739
FXUS61 KOKX 242041
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
341 PM EST Fri Jan 24 2025
.SYNOPSIS...
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A weak cold front moves across the region going into this evening.
High pressure then builds in thereafter through Saturday. High
pressure shift south 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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For tonight, a weak cold front at the surface is expected to move
across the region during the evening hours. Just expecting an
increase in clouds 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/...
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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.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
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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.-- End Changed Discussion --
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
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A cold front will move across the terminals this evening followed by
high pressure building south of the area tonight into tomorrow.
VFR.
WNW winds around 10kt become more NW by this evening. Occasional
gusts upwards of 20kt are possible through early this evening, but
not frequent enough to include in the TAFs. Wind shifts to SW
tomorrow late morning into the early afternoon with gusts upwards of
20kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Occasional gusts to 20kt possible though early evening. Gusts up to
20-25kt possible on Saturday.
.OUTLOOK FOR 21Z SATURDAY THROUGH WEDNESDAY...
Saturday afternoon: VFR.
Sunday-Tuesday: VFR. W-WSW gusts 20-25 kt.
Wednesday: MVFR or lower possible in any snow showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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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.-- End Changed Discussion --
&&
.HYDROLOGY...
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Mainly dry conditions are expected through Sunday. Any
precipitation Sunday would be in the form of snow showers and
less than a tenth of an inch liquid equivalent. The probability
for these are just slight chance.
Predominantly dry conditions continue through next week, thus there
are no hydrology related concerns.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM Saturday to 6 PM EST Sunday for
ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JE/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...JE
AVIATION...MW
MARINE...JE/JM
HYDROLOGY...JE/JM