Area Forecast Discussion
Issued by NWS Upton, NY

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
944
FXUS61 KOKX 080711
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
311 AM EDT Tue Jul 8 2025

.SYNOPSIS...
A slow moving cold front settles over the area this afternoon
and evening. The front likely stalls nearby the rest of the
week leading to unsettled conditions. The front may push further
south of the area for the upcoming weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages:

*Hot and humid today with temperatures in the upper 80s to
 middle 90s with heat indices in the upper 90s to around 100.
 The heat advisory has been expanded to include all of the area
 except southeast Suffolk County this afternoon/early evening.

*Showers and thunderstorms this afternoon and evening may
 produce torrential downpours leading to a risk of flash
 flooding. A flood watch is in effect for the entire area 2pm
 this afternoon through 2am Wednesday.

*A few thunderstorms may also be severe with damaging wind gusts
 with the potential a bit higher across NE NJ, NYC metro, and
 portions of the Lower Hudson Valley.

A slow moving cold front will enter the area today and may stall
nearby tonight. The front will interact with a tropical air
mass with PWATs around 2-2.25 inches. Models also indicate a
modest 80-90 kt jet streak over New England with the region
setting up in the favored right entrance region. This will add
some synoptic support for convective development this afternoon
and evening. The combination of these ingredients brings the
potential of mainly localized flash flooding. WPC has
maintained a slight risk for excessive rainfall across the
entire area. The last few runs of the HREF indicate a 3-hr QPF
PMM 10 percent probability of greater than 3 inches in 3 hours
late this afternoon and evening. It should be noted that we have
typically seen this probability of 30 percent or more
coinciding with some of the more significant flash flood events
in recent years. While the current 3-hr QPF PMM  for greater
than 3 inches is around 10 percent, it does indicate potential
of excessive rainfall. The CAMs vary with the location of the
convection, so confidence is not high where the flood potential
may be greatest. However, where the CAMs do simulate convection,
1-hr rainfall rates could be 1-2" if not even slightly higher
in the heaviest activity. The high end of these rates may end up
localized, but the threat does exist area wide. For these
reasons described above, have issued a flood watch for the
entire area from 2pm this afternoon through 2 am Wednesday.
Total rainfall out of this event will vary widely, but the
heaviest activity could produce 2-3 inches with locally higher
amounts. Some convection may persist overnight, but coverage
should start to diminish. If trends on the guidance later today
indicate convection may persist longer, parts of the watch may
need be extended.

There is also a severe thunderstorm threat this afternoon and
evening. CAPE values of 1500-2000 J/kg should develop with
strong heating. Shear is not impressive as the mid level flow is
relatively weak, but an average of about 25 kt should allow for
clusters or small line segments to develop. The deep moisture
content of the air could allow for some damaging wind gusts in
the most organized activity. SPC has expanded the slight risk
into NE NJ, NYC metro, and portions of the Lower Hudson Valley
and has maintained a marginal risk elsewhere.

The other concern for today will be hot temperatures and high
humidity values. A review of observational data from Monday
indicates many spots in the Lower Hudson Valley and southern CT
observed a few hours of heat indices at or just above 95. The
forecast heat indices late this morning and early afternoon
reach the mid to upper 90s. This supports the two day heat
advisory criteria. For Western Suffolk and the north fork of
Suffolk County, heat indices peak around 100 degrees this
afternoon, supporting the 1 day criteria. For these reasons,
the heat advisory has been expanded to include all but SE
Suffolk where heat indices peak in the low 90s. Southeast CT is
also borderline, but due to collaboration with WFO BOX, have
included Middlesex and New London.

Otherwise, it will remain muggy tonight. Lows look fall into the
upper 60s inland and low/mid 70s near the coast.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Unsettled conditions will persist Wednesday and Thursday.
Temperatures should be held down a bit with the front stalled
nearby. More organized support for convection may lie to our
southwest on Wednesday. Heights then fall as a shortwave trough
approaches Wednesday night. This could bring an expansion of
showers and possible storms, lingering into Thursday. Guidance
continues to differ on the evolution and timing of the greatest
coverage however, so confidence is low on any impacts at this
time. The main concern will continue to be locally heavy
downpours. WPC has maintained a marginal risk for excessive
rainfall both days.

High temperatures on Wednesday look to reach the middle and
upper 80s. A few isolated spots could touch 95 heat index, but
currently not anticipating this to be widespread due to
increased cloud cover. Temperatures trend lower on Thursday with
highs mainly in the low to mid 80s and heat indices peaking
around 90 in the warmest spots.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The NBM was followed with no changes.

Key Points:

*  A stalled front will remain in the vicinity of the forecast area
   Friday into early next week.

*  Expect a chance of showers and/or thunderstorms each afternoon
   each day, especially west of NYC.

*  Temperatures should be right around average for this time of
   the year with highs each day in the 80s.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A cold front approaches the terminals today and remains in
the vicinity through the TAF period.

MVFR to IFR conditions tonight, mainly for eastern terminals, with
better conditions as you head west. While KJFK may remain sub-IFR
all night KEWR may only briefly see MVFR.

Mainly dry conditions through about 18z, then periods of heavier
showers and thunderstorms return in the afternoon an evening with
some uncertainty in exact timing and coverage. Will continue to
keep the mention of TSRA in a PROB30 for now.

Light and variable once through sunrise. Winds then become SW to
WSW wind sets up Tuesday at around 10 kt by mid to late
morning. Some of the interior terminals may see winds more W
through the day. Given the nearby front there is more
uncertainty than usual with wind direction starting this
afternoon. Winds become light tonight.

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

AMD possible overnight with changes in flight category in low
stratus/fog.

More uncertainty than usual with wind direction this afternoon given
nearby front.

Still uncertainty with exact timing of showers/thunderstorms.

.OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...

Tuesday Night: MVFR possible.

Wednesday through Friday: Afternoon and evening showers/tstms
possible each day, with brief MVFR or IFR conditions.

Saturday: Mainly VFR. A slight chance for showers and an isolated
thunderstorm with MVFR or lower conditions.

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

&&

.MARINE...
Seas build toward 5 ft early this morning on the ocean from Fire
Island Inlet on east with a building SE swell. These conditions
will persist through early Wednesday morning. The SCA remains in
effect for these waters. Otherwise, winds and seas should
largely remain below SCA levels the rest of the week and
potentially into next weekend.

&&

.HYDROLOGY...
A flood watch has been issued for the entire area 2pm this
afternoon through 2am Wednesday. Showers and thunderstorms this
afternoon and evening have the potential to produce torrential
downpours with rainfall rates 1-2" an hour. It is quite possible
for a spots to exceed 2" an hour at times in the heaviest
activity. WPC has maintained a slight risk for excessive rain across
the entire area highlighting the mainly localized flash flooding
risk.

A marginal risk of excessive rainfall remains in place for much
of the area on Wednesday and Thursday with a continued localized
flash flooding threat.

&&

.TIDES/COASTAL FLOODING...
There is a high rip current risk at all ocean beaches into this
evening due to building surf to 4-5 ft and building SE swell.
The risk remains high on Wednesday due to the linger SE swell.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for CTZ005>012.
     Air Quality Alert from 11 AM this morning to 11 PM EDT this
     evening for CTZ005>012.
     Flood Watch from 2 PM EDT this afternoon through late tonight
     for CTZ005>012.
NY...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for NYZ067>075-078>080-176>179.
     Air Quality Alert from 11 AM this morning to 11 PM EDT this
     evening for NYZ078>081-177-179.
     Flood Watch from 2 PM EDT this afternoon through late tonight
     for NYZ067>075-078>081-176>179.
     High Risk for Rip Currents from 6 AM EDT this morning through this
     evening for NYZ075-080-081-178-179.
NJ...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for NJZ002-004-006-103>108.
     Flood Watch from 2 PM EDT this afternoon through late tonight
     for NJZ002-004-006-103>108.
MARINE...Small Craft Advisory until 2 AM EDT Wednesday for ANZ350-353.

&&

$$

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