266
FXUS61 KOKX 230927
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
527 AM EDT Sun Jun 23 2024

.SYNOPSIS...
A cold front slowly approaches today and moves through late tonight
into early Monday morning. High pressure then builds in through
Tuesday. High pressure moves across the area Tuesday as a cold front
approaches from the west. The front crosses the region Wednesday
night into Thursday morning. High pressure will then return for
Thursday night into Friday, and move off the northeast coast
Saturday as another cold front begins to approach.

&&

.NEAR TERM /THROUGH TONIGHT/...
The forecast area will be warm sectored today, between a warm front
north of the area, moving farther north, and a slowly
approaching cold front to the west.

Continued hot and humid today as an increasing south to
southwesterly flow maintains the anomalously warm air mass. In
fact, conditions look to become breezy on the developing
southwesterly flow as a low level jet develops later this
afternoon. Although jet looks strongest along the coast, with
50+ kt possible at 950 hPa, it does also strengthen inland, just
not to that degree. This will produce gusts of 25 to just over
30 mph along the coast, and 20 to 25 mph elsewhere. The low
level jet will also be important for the potential for severe
storms later today.

850 hPa temperatures will be in the 18-21C range today, so similar
highs are expected today as compared to Saturday. Lower to middle
90s in NYC and NE NJ (isolated spots may reach upper 90s in and
around Newark). However if clouds and precipitation move in sooner
than is forecast, highs will be slightly lower. With dew points in
the lower to middle 70s across the region, this will produce
widespread areas of heat index values between 95 and 100, with 100
to 104 possible across NYC, NE NJ, portions of the Lower Hudson
Valley and into Fairfield County in CT. Southern Suffolk and the
Twin Forks of Long Island as well as portions of southeast CT look
to stay below Heat Advisory criteria. Continued the Heat Advisories
from previous forecast, even in areas that might not hit today
(southern Middlesex and all of New London county) just due to the
uncertainty out that way in regards to temperatures and dew points.

The cold front slowly advances to the area today. However, a
prefrontal trough develops across eastern PA and this will be the
focus of much of the the thunderstorm activity today, providing just
enough lift out ahead of it as it too move slowly east.

The timing for the storms is generally after 2 pm today, just
getting into Orange County. CAMs are pointing to one or two lines of
storms moving through. During this time frame, MLCAPE values across
the area increase to 1500-2000 J/kg and 0-6 km bulk shear increase
to 35 to 45 kt. Along with the increased moisture transport along
the developing low level jet previously described, the stage is
set for some severe thunderstorms to move through today. It
looks like the best chances are north and west of NYC and as the
storms move east, they look to run into slightly less stable
air and it will be later in the day for eastern areas, so there
will be loss of some daytime heating. Still, severe storms
cannot be totally ruled out as the storms may transition from
more surface base to elevated.

SPC has placed the entire area in a slight risk for severe storms,
with the main threats being damaging winds and isolated tornadoes.
Large hail is also a threat, mainly across the Lower Hudson Valley
and southern CT.

Along with the severe threat, there is the threat for flash
flooding with PWAT values in the 1.75" to 2.00+" range. The
Weather Prediction Center has placed the entire area in a
marginal risk for excessive rainfall.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
Showers and thunderstorms continue to move east tonight.
Much of the activity will end after the first or second line of
storms moves through, with precipitation cutting off from west to
east through late tonight. Some CAMs show some activity with the
actual front late tonight across Long Island. Think most of the
activity will be done earlier in the night as previous storms will
have helped to stabilize the atmosphere. However, kept a slight
chance for showers and thunderstorms across Long Island and southern
CT for the possibility of redevelopment of storms along the cold
front as it moves through these areas late tonight.

Otherwise, it will be another warm night tonight with lows mainly in
the 70s. Some cooler air may work in late tonight across northern
portions of the Lower Hudson Valley for lows in the middle to upper
60s there.

Mainly dry conditions moves in for Monday. There is just a slight
chance for showers and thunderstorms across the Lower Hudson Valley
and inland SW CT with the upper level trough moves through. High
pressure continues to build in Monday night.

Highs on Monday will be cooler, but still above normal for this time
of year, with temperatures in the upper 70s to middle 80s.
Humidity levels will drop during the day as dew points fall into
the 60s and upper 50s.

With high pressure pushing off the East Coast on Tuesday, expect a
return to warmer temperatures, with highs in the middle 80s to
around 90. However, humidity levels should still be more on the
tolerable side for most as dew points remain in the 50s and 60s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Key Points:

* Temperatures will remain near to just above normal through the
  extended period.

* A slow moving cold front may bring locally heavy rainfall from
  late day Wednesday through Wednesday night.

Updated forecast remains consistent with the previous forecast.
A near zonal flow Tuesday night will allow for a couple of northern
stream shortwaves to track north of the region Wednesday through
Thursday, as the associated surface low moves through upstate New
York. Precipitable waters values will be increasing to 1 3/4 inches
late Wednesday into Wednesday night, and with a low level jet
increasing to 40-50kt, along with warm cloud processes, periods of
moderate to heavy rainfall may occur Wednesday night. Once this
system moves east a near zonal to southwest flow becomes
reestablished into the upcoming weekend.
Surface high pressure moving out of southern Canada will bring a
slightly drier, and cooler, airmass to the region for Thursday and
Friday. Then with the high moving off the northeast coast late
Friday night into Saturday as return flow sets up and temperatures
return to above normal, along with increasing humidity as dew points
rise into the mid 60s.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
High pressure over the Western Atlantic moves eastward today as a
nearly stationary front north of the area moves north as a warm
front this morning, as associated low pressure moves through upstate
New York. An associated cold front moves into the area late tonight
into Monday morning.

Mainly VFR, with IFR to LIFR with stratus and fog across the
terminals east of New York City. Conditions improve to VFR 12Z to
14Z. Also, a few showers, and thunderstorms, were scattered east of
the NYC terminals, and tracking east. Another round of showers and
thunderstorms is expected this afternoon, some of the thunderstorms
could produce heavy rainfall and gusty winds.
Have not included the wind gusts, and heavy rainfall, at this time
with timing uncertainties.

Winds light and variable to light southerly overnight, become
southerly at all the terminals with speeds increasing to 10-15kt,
with gusts 25-30kt by midday. There may be an occasional higher gust
near the coast. Strong and gusty winds will be possible in and near
tstms.


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

Timing of convection on Sunday could be off by a couple hours.

MVFR or lower conditions possible early Sunday AM if low stratus or
fog is able to develop.

OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...

Late Sunday night: A chance of showers and thunderstorms with MVFR
conditions east of the NYC terminals then becoming VFR. VFR at the
NYC terminals and west. S/SW winds shift to W with gusts to around
20kt.

Monday: VFR. West wind G20-25kt.

Tuesday: VFR.

Wednesday: Mainly VFR. A chance of showers and thunderstorms in the
afternoon and at night, with MVFR or lower possible. SW wind 15-
20ktG20-25kt near the coast.

Thursday: MVFR or lower possible early with a chance of showers,
then VFR.

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

&&

.MARINE...
SCA continue for the ocean waters. By early afternoon Sunday
small craft conditions begin to develop for a good portion of
the near- shore waters, with perhaps the exception of NY Harbor
with gusts 25, to even 30 kts further east. There may be
occasional gusts to gale force, mainly for eastern waters.

Ocean seas approach 9-10 ft late tonight. A cold front
moves through tonight with gusts falling below small craft
criteria on the nearshore waters, but seas and gusts slower to
subside on the ocean waters. Towards late Monday afternoon and
evening seas should eventually subside enough for sub small
craft conditions to return to the ocean waters by nightfall
Monday night. SCAs on the ocean were extended through the day
Monday.

Winds and seas across all the forecast waters remain below advisory
levels Tuesday night. Increasing southerly winds ahead of an
approaching cold front Wednesday and Wednesday night will allow for
conditions on the oceans to approach SCA levels. Ocean seas may
remain near SCA levels through Thursday as winds shift to west
behind the cold front.

&&

.HYDROLOGY...
WPC has placed the entire area in a marginal risk of excessive
rainfall today. With a very humid airmass in place any stronger
storms could produce heavy rain with isolated local instances
of up to a few inches possible in a short time, especially with
PWAT values approaching and slightly exceeding 2".

There is a chance for locally heavy rain from late day Wednesday
afternoon into Wednesday night with a front moving through the
region.

&&

.TIDES/COASTAL FLOODING...
There will be a high rip current risk for both Sunday and Monday for
all ocean beaches with higher wave energy approaching the shoreline
with a S to SW wind wave on Sunday. The winds becoming more offshore
on Monday, but with the high risk continuing.

&&

.CLIMATE...
Here are current record high temperatures for Sunday...

Sunday, June 23

NYC: 96(1888)
LGA: 95(1965)
JFK: 94(2010)
EWR: 97(1965)
ISP: 91(1999)
BDR: 91(2010)

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ005>011.
NY...Heat Advisory until 8 PM EDT this evening for NYZ067>075-078-
     176>179.
     High Risk for Rip Currents through Monday evening for NYZ075-080-
     081-178-179.
NJ...Heat Advisory until 8 PM EDT this evening for NJZ002-004-006-
     103>108.
MARINE...Small Craft Advisory from noon today to midnight EDT tonight
     for ANZ331-332-335-340-345.
     Small Craft Advisory until 6 PM EDT Monday for ANZ350-353-355.

&&

$$

SYNOPSIS...JP
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...MET
AVIATION...MET
MARINE...JP/MET
HYDROLOGY...JP/MET
TIDES/COASTAL FLOODING...
CLIMATE...