Norwalk, Connecticut 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

244
FXUS61 KOKX 171342
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
942 AM EDT Sat May 17 2025

.SYNOPSIS...
A warm front continues pushing north this morning, followed by a
cold front passage late this evening. Low pressure slowly moves
across New England on Sunday sending a secondary cold front
across the area. The low slowly exits the New England coast on
Monday as high pressure gradually builds in from the northwest.
High pressure takes control Monday night into early Tuesday
night. A frontal system impacts the area Wednesday into Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Morning fog has improved across Long Island but is still hanging
on across portions of Southern Connecticut. The warm front
lifting north as well as a pre-frontal trough moving across the
area will help improve visibilities the rest of the morning.

A band of decaying showers associated with the pre-frontal
trough will slide across the area through midday. Many areas may
stay dry with just some sprinkles or a brief shower. Some CAMs
were too aggressive in redeveloping this activity into new
convection, but based on latest observational trends this
appears unlikely.

Confidence with afternoon and evening convection remains low.
The weak shortwave associated with the aforementioned vorticity
will leave behind some subsidence as well as mid level dry air
this afternoon. The flow will also start becoming SW into the
afternoon which may also help mix out some of the higher dew
points. Another limiting factor will be the most organized
forcing remaining well to our north and west this afternoon and
evening immediately ahead of the parent upper low and surface
low over the Great Lakes. There is also a question of how much
instability will exist this afternoon despite limited cloud
cover, mainly due to the aforementioned dry air. Due to all of
these factors, have lowered PoPs this afternoon and evening and
placed the highest probabilities over the Lower Hudson Valley
and interior SW CT. The activity if it develops will be isolated
further south and east closer to the coast/Long Island and may
just be associated with the cold front passage this evening.

The severe weather risk remains marginal as there is enough mid
level flow for shear supportive of updraft organization. The
main limiting factor again is with an organized trigger and the
amount of instability. While SPC has the area in a marginal
risk, think the probability for an isolated severe storm is
highest across the Lower Hudson Valley with the main threat from
damaging winds and potentially hail.

Convection may linger towards or just after sunset with the cold
front passage, but the severe concern diminishes quickly with
loss of heating. Any lingering showers should diminish through
the rest of the evening.

Highs in the upper 70s to mid 80s are expected today. Winds will
likely gust 25 to 30 mph, especially across NE NJ, NYC metro,
and the Lower Hudson Valley where mixing is maximized.

The cold front pushes through likely just before or around midnight
and will finally start to filter in a drier airmass in a westerly
flow.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The upper level low will be centered to our north most of Sunday as
it very gradually shifts east. Some energy rotating around the low
will aid in pushing a secondary cold front through the area in the
evening hours. Some light rain showers are possible with this
feature, mainly across the interior. No thunder is forecast. Skies
also likely fill in around 4 kft, leading to mostly cloudy
conditions for the afternoon. In the cooler airmass, highs are
forecast to be in the upper 60s to lower 70s.

Surface troughing could continue into Monday as the low lingers off
the New England coast. Dry and sunny conditions are expected with
similar high temperatures as Sunday.

Both days could be gusty with some deeper mixing each day. 25 to 30
mph gusts are expected.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Key Message:

 * A frontal system likely impacts the region beginning   Wednesday,
and continues into Thursday, and possibly into Friday.

No significant changes were made to the forecast for Tuesday into
the end of the week, as a frontal system remains likely to impact
the region late Tuesday night into Friday. An upper closed low
develop over the mid section into the upper Midwest by late Tuesday
night, and then the upper trough deepens and the closed low and
upper trough are slow to move eastward into the beginning of next
weekend. At the surface a deepening low moves out of the Mid
Mississippi Valley and into the Ohio Valley late Tuesday into
Wednesday. This low then moves slowly across the northeast Thursday
into Friday in association of the upper low becoming nearly
stacked. With a secondary surface low developing late Wednesday
into Wednesday night and increased precipitable waters values and
lift, there is the potential for a period of moderate rainfall.
Also, depending on the track of the low Thursday`s temperatures are
more uncertain. However, overall temperatures will be near or slightly
below normal levels Tuesday through Friday.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
A warm front moves through the area during the day. A cold front
moves across the region late this evening.

IFR to LIFR conditions early this morning are expected to
quickly improve to VFR 13Z to 14Z, earliest across northeastern
New Jersey and the NYC terminals. VFR then remains through the
forecast period. A few light showers are possible this morning
at the NYC metro terminals with no impacts to conditions. The
chance for thunderstorms late this afternoon into this evening
have diminished, and may be widely scattered. However,
continued with the PROB30. Best chance will be at KSWF, and
changed over to TEMPO.

South winds this morning increase to 10-15kt with some gusts
17-23kt late morning through the afternoon. With a cold front
passage late this evening winds shift to the W/NW, and may
become gusty late tonight. Gusts are more likely during the day
Sunday.


   ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Any remaining LIFR to IFR conditions at 12Z quickly improve to
VFR by 13Z/14Z. A few light showers are possible this morning,
with no impacts to conditions. Thunderstorm chances for late day
into the evening have diminished, and continued the PROB30.
There is a chance that thunder does not occur.


.OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...

Sunday: VFR. Slight chance of showers inland with MVFR
possible. W winds G20-30kt.

Monday - Tuesday: VFR. Monday NW winds G20-25kt day into evening.

Wednesday: MVFR or lower with showers likely, a slight chance of
thunderstorms in the afternoon. E wind gusts 15-20kt.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
Fog should begin improving on the Long Island Sound with
visibilities above 1 nm by 11 am. A marine weather statement
continues until 11 am. Otherwise, conditions will remain below
Small Craft Advisory levels for the most part today. However,
some nearshore gusts could reach 25 kt, mainly in the NY Harbor
and western LI Sound.

Winds pick back up on Sunday and a Small Craft Advisory is in effect
during the daylight hours. Gusts could reach 25 to 30 kt, with seas
over the ocean reaching 4-5 ft. There is potential for the SCA to be
extended through Monday as marginal conditions are expected.

Winds and seas remain below advisory levels on all the forecast
waters Tuesday into Wednesday. With the approach of a frontal system
during Wednesday and easterly flow will be increasing and by late
day SCA conditions may develop on the ocean waters. With the
increased and persistent east flow into Thursday winds and seas on
the ocean waters will likely be at SCA levels. As low pressure
tracks northeast of the area Thursday night a northerly flow
develops and winds diminish, however, ocean seas are likely to
remain elevated into Thursday night.

&&

.HYDROLOGY...
There are no hydrologic concerns through next week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM to 6 PM EDT Sunday for ANZ331-
     332-335-338-340-345-350-353-355.

&&

$$

SYNOPSIS...MET/JT
NEAR TERM...DS/JT
SHORT TERM...JT
LONG TERM...MET
AVIATION...MET
MARINE...MET/JT
HYDROLOGY...MET/JT