779
FXUS61 KOKX 010702
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
202 AM EST Sat Feb 1 2025
.SYNOPSIS...
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A frontal wave of low pressure will move east of the region into
this morning. High pressure will then build in from the Great
Lakes today into tonight, while low pressure deepens over the
western Atlantic. A warm front then approaches on Sunday and
passes through during Sunday night. The trailing cold front from
this low pressure system passing to the north will pass through
Monday night, followed by high pressure through early
Wednesday. Another frontal system will then impact the area
later on Wednesday into Thursday. High pressure is expected to
follow on Friday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
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A frontal wave of low pressure over ern sections of the fcst
area will pass east into this morning. Upward forcing
associated with the low, including synoptic scale lift from an
upper jet streak, is still bringing rain to Long Island. Rain
should clear eastern Long Island by around 6 AM.
Light winds and low dewpoint depressions have led to areas of
fog. Patchy dense fog is occurring in spots, but should lift as
post-frontal N-NW flow begins. Fog is expected to become less as
northerly flow allows for drier air to move into the area
towards daybreak.-- End Changed Discussion --
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
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High pressure from the Great Lakes will be building in through
the day. The relatively tight pressure gradient between this
high pressure area and an area deepening low pressure out in the
Northern Atlantic will create a gusty NW flow, advecting in
colder air throughout the day.
Expecting actually colder temperatures this afternoon compared
to this morning. Used a colder blend of guidance for high
temperatures which will be set in the morning and range mainly
in the low to upper 30s. Low 30s for the interior and upper 30s
along the coast and within NYC.
Some mid level ridging will allow for more subsidence and drying
atmospheric column will make for a sunnier day. But with cold
air advection, actual temperatures will be colder than the
previous day and apparent temperatures will certainly feel much
colder than the previous day. The highest the forecast wind
chills reach today is the upper teens to upper 20s.
Winds then diminish tonight as the center of high shifts to
our north and the pressure gradient weakens. Mainly clear
conditions and light to calm winds will allow for radiational
cooling, with low temperatures dropping into the single digits
across the northernmost zones. Teens for most other locations,
except low 20s in the city.
For Sunday, looks like it should be dry most of the day.
Overrunning precip will however advance from the west ahead of
a warm front. This front is in association with a quick-moving
low pressure system well to our north. Snow will be possible
towards late in the day north of the city. Snow chances then
become more likely Sunday night north of the city as the warm
front moves through, with the highest chances being over SE CT.
Looks like it should be coming to an end by the time a warm nose
pushing in could result in a wintry mix late at night. Snow
amounts of an inch or less anticipated - highest generally
across the northernmost zones. For the city, LI and the urban
corridor of NE NJ, precip chances are capped at chance, and it
should be warm enough for rain during the whole event.-- End Changed Discussion --
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
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A nearly zonal flow will feature some timing issues with a
midweek storm system that will impact the area. The latter of
which will be driven by kink in the flow late in the week as an
amplifying shortwave trough drops across the Great Lakes
Thursday and across the Northeast on Friday. Before then though,
a cold front will pass through the area Monday night as low
pressure passes well to the north. This looks to be uneventful
with perhaps an isolated shower. More importantly, it will
return the area to temperatures closer to normal for early
February and potentially set the stage for some wintry weather
later in the week. High pressure briefly returns Tuesday into
early Wednesday.
Where there are issues that still need to be resolved are with
low pressure emerging from the Central Plains midweek and the
overrunning precipitations that breaks out well in advance of
the associated warm front. The parent low likely tracks west of
the area with warm air surging in aloft and snow or a rain/snow
mix the onset that goes over to rain Wednesday night. A
confluent flow between the two branches of the polar jet lifts
out to the northeast on Wednesday. How quickly that happens will
determine the extent of cold air and how quickly it erodes.
There is high confidence that enough warm air moves in aloft for
a changeover to rain, but an extended period of freezing rain
is possible north and west of the NYC metro Wednesday night. The
NBM still is showing quite a temperature spread for the midweek
system with box and whisker plots showing as much as 20 degree
spreads between the 25th and 75th percentiles. The deterministic
is very close to the median during this time. Expect all rains
on Thursday before it comes to an end late Thursday night
following a cold frontal passage. Temperatures in the warm
sector Thursday may get into the 50s, but falling back into the
40s Friday. Thus, a period of quickly changing weather.-- End Changed Discussion --
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
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Low pressure over the area will move east overnight along with
an associated cold front. High pressure will then build from
the Great Lakes today, while while the low deepens and moves
out over the western Atlantic.
Widespread IFR/LIFR conditions will persist overnight, with rain
ending. Improving conditions expected toward daybreak, with a
return to to VFR at all terminals by 13Z..
Winds shift N-NW and increase after cold fropa to 15-20 kt with
gusts 25-30 kt. A few higher gusts up to 35 kt are possible.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for timing of category changes and
shift/increase in N-NW winds. VFR conditions could return
earlier than fcst.
.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
Late tonight: VFR. NW winds 10-15 kt with gusts 20-25kt early in
the evening, then diminishing.
Sunday: Chance of MVFR or lower cond at night in rain and/or
snow.
Monday and Tuesday: VFR.
Wednesday: MVFR or lower cond in developing rain and/or snow.
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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With the relatively tight pressure gradient between approaching
high pressure from the north and west and deepening low pressure
well to the north and east, a gusty NW flow will reach SCA
levels for all waters throughout today. SCA already in effect on
the ocean and after 6AM goes into effect for all forecast
waters.
The SCA continues on the ocean into tonight as a lingering
swell should keep seas elevated. There may be a few SCA level
gusts for the non-ocean waters this evening but a decreasing
trend is expected so just the ocean has SCA for tonight. Late
tonight, just the ocean east of Fire Island Inlet has SCA.
Sub-advisory conditions then prevail for Sunday through
Wednesday. The only exception would be marginal 25-kt gusts on
the ocean possible ahead of a cold front on Mon and behind it
Mon night-Tue.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns at this time.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM this morning to 6 PM EST this
evening for ANZ331-332-335-338-340-345.
Small Craft Advisory until 6 AM EST Sunday for ANZ350-353.
Small Craft Advisory until 1 AM EST Sunday for ANZ355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JM/JC/DW
NEAR TERM...JM/JC/DW
SHORT TERM...JM/JC
LONG TERM...DW
AVIATION...BG/JP
MARINE...JM/DW/MW
HYDROLOGY...DW/MW