Groton, Connecticut 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

150
FXUS61 KOKX 262006
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
406 PM EDT Thu Jun 26 2025

.SYNOPSIS...
High pressure over New England will remain in control through
Friday. A warm front will then begin to approach Friday night,
lift through Saturday morning, and stall to the north. As a
frontal wave passes Saturday into Saturday night, the front will
drift back south and stall over the area Sunday into Sunday
night. The warm front will surge north Monday into Tuesday in
response to a passing Canadian low. A cold front will pass
Tuesday night, followed by high pressure during mid week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 330 PM, except for Staten Island and nearby portions of
NE NJ, overcast skies cover nearly all the CWA. Meanwhile, a
few weakening showers have made it into Orange County, and do
not expect this activity to make it much farther south/east
before sunset. For tonight, expect cloudy skies throughout,
with only slight chance of a stray shower across parts of the
NYC metro area and Long Island, with low temps in the upper
50s/lower 60s.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Winds on Fri should veer more to the SE, with skies remaining
mostly cloudy and only the slight chance of an afternoon showers
from NYC north/west. Do not expect much difference in high temps
compared to those of Thu afternoon, perhaps slightly cooler
across Long Island and slightly warmer across interior S CT,
with highs generally 70-75.

With the approach of the warm front Fri night, expect a non-
diurnal temp curve, with evening lows in the lower/mid 60s. then
temps remaining steady or slowly rising overnight to the
mid/upper 60s, with dewpoints also following suit. Also expect
chance of showers and possible tstms with the approaching front,
and some patchy fog along the coast.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Key Messages:

* Warmer temperatures from a warm front Saturday.

* Showers and thunderstorms with brief heavy downpours Saturday
  into Saturday night.

* Mostly dry Sunday into early Monday.

* Unsettled weather returns late Monday into Tuesday night.

* Drying out mid-week next week.

On Saturday, a warm front that was stalled to our south advances
through in the morning and stalls to our north in the afternoon.
This will lead to southerly flow that will advect in warmer,
wetter air. Confidence in the warm front`s passage has been low
confidence prior to this, but most 12Z guidance now agrees on
its passage north through our area. High temperatures have been
adjusted slightly higher than the deterministic NBM (which is
still on the cool side around the 25th percentile). Highs on
Saturday are now forecast to be in the upper-80s for
southwestern portions of the CWA (near NYC and NE NJ) and are in
the low-80s/upper-70s for northeastern portions of the CWA
(near SE CT).

As the warm front passes on Saturday, a frontal wave passes to
our north. This occurs in tandem with a mid-level shortwave
that increases upper-level energy aloft. Given warmer
temperatures and higher dewpoints, scattered to numerous showers
and thunderstorms are forecast Saturday into Saturday night.
Some of which could produce brief heavy downpours. Therefore,
WPC has gone with a marginal risk for excessive rainfall for
areas N & W of NYC where some of the best dynamics are expected.
MLCAPE could peak to around 2000-2500 J/kg in this area. Given
warm temperatures and ample moisture, this could lead to
efficient rainfall rates. In addition to available instability,
expected shear and sounding profiles look conducive for possible
isolated severe weather N&W of NYC Saturday evening, and
possibly extending east of NYC. Primary risk would be for
damaging winds. As a result, SPC has issued a marginal risk for
severe weather for the western half of our CWA.

The warm front advances back south Saturday night. This front
then stalls over the area Sunday into Sunday night. Weak high
pressure takes hold during this period as the frontal wave exits
northeast. This period will be mainly dry, though an isolated
shower can not be ruled out. Temperatures have been forecasted
closer to the NBM given slight variations in where Saturday
morning and stalls north. A frontal wave passes Saturday into
Saturday night. Saturday night, the warm front pushes back south
and stalls over our area Sunday into Sunday night with weak
high pressure present. We`ll be warm sectored as the warm front
surges north Monday in response to a passing Canadian low. This
lasts into Tuesday until a cold front passes Tuesday night. High
the front stalls over us on Sunday among available 12Z
guidance.

The stalled front surges back north as a warm front Monday,
being captured by an occluded Canadian low and mid-level
shortwave. This leaves us warm-sectored until a cold front
passes Tuesday night. Expecting more unsettled weather through
this timeframe.

Following the cold front Tuesday night, high pressure takes hold
again, leaving us dry for the middle of the week. Temperatures
are currently forecast to remain around or slightly above
climatological norms Sunday through mid-week next week.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
A cold front stalls over the Middle Atlantic tonight into
Friday. High pressure builds in from the northeast through the
TAF period.

Improvement to VFR should occur through 22Z. Scattered showers
are possible this evening, mainly from the NYC metro terminals
on NW. Have left mention out of the TAF except at KSWF. Ceilings
are expected to begin lowering to MVFR late tonight into early
Friday morning, prevailing through the rest of the morning.
Improvement to VFR is likely in the afternoon. The only
exception is at KGON where conditions should remain VFR through
the TAF period.

NE flow 10-15 kt this afternoon with occasional gusts up to 20
kt. Winds may weaken somewhat tonight, but should increase
again Friday morning. E winds 10-15 kt with gusts up to 20 kt
expected by late Friday morning.

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

Improvement to VFR may be off by 1-2 hours this afternoon.

Occasional gusts 15-20 kt possible this afternoon.

AMD likely for timing of MVFR cigs late tonight into Friday.

.OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...

Late Friday afternoon and Friday night: MVFR cigs and E winds
G20kt. IFR or lower possible at night.

Saturday: IFR or lower in the morning. Showers likely with a
chance of thunderstorms and MVFR in the afternoon and evening.

Sunday and Monday: Mainly VFR.

Monday night and Tuesday: Showers and thunderstorms with MVFR
possible, especially Tuesday afternoon and evening.

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

&&

.MARINE...
SCA remains in effect for the ocean waters and has been extended
into Fri night. Seas 4-5 ft should peak at 5-7 ft from very
late tonight into Fri morning while persistent E flow increases
to 20-25 kt. Winds drop below 25 kt by Fri afternoon, but seas
should take until late Fri night to subside below 5 ft.

&&

.HYDROLOGY...
Brief heavy downpours are possible late Saturday into Saturday
night, and could lead to isolated instances of nuisance
flooding in urban, low lying, and/or poor drainage locations.

&&

.TIDES/COASTAL FLOODING...
Coastal Flood Advisories are in effect for tonight`s high tide
cycle along the shorelines of NY Harbor, Jamaica Bay, and S
Nassau, well as along the western Sound in Westchester and
Fairfield in SW CT, with up to a foot of inundation expected.

Coastal Flood Statement was also issued for up to a half foot
of inundation along the vulnerable areas along the Peconic and
Shinnecock Bays. Water levels near Riverhead could be locally
higher, with up to a foot of inundation possible there.

Additional spotty minor coastal flooding is possible again
during the Friday evening high tide cycle, as water levels come
down slightly.

There is a high rip current risk for all south shore Long Island
and NYC beaches Friday. Surf heights of 3-3.5 feet with a long
shore current will lead to this high risk. Surf height lowers to
2 feet on Saturday with onshore flow, so the rip current risk
will lower to moderate on Saturday.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
     Friday for CTZ009.
NY...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
     Friday for NYZ071.
     Coastal Flood Advisory from 8 PM this evening to midnight EDT
     tonight for NYZ072-074-075-178-179.
     High Risk for Rip Currents from Friday morning through Friday
     evening for NYZ075-080-081-178-179.
NJ...Coastal Flood Advisory from 8 PM this evening to midnight EDT
     tonight for NJZ006-106-108.
MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ350-353-
     355.

&&

$$

SYNOPSIS...BG/BR
NEAR TERM...BG
SHORT TERM...BG
LONG TERM...BR
AVIATION...DS
MARINE...BG/BR
HYDROLOGY...BG/BR
TIDES/COASTAL FLOODING...BG/BR