397
FXUS61 KOKX 141941
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
341 PM EDT Fri Jun 14 2024

.SYNOPSIS...
A cold front will move through the area this evening with high
pressure building in from the northwest behind it. High pressure
becomes centered over the area Sunday morning and moves offshore by
Sunday evening. The high remains in control through late next
week.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Cold front will be pushing through the forecast area into this
evening, shifting east of us overnight. The front will initially
have SBCAPES of up to around 1500 J/kg in some areas to work
with, with residual 500-1000 J/kg of MUCAPE potential overnight
when the mid-level shortwave and upper jet streak dynamics pass
through. This support aloft will keep chances of showers and
thunderstorms ongoing into the late night hours.

Severe thunderstorms remain possible into this evening with the
threat of high wind gusts with 30-40kt 0-6km bulk shear as well as
inverted-v low level profiles and DCAPES perhaps approaching 700
J/kg. Large hail will remain a threat as well with -10 to -30C
potentially up to around 500 J/kg. A slightly backed profile
aloft will however mitigate the hail threat somewhat.

Tall/skinny CAPE will be present with PWATs expected to to
climb up to around 1.6 inches promote a flooding threat, but
the fairly progressive motion of storm cells should offset this
a bit. But looking at recent rainfall rates and the orientation
of an area of rain over central PA, there is some concern for a
flash flooding threat towards sundown for typically more
susceptible areas of NE NJ and maybe even NYC as well. See the
hydrology section for more details.

Rain threat should be done by daybreak, with low temperatures
mostly in the 60s.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
High pressure builds in for the weekend with dry and less muggy
conditions as dewpoints fall to around 50. Both days look to feature
mostly sunny conditions, with some cumulus development on Saturday
and perhaps some cirrus streaming by on Sunday. Highs mostly around
80 on Saturday, with slightly cooler conditions on Sunday for
coastal areas as winds shift onshore.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
The key point for the long term is that there is increasing
confidence in a prolonged heat wave in the middle to late next week
with heat indices approaching or exceeding 100F at times Tuesday
through Friday.

Ongoing deep-layered ridging on Monday continues into at least
Wednesday. Models show slight flattening of the ridge aloft with
maybe a weak surface trough setting up for both Thursday and Friday.
Will continue to advertise dry weather through at least Thursday
given the subsidence/capping working against whatever CAPE may
manage to build up to. Slight chance/chance PoPs for Friday as per
NBM. Still too early to have any confidence in any over-the-ridge
convection spilling over into the forecast area for any of the days
in the long term.

Based on global deterministic and ensemble guidance, best guess for
850mb temps for Monday are 16-17C, approaching 20C on Tuesday, then
20-21C Wednesday through Friday. After high temperatures of mostly
85-90 on Monday, highs mostly in the middle and upper 90s are
expected away from the coast Tuesday through Friday. Although it`s
too soon to have high confidence in detailed heat indices during
this period, at least advisory criteria would likely be met for a
good portion of the forecast area starting on Tuesday given the
current forecast. So far, models aren`t indicating a very dry
boundary layer each afternoon or west to NW surface winds, so these
two factors would limit daytime mixing out of surface dewpoints.

Given the potential duration of the heat, it`ll be important to take
precautions to protect one`s health, particularly those without
effective cooling and/or adequate hydration. Some heat-sensitive
industries and infrastructure will likely be impacted by the extent
of this heat as well.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A pre frontal trough was moving into the lower Hudson Valley and
into northeastern New Jersey at 17Z with showers and an isolated
thunderstorm possible. A cold front will follow late this
afternoon through late tonight.

VFR expected outside of any showers and thunderstorms when MVFR
conditions are expected, with brief IFR possible in stronger
thunderstorms. Timing of the thunderstorms continues to trend
slightly later, with thunderstorms in the NYC metro area 21Z to
01Z, and to the east 23Z to 03Z. Stronger storms, with gusty
winds and small hail possible, will be more likely across the
lower Hudson Valley into northeastern New Jersey, and the NYC
terminals. A few showers will remain possible in the vicinity
of, and post frontal into late tonight.

S to SW winds ahead of the cold front may briefly become light
and variable in the vicinity of the pre frontal trough. Post
cold front winds shift to NW to N and become gusty. Overnight
gusts may be more occasional.


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

Showers were moving across the terminals, with an isolated
thunderstorm possible, through 20Z.

More organized thunderstorms will become likely late afternoon
into this evening 22Z to 01Z. Timing has trended slightly
later, and that trend may continue. A stronger storm remains
possible with gusts up to 40kt and small hail possible.


OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...

Saturday afternoon through Wednesday: VFR.

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

&&

.MARINE...
A southerly flow will occasionally gust up to 25kt this afternoon on
the ocean waters, otherwise, sub-advisory conditions outside of any
thunderstorms, which may be strong to severe.

For the weekend through Monday, sub-advisory conditions prevail.
There may be a chance of a few S-SW gusts to 25kt and seas
approaching 5 ft each afternoon/early evening for Mon-Wed on the
ocean west of Fire Island inlet. SCAs probably won`t be needed for
each day.

&&

.HYDROLOGY...
The entire area remains in a marginal risk of excessive rainfall.
Expecting mostly minor urban poor drainage flooding, but localized
flash flooding cannot be ruled out, particularly for parts of NE
NJ and possibly NYC a well. Although rain will be heavy at
times, the progressive nature of the thunderstorms is expected
to keep flooding more minor in nature, however the orientation
of the rainfall may promote the chance of flash flooding.
Average storm total rainfall amounts will be between half an
inch and 1.50 inches, with pockets of 2-plus inches possible.

&&

.TIDES/COASTAL FLOODING...
There is a high risk for rip current development along Atlantic
facing beaches today with southerly flow 15 to 20 kt along the
shoreline and surf up to 4 ft expected.

Conditions begin to improve by Saturday, with a moderate risk
forecast as winds shift offshore.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ075-
     080-081-178-179.
NJ...None.
MARINE...None.

&&

$$

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