470
FXUS61 KOKX 142023
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
423 PM EDT Sun Jul 14 2024

.SYNOPSIS...
A thermal trough will be in place Monday and Tuesday. A cold
front approaches from the west on Wednesday, moving through
Wednesday night into Thursday morning. High pressure will follow
for the end of the week.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
There may be a few showers and storms early this evening, otherwise
becoming partly cloudy and remaining quite warm and humid. A light S
to SW flow will remain in place. An old frontal system / trough will
remain nearby, but with the loss of daytime heating the prevailing
thought is that it stays rain and storm free. Lows will range
primarily in the 70s region wide, but around 80 across some of the
NYC and NE NJ metro.

During Monday heat headlines continues, but expand to a large
majority of the area. A good amount of sunshine is expected with hot
and humid conditions. Temperatures should be able to reach the lower
and a few middle 90s for the NYC / NE NJ metro with mainly lower
half of the 90s elsewhere and some 80s for immediate eastern coastal
communities with a wind off the ocean. However, the southerly flow
will result in higher dew point values for these locales, and thus
not a lot of relief from the combination of the heat and humidity.
Timing questions remain as far as convection chances for Monday
afternoon and into Monday evening. Some of the convective allowing
models have scattered storms moving in for the late afternoon, while
some others have it arriving closer to sun down for NW areas and
late in the evening further east. A thermal trough will be over the
area, along with moderate instability and a shortwave approaching
from the west. Also a tropical like environment will be in place
with the primary concern with any storms being intense rainfall, but
localized and short in duration. It will likely be a scenario where
the instability axis will be draped WSW to NE across the area. This
will have direct implications on the progression and how far east
the activity can get late Monday and Monday evening. This fits with
the Storm Prediction Center having a marginal risk of severe weather
for western portions of the CWA. Have primarily chance PoPs for the
late afternoon and early evening, with relatively slightly lower
PoPs further SE.

No changes with heat headlines / advisories. With respect to
heat numbers went with a MAV MET consensus blend, especially
with respect to dew points.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
After convective and shower chances early, look for muggy and partly
cloudy conditions. Another night with minimum temps in the urban
areas staying well into the 70s to around 80 in the NYC metro.

Tuesday looks somewhat similar to Monday with respect to the heat
and humidity. Slightly higher heat indices do get a bit further east
into eastern portions of LI and CT. Also another shortwave or a
series of shortwaves approaches late in the day, but the guidance
differs with respect to the amplitude and placement to the north of
the shortwave activity. For now handling this with slight chance
PoPs for a good portion of the area, with chance PoPs into NW
portions of So. CT and into much of the Lower Hudson Valley with the
shortwave concentration slightly further to the north.

No changes with heat headlines / advisories.
With respect to heat numbers went with a MAV MET consensus blend,
especially with respect to dew points.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

Key points:

* Heat wave likely continues Wednesday with hot and humid
  conditions. Max heat indices 95 to 100 for much of the
  region.

* Showers and thunderstorms develop along and ahead of an
  approaching cold front Wednesday afternoon and night,
  bringing the risk of strong to possibly severe thunderstorms
  and heavy rainfall.

* Cooler, drier conditions expected behind the front Thursday
  and into the weekend.

Expect another day of high heat and humidity Wednesday as a
cold front approaches from the west. While there is little
change in the airmass ahead of the front, there is some
uncertainty with frontal timing (albeit not too bad), the onset
of showers and thunderstorms, and convective debris from
upstream activity. Heat indices are generally forecast to be 95
to 100 for much of the area, but due to those uncertainties, the
heat advisory will not be extended into Wednesday at this time.
Also continued to blend in the CONSALL with NBM dew points to
knock them down slightly. NBM typically has been too high and
with winds S/SW, mixing may be deeper, especially north and west
of NYC.

Showers and thunderstorms become likely Wednesday afternoon into
the night with the approach of a cold front, which passes
through the area overnight. A few storms could become strong
and/or severe with some strengthening of the mid level flow and
moderate to potentially high instability. Heavy rainfall also a
good bet with PWATs around 2 inches. There is backing of the
upper flow to the SW as the trough approaches, so this will
have to be watched for potential training of the convection.

Chances for showers and thunderstorms will linger into
Thursday, but recent trends in the global guidance have shown a
drying trend. There are some differences with the magnitude and
progression of the upper trough that will impact how quickly the
front drops south. High pressure will look to follow for the
end of the week with some drier, more seasonable air moving into
the area.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
A surface trough will set up over the region this afternoon and
remain into Monday.

Mainly VFR through the TAF period. There remains potential for IFR
or LIFR across eastern Long Island and southeast Connecticut late
tonight into early Monday morning.

Winds will continue becoming S this afternoon around 10 kt.
Wind speeds will diminish tonight as the direction becomes SSW or
SW. A SW-SSW flow is expected Monday, becoming more S for coastal
terminals in the afternoon.

Showers and thunderstorms are possible late Monday afternoon and
evening.

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

Shower, possibly a thunderstorm may occur through 19z for KEWR and
KTEB, with lower probability for KJFK and KLGA 19-20z.

Adjustments to shower/thunderstorm timing Monday afternoon and
evening are likely.

OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...

Monday Afternoon-Night: Mainly VFR. Chance of showers and
thunderstorms with MVFR, mainly NYC metro on NW, in the afternoon
and evening.

Tuesday: Mainly VFR. A chance of afternoon into early evening
showers and thunderstorms and MVFR, mainly from NYC metro on NW.
SW wind gusts 15-20 kt afternoon into early evening.

Wednesday: VFR to start. MVFR or lower in showers and thunderstorms
late afternoon into the evening.

Thursday: Mainly VFR. Chance of showers and thunderstorms.

Friday: VFR.

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

&&

.MARINE...
Another round of patchy and areas of fog tonight, with the best
chance across eastern ocean and perhaps the eastern near shore
waters. Sub small craft conditions are expected to prevail through
Tuesday. The pressure gradient remains relatively weak tonight into
Monday morning, with a S to SW flow increasing late Monday
potentially leading to a brief period of occasional small craft
gusts for the western ocean waters. Otherwise ocean seas should be
ranging primarily from 3 to 4 ft during this time frame.

A period of SCA conditions is possible, mainly on the ocean,
Tuesday night into Wednesday night with increased southerly flow
ahead of an approaching cold front. Ocean seas may linger at or
above 5 ft Thursday before subsiding. High pressure builds in
for the end of the week with sub-SCA conditions.

&&

.HYDROLOGY...
With a humid air mass in places, any thunderstorms that can develop
have the potential to produce locally heavy downpours. The risk of
hydrologic impacts is limited to the local scale, and mainly for
urban and poor drainage locations through mid week.

&&

.TIDES/COASTAL FLOODING...
A high rip current risk continues through this evening for the
beaches of southeastern Suffolk County. A southerly swell of 4 ft 7s
will be slow to subside into Monday. RCMOS and NWPS are generally in
good agreement with the high risk for the far eastern beaches. A
moderate risk can be expected elsewhere.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from noon Monday to 10 PM EDT Tuesday for
     CTZ005>011.
NY...Heat Advisory from noon Monday to 10 PM EDT Tuesday for
     NYZ067>071-078>080.
     Heat Advisory until 10 PM EDT Tuesday for NYZ072>075-176>179.
     High Risk for Rip Currents until 9 PM EDT this evening for NYZ081.
NJ...Heat Advisory from noon Monday to 10 PM EDT Tuesday for NJZ002.
     Heat Advisory until 10 PM EDT Tuesday for NJZ004-006-103>108.
MARINE...None.

&&

$$

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