421
FXUS61 KOKX 161841
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
241 PM EDT Mon Sep 16 2024

.SYNOPSIS...
High pressure over the area will gradually retreat north on
Tuesday. A frontal system will then slowly approach from the
southwest through mid week as the high drifts east out into the
Atlantic. Low pressure may linger nearby Thursday along a cold
front. The front will move across on Friday, followed by high
pressure building from southeast Canada for the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Forecast mostly on track.

With deep layered ridging aloft and a large dome of high
pressure at the surface, dry weather continues with mostly
sunny skies under some high clouds. Temperatures should be at
seasonable levels for mid September, with winds mainly out of
the E-NE less than 10 kt inland and SE-S close to the coast, all
becoming SE by late day.

For tonight, ridging holds for the most part, with just a subtle
shift to the northeast. More in the way of high clouds should
work in, also some low clouds from the south and east after
midnight and some patchy fog in outlying areas mostly per 12Z
HREF probabilities as low level moisture increases.

Temperatures should bottom out in the lower 60s invof NYC, in
the upper 40s well NW of NYC, and in the 50s elsewhere.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Surface high pressure will gradually begin to wane in strength
on Tuesday. Morning low clouds will take some time to burn off
given the high cloud cover also present, giving way to sunshine
filtered through bkn high clouds in the afternoon. Mid level
clouds now look to hold off until daytime Wed. Have gone on the
higher side of MOS for temps for Tue, with temps actually a
little warmer despite any afternoon clouds as low level
thicknesses remain nearly steady, with highs once again in the
70s to near 80.

Expect a repeat of low cloud cover coming back in Tue night,
also some patchy fog mainly well inland, while high clouds also
thicken. It should remain dry, with low temps from the 50s to
the lower 60s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The high slowly drifts east through mid week while low pressure
over the Carolinas slowly heads NW toward the Ohio Valley. An
associated frontal system will approach from the south and will
begin to impact the region on Wed.

The low and frontal system get caught under the upper level
ridging over the eastern US from mid to late week and a
prolonged period of some unsettled weather is possible as weak
flow under the ridge will mean slow movement of these features.
Right now, it looks like the most likely period of rain is on
Wednesday morning through Wednesday night. There is a deep
moisture feed from the tropics and training possible. Dewpoints
rise well into the 60s Wednesday into Thursday and PW around 2
inches are seen in most of the guidance. Of course, this is all
dependent on certain mesoscale features that cannot be resolved
at this point. With the previously mentioned uncertainty, stuck
close to the earlier NBM and did not go any higher than chance
PoP.

A mid level trough remains over the region Thursday through
Friday and weakens Saturday. Mid level ridging eventually takes
over to close out the weekend.

At the surface, low pressure may still be not too far away to
the south of Long Island Thursday into Thursday night. Chances
for showers will remain in the forecast.

A back door cold front moves across Friday, keeping shower
chances in the forecast. However PoP should be more in the
slight chance range since moisture becomes more limited as low
to the south weakens and moves farther away.

For Friday night into the weekend, dry conditions return as high
pressure builds in from the north. Clouds may very well linger
around to start but will be on a decreasing trend.

Temperatures favored the 50th NBM percentile as the pressure
gradient between low pressure to the south and high pressure
to the north remains, giving NE flow much of the time during the
long term. Gusty conditions expected along the coast as well.
NBM 50th percentile showed lower temperature for eastern half of
the region and along the coast compared to NBM. The
temperatures are expected to be below normal during the day.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
High pressure will remain centered off the New England coast
through Tuesday.

VFR through this evening. MVFR to IFR ceilings are likely late
tonight into early Tuesday morning. Some MVFR to IFR fog is also
possible for outlying terminals. Conditions should improve by
14-16z at most locations with VFR prevailing into Tuesday
afternoon.

Winds will become ESE-SE this afternoon around 10 kt or less.
Winds weaken tonight as they back to the NE, remaining light
Tuesday morning. Winds should veer to the E late Tuesday morning
into the afternoon.

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

Timing of ESE-SE wind shift at KLGA and KEWR may be off by 1-2
hours.

Amendments likely for ceilings/flight categories overnight into
Tuesday morning.

OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...

Tuesday: Mainly VFR. Chance of MVFR or lower conditions late
Tuesday night.

Wednesday-Thursday: Chance of showers with MVFR or lower
conditions. ENE winds 10-15G20kt, mainly at the coastal
terminals Wednesday.

Friday: Mainly VFR. Slight chance of showers. NE wind gusts
15-20 kt possible.

Saturday: VFR. NE winds 15-20G25 kt possible, especially near
the coast.

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

&&

.MARINE...
Ocean seas are just under 5 ft at buoy 44025 just south of the
coastal waters as relatively long period 3-4 ft SE swell
interacts with 2-3 ft wind waves in E flow. Meanwhile seas at
44079 SE of Montauk are running around 3 ft. SCA remains in
effect from late tonight through 8 PM Tue.

More widespread 5 ft seas on the ocean waters are expected
Wednesday through Fri night on a persistent E flow. Wind gusts
on the non ocean waters could also reach 25 kt at times Fri
into Fri night.

&&

.HYDROLOGY...
No issues expected. An extended period of rain is possible from
Tuesday night through Wednesday night with a tropical feed and
training possible. There is still some uncertainty with regards
to the amount of rain we may see. The Weather Prediction Center
has placed the area under a marginal risk for excessive rainfall
on Wednesday. One factor against flooding would be the
antecedent dry conditions over the last week.

&&

.TIDES/COASTAL FLOODING...
With an approaching full moon on the 17th, astronomical high tides
will be rising into much of this week, with total water levels
rising as well as continuous E flow builds seas and allows for
some piling of water. While some of the guidance is showing
water levels increasing, there is a general consensus of keeping
them below minor coastal flooding benchmarks for the most part,
although Stevens NYHOPS suggests minor flooding for the south
shore bays and the western Sound toward late Tue into Wed.

There is a moderate risk of rip current development at the ocean
beaches today with an E flow developing. The risk should
increase to high on Tue.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 5 AM to 8 PM EDT Tuesday for ANZ350-
     353-355.

&&

$$

SYNOPSIS...BG/JM/BR
NEAR TERM...BG/BR
SHORT TERM...BR
LONG TERM...JM
AVIATION...DS
MARINE...BG/JM/BR
HYDROLOGY...JM/BR
TIDES/COASTAL FLOODING...