NYC Office Forecast Discussion

FXUS61 KOKX 030251

Area Forecast Discussion
National Weather Service New York NY
1051 PM EDT Mon Oct 2 2023

High pressure will remain near the region through mid week.
High pressure moves north and east of the region Wednesday night
through Thursday. The high will give way to a frontal system
Friday into Saturday night, with a cold front passage late
Saturday into Saturday night. High pressure builds to the south
Sunday and Monday.


Updated for current conditions and short term trends. Slight
adjustments with local temps and dew points for the most part
over the next several hours, otherwise fx remains on track.
Previous discussion follows.

The region will remain on the eastern side of an upper level
ridge which will not exhibit much changes in geopotential
height. At the surface, the center of high pressure will get
within closer proximity to the region. The pressure gradient
will be weak allowing for winds to diminish. Subsidence from the
ridging will lead to mainly clear sky conditions.

With HRRR overestimating the amount of smoke in the area, the
forecast does not have any mention of haze through tonight.

Blended in some BC MOS guidance with the cooler MET guidance
overnight to better account for local variance in temps based on
radiational type set up. Usually like to take the coolest of
MOS with high pressure moving overhead, as this sets up optimal
radiational cooling conditions with clear sky conditions and
calm winds. The MET guidance conveys a more vast range of lows
to better depict the range of temperatures from mid to upper
40s in Pine Barrens of LI and interior valleys to mainly lower
60s within the NYC Metro.

Also, expecting temperatures to fall right to the dewpoint in
quite a few locations late tonight into early Tuesday morning,
allowing for low level saturation. Patchy radiational fog is
expected, especially in outlying and river valley locations.
While NAM BUFKIT sounding profiles seems to be over-forecasting
the amount of moisture, there are hints of this fog development
as well within the RAP BUFKIT sounding profiles.


The upper level ridge continues to move in with its axis
approaching closer for Tuesday. At the surface, high pressure
will remain near but become centered more to the south of the
region. Models indicate some daytime trough development within
the forecast region. Models also convey 850mb temperatures
increasing a few degrees with values mainly between 16 and 18
degrees C.

Went on the higher side of forecast guidance, and chose the ECS
as well as MAV and MET guidance with some minor adjustments
upward. Surface westerly flow component will also allow for
relatively higher temperatures along the coast and Twin Forks.
Upper 70s to lower 80s is the range of forecast highs.

The westerly flow and ridging will allow for mostly sunny
conditions overall for Tuesday with any fog in the morning
burning off relatively quickly.

For Tuesday night, lows are forecast to be several degrees
warmer than lows the previous night. Lows forecast range from
the lower 50s to upper 60s. Dewpoints trending a few degrees
higher for Tuesday night as well. Forecast again has patchy
radiational fog as temperatures reach near the dewpoint
especially for interior and outlying locations.

For Wednesday, surface high pressure slides just east of the
area late in the day, allowing for more southerly winds to
develop. Winds are forecast to remain light. High temperatures
expected to be pretty similar to the previous day.


A high amplitude ridge will be moving into the western North
Atlantic Ocean Wednesday night as the surface high moves east of
the New England coast and Canadian Maritimes. Heights begin to
lower after 18Z Thursday as a deep trough moves through the
central US. An upper low closes off late Friday as the upper
trough become slightly negative. This will slow the eastward
progression of a cold front, which is expected late Saturday
into Saturday night. A warm, and increasingly humid, airmass
will remain in place Thursday and Friday, with temperatures
averaging around 5 degrees above normal levels. Precipitable
water values increase steadily late Thursday into Friday night,
reaching a peak around 1.5 inches. There remains a chance that a
widespread one inch rainfall occurs late Friday into Saturday
night. The closed upper low may linger across southeastern
Canada into the northeast, with the surface low to the northeast
of the region, into the beginning of next week.


VFR as high pressure settles over the area during the TAF period.
Some outlying terminals may have a period of patchy fog with
possible MVFR visibilities after 6z, but confidence of MVFR fog
occurrence remains low to include in TAFs at this time.

Light and variable winds overnight. By the late morning the
winds become W to NW with speeds remaining under 10 kt. Sea
breeze development takes place in the afternoon for coastal
terminals from 18 to 21z, as the winds become more SW to S.

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

Cannot completely rule out some patchy fog at KJFK terminal
towards the start of the morning push, but confidence remains
too low to include in the TAF at this time. Timing of potential
wind shift due to coastal sea breezes may be off by a couple of
hours on Tuesday.


Tuesday night through Thursday night...VFR.

Friday...MVFR or lower conds possible with an increasing chance of
light showers.

Saturday...Mainly MVFR or lower with showers.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/


Conditions on the waters are expected to remain below SCA
thresholds through Wednesday with high pressure remaining in
control. The pressure gradient will remain relatively weak.

Winds and seas remain below SCA levels across the forecast waters
Wednesday night through Friday. With an increasing southeasterly
flow ahead of a cold front during Friday ocean seas build to around
5 feet by Friday night. Winds and gusts increase with the cold
front Saturday into Saturday night, and ocean gusts may reach 25
kt behind the front Saturday night. Ocean seas will build
Saturday into Saturday night as long period swells from distant
Tropical Storm Philippe move into the waters. Refer to the
National Hurricane Center, for official
forecasts on Tropical Storm Philippe.


Dry conditions are expected through Thursday with no hydrologic
problems expected.

At this time, no significant hydrologic impacts are expected
with rainfall Friday into Saturday night.


Astronomical tides are slowly lowering, and with light and variable
winds tonight, becoming light westerly Tuesday, significant tidal
departures are not expected, with all areas falling below the minor
coastal flood benchmarks for the high tide cycles Tuesday morning
into the afternoon.


The Peconic River at Riverhead NY tidal gauge remains out
of service for unrepresentative data (water levels about 3 ft
too high). The gauge is being looked into by our partners at the






NWS OKX Office Area Forecast Discussion