869
FXUS61 KOKX 150555
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
155 AM EDT Sun Sep 15 2024
.SYNOPSIS...
High pressure across the Northeast will remain in control
through the beginning of the new week. A frontal system then
slowly approaches from the southwest through mid-week and
remains in the vicinity through the end of next week. A back
door cold front moves through late next week into the first half
of next weekend.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Updated for current conditions, lowering temperatures and dew
points mainly across the Pine Barrens region. Initial drop off
in the temperatures and dew pints under currently clear skies
and relatively light winds will be slowed as forecast stratus
moves in from the east late tonight and toward morning. Patchy
stratus was drifting westward along the Cape Cod coast at 02Z.
A anomalously strong upper high (+2SD) building in from the
west will allow surface high pressure to strengthen and work
south along the New England coast tonight. A dissipating back
door cold front will precede the building high, likely washing
out near or over the area. However, it may bring enough dry and
increasing easterly flow to to limit low clouds and fog to be
patchy in nature and mainly across LI and SE CT. In fact,
moisture profiles show the moisture to be very shallow.
Lows will mainly be in the upper 50s to lower 60s, but mid 60s
across the NYC metro.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
A large dome of high pressure will reside across the areas
during this time with easterly flow and temperatures at or just
below normal.
A developing low along the Carolina coast is forecast to track
well south and west of the area on Monday. NHC is monitoring
this area for potential tropical development. The high will
gradually weaken and retreat offshore Sunday night into Monday.
Airmass looks dry enough to leave out the mention of fog Sunday
night into Monday.
&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Tranquil weather will continue through Monday night with deep
layered ridging aloft and high pressure at the surface centered off
the northwestern Atlantic, which slowly drifts east through mid-
week. At the same time, low pressure over the Carolinas will slowly
trek northwestward toward the Ohio Valley through mid-week. The
associated frontal system will approach from the southwest and will
begin to impact the region starting mainly Tuesday night, though
isolated showers cannot be ruled out during the day Tuesday,
especially given uncertainty with the placement of the low and the
frontal system this far out.
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 Tuesday night through Thursday,
especially if the 12Z GFS pans out, with a deep moisture feed from
the tropics and training possible. There is a low chance right now
of flooding, and the Weather Prediction Center has place the entire
forecast area in a marginal risk of excessive rainfall Wednesday
into Thursday. There is a great deal of uncertainty, especially
given the previously mentioned weak flow and the forecast is likely
to change over the next few days. Due to uncertainty, stuck close to
the NBM and did not go any higher than chance POPs through the long
term.
Thereafter, the system finally begins to nudge south with the
approach of a back door cold front that moves through Friday night.
High pressure builds in from the northeast on Saturday.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Tranquil weather will continue through Monday night with deep
layered ridging aloft and high pressure at the surface centered off
the northwestern Atlantic, which slowly drifts east through mid-
week. At the same time, low pressure over the Carolinas will slowly
trek northwestward toward the Ohio Valley through mid-week. The
associated frontal system will approach from the southwest and will
begin to impact the region starting mainly Tuesday night, though
isolated showers cannot be ruled out during the day Tuesday,
especially given uncertainty with the placement of the low and the
frontal system this far out.
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 Tuesday night through Thursday,
especially if the 12Z GFS pans out, with a deep moisture feed from
the tropics and training possible. There is a low chance right now
of flooding, and the Weather Prediction Center has place the entire
forecast area in a marginal risk of excessive rainfall Wednesday
into Thursday. There is a great deal of uncertainty, especially
given the previously mentioned weak flow and the forecast is likely
to change over the next few days. Due to uncertainty, stuck close to
the NBM and did not go any higher than chance POPs through the long
term.
Thereafter, the system finally begins to nudge south with the
approach of a back door cold front that moves through Friday night.
High pressure builds in from the northeast on Saturday.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
High pressure will remain centered to the north and east.
VFR into the overnight, with IFR ceilings expected to develop,
and move in from the east/northeast to the east/southwest.
There are timing uncertainties with KBDR and KISP forecast to
lower between 08Z-09Z and and possibly into KLGA and KJFK around
10Z. Less certain is IFR ceilings moving into KEWR and KTEB
before sunrise, and with less confidence have left IFR out at
this time. KGON has already lowered to IFR. Conditions improve
back to VFR early Sunday morning.
Light SE to E winds become generally light and variable to light
E/NE tonight. Light flow increases to 5-10 kt Sunday morning,
becoming SE mid to late afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
There is a chance of IFR ceilings for a couple of hours at KLGA
and KJFK, 10Z to 12Z, and less certain at KEWR and KTEB.
Amendments possible.
OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...
Sunday night through Tuesday: Chance of MVFR or lower cond with
low clouds/fog each late night/early morning, otherwise VFR.
Wednesday and Thursday: Chance of showers with MVFR or lower cond
possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
High pressure will remain north and east of the waters through
Monday. The easterly flow increases to 10-15kt on the ocean
waters for Sunday and Monday with a few gusts possibly approaching
20 kt. This will allow for seas to slowly build with the potential
for SCA seas around 5 ft moving into the waters Monday afternoon,
especially west of Fire Island Inlet.
Sub-advisory conditions are in the forecast through Thursday.
However, an extended period of easterly flow over the ocean waters
may allow seas to build to near 5 ft Tuesday night through Thursday.
&&
.HYDROLOGY...
An extended period of rain is possible from Tuesday night
through Thursday with a tropical feed and training possible.
There is a great deal of uncertainty this far out. The Weather
Prediction Center has placed the entire forecast area in
marginal risk for excessive rainfall. One factor against
flooding would be the antecedent dry conditions over the last
week.
&&
.TIDES/COASTAL FLOODING...
With an approaching full moon for next week on the 17th,
astronomical high tides will be rising leading up to that date
and continuing into much of next week. Continuous easterly flow
will help build seas and allow for some piling of water. Winds
are expected to remain generally light, near 10 kt or less.
While some of the guidance is showing water levels increasing,
there is general consensus of keeping them below minor coastal
flooding benchmarks. However, this will likely depend on the
development of low pressure off the Carolina coast early next
week.
There is a moderate risk of rip current development at the
ocean beaches Sunday and Monday with an easterly flow
developing.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JP/DW
NEAR TERM...JP/MET/DW
SHORT TERM...DW
LONG TERM...JP
AVIATION...BC
MARINE...JP/DW
HYDROLOGY...JP/DW
TIDES/COASTAL FLOODING...