-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 141019
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
619 AM EDT Sun Apr 14 2024

.SYNOPSIS...
Weak high pressure over the area this morning slides east, giving
way to a quick moving low pressure system approaching from the
Great Lakes. The low will pass to the north this evening and drag
a cold front across the area. High pressure returns for the first
half of the week. A slow moving warm front then approaches from
the southwest Wednesday night into Thursday, followed by a cold
front late in the week as low pressure passes well to the
northwest.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Latest CAMs are pointing to the chance for showers this
afternoon as a dissipating complex over the eastern Great Lakes
this morning approaches from the NW. For the time, mainly have
a slight chance this afternoon. In addition, the 06Z 3km NAM
and latest HRRR are showing multiples waves of convection,
mainly on the weak side this afternoon into this evening. These
may be riding along the approaching warm front. This could also
lessen the instability for the actually cold front this evening.
Need to see how this evolution is reflected in later guidance
before making any significant changes.

Otherwise, jet energy passing across the Great Lakes region
today will send low pressure to the north of the area this
evening, dragging a cold front through the area. It will be
preceded by a warm front this afternoon, but the cold front will
be the main focus of attention as a line of showers and
thunderstorms develops along it and moves into the area toward
evening. There is the potential for a few strong and/or severe
thunderstorms with the main threat being strong to damaging wind
gusts. SPC has placed portions of the forecast under a Marginal
and Slight Risk. However, the main threat will be primarily
north and west of NYC.

While there is deep-layer shear present with strong mid-level
flow, instability is generally weak and confined primarily to
the mid levels. Surface-based CAPE is located mainly north and
west of the NYC metro with SPC HREF max CAPE values of 500-1000
J/KG. Mean CAPE values are less than 250 J/KG. This is partly
due to the frontal timing in the evening after max insolation,
but also dry air in the low-levels. CAMs generally show the line
dissipating this evening as it approaches the area and in some
cases with no more than a spotty shower reaching the coast. So
the best chance will be across the interior with chances
decreasing toward the coast.

Much of today though will be dry and warm with highs in the
upper 50s to lowers 60s along the coast, and around 70 from NYC
and points north and west. A few warm advection showers can`t be
ruled out this afternoon with a period of mid and high level
cloudiness moving through. West winds this morning will veer
around to the SW-S this afternoon, ramping up with wind gusts of
25 to 30 mph. Coastal locations will see temps peak late
morning/early afternoon before southerly winds bring cooler
maritime air to the coast, especially along the oceanfront and
twin forks of LI.

The cold front passes south of LI during the early morning
hours Monday with clearing skies. Lows will remain above normal
in the upper 40s to mid 50s, warmest across the NYC/NJ metro.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
The amplifying upper trough across eastern Canada during this
time will allow for some weak cold advection to continue on
Monday, albeit still well above normal. Monday will be the
warmest day with even coastal locations getting in on the
action with highs well into the 60s. The NYC/NJ metro is
expected to get into the lower 70s. Highs drop a few degrees on
Tuesday, but remaining above normal. During this time, ridging
over the mid section of the builds east and conditions are
expected to be dry and sunny.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
*Key Messages*

*Unsettled conditions from mid to late week with daily shower
chances from late Wednesday on.

*Normal to slightly above normal temperatures midweek into next
weekend.

Not much change in the forecast thinking for the period. The NBM was
followed for this update with some minor changes to PoPs and thunder
for Thursday. The global ensemble means continue to be in consistent
agreement with synoptic scale ridging deamplifying to a more zonal
flow by the end of the workweek and into next weekend.

Mainly dry weather is expected through Wednesday AM, though clouds
will be on the increase as a warm front attached to a deepening sfc
low across the upper midwest approaches from the southwest. Shower
chances increase through Wednesday late afternoon and into the
evening as the front slowly moves north. While PWATS look to be near
1.25" per latest model soundings (near the daily max via SPC
sounding climo for OKX), better forcing remains back to the west, so
expecting mainly light rain event at this point, with NBM showing
less than 0.5" areawide though Thursday evening. Latest global
ensemble guidance indicating that the area may not be as warm
sectored as previous guidance indicated, with the warm front
remaining over or just south of the area. That would limit any
convective potential, and so have maintained previous forecast
without mention of thunder Thursday afternoon and evening, for now.

Friday remains unsettled as another quick moving frontal system
impacts the area, with shower chances remaining especially in the
afternoon into early Friday.

Temperatures will remain near to slightly above normal for much of
the week.

&&

.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
High pressure today gives way to a quick moving low
pressure system with its cold front moving through this evening.

VFR for most of the day. Potential for 1-3 hr period of MVFR in
SHRA/TSRA btwn 22z and 04z Sunday evening.  Greatest chance/highest
confidence at KSWF/KHPN.

Winds shift to the SW this morning, with gusts 20 to 25 kt returning
by the late morning to early afternoon, and potentially reaching
S/SW G 25 to 30 kt by late afternoon.

Windshift to W/NW possible with TSRA or gust front/cold front
passage late afternoon/early evening, particularly western terminals.

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

High confidence in VFR with W/SW winds around 10 kt for morning push.

S seabreeze of 20-25g30kt likely for JFK in mid to late afternoon.
SW gusts 25-30kt likely for KLGA/KEWR/KTEB in the mid to late
afternoon.

Timing of TSRA may be off by +/- an hour or two Sunday afternoon.
Low to medium confidence of occurrence at this point for NYC
terminals.

Potential for LLWS btwn 22z and 04z SW winds around 50kt.

OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...

Sunday Night: Chance of MVFR in SHRA/TSRA for western terminals in
the evening. SW to W windshift. VFR and W/NW winds around 10 kt aft
midnight.

Mon through Tue: Mainly VFR.

Wed and Thu: Slight chc of MVFR late Wed.

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

&&

.MARINE...
A SCA is in effect for the ocean waters into Monday, and for NY
Harbor, the South Shore Bays, and the western sound into this
evening.

An approaching frontal system today will result in west winds
backing around to the S-SW and ramping up to SCA criteria with
even a few gusts on the ocean approaching gale force. Seas on
the ocean build to 5 to 9 ft by this evening. Winds will then
begin to gradually weaken this evening as a cold front works
across the area and south of the waters by early Monday
morning. SCA seas will linger on the ocean into Monday.

Thereafter, Sub small craft conditions are likely on all waters
through Wednesday. SCA conditions may then return to the ocean
waters on Thursday as a frontal system approaches.

&&

.HYDROLOGY...
There are no hydrologic concerns thought the forecast period.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from noon today to 8 PM EDT this evening
     for ANZ335.
     Small Craft Advisory from noon today to midnight EDT tonight
     for ANZ338-345.
     Small Craft Advisory until 2 PM EDT Monday for ANZ350-353-355.

&&

$$

SYNOPSIS...DBR/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...DBR
AVIATION...DBR
MARINE...DBR/DW
HYDROLOGY...DBR/DW