151
FXUS61 KBOX 140228
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1028 PM EDT Tue Aug 13 2024

.SYNOPSIS...
Dry and very pleasant weather continues into Wednesday. Another
round of scattered showers and perhaps a few thunderstorms, is
expected Thursday. Dry weather likely returns Friday and may
linger into Saturday, especially across RI and eastern MA. Then
a frontal system may bring scattered showers and thunderstorms
Sunday through Tuesday. Probably not a washout, with periods of
dry weather too during this time. Meanwhile, Ernesto will track
well southeast of New England, but it will bring rough surf and
strong rip currents to south facing ocean beaches of RI and MA
this weekend.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Quiet weather continues across southern New England. No major
changes to the ongoing forecast.

8 PM update...

Dry NW flow through the column over SNE along with PWATs less
than 1 inch, will provide dry weather tonight. Mostly clear
conditions, a dry airmass and light winds will promote another
night of radiational cooling. Given this setup, min temps
tonight were derived from the cooler MOS guidance. This yields
another round of lows in the mid to upper 50s, except low to mid
60s in the urban centers of Boston, Providence, Hartford,
Worcester, including the coastline, Cape Cod and the islands.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Wednesday will feature more of the same weather from today as the
high nudges further east over New England. It once again leads to
mostly clear skies to start with light winds. Our closer proximity
to the high also means less wind and sea breezes setting up along
the coast keeping the immediate shore in the mid 70s (with mid 80s
inland). Diurnal cumulus will be more numerous on Wednesday thanks
to moisture below 800 mb. The one wrinkle is a small disturbance
rotating around the exiting mid level trough, but lack of moisture
above 800 mb, weak forcing, and surface high pressure will help keep
the majority of locations dry. Even so, can`t rule out a smattering
of isolated showers and even a thunderstorm in the afternoon.
Diurnal clouds and any showers will dissipate after sundown but more
cloudcover will move in from the north thanks to a weak shortwave
overhead.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Highlights

* Scattered showers and thunderstorms Thursday followed by dry and
  seasonably warm conditions Friday

* Trending unsettled weather this weekend, with Sunday appearing
  wetter than Sat, although periods of dry weather too

* Ernesto likely tracks well southeast of New England, but will
  bring rough surf and rip currents this weekend to south facing
  ocean beaches of MA/RI

Thursday and Friday...

Closed low forms over the maritimes Wed night, then retrogrades
toward New England Thu. Increasing cyclonic flow and cold pool aloft
combined with mid level moisture, will yield scattered showers and
isolated thunderstorms Thursday. Similar type day to what we
observed yesterday/Monday. -14C temps at 500 mb will yield steep mid
and low level lapse rates, supporting a low probability of an
isolated gusty thunderstorm with small hail. 12z CSU machine
learning probs reinforce this idea. Drier and sunnier Friday, as
short wave ridging advects across the region, along with warming
temps aloft. Seasonably warm and somewhat humid both days, with
highs upper 70s to lower 80s, mid 80s possible Fri and dew pts in
the 60s both days. Typical August weather. Light and variable winds
each day, along with afternoon seabreezes keeping the coastline a
few degs cooler.

The Weekend...

Next short wave trough exits the Great Lakes and approaches New
England. Although, there may be sufficient short wave ridging over
SNE between Ernesto tracking southeast of New England and
approaching Great Lakes trough, for mainly dry weather to prevail
across RI and eastern MA.  Higher probs of showers and thunderstorms
would exist each day across CT into western-central MA. Although,
too far out in time to say with much certainty, but something to
keep in mind as we approach the weekend. As PWATs increase to above
normal this weekend, any convection will have the potential for
brief heavy rain. Not expecting a washout as there will be periods
of dry weather too. Seasonably warm both days with highs in the
upper 70s and lower 80s. As southwest flow strengthens Sunday,
humidity increases with dew pts rising from the 60s Sat into the low
70s Sunday. As for Ernesto, above average forecast confidence in
storm track, with all guidance tracking this system well southeast
of New England. Thus, no impacts expected. However, large/rough surf
and dangerous rip currents from Ernesto arrive this weekend,
especially at south facing ocean beaches.  See the latest tropical
forecast and updates from The National Hurricane Center at
nhc.noaa.gov.

Early Next Week...

Great Lakes trough finally advects across the region, with scattered
showers and thunderstorms possible both days, especially Mon with
some improvement possible Tue, pending exact trough departure time.
For what it`s worth at this time range, 00z CSU machine learning
probs do offer low chance of strong thunderstorm winds both days.
Warm and humid with highs in the upper 70s and lower 80s. It will
feel quite warm, with dew pts in the low 70s.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Forecast Confidence Levels:

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

03Z TAF Update...no change from previous TAFs, VFR, dry weather
and light/variable winds. Earlier discussion below.

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

Tonight...High Confidence.

VFR. Low probability of localized fog developing toward
daybreak in the typically lowest lying locations. Calm/Light NW
winds.

Wednesday...High Confidence.

VFR. Light north winds, with seabreezes likely to develop along
the immediate coasts.

Wednesday night...High Confidence.

VFR. Winds light and variable.

KBOS TAF...High Confidence

KBDL TAF...High Confidence.

Outlook /Thursday through Sunday/...

Thursday: VFR. Chance SHRA, isolated TSRA.

Thursday Night through Friday Night: VFR.

Saturday: VFR. Breezy. Slight chance SHRA.

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

Sunday: Mainly VFR, with areas MVFR possible. Breezy. Chance
SHRA, isolated TSRA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Wednesday night...High Confidence.

A ridge of high pressure to our west will result in pleasant
boating weather winds/seas below Small Craft Advisory thresholds
through Wednesday night. Visibility should be quite good as
well.

Outlook /Thursday through Sunday/...

Thursday through Friday: Winds less than 25 kt.

Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft.

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

Saturday Night: Winds less than 25 kt. Seas up to 5 ft. Slight
chance of rain showers.

Sunday: Winds less than 25 kt. Local rough seas. Chance of rain
showers.

&&

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

&&

$$

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