cigs 5-7k ft developing in the interior. Low
risk for an isolated afternoon shower or t-storm in the
Berkshires. Coastal sea-breezes developing, otherwise SE-S wind
5-10 kt.

Tonight and Wednesday...Overall high confidence, but lower
confidence in stratus development.

VFR, but patchy stratus may develop overnight into early Wed
over Cape/Islands and possibly the south coast. Light winds
tonight, then SW 10-20 kt developing Wed.

KBOS TAF...High confidence.

KBDL TAF...High confidence.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: Mainly VFR, with local IFR possible. SHRA
likely, isolated TSRA.

Thursday: Mainly MVFR, with areas IFR possible. SHRA likely,
isolated TSRA.

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

Friday: Mainly VFR, with local MVFR possible. Chance SHRA,
isolated TSRA.

Friday Night: VFR. Slight chance SHRA.

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

&&

.MARINE...
Forecaster Confidence Levels:

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

High confidence through Wednesday.

Tranquil boating conditions through tonight. Generally E-SE winds up
to 10 kt today becoming SW tonight. Increasing SW winds developing
Wed with gusts up to 20 kt. Seas below SCA.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: Winds less than 25 kt. Chance of rain showers,
isolated thunderstorms.

Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Rain showers likely, isolated thunderstorms.

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

Friday through Saturday: 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.

&&

$$

SYNOPSIS...KJC/RM
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...RM
AVIATION...KJC/RM
MARINE...KJC/RM