549
FXUS61 KBOX 062318
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
718 PM EDT Sat Jul 6 2024

.SYNOPSIS...
Aside from a lone shower or thunderstorm, warm and muggy
conditions will persist tonight. Summertime heat and humidity
should prevail next week, along with scattered showers and
thunderstorms, especially Wednesday through Saturday.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
715 PM Update:

Still have a good amount of instability across interior this
evening with MLCAPE as high as 2000 J/kg but airmass shows more
inhibition (CIN) farther east into central/eastern MA, eastern
CT, and RI. Storms have been firing to our west and north and we
are starting to see some new activity developing near
Berkshires. This should be the area to focus on early tonight
where instability is collocated with strong 0-6km shear, but mid
level lapse rates are meager at best which will prevent activity
from becoming more organized. Minor flooding from brief
downpours is main threat but storms are moving along quickly.
High-res guidance continues to struggle with both timing and
location in weakly forced environment.

Otherwise, low cloud bank was spreading inland from RI and SE MA
and should expand farther inland tonight, most likely into
Worcester Hills and more of Merrimack Valley. Patches of dense
fog also expected with persistent SW flow, mainly along and SE
of Providence to Plymouth line.

Warm and muggy night is in store with lows in upper 60s and 70s.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
A front slowly sags into southern New England late tonight into
Sunday. Not much push behind this front, so thinking this front
is still lingering nearby into Sunday night, most likely toward
the coast.

Very humid conditions and above normal temperatures continue.
That said, a subtle intrusion of drier air in the mid levels
aloft should provide more of a cap on showers and thunderstorms
during this time.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Highlights:

 * Summertime heat and humidity most of next week - potential
   Heat Advisory for some Mon/Tue
 * Scattered showers/storms mainly Wed-Fri

Ensembles are in good agreement next week and feature persistent
subtropical ridge over the western Atlantic and upper trough
near Great Lakes. This pattern favors typical summertime heat
and humidity as SW flow aloft transports very warm and humid air
up the East Coast.

Core of heat and humidity looks to be Mon/Tue. We could reach
Heat Advisory criteria (heat index 95-99F for 2 or more hours
on consecutive days) away from coast and especially in the
Connecticut and Merrimack Valleys as well as interior eastern
MA. For rest of next week, presence of more cloud cover should
keep highs in 80s, but overnight lows will probably stay in 70s,
especially in urban areas.

As we`ve seen over the past week, there probably won`t be a lot
of larger scale forcing present to result in organized showers
or thunderstorms. Rather, we should see weaker short waves from
Great Lakes dampen out as they run into upper ridge offshore.
Timing of these short waves is always a problem in the model
world, especially at longer time ranges, but it does appear our
better chances of showers/storms will be in the Wed-Sat
timeframe (afternoon and evening) as we also have weak surface
fronts nearby.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
Forecast Confidence Levels:

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

00z TAFs: Moderate confidence (60%).

Trend will be for conditions to lower to MVFR in western MA/CT
and to IFR/LIFR across much of eastern CT, RI, and central/
eastern MA overnight. TS should be confined to western MA early
tonight but another passing shower or storm is possible
overnight.

Slow improvement to VFR from NW to SE Sunday morning, but went
more pessimistic near Cape Cod and Islands where persistent SW
flow should keep IFR ceilings locked in all day, although
visibility should improve by midday. Expecting LIFR to return
there around sunset Sunday with VFR elsewhere.

KBOS TAF...High confidence (70%). Timing of improvement Sunday
may be a couple of hours too slow.

KBDL TAF...High confidence (80%).

Outlook /Monday through Thursday/...

Monday through Monday Night: VFR.

Tuesday: VFR. Slight chance SHRA, isolated TSRA.

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

Wednesday: VFR. Breezy. Chance SHRA, isolated TSRA.

Wednesday Night: VFR. Chance SHRA.

Thursday: VFR. Chance SHRA, isolated TSRA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Sunday Night:

S to SW flow continues as a front slowly approaches the waters
tonight, then likely stalls across the waters Sunday into Sunday
night. A few gusts up to 25 kt, along with marginal 5-foot seas
across the southern coastal waters, so continued the Small Craft
Advisories into Sunday. Areas of fog may reduce visibility below
1 mile late tonight. Visibility expected to improve Sunday.

Outlook /Monday through Thursday/...

Monday through Tuesday: Winds less than 25 kt.

Tuesday Night: Winds less than 25 kt. Slight chance of rain
showers, isolated thunderstorms.

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

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Risk for Rip Currents until 8 PM EDT this evening for
     MAZ020>024.
RI...High Risk for Rip Currents until 8 PM EDT this evening for
     RIZ006>008.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
     ANZ232>235-237.
     Small Craft Advisory until 8 AM EDT Sunday for ANZ254.
     Small Craft Advisory until 11 AM EDT Sunday for ANZ255-256.

&&

$$

SYNOPSIS...Belk/JWD
NEAR TERM...Belk/JWD
SHORT TERM...Belk
LONG TERM...JWD
AVIATION...Belk/JWD
MARINE...Belk/JWD