194
FXUS61 KOKX 231753
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
153 PM EDT Sun Jun 23 2024

.SYNOPSIS...
A cold front slowly approaches this afternoon and moves through
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 /UNTIL 6 PM THIS EVENING/...
Breaks of sunshine have emerged across some parts of the region
early this afternoon, though visible satellite still depicts
plenty of cloud cover overhead locally and off to the west that
could be limiting temperatures and initial convection
development somewhat. Approaching surface cold front is just
beginning to push into NW PA and far western NY, but will
eventually advance into the local Tri-State overnight. Ahead of
this a prefrontal trough should be able to help initiate
scattered convection moving later into the afternoon. Certainly
a moist environment to work with as surface dew pts are near 70
and a developing LLJ will only add to the moisture in the
column. SPC mesoanalysis at 17Z indicates SBCAPE well over 2000
J/kg across NE NJ and the lower Hudson Valley, and effective
shear values approach or exceed 40 kt in this same area, which
supports at least the potential for any convection that develops
to become severe. Timing of this threat appears to be a bit
later than recent days, beginning likely after 3 or 4 pm, and
then persisting into the evening. Possible an additional round
moves through overnight just ahead of the front based on some of
the CAMs output, and this will need to be monitored. Forecast
remains on track and previous discussion follows.

The 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.

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 /6 PM THIS EVENING 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 late tonight. 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 SUNDAY/...
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 /18Z SUNDAY THROUGH FRIDAY/...
A warm front to the north continues to move northward. A cold front
moves into the area late tonight into Monday morning. High pressure
builds in late on Monday.

Mainly VFR for today, but with showers and thunderstorms towards
late afternoon and evening. This will bring pockets of brief MVFR
conditions. Some storms could produce heavy rainfall and strong
gusty winds. Expect gusty winds with any thunderstorms, and a few
storms may produce gusts as high as 60 kt, although timing and areal
extent is quite uncertain. Have two TEMPO group for thunderstorms;
the second TEMPO group towards midnight for the city terminals and a
few hours later for the more eastern terminals. Uncertainty remains
higher than average for both TEMPO groups. Some lower ceilings may
briefly impact far eastern terminals late in the overnight before
the frontal passage.

S winds gradually increase through the afternoon with sustained
around 15 kt, with gusts 25-30 kt for some southern coastal
terminals. There may be an occasional higher gust near the coast.
And stronger gusty winds are possible in and near thunderstorms.

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

Timing and coverage of convection towards this evening and during
the overnight remains highly uncertain.


OUTLOOK FOR 18Z MONDAY THROUGH THURSDAY...

Monday afternoon: VFR. W to NW wind G20-25 kt.

Tuesday: VFR.

Wednesday: Mainly VFR. A chance of showers and thunderstorms in the
late  afternoon and at night, with MVFR or lower possible. SW wind
15-20 kt G20-25 kt near the coast.

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

Friday: VFR.

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

&&

.MARINE...
Small Craft Advisory in effect for all waters this afternoon.
Increasing southerly flow will gust 25 to 30 kt into this
evening. There may be occasional gusts to gale force, mainly for
eastern ocean 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 today and Monday
for all ocean beaches with higher wave energy approaching the
shoreline with a S to SW wind wave today. The winds become 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 until midnight EDT tonight for ANZ331-332-
     335-340-345.
     Small Craft Advisory until 6 PM EDT Monday for ANZ350-353-355.

&&

$$

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