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077
FXUS61 KBOX 281414
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1014 AM EDT Tue May 28 2024

.SYNOPSIS...
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Summer warmth and humidity today with a chance for a brief
isolated shower. Temperatures then cool off to more seasonable
levels into the mid to late week period, along with lower
humidity. Though dry weather should generally prevail, there
are better chances for rain to develop Wednesday night into
Thursday. Mostly sunny and dry weather conditions for the
weekend into early next week, with a warming trend.
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&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...

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1015 AM update...

Dry slot overspreading the region and resulting in low clouds
eroding and giving way to partly to mostly sunny conditions.
This dry slot will limit any diurnal convection to very isolated
and brief activity, with most if not the entire day featuring
dry weather. Highest chance (15-20%) across the high terrain.
Drier/less humid airmass advecting in from the west, with dew
pt falling into the 50s across western CT/MA. This airmass
overspreads SNE from west to east as the day progresses. Hence,
less humid as the day evolves. Still warm air aloft, with 925
temps +18C to +19C this afternoon +13C at 850), warmest across
eastern MA. This will support highs into the low 80s, including
Boston, given SW breeze 10 to 20 mph. Cooler south coast given
SW trajectory off cool ocean with SSTs 55-60.
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&&

.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...

Highlights:

* Mild and dry overnight, followed by a seasonable midweek with
  renewed chance for showers and rumbles of thunder.

Tonight: A dry night ahead with mainly clear skies, clouds do linger
in the higher terrain of northwest Massachusetts. Wind shifts more
to the west, dewpoints fall into the low and middle 50s with
temperatures in the upper 50s and low 60s.

Wednesday: Our next chance at rain comes in Wednesday afternoon with
a shortwave riding the base of the mid-level trough. Do not think
the day will be a washout, but do think there will be a few
scattered showers and rumbles of thunder mainly across Rhode Island
and southeast Massachusetts after 16z/18z. NAM profiles show limited
MUCAPE around 500J/kg, but low level lapse rates are rather
impressive at 8-9 C/km. Limiting the growth are poor mid level lapse
rates, less than 6C/km. FWIW - SPC does keep us in general thunder
on Wednesday. Temperatures return to more seasonable highs,
temperatures aloft are cooling, leading to highs in the middle and
upper 70s, slightly cooler at the coast where highs are in the low
70s. Wind shifts northwest across the interior during the afternoon,
while at the coast wind direction remains out of the southwest.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...

Highlights:

* Temperatures will be cooler on Thursday, increasing steadily each
  day through early next week.

* Rain is expected to continue Wednesday night into Thursday
  followed by an extended stretch of dry weather through at least
  early next week.

Details...

The synoptic pattern for the extended forecast will feature a deep
mid level trough/cold pool aloft leading to unsettled weather
initially, followed by mid level ridging and a drier, warmer pattern
for late week into early next week.

For the Wednesday night through Thursday light rain showers will be
more likely as the trough and associated cold pool move overhead.
PWATs are not overly impressive at around an inch, and total
rainfall isn`t expected to be much more than a half inch or so where
the showers develop which is supported by ensemble guidance. Some
uncertainty as to the areal extent of the showers at this distance
in time, but odds are that not everyone will get a soaking. A
surface cold front sinking through on Thursday together with the
cooler airmass overhead will lead to the coolest day of the forecast
on Thursday, in the upper 60s/low 70s.

Late Friday into the weekend mid level heights will be on the rise
as high pressure moves overhead at the surface. This will lead to a
drying and warming airmass with steadily rising temperatures each
day. High temps will be back to normal by Friday (low to mid 70s)
and then steadily increase each day until by Monday we`re looking at
highs in the low to mid 80s. Humidity will be more comfortable early
in the weekend, with dewpoints steadily rising as we go into early
next week making it feel more humid next week but not excessive.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
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Forecast Confidence Levels:

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

15z TAF Update: high confidence on improving trends to
eventually VFR (all terminals) in the TAFs. Earlier discussion
below.

==================================================================

Today... High to moderate confidence.

Cold front stalls across southern New England, generally across
the eastern third, yielding VFR conditions after 15Z, exception
being the Cape and Islands, especially ACK, which will struggle
to shake IFR. Will say, have lower confidence in timing of
improvement of CIGs for Cape and Islands. Brisk WSW flow of up
to 20kt. Widely isolated low topped thunderstorms are possible
in northern MA after 21Z.

Tonight... High confidence.

Generally VFR, the outer Cape and Islands may return to MVFR,
there confidence is not as high. In addition, can not rule out
some marine stratus and fog. Breezy WSW flow continues.

Wednesday... High to moderate confidence.

Generally VFR, CIGs 040-060 ft with chance SHRA or an isolated
TSRA by early afternoon. Winds are W to NW across the interior
and SW to W across the coast.

KBOS TAF...High confidence in TAF trends, moderate in timing.

IFR, rain continues through about 07z-09z and shifts offshore;
the IFR cigs likely to continue until ~13z with a more rapid
return to VFR. S winds around 10-13 kt before shifting to SW by
early AM. Wind gusts increase to 18-20 kts after 16z, low chance
for a widely isolated thunderstorm after 21z, confidence remains
too low to include, even in a PROB30.

KBDL TAF...High confidence in TAF trends, moderate in timing.

IFR, cigs to trend MVFR by 09-12z with more rapid improvement
to VFR by mid morning. S winds around 10-12 kt before becoming
SW. Wind gusts increase to 18-20 kts after 15z, low chance
for a widely isolated thunderstorm after 21z, confidence remains
too low to include, even in a PROB30.

Outlook /Wednesday Night through Saturday/...

Wednesday Night through Thursday Night: VFR. Chance SHRA.

Friday: VFR. Slight chance SHRA.

Friday Night through Saturday: VFR.
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&&

.MARINE...
Forecaster Confidence Levels:

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

Small craft advisories continue on outer waters tonight through
tonight, with SW winds 20 to 25 kt and seas building to around
4-5 ft.

Today into tonight, SW to WSW winds 15-20 kt, isolated gusts to
25 kt are expected with seas rising to around 4-6 ft on the
southern and eastern outer waters and around 3 ft or less
nearshore.

Wednesday, SW winds 10-15 kt, gust to 20 kt with seas 3-4 ft on
the southern and eastern outer waters and around 2 ft or less
nearshore.

Outlook /Wednesday Night through Saturday/...

Wednesday Night through Thursday Night: Winds less than 25 kt.
Chance of rain showers.

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

Friday Night through Saturday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 5 AM EDT Wednesday for ANZ250-
     254>256.

&&

$$

SYNOPSIS...BW/Dooley
NEAR TERM...Nocera/BW/Dooley
SHORT TERM...Dooley
LONG TERM...BW
AVIATION...Nocera/BW/Dooley
MARINE...BW/Dooley