discussion on 2024-04-14

000
FXUS61 KOKX 142015
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
415 PM EDT Sun Apr 14 2024

.SYNOPSIS...
-- Changed Discussion --Low pressure will pass to the north this evening and drag a cold
front across the area. High pressure builds in Monday through
Monday night, moving over the area on Tuesday. 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.-- End Changed Discussion --

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --Low pressure will pass to the north of the area this evening,
dragging a cold front through the which will be the main focus
for a line of showers and thunderstorms which has developed over
central NY stretching westward into Lake Erie. This line is in
association with a cold front that is forecast to move through
the region later this evening and tonight. Meanwhile, showers
and thunderstorms will move through southern CT in association
with a warm front moving northeastward. There continues to be
the potential for a few strong and/or severe thunderstorms with
the main threat being strong to damaging wind gusts. Small hail
cannot be ruled out as well. 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, though a strong
gust to 40 to 50 mph cannot be totally ruled out for 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, as is any elevated CAPE seen in forecast sounding well
north and west of NYC. 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. There is
some modestly steep lapse rate in the lower to mid levels, but
again, these look to weaken as the evening and night continues. CAMs
continue to 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. SPC HREF shows the highest chances
for the strongest max updrafts well west of the forecast area,
across western PA, with a smaller chance across northwest PA as
the cold front moves through. So the best chance will be across
the interior with chances decreasing toward the coast.

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 /6 AM MONDAY MORNING THROUGH TUESDAY/...
-- Changed Discussion --Surface high pressure builds in from central Canada Monday as
the amplifying upper trough across eastern Canada during this
time will allow for some weak cold advection on Monday. Despite
this, downsloping winds will mean 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 middle 70s. Lows drop into the 40s to around 50 Monday
night with clear skies and light winds.-- End Changed Discussion --

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --*Key Messages*

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

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

Overall not much change in the long term period.

High pressure remains in place Tuesday and Tuesday night with dry
weather expected. Temperatures will be somewhat mild with highs in
the 60s to lower 70s.

Unsettled conditions return mid and late week as a warm front slowly
approaches from the south on Wednesday. The warm front associated
with a low pressure in the middle of the country. Expect shower
chances to increase through the day as the front either slowly
approaches or stalls over the area. PWATS increase to over an inch,
however better forcing remains west of the region. Expecting mainly
light rain at this point. Latest forecast 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 will continue to keep
any thunder out of the forecast for now.

The chance for unsettled weather remains Friday into Saturday as
another quick moving frontal system may impact the area, with shower
chances remaining. There is some uncertainty with this second cold
front will limit POPs to just chance.

Temperatures will remain near to slightly above normal for much of
the week.-- End Changed Discussion --

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --A cold front moves in tonight. This cold front weakens across the
area and slides south of the area late tonight into Monday.

One round of rain showers is moving across this afternoon, passing
across KSWF and CT terminals. Then, a second round of showers and
thunderstorms develops and moves in this evening, probably as a
broken line of rain showers and thunderstorms. Brief gusty strong
winds and MVFR will be possible with thunderstorms with higher
chances at KSWF. Timing of showers and thunderstorms mainly in a 0-
4Z timeframe. Otherwise, VFR continues and is expected to hold on
through the remainder of the TAF period.

Winds will be increasing S-SW near 15 to 20 kt with gusts near 25-30
kt along the coast with lower winds farther inland. Winds become
more NW late tonight and decrease to near 5-10 kt. Winds return back
to a more westerly flow Monday late morning into the afternoon with
wind speeds around 10 kts.

Already have SW low level winds near 40-45 kt at 1kft at KJFK late
this afternoon and this is expected to continue into early this
evening.

There is forecast to be a period of low level wind shear with SW
winds of near 50 kt near 2kft this evening around 0 to 4z for NYC
and coastal terminals.

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

Timing of TSRA and MVFR may be off by +/- 1 to 3 hours.

Occasional higher gusts around 35 kt possible for NYC terminals this
afternoon through this evening.

Showers and thunderstorms may weaken and dissipate this evening
before or near when they are entering NYC terminals.

OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...

Mon: VFR. W-NW gusts 15-20 kt in the afternoon into early evening.

Mon night through Tue: Mainly VFR.

Wed and Thu: MVFR or lower possible at times with potential for rain
showers, most likely in the Wed night into early Thu time period.
Easterly winds near 10-15 kt with gusts near 20 kt late Wed night
into Thu.

Fri: Chance of rain showers and MVFR.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90A cold front moves in tonight. This cold front weakens across the
area and slides south of the area late tonight into Monday.

Already have SW low level winds near 40-45 kt at 1kft at KJFK late
this afternoon and this is expected to continue into early this
evening.

There is forecast to be a period of low level wind shear with SW
winds of near 50 kt near 2kft this evening around 0 to 4z for NYC
and coastal terminals.

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

Timing of TSRA and MVFR may be off by +/- 1 to 3 hours.

Occasional higher gusts around 35 kt possible for NYC terminals this
afternoon through this evening.

Showers and thunderstorms may weaken and dissipate this evening
before or near when they are entering NYC terminals.

OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...

Mon: VFR. W-NW gusts 15-20 kt in the afternoon into early evening.

Mon night through Tue: Mainly VFR.

Fri: Chance of rain showers and MVFR.

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

.MARINE...
-- Changed Discussion --SCAs continue for the ocean waters into Monday, and for NY
Harbor, the South Shore Bays, and the western sound into this
evening. The approaching frontal system today will result in
west winds shifting to the S-SW and ramping up to SCA criteria
with even a few gusts on the ocean approaching gale force this
evening. 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
pushes south of the area and high pressure builds in tonight.
SCA seas will linger on the ocean into Monday. Winds across the
central and eastern sound waters are expected to largely remain
below SCA criteria, however occasional gusts to 25 kt are
possible.

Sub-SCA conditions are expected on all waters Tuesday through
Wednesday. SCA conditions may then return to the ocean waters on
Thursday as a frontal system approaches.-- End Changed Discussion --

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

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

SYNOPSIS...BC/JP
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...BC
AVIATION...JM
MARINE...BC/JP
HYDROLOGY...BC/JP