Sag Harbor, New York Weather Forecast Discussion

823
FXUS61 KOKX 161603
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1203 PM EDT Tue Sep 16 2025
.SYNOPSIS...
High pressure over New England will drift offshore today.
Weak low pressure will approach from the south tonight into
Wednesday, then move east Wednesday night and Thursday. A cold
front passes across the area Friday allowing high pressure to
build in through the weekend. The high pressure may start moving
offshore early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
High amplitude ridging will remain over the northeast today
as a broad cutoff upper low meanders over the southeast. The
ridging begins to weaken tonight allowing the cutoff low and its
associated surface low to start lifting northward towards the
Middle Atlantic.
Surface high pressure over New England will drift offshore
through this evening. While mid and high clouds will increase
and start thickening, the layer below 15kft will remain quite
dry through sunset. NBM PoPs seemed a bit too high this
afternoon along the coast, so have adjusted them down to below
15 percent. This is supported by the aforementioned lower level
dry air and lingering surface ridging. Highs should end up close
to normal in the lower to middle 70s with coolest readings
along the immediate coast with onshore flow and increasing
clouds.
Surface high pressure will remain off the New England coast
tonight as the low pressure gradually lifts towards the north.
Increasing low level moisture, especially across the southern
half of the area brings a chance of showers tonight. A few
showers could drift north into the interior overnight, but
probabilities are lower here. Have kept thunder mention out of
the forecast as any elevated CAPE is very marginal and there is
no surface CAPE with the onshore flow over the area. Lows range
from the mid to upper 50s inland to lower 60s near the coast.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
The cutoff low and its associated weak surface low pressure
continue lifting towards the area on Wednesday. The system
eventually becomes an open trough and flattens Wednesday night
into Thursday as the weak surface low drift offshore well south
and east of Long Island.
Chances of showers will continue Wednesday. The 00z CAMS
indicate mixed signals with the amount of showers moving north
across the area. Several of the CAMs are quite dry with very
little activity while a few are showing a bit more coverage (00z
HRRR) on Wednesday. The main challenge with this pattern is how
much the lingering surface ridging will impact shower
development/maintenance. Given these reasons, did not want
to sway too much from the latest NBM, which continues to have
the highest probabilities remaining across the southern half of
the area, specifically close to the coast. There continues to be
a lack of instability and have therefore left mention of
thunder out of the forecast on Wednesday. Showers remain
possible Wednesday night into early Thursday morning with a
trend towards dry conditions Thursday afternoon and Thursday
night as the system pushes to the east.
Overall, light to moderate rain is expected in any shower
that occurs with this event. Average rainfall amounts range
from a few hundredths inland to a few tenths closer to the
coast.
Temperatures on Wednesday will be held down due to cloud cover
and potential showers. Highs will only reach the lower 70s.
Temperatures rebound on Thursday into the upper 70s to low 80s,
especially as clouds decrease into the afternoon.
Temperatures on Tuesday will range from the lower to middle 70s
near the coast and upper 70s inland. Temperatures on Wednesday
will remain in the lower 70s with cloud cover and easterly flow.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
No changes made to the long term with the latest NBM used with
this update.
Key Points:
*Friday will be the warmest day of the period ahead of a dry
 cold front passage. Highs will rise into the low to mid 80s in
 NE NJ and NYC metro with upper 70s to lower 80s elsewhere.
*A cold front passage late Friday will be followed by building
 high pressure and continued dry conditions this weekend into
 early next week.
*Highs will mainly be in the low 70s this weekend with cooler
 nighttime temperatures ranging from the upper 40s inland and
 low to mid 50s elsewhere.
*Temperatures should start trending warmer early next week.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
High pressure remains near the region today. The high slides
east tonight as low pressure remains south of the area.
VFR today, likely remaining VFR through at least midnight. MVFR and
-shra becoming likely during the Wednesday morning push and lasting
through the morning for all but KSWF/KBDR/KGON.
NE winds 10-15kt veering E this afternoon with gusts 20-25kt, though
more occasional at some terminals. Gusts subside and winds diminish
under 10 kt in the evening. Winds become more northeasterly late
tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts may be only occasional today.
.OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
Wednesday: MVFR or lower likely with SHRA.
Thursday: Chance of MVFR and SHRA in the morning, otherwise VFR.
Friday-Saturday: VFR. NW gusts 20-25kt on Friday.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
A persistent easterly flow ahead of a slowly approaching
weak low pressure will increase winds and build seas today.
These conditions will then persist through Wednesday. An SCA
remains in effect on the ocean waters through tonight. The
Advisory has also been extended through Wednesday afternoon.
While the Advisory has mainly been issued due to elevated seas
between 5-6 ft, winds may gust up to 25 kt this afternoon into
Wednesday morning. Conditions on the non- ocean waters will
remain below SCA levels, but could see winds gust to 20 kt this
afternoon into Wednesday. Winds and seas will begin subsiding
Wednesday night and especially Thursday as the system pulls away
to the east. Conditions will remain below SCA levels Friday
through the upcoming weekend.
&&
.HYDROLOGY...
There are no hydrologic concerns through early next week.
&&
.TIDES/COASTAL FLOODING...
There is a high rip current risk at the ocean beaches through
this evening with ENE flow, building surf to around 5 ft, and
easterly swells. The risk remains high on Wednesday for NYC,
Nassau, and southwest Suffolk beaches. For southwest Suffolk
beaches, the risk is moderate as surf may begin subsiding to 4
ft. However, it is possible for it to be a high risk if surf
does not subside as quickly.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents until 8 PM EDT this evening for NYZ075-
     080-081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT Wednesday for ANZ350-353-
     355.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...DS
AVIATION...BC/JC
MARINE...DS
HYDROLOGY...DS
TIDES/COASTAL FLOODING...

NWS OKX Office Area Forecast Discussion