467
FXUS61 KOKX 201843
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
243 PM EDT Sun Jul 20 2025
.SYNOPSIS...
A warm front pushes through the area this morning, followed by
a cold frontal passage this evening. High pressure builds in
Monday into Tuesday, and centers over the area Tuesday night
into Wednesday. The high shifts offshore Wednesday night into
Thursday. A low passing into east Quebec Friday will bring
through a cold front late Friday into Friday night.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Key Messages:
* Isolated to scattered severe thunderstorms with damaging wind
gusts possible late this afternoon through around 10pm.
A deep shortwave pivots towards northern New England this eve
accompanied by left front quad of 70 kt ulj, with a cold front
approaching from Central NY/PA.
This forcing is allowing for scattered thunderstorms
development ahead/along it in a marginal to moderately unstable
and moderately sheared (0-6km bulk shear of 35 to 40 kt)
environment across E PA and Central NY this afternoon. This
environment with steep low-level lapse rates, high PWAT, and a
bit of mid-level dry air entrainment potential is conditionally
favorable for damaging wind gusts (60+ mph) from bowing line
segments (15% probability w/i a 25 mile radius) across the local
Tri-State late this afternoon into evening. There is a 5% prob
of 70 mph wind gusts w/i a 25 mile radius if convection can
organize into bowing segments in a favorable downburst profile.
Limiting factors for severe coverage/intensity is a skinny CAPE
profile with weak mid- level lapse rates. A secondary large
hail threat exists with any discrete cells and isolated tornado
threat with cell-boundary interactions. A Severe Thunderstorm
Watch may be issued within the next hour or so.
Cold front, with showers and thunderstorms activity should slide
east by midnight, with a much cooler and drier airmass filtered in
behind the cold front on gusty NW flow. Lows tonight in the
lower 60s interior, to around 70 for the city/coast, with Tds
dropping into the lower 60s by daybreak.-- End Changed Discussion --
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
Polar trough/closed low slides into northern New England Monday
and then slides east through SE Canada Mon NIght. Mean
troughing and NW flow aloft continues through Tuesday Night.
At the surface, initial cold front slides well east of the area
by Monday morning, with reinforcing Canadian cold front passing
through Mon aft/eve.
A relatively tight gradient between developing Canadian
Maritimes low and Canadian high pressure over Ontario, will have
a gusty caa NW flow 15-20g25 mph developing tonight and
continue on Monday, remaining gusty into Monday Night. Highs on
Monday expected to run slightly below seasonable despite
abundant sunshine, with CAA through the day dropping 850 mb
temps into the high single digits. Highs in the lower to mid 80s
for the coast, to upper 70s for interior, with Tds likely
dropping into the 40s to lower 50s.
Potential for some radiational cooling conds across far
outlying areas, but pressure gradient may be strong enough to
keep temps from bottoming. Very comfortable temps in the 50s to
lower 60s, but a few upper 40s possible across interior and pine
barrens if a period radiational cooling materializes.
Canadian high pressure continues to sink SE over the region
Tuesday into Tuesday Night, with temps running a few degrees
below seasonable for late July. High in the upper 70s to lower
80s area-wide with Tds in the 40s to around 50. Potential for
more robust radiational cooling Tuesday NIght, with widespread
lows in the 50s outside of the urban centers, and possibly a
few upper 40s across interior and pine barrens.-- End Changed Discussion --
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Key Messages:
* Dry Wed through Thu night.
* Showers & thunderstorms possible with cold front Fri/Fri night
then again from the front stalling to the south late on Sat.
* Temps climb Wed into Thu. Heat index may exceed 100 by Fri.
In the upper-levels, a ridge continues to amplify over the eastern
US Wednesday into Wednesday night. This ridge then flattens Thursday
into Thursday night. A series of midlevel shortwaves then pass
Friday into the weekend.
At the surface, high pressure remains the dominant feature centered
over the area on Wednesday. This high then shifts offshore Wednesday
night 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.
Wednesday through Friday, temperatures will warm each day 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 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.
Given ample heating, shortwave energy passing aloft, high dewpoints
& atmospheric moisture, and lift from an approaching/passing cold
front, scattered showers and thunderstorms are expected late Friday
into early Friday night. Showers and thunderstorms will again be
possible Saturday afternoon into early early Saturday night due to
the front stalled nearby to the south with another shortwave passing
aloft.-- End Changed Discussion --
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A cold front approaches this afternoon and moves through this
evening.
Mainly VFR to start the afternoon. A isolated-scattered line of
convection is then expected between 19Z and 02Z along and ahead of
the approaching cold front, with a severe wind gust threat possible
but confidence remains too low to include in TAFs at this time. This
thunderstorm chance is being handled with PROB30 for most terminals,
this includes the city terminals. A tempo group for TSRA was used in
TAFs for KSWF, KHPN, and KGON as the risk of thunderstorm occurrence
is slightly higher for these terminals. The cold front will clear
KSWF around 23Z, NYC terminals 00-01Z, and LI and CT terminals 01-
02Z with any brief MVFR conditions quickly returning to VFR.
S to SW winds for this afternoon mainly around 10kt. A few
occasional gusts for the coastal terminals remains a possibility but
was not included in TAFs for this afternoon. Winds become NW tonight
behind the cold front 10-13kt with G20kt for city terminals
overnight, with gusts less likely or more occasional for outlying
terminals. NW gusts prevail at all terminals towards 13-14z on
Monday morning.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments may be needed for TSRA activity this afternoon and the
first half of the evening (until 01-02z).
.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday: Mainly VFR. NW winds 10-15g20kt.
Monday night through Thursday: VFR.
Friday: VFR likely through morning, possibly followed by periods of
sub VFR in showers and thunderstorms for the afternoon and evening.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
There is potential for a few strong to severe thunderstorms late
this afternoon and evening. Locally stronger wind gusts and higher
waves are possible in any thunderstorms.
Occasional nearshore gusts to 25 kt possible late tonight thru
Monday evening in a gusty NW flow behind cold frontal passage.
Otherwise, winds and waves are expected to stay below Small Craft
Advisory criteria late Monday Night through Wednesday Night as
high pressure moves overhead.
Winds may approach SCA gusts on waters both late Thursday a and then
again late Friday with the cold front.-- End Changed Discussion --
&&
.HYDROLOGY...
At this time, there are no hydrologic concerns through the week.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
A low rip current development risk is expected for all ocean
beaches on Monday with a moisture of mainly 1 ft S/SE swells.
Similarly a low rip current development risk is likely for
Tuesday with developing 2 ft easterly wind wave and a series of
1 ft S/SE swells. 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.
In addition, water levels may touch minor flood thresholds
across the most vulnerable NY Harbor, southern and eastern
NYC/LI bay, and W LI sound, locations during the evening high
tide the next few days.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BR/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...BR
AVIATION...JE
MARINE...BR/NV
HYDROLOGY...BR/NV
TIDES/COASTAL FLOODING...NV