576
FXUS61 KOKX 150536
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
136 AM EDT Mon Jul 15 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 THIS MORNING/...
Patchy stratus and fog along coastal New London in CT should begin
to dissipate into the early morning hours. Otherwise, a dry remainder
of the night with temperatures primarily in the 70s, but close to
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 THIS MORNING THROUGH 6 PM 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 /06Z MONDAY THROUGH FRIDAY/...
A weak surface trough remains in the vicinity today.

VFR, except LIFR at KGON early in the forecast period. Sct TSTMs
possible for a few hours this afternoon, then another chance for
additional showers/TSTMs this evening - but mainly at KSWF.

Winds remain light S/SW at the NYC metro terminals through
the morning push, and light and variable at the outlying
terminals. A SW/SSW flow continues for the rest of the day,
increasing to around 10kt, and becoming more S for coastal
terminals in the afternoon.


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

Low confidence in TSTM occurrence during the afternoon with
timing possibly off by 1-2 hours. Chance that a mention of
TSTMs this evening could be added to the forecast.

OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY...

Late tonight: VFR.

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, with a chance of showers and
thunderstorms late at night.

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...
Patchy fog, mainly along coastal SE CT, possible into early
Monday morning. The pressure gradient remains relatively weak,
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 and sub SCA conditions prevail on all
waters through Tuesday.

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...
There is moderate rip current risk on the ocean beaches Monday
and Tuesday due to 3-4 ft S swell 6-8s and S winds 10-15kt.
RCMOS and NWPS are generally in good agreement.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from noon today to 10 PM EDT Tuesday for
     CTZ005>011.
NY...Heat Advisory from noon today to 10 PM EDT Tuesday for
     NYZ067>071-078>080.
     Heat Advisory until 10 PM EDT Tuesday for NYZ072>075-176>179.
NJ...Heat Advisory from noon today 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/DR
SHORT TERM...JE
LONG TERM...DW
AVIATION...JC
MARINE...JE/DW
HYDROLOGY...JE/DW
TIDES/COASTAL FLOODING...