192
FXUS61 KOKX 250016
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
716 PM EST Fri Jan 24 2025
.SYNOPSIS...
-- Changed Discussion --
A weak cold front or trough moves across the region this
evening. High pressure then builds in from the southwest late
tonight into the morning. High pressure shifts east of the
region Saturday night into Sunday. A frontal system moves across
Sunday. A pair of cold fronts moves across for mid week with a
weak low possibly on the second cold front moving through
quickly. High pressure builds for late in the week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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No significant changes, only slight adjustments were made to
sky cover and hourly temps due to temperatures falling quickly
in most rural locations. Previous discussion follows.
For tonight, a weak cold front at the surface gets east of the
region late this evening. Just some clouds initially with dry
conditions remaining with the frontal passage. Rising pressure
is then expected as high pressure builds in from the west. This
will lead to decreasing clouds and decreasing winds late evening
into overnight, optimizing radiational cooling. Used the
relatively cooler MET MOS guidance for lows tonight. Range of
lows, around 5 to 10 for interior and rural locations to lower
20s within NYC.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
High pressure will continue building in from the west on Saturday.
Surface winds become more westerly with more SW direction switch
later in the day. Max temperatures are forecast to be slightly
colder than those of the previous day, lower 30s along the coast and
upper 20s across the interior.
For Saturday night, clouds will be on the increase as an upper level
shortwave and surface frontal system approach from the north and
west. This will mitigate the radiational cooling. Winds lighten
across the interior but remain nearly steady along the coast from
the southwest. Less of a spatial range in low temperatures expected
with upper teens across parts of the interior to upper 20s within
much of NYC using a consensus of MOS.
For Sunday, the upper level shortwave moves across as does a surface
frontal system. This disturbance will be lacking moisture and have
most positive vorticity advection north of the area. As a result,
the vertical forcing for the local region will be weaker and the
forecast just has an increase in clouds and a slight chance of snow
showers for eastern sections as they will be closer to the positive
vorticity advection.
High temperatures forecast on Sunday from a consensus of MOS range
from the upper 30s across much of the interior to lower 40s along
much of the coast. Models indicate warmer 850mb temperatures
compared to the previous day and the pressure gradient will be
tighter, allowing for a deeper westerly flow that will allow for
more mixing as westerly winds will be more breezy. Highs will
probably be established by early afternoon and then be more steady
as cold air advection increases mid to late afternoon.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A dry and seasonable weather regime prevails in the long term. It
likely turns colder later in the period as temperatures may dip back
below seasonal levels getting towards late Wed through Fri.
The northern branch of the jet stream will remain dominant
throughout. With energy closed off in the southern branch across the
SW CONUS there should continue to be the lack of a moisture source
for the northern branch to work with. The polar jet stream is
expected to remain nearby throughout the period.
The question throughout this period revolves around uncertainty
around the degree and timing of another shot of cold air and the
potential return of below normal temperatures. The National Blend of
Models (NBM) continues to show an substantial increase in spread
with temperatures beginning Tuesday night and through the late week
timeframe. As far as the details a pair of cold fronts arrives with
more of a traditional polar boundary as advertised by the GFS and
DWD global deterministic guidance for Tuesday. The ECMWF and GEM are
a bit delayed with any frontal boundary on Tuesday. Towards late
Wednesday the global deterministic guidance comes into better
agreement with a stronger boundary slipping further south than its
predecessor and arriving sometime Wednesday or possibly Wednesday
night. The NBM shows a downward trend in temperatures Wednesday
night through the first half of Friday. However the spread in
temperatures and thus the uncertainty increases earlier than that
for late Tue. This is mainly due to the progression of the first
cold frontal boundary. In any event, the boundary should be moisture
starved with a dry air mass out in front of it. Given the large
uncertainty with temperatures later in the week did follow NBM /
Consensus blended guidance closely. If the colder cluster of the
ensemble guidance is correct, then single digit to around zero wind
chills may return towards Thursday and Thursday night.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
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A weak cold front or trough will move across the terminals this
evening, followed by high pressure building in from the southwest
later tonight into the morning. High pressure then gives way to
a frontal system approaching from the Great Lakes.
VFR. Mid and upper deck lowers Saturday afternoon and evening.
WNW winds generally less than 10 kt tonight will become more NW
and possibly N for a time overnight. Winds will then shift to
the SW around 10 kt late morning into the early afternoon with
gusts up to 20kt possible.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts may be more occasional than frequent on Saturday.
.OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
Saturday Night: VFR.
Sunday-Tuesday: VFR. W-WSW gusts 20-25 kt.
Wednesday: Chance of MVFR or lower in snow showers. W gusts
20-25kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Expecting a prevalence of sub-SCA conditions on the forecast marine
zones through Saturday morning with a weak pressure gradient in
place.
Winds and ocean seas then increase as pressure gradient tightens
between departing high pressure and incoming low pressure to the
north and west Saturday into Saturday night. Some 25 kt gusts
are forecast late day on the ocean, but frequency just expected
to be occasional. Gusts to 25 to 30 kt expected to become more
frequent on the ocean Saturday night. Ocean seas also forecast
to build to near 5 ft Saturday night.
The low stays well north of the waters on Sunday but will be in
closer proximity to the local waters. The pressure gradient tightens
between this low and another high starting to approach from the
south and west. More of a gusty westerly flow is expected. Gusts to
25 to 30 kt expected to be more widespread. Ocean seas forecast
to build to near 6 ft Sunday.
SCA is currently in effect for the ocean waters Saturday night
through Sunday. With SCA gusts expected to be more marginal and
intermittent on the non-ocean waters, held off on SCA issuance for
non-ocean zones.
A brief period of sub advisory conditions is possible Sunday night.
However, small craft conditions should re-develop across all waters
Monday and carry into Tuesday morning on a west to west-southwest
wind. Late Monday and Monday night occasional gusts to gale force
are possible for portions of the ocean waters. Sub small craft
conditions should then return to the non-ocean waters by Tuesday
night with small craft seas likely still lingering for much of the
ocean into a good portion of Wednesday.
&&
.HYDROLOGY...
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No significant hydrologic impacts through next week.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM Saturday to 6 PM EST Sunday for
ANZ350-353-355.
&&
$$
SYNOPSIS...JE/JM/DW
NEAR TERM...JE/JM/DW
SHORT TERM...JM
LONG TERM...JE
AVIATION...DW
MARINE...JE/JM
HYDROLOGY...DW