688
FXUS61 KOKX 261907 CCA
AFDOKX

Area Forecast Discussion...CORRECTED
National Weather Service New York NY
307 PM EDT Sun Jul 26 2026

.WHAT HAS CHANGED...
Potential for significant rainfall Tuesday and Wednesday, but
there is still a good amount of uncertainty on where the heaviest
rainfall will set up.

&&

.KEY MESSAGES...

1) Unsettled weather with periods of showers and embedded
thunderstorms late Monday into Thursday due to a slow moving low
pressure system. The best chance for heavy rainfall will be
Tuesday afternoon into Wednesday.

2) Potential for minor coastal flooding mid to late week with
a coastal low.

&&

.DISCUSSION...
.KEY MESSAGE 1...

After a stretch of very pleasant weather with temperatures
slightly below normal and low humidity, conditions will begin
to take a downhill swing in coming days.

Weakening high pressure will give way to gradually increasing
humidity on Monday with a southerly flow allowing dew points to
rise into the 60s. Highs will be similar to recent days in the
lower to mid 80s. At the same time, the airmass will gradually
destabilize as the mean upper trough remains across the area
with several shortwave move across the area. Mainly scattered
showers and thunderstorms break out Monday afternoon and
evening from NYC points north and west. Some of this may work
east Monday night. Pulse severe is a possibility north and west
of NYC in the afternoon in a weakly sheared, moderately
unstable environment. In addition, weak winds aloft will allow
for slow storm movement. However, the life cycle of any
thunderstorms should be short. Flood threat should mainly be of
the minor nuisance variety.

The threat for a more substantial rainfall/flood threat will
come Tuesday into Wednesday. Models are in good agreement in
amplifying the upper trough across the Northeast Tuesday, then
closing off an upper low Tuesday night into Wednesday. A
consensus approach closes off the upper low in close proximity
to the forecast area. This will be critical along with the
surface low location to determine where the best warm conveyor
belt rains set up, either across the area or farther east
across coastal New England. At this time of year, the
combination of an upper low and PWATs closing in on 2 inches
bears watching. However, we are still not within a 48h window
to see how the CAMs will handle the forecast. Convective
parameterization in the non-CAMs is likely to suffer from
convective feedback issues. NAM12 is likely such the case as it
has around 8 inches of rainfall across western LI, NYC, NE NJ
and lower portions of the Lower Hudson Valley, then falling off
to the north and east. The globals are more in the 1 to 3 inch
range, highest in the hills north and west of NYC. An E/SE flow
will likely enhance rainfall across the higher inland locations.

Now while embedded convection is likely with a moderate to
heavy rainfall at the onset, a low track to the south of the
area will keep the airmass more stable, with a better chance of
a stratiform rain as we get into Wednesday. Even so, deep
moisture and an anomalously deep low, will make for very
efficient rain processes. The flood threat could transition to
more of a long duration versus flash flood threat. WPC has the
area in a slight risk of excessive rainfall during this time.

The rainfall forecast at this time ranges from 1.50 inches
across eastern LI/SE CT, to 2 to 3 inches across the rest of the
area. Hourly rainfall rates are more of question based on the
low track and how unstable the airmass gets. The heavy rainfall
axis will likely fluctuate the next couple of days and it is
too early to be specific with rainfall amounts. However, know
the ingredients are there for a significant rainfall.

Rain could linger into Thursday on the backside of the upper
low with a northerly flow. This looks to be more scattered in
nature.

Temperatures during the daytime hours Tuesday and Wednesday
will likely remain below normal due the southerly flow, cloud
cover, and rain chances. Overnight lows will be near normal in
the 60s to around 70. For Thursday, rain chances and cloud cover
still look to keep highs below normal in the 70s.

.KEY MESSAGE 2...
With the approach of a full moon midweek and an onshore E/SE
flow with low pressure passing close by, minor coastal flooding
is a possibility. There is still a fair amount of uncertainty
at this time. Latest forecast brings some of the south shore
back bay locations of LI and western LI Sound to just below
minor coastal flood benchmarks during the evening/nighttime
high tide cycles.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Mainly VFR with high pressure in control through Monday
morning. A weak surface trough develops in the vicinity Monday
afternoon, which may develop a few showers and thunderstorms,
mainly west of the NYC terminals. PROB30 for TSRA has been added
to EWR, TEB, and SWF Monday afternoon and early evening.

SE winds under 10 kt this afternoon will veer to the S this evening
as speeds weaken. Light and variable winds overnight will become S
Monday morning, becoming around 10 kt Monday afternoon.

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

Timing of wind shift to the SE at LGA may be off by 1-2 hours
this afternoon.

Amendments to PROB30 timing Monday afternoon/eve at EWR and TEB
are possible. A PROB30 may needed at JFK and LGA if confidence
increases in subsequent forecasts.

.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...

Monday Aftenoon-Night: Chance of showers and possibly a
thunderstorm, mainly NYC metro on NW.

Tuesday: MVFR or lower conditions possible. Showers and chance of
thunderstorms, especially in the afternoon and evening. S winds G15-
20kt.

Wednesday: MVFR or lower conditions likely with showers, possibly a
thunderstorm. E winds G15-20kt.

Thursday: MVFR or lower possible. Showers possible and a slight
chance of a thunderstorm. N-NW wind G15-20kt.

Friday: Mainly VFR.

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

&&

.MARINE...
SCA conditions are likely to return to the ocean waters and
possibly to all waters late Tue-Wed, but will be dependent on
timing of a low pressure system. Lingering elevated seas could
continue on the ocean into Thursday.

Rip Currents: A moderate risk of rip currents will continue
through Tuesday at ocean beaches with a 2-3 ft E-SE wind
wave/swell.

&&

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

&&

$$

DISCUSSION...DW
AVIATION...DS
MARINE...DW