Watch Hill, Rhode Island 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

968
FXUS61 KBOX 151957
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
357 PM EDT Thu May 15 2025

.SYNOPSIS...

Weakening low pressure will bring scattered showers or thunderstorms
at times through the end of the week as it reaches New England, but
a majority of the time will be dry. Scattered showers or
thunderstorms will be a possibility to start the weekend before a
cooling trend and drier conditions move into the region to start
next week. Unsettled weather returns mid to late week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Key Messages:

* Isolated to widely scattered aftn showers/t-storms this
  afternoon, some which may contain a localized heavy-downpour
  risk.

* Low clouds and areas of fog overnight, locally dense in some
  location.

Details:

Radar this afternoon (2:30PM) shows scattered convective showers
and a few storms developing from the south pushing northward
across RI, CT, and mainly central MA. Expect this to continue
through the afternoon hours. There is plenty of moisture around
with around 1.2-1.4" of precipitable water across southern New
England and marginal elevated instability. Given the warm cloud
depths and skinny CAPE sounding profiles, there is still a risk
for a storm or two to be capable of localized heavy rainfall.
Showers and storms decrease this evening.

Main event for tonight will be the low stratus and fog. The
moist airmass, warm temperatures aloft, and calm winds will
support development of areas of fog and low stratus tonight.
Impacts will be lowered visibilities to as low as 1/2 to 1/4 of
a mile in localized spots tonight through early Friday morning.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
Key Messages:

* Gradual clear of low clouds and fog Friday morning through
   the afternoon.

* Potential for scattered showers and storms in the afternoon,
  with the higher chances for western and central MA.


Details:

Friday morning will start with low clouds and areas of fog.
Subtle height rises work into the region in the morning which
will help bring breaks in the clouds in the afternoon. The Cape
and Islands will likely be slower to improve than the interior. Model
soundings show gradual improvements after 8 AM Friday morning
with further improvements in the afternoon. As clouds break,
we`ll get more sunshine in that timeframe which will help build
a bit more instability, mainly across western MA along with help
of the approaching front to bring weak lift. Will a moist
airmass prevailing, this will support scattered showers and
storms in the afternoon, with the higher chances for western MA,
central MA, and parts of CT. A few stray showers or storms may
move into central and northeast MA.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...

Key Messages...

* A round of strong to severe storms expected on Saturday afternoon
  and evening.

* Drier and cooler to start next week followed by more unsettled
  weather.

A mid level trough and surface low digging into the Great Lakes on
Saturday will bring a round of strong to severe storms to southern
New England Saturday afternoon and evening. Ahead of this system a
warm front moves north and brings dewpoints well into the 60s by
Saturday afternoon on warm and moist southerly flow. This will make
for a warm (upper 70s to near 80) and relatively humid day on
Saturday and help to generate a good amount of instability in the
warm sector, on the order of 500-1500 J/kg of MUCAPE. A stout
inversion around 900 mb looks to keep the majority of convection
elevated, but as the cold front approaches there is potential to
break that cap, especially northwestern/interior SNE where the
strongest instability lies. Meanwhile, 0-6 km bulk shear around 25-
30 kts would be enough to prolong some of the updrafts and allow for
a few strong to severe storms, of which the main threat would be
damaging winds and secondarily large hail. However, 0-1km shear (25-
30kts) and 0-1km helicity (~150m2s2) are enough to mention a non
zero chance of a tornado in western MA. While CSU machine learning
probs of severe weather have decreased a bit in the last 24 hours,
they continue to indicate a 2-5% chance for tornadoes, 5-30% chance
of severe wind, and 5-15% chance of severe hail. The SREF also
indicates a 20-50% chance of overlapping 500+ J/kg CAPE with 30+kts
0-6 bulk shear. This is a good indicator of chance of severe
weather. We`re just getting into the hi-res guidance at this point,
but timing-wise the storms look to move through from west to east,
generally noon to 8PM. So, Saturday shouldn`t be a washout but
expect generally a 3-4 hour period of showers and storms at any one
location.

The cold front then sweeps through Saturday night so Sunday will
feel cooler (upper 60s and low 70s) and less humid with dewpoints
back in the 40s and low 50s. Expect a mix of clouds and sun with
scattered diurnal showers thanks to the cold pool aloft and slow to
exit low. Mid level ridging then pushes in with weak surface high
pressure to start the week so we`ll see slightly more sun and mostly
dry weather for Monday and Tuesday. However, uncertainty is higher,
especially as we get into Tuesday and mid week; a nearby mid level
system over eastern Canada may be in close enough proximity to bring
some scattered showers Tuesday. This is followed by signs of a
deeper, move organized low bringing more widespread rain to the
region mid week into the latter half of the week.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

18z TAF Update:

Today: Moderate confidence.

Mix of IFR and low end MVFR cigs this afternoon. Widely
scattered showers and few storms possible 18z-00z today. Not
quite high enough coverage to include as a PROB30 group at most
of the terminals. Light SE/E winds around 5-10 kt.

Tonight: Moderate confidence.

Any residual showers will dissipate after 00z. Areas of IFR to
LIFR fog and stratus develop after 00z. Showed most airports
around 1/2 to 4SM, but fog could become locally dense and
visbys could be as low as 1/4SM, especially western airports and
Cape/Islands. Light to calm winds.

Friday: High confidence in trends, but moderate on timing.

IFR-LIFR from overnight should start to improve out of IFR
13-16z then toward VFR in the afternoon (around/after 18z). The
Cape/Islands will be slower to improve, but should see gradual
improvements after 15/16z. Some risk for SHRA/TS possible west
of ORH after 18z but stronger activity seems more likely west of
the Berkshires. Not high enough confidence to include in the TAF
at this point. Light S winds 5-9 kts.


KBOS TAF...Moderate confidence.MVFR with brief VFR this
afternoon, then start to lower again to IFR-LIFR levels around
and after 00z. Fog develops after 00z. Conditions gradually
improve after 12z through the day Friday. Lower confidence on
timing of VFR, but more likely mid to late afternoon.

KBDL TAF...Moderate confidence. Low chance for scattered shower
or thunderstorm through 00z. IFR-LIFR in fog/stratus tonight,
locally dense fog possible.

Outlook /Saturday Night through Tuesday/...

Saturday Night: VFR. Chance SHRA.

Sunday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA.

Sunday Night: Mainly VFR, with local MVFR possible. Breezy.
Slight chance SHRA.

Monday through Tuesday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

330 AM Update:

High confidence overall.

E/SE winds remain below SCA levels Thu and Fri. Seas will be
building on the southern ocean waters where SCAs still continue.
Few showers or a thunderstorm possible early this morning, with
areas of marine fog developing tonight and could linger into a
good part of Fri.

Outlook /Saturday Night through Tuesday/...

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

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

Sunday Night through Monday: Winds less than 25 kt. Areas of
seas approaching 5 ft.

Monday Night through Tuesday: Winds less than 25 kt. Seas
locally approaching 5 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 4 PM EDT this afternoon for ANZ235-
     237.
     Small Craft Advisory until 1 AM EDT Friday for ANZ254>256.

&&

$$

SYNOPSIS...Hrencecin/Mensch
NEAR TERM...Mensch
SHORT TERM...Mensch
LONG TERM...BW
AVIATION...BW/Mensch
MARINE...BW/Mensch