okx-afd on 2025-07-18

024
FXUS61 KOKX 181752
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
152 PM EDT Fri Jul 18 2025

.SYNOPSIS...
-- Changed Discussion --High pressure moves across the Northeast tonight, then offshore on
Saturday. A warm front then approaches Saturday night and passes
through the region late tonight into Sunday, followed by a cold
front entering late in the day and moving south and east of the
area early Sunday evening. High pressure then dominates through
Wednesday. A cold front slowly approaches late Thursday through
Friday.-- End Changed Discussion --

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --High pressure will be centered to our north tonight with a mostly
clear sky and a continuation of relatively comfortable dewpoints
mostly in the range of 55-60. This combined with light to calm winds
will allow low temperatures to fall into the mid 50s well inland and
across the Pine Barrens, with upper 50s to upper 60s for most other
locations. As usual, NBM looked too warm for these coolest spots
during good radiational cooling conditions, so made some local
adjustments.-- End Changed Discussion --

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
-- Changed Discussion --High pressure shifts off the southern New England coast on Saturday,
allowing for moisture to increase on a return southerly flow. PVA
ahead of a shortwave approaches from the SW in the afternoon,
bringing the chance of showers, and with enough CAPE, maybe a
thunderstorm too. Showers would be confined to mostly NE NJ, the
city, and adjacent areas. NBM looked good for high temperatures.

A warm front approaches during Saturday night and is progged to move
through part of the forecast area by 12z Sunday. Associated lift
with and ahead of the front brings an increased chance of showers
and possible thunderstorm to the entire area. Stuck with NBM PoPs,
however feel that they could be too low as recent nighttime warm
front passages have produced higher shower coverage than what
NBM probabilities have implied.

The warm front then continues its progress north through the rest of
the forecast area during Sunday morning. A trailing cold front then
begins to cross the forecast area during the second half of the
afternoon. Better overall chances of showers and thunderstorms
appear to be with the cold front passage. As for severe weather
chances, SPC has the entire area under a marginal risk (5% chance)
of severe weather for Sunday. The cold front could be interacting
with an airmass with 1000-2000 J/kg SBCAPE. With bulk shear of
potentially 30-40kt, unidirectional flow and an inverted-v profile
in the boundary layer, strong to severe wind gusts would be possible
with thunderstorms.

Heat indices on Sunday reach the mid to upper 90s for the NYC metro
area, but with just one day of this, no heat advisories would be
issued.-- End Changed Discussion --

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --***KEY POINT***

* Heat and humidity return for the end of next week.

An extended period of quite weather is expected during the long term
forecast as an upper trough exits the northeast Sunday night with an
upper ridge building into Thursday, and then weakening as another
shortwave trough moves into eastern Canada and the northeast late
Thursday into Friday. At the surface a cold front will be exiting to
the south and east early Sunday evening with high pressure
dominating into Thursday. A weak surface trough develops inland
Wednesday afternoon with a slight chance of precipitation. A
stronger surface trough develops for late Thursday into Thursday
night with high pressure weakening and shifting south and east. And
there will be higher, and more widespread, chances for
precipitation. Temperatures will be near seasonal normals Sunday
night into Tuesday night, then the heat will build with temperatures
above normal Wednesday into the end of the week. Humidity levels
will also be increasing beginning Wednesday as a return flow setup
up later Wednesday with high pressure moving east of the area. For
Thursday and Friday with the combination of heat, with highs in the
upper 80s to mid 90s, and humidity, with dew points in the lower 70s,
there is the potential for a heat advisory for Thursday and Friday
with a 2 day period of heat indices reaching 95 to 103 across much
of the area.-- End Changed Discussion --

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --High pressure builds across the area through tonight, then offshore
on Saturday.

VFR. SHRA/TSRA is possible late Saturday, but coverage and timing
varies too much to include in the TAFs, at this time.

Winds around 10 kts will diminish into this evening becoming light
and variable or N below 5 kts overnight. Tomorrow winds become S 5-
10 kts.

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

No amendments expected at this time.

.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...

Saturday Night: Mainly VFR. Showers/isolated thunderstorms,
possible.

Saturday night and Sunday: Showers possible with a chance of
thunderstorms. MVFR or lower conditions possible.

Sunday night through Wednesday: VFR.

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

.MARINE...
-- Changed Discussion --Sub-advisory conditions expected through Sunday with a weak
enough pressure gradient in place. Winds and seas remain below
SCA thresholds across the forecast waters from Sunday night
through Wednesday night as high pressure dominates.-- End Changed Discussion --

.HYDROLOGY...
-- Changed Discussion --Widespread hydrologic impacts are not anticipated through this
weekend. However, with precipitable waters values near 2 inches, any
thunderstorms could produce brief/locally heavy rain rainfall.
Higher overall chances of thunderstorms would be Sunday afternoon,
but storms would be moving quickly enough to mitigate a flash
flooding threat.

There are no hydrologic impacts expected from Sunday night through
next week with dry weather much of the time.-- End Changed Discussion --

.TIDES/COASTAL FLOODING...
A moderate rip current risk has been forecast for the Nassau and
Suffolk beaches for today, with 4-ft wind waves at 6-sec period
still out of the SW. The rip current risk for Sat has been
changed to low, with 2-ft southerly wind waves at 6-sec period
and S winds mostly 10 kt or less.

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

SYNOPSIS...JC/MET
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...MET
AVIATION...BR
MARINE...JC/MET
HYDROLOGY...JC/MET
TIDES/COASTAL FLOODING...