Area Forecast Discussion
Issued by NWS Upton, NY

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
367
FXUS61 KOKX 281756
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
156 PM EDT Sat Jun 28 2025

.SYNOPSIS...
A warm front lifts north through the area today, followed by a cold
frontal passage late tonight. High pressure will then be in place
for Sunday. The front returns north as a warm front Monday,
followed by a cold frontal passage late Tuesday. Weak high
pressure briefly takes control on Wednesday. A weak cold front
swings through Thursday, followed by high pressure late in the
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Warm front has lifted to the NE with skies clearing across the
area. The airmass will now have a chance to destabilize ahead
of a line of showers and thunderstorms heading into central PA.
CAMs have some differences in timing, but most weaken the line
as works into the area. SPC has elevated areas to the north and
west of NYC to a slight risk as there is a chance this line
cold move closer to the area per the latest SPC Day one outlook.

Temperatures will warm fairly significantly compared to the
last few days. Afternoon highs should reach the low 80s across
Long Island and southern Connecticut due to onshore flow
influence. However, the NYC metro, NE NJ, and Lower Hudson
Valley should rise into the middle and upper 80s. Dew points
increase into the lower 70s yielding max heat indices in urban
NE NJ in the mid to upper 90s with around 90 away from the coast
and influence of the marine layer.

Potential for convection looks to more toward this evening and
possibly not getting to coastal locations until 10 pm and even
then it is not high confidence forecast. Forecast soundings
indicate capping around 5 kft into the afternoon and there may
be a weak middle level cap/warm air to limit convective
development. Heights falls are subtle. The main forcing will
come from surface convergence and some lift from weak energy
aloft. These features should be enough to allow convection to
develop in an environment with about 1000 J/kg of MLCAPE and
about 25 kt of 0-6 km unidirectional shear. The stronger
flow/shear looks to reside northeast of the area and greater
instability likely remains across the Middle Atlantic. As the
line encounters the marine environment, the line should weaken
as it encounters more stable air across Long Island and
Connecticut towards or just after sunset. SPC has maintained a
marginal risk for a severe thunderstorm west of Long Island and
Connecticut. The main concern is from damaging wind gusts.

Locally heavy downpours are possible as PWATs increase to
around 1.80 in. However, the progressive nature of the system
will limit duration of heavy rain and limit the overall flood
threat. Minor urban and poor drainage flooding is possible. The
front and shortwave push east of the area late tonight into
early Sunday morning.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
High pressure builds in behind the cold front on Sunday, but the
front stalls not too far to our south. This should be enough to
allow some drier air to move into the area. The building high
pressure and lingering troughing just to our east sets the stage
for a predominately westerly flow on Sunday. This should hold
off sea breezes until potentially late in the day. Guidance has
trended warmer on Sunday with highs now in the middle to upper
80s. Heat indices look to remain near the actual air temperature
as dew points should mix out into the lower 60s due to the
westerly flow.

It should be a mostly sunny day anyway, with maybe some cirrus
around. 850mb temps progged at 17- 18C along with a westerly
flow should allow for low 90s in parts of NYC and the urban
corridor of NE NJ and 85-90 for most other locations. Heat index
values will however be very close to ambient temperatures as
dewpoints through the top of the boundary layer are low enough
for surface dewpoints to mix out fairly easily during the
afternoon.

Dry for Sunday night and Monday morning, then the stalled boundary
to our south pushes north as a weak warm front and moves through
here mainly during the afternoon hours. There could be a shower/tstm
mainly west of the Hudson River by the end of the day as shortwave
lift approaches, but probabilities look to be limited by only modest
CAPE and some capping in the mid levels. A better chance of showers
and perhaps a thunderstorm arrives Monday night with stronger lift
aloft.

NBM looked good for the most part regarding high temperatures for
Monday, but a few minor local adjustments were made. Higher
dewpoints within the boundary layer along with a southerly surface
flow will make it tougher for surface dewpoints to mix out this
time. Advisory thresholds for heat are however not expected to be
reached.

&&

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

* Seasonably warm and humid through Thursday

* Less humid towards the 4th of July

A typical summer air mass will be in places during the period. A
series of cold fronts are progged to swing through, most noticeably
to begin the period later Tuesday, with another cold front later
Thursday or Thursday night.

The first of these cold fronts will bring the region a chance of
showers and thunderstorms late Tuesday and Tuesday evening. Due to
large scale trough swinging through have gone likely PoPs for a good
portion of the region late Tuesday. Followed the NBM closely here
with just minor adjustments. Have gone solid chance thunder due to
forecasted height falls and good agreement on trough and frontal
timing. Should be in-between frontal boundaries and any shortwave
features on Wednesday, so despite high pressure it should remain
primarily dry. Another cold front approaches during Thursday, but at
this time NWP is not indicating as much dynamics and frontal forcing
with this boundary. It appears that this cold front will serve
mainly to lower humidity levels late in the week towards the 4th of
July holiday with only a slight chance of showers / thunderstorms
late Thursday and Thursday evening.

Overall stayed very close to NBM guidance with only slight
adjustments overall with PoP for the second half of Tuesday and
Thursday.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A warm front continues to push through the area this afternoon.
A cold front will then move through late tonight into Sunday
morning.

Skies continue to scatter out, with some lingering MVFR and even
spotty IFR expected early in the TAF period. Improvement for
KISP, KBDR and KGON will likely be in the late afternoon. VFR
then expected until fog and low stratus possibly return tonight
bringing back MVFR to IFR conditions. VFR again by around 11z
Sunday morning.

Showers and thunderstorms remain possible this evening, but
confidence is still relatively low. Kept -TSRA in a PROB30
group, except for KSWF where confidence is higher and a TEMPO
remains.

S/SW winds through this evening, becoming more W/NW behind the
cold front overnight. Winds mainly W Sunday except at some
coastal locations where a sea breeze is possible.

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

Uncertainty in how low conditions go this evening and overnight.
May be more of a vsby issue than cigs.

Showers and thunderstorms possible this evening. Confidence is
higher for showers, but thunder chances remain low. The
potential window is 23z-04z, but any activity, if it happens,
will likely only last up to an hour.


.OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...

Sunday Afternoon: VFR.

Monday: VFR during the day. A chance of showers and thunderstorms at
night. MVFR or lower possible at night.

Tuesday: Showers and thunderstorms with MVFR or lower possible,
especially afternoon and evening. SW wind gusts 15-20 kt day into
early eve.

Wednesday: VFR.

Thursday: Mainly VFR, with afternoon showers and thunderstorms
possible north and west of NYC

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

&&

.MARINE...
Sub-SCA conditions are expected through early Tuesday. Wind gusts
and waves should start to approach SCA conditions for the
central and eastern ocean waters Tuesday afternoon, with small
craft conditions likely Tuesday night into early Wednesday in
response to a cold front. Thereafter, sub-SCA conditions return
into mid and late week.

&&

.HYDROLOGY...
No significant hydrologic concerns are anticipated through next
week. Locally heavy downpours will be quick moving late today into
this evening with only minor nuisance flooding expected.

&&

.TIDES/COASTAL FLOODING...
There is a moderate risk of rip current development across the ocean
beaches today and Sunday.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...JC/JE/DW
NEAR TERM...JC/DW
SHORT TERM...JC
LONG TERM...JC
AVIATION...JT
MARINE...JC/JE
HYDROLOGY...JC/JE
TIDES/COASTAL FLOODING...