359
FXUS61 KOKX 220253
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1053 PM EDT Mon Jul 21 2025
.SYNOPSIS...
High pressure builds through Tuesday, before moving east and
eventually just offshore later mid week. High pressure should remain
in control through early Friday. A cold front moves through late
Friday with another frontal system possibly impacting the area for
the weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
High pressure across Southern Canada will continue to build down
tonight and into Tuesday. With synoptic scale sinking motion
attempting to take control, the period should remain predominantly
dry. The only thing of note is a weak low pressure / inverted trough
feature indicated by the higher res guidance just south of Long
Island and off the Southern New Jersey coast. The reflectivity
forecast this evening into tonight hints at the low possibility of a
few showers. Other than some shallow moisture or relatively higher
RH in the lower levels, forecast soundings appear quite dry above
the lower levels. With the lack of depth of any moisture will
anticipate that it stays dry across the region with any shower or
sprinkle activity likely remaining south and offshore. Also mid and
upper level heights begin to slowly rise.
Therefore the theme is for dry and cooler weather as the Canadian
airmass strengthens its grip on the region. Dew point readings by
tonight should generally fall into the 50s. Temperatures in the far
northern and northwestern interior spots may get as low as the lower
50s. Thus it will be much more comfortable with the lower humidity
with a light N to NE wind. On Tuesday with high pressure getting
nearby expect light winds again with temperatures cooler in most
spots, and a few degrees below normal. Most afternoon max
temperatures will get into the upper 70s and lower 80s with mainly
sunny day.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
Clear skies and another comfortable night for Tuesday night,
although not quite as cool in the outlying locations as the previous
night. Most lows will be in the 60s, with some upper half of the 50s
in the northern and northwestern interior locations with light to
calm winds.
By Wednesday the air mass begins to undergo some modification as 500
mb heights build to around 590 dm with 1000-500mb thicknesses
beginning to inch up. Also, later in the day a light return flow
attempts to get initiated as the region begins to get on the back
side of high pressure which gets further east. Therefore dew point
readings begin to inch up some and get back into the lower 60s.
Temperatures will also get back to normal levels with mainly middle
and upper 80s for day time maxes, with a few spots in urban NE NJ
possibly reaching 90.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
No significant changes to the long term forecast so the NBM was
generally followed.
Key Messages:
* Dry through Thursday night.
* Showers & thunderstorms possible with cold front Fri/Fri night
then again from the front stalling to the south on the weekend.
* Temps climb Thursday. Heat index may exceed 100 by Friday for
much of the area.
An upper level ridge flattens Thursday into Thursday night. A series
of midlevel shortwaves then pass Friday into the weekend.
High pressure shifts offshore into Thursday. A low passing into east
Quebec Friday moves into the North Atlantic Friday night into
Saturday. This low brings through a cold front late Friday into
Friday night. The cold front then stalls south of the area into
Saturday. This will bring the chance for showers and thunderstorms,
particularly in the afternoons and early evenings Friday through
Sunday.
Temperatures will warm Thursday and Friday in response to the high
moving east and higher heights aloft. Heat index values may exceed
95 on Thursday for parts of the area and even near 100 in select
locations, then exceed 100 for large portions of the area on Friday
with some spots possibly exceeding 105. This means we should see
solid heat advisory criteria on Friday with heat warning criteria
possibly being met in some areas. The heat, while lower, will still
be strong into Saturday with heat index values of 95-100 expected.
Temperatures lower a bit more on Sunday with highs in the middle to
upper 80s.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
High pressure builds in from the northwest tonight, and remains
over the region Tuesday.
VFR through the forecast period.
Winds N/NW, around 10 kt or less. Any leftover gusts will
gradually diminish through around 02z. Winds become NE
overnight then more easterly/southeasterly on Tuesday around 10
kt or less.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Can rule out an occasional gust on Tuesday.
.OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...
Tuesday night through Wednesday: VFR.
Thursday: VFR. south winds G20-25kt, highest at the coast.
Friday: VFR likely through morning, possibly followed by periods of
sub VFR in showers and thunderstorms for the afternoon and evening.
Saturday: VFR with afternoon thunderstorms.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
With a decreasing pressure gradient with building high pressure look
for tranquil conditions across the coastal waters tonight into
Tuesday. Ocean seas will mainly range from 1 to 3 ft through
Wednesday. Winds may approach SCA gusts on waters both late
Thursday and then again late Friday with the approach of a cold
front.
&&
.HYDROLOGY...
There are no hydrologic concerns.
&&
.TIDES/COASTAL FLOODING...
The low rip current risk continues for all ocean beaches Tuesday and
Wednesday. With that said, with a large tidal range due to an
approaching new moon, rip development could be moderate a couple of
hours either side of low tide. Additionally, if an easterly flow is
stronger than forecast on Tuesday and wave heights trend higher, a
moderate may be needed.
In addition, there is a chance that water levels come close or
actually touch minor flood thresholds across the most vulnerable
southern and eastern NYC/LI bays, and potentially some W LI sound
locations over the next few days. However, by judging the most
recent NYHOPS / Stevens higher high tide bias current thinking leans
towards just falling short of minor coastal flood benchmarks. Thus
have held off on any coastal flood statements for the time being.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JE/MW
NEAR TERM...BC/JE
SHORT TERM...JE
LONG TERM...MW
AVIATION...BC
MARINE...JE/MW
HYDROLOGY...JE/MW
TIDES/COASTAL FLOODING...