343
FXUS61 KOKX 072117
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
417 PM EST Fri Feb 7 2025
.SYNOPSIS...
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High pressure builds in from the west through the first half of
Saturday. Low pressure then approaches from the Ohio Valley on
Saturday with a secondary low taking shape south of Long Island
Saturday night. Low pressure departs to the east Sunday as high
pressure builds to the west. High pressure will be in control
Sunday night into Monday. A series of low pressures may impact
the waters Tuesday through Thursday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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The passage of a northern branch shortwave trough and deepening
low pressure over the Canadian Maritimes will continue to allow
colder air to filter into the area tonight on NW winds. Wind
gusts of 20 to 30 mph early this evening will quickly subside as
high pressure builds east from the Ohio Valley. Expect a mainly
clear night with some high clouds filtering in from the west
toward daybreak. Lows will range from the upper teens inland to
the lower and middle 20s at the coast. This is right around
normal.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
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There is good model agreement in taking a southern branch low
over the Mid Mississippi Valley east on Saturday and into the
Ohio Valley by late afternoon/early evening. As the upper
forcing approaches the coast Saturday night, a secondary low
takes shape south of Long Island, passing to the south and east
overnight. How quickly this secondary low takes shape will be
critical into how strong of an elevated warm layer gets into
the area ahead of the weakening primary low to the west. There
seems to be good agreement with a warm nose pushing into the
NYC/NE metro, southern portions of the Lower Hudson Valley, and
western LI around 10 pm - Midnight. Beyond that, the warm air
may not get too much farther north and east as the coastal low
takes shape to the south and SE winds back around to the E/NE
and mid level cool. While this is a close call with the
precipitation likely transitioning to a mix closer to the coast,
strong thermal forcing and frontogenetic forcing will provide a
quick front end dump of snow for most locations with snowfall
rates an inch plus for about a 2 to 3 hour period. Most of this
occurs from Saturday evening into early Sunday morning with a
transition to a lighter precipitation mixed with sleet, freezing
drizzle, and possibly plain rain at the coast (LI and NYC).
Light precipitation will then linger into Sunday morning with
little additional snowfall and/or ice accretion. Any icing looks
light, perhaps a glaze on top of the already fallen snow.
Snowfall totals of 3 to 5 inches are expected across LI and the
NYC/NJ metro, where a winter weather advisory is in effect.
Across interior NE NJ, the Lower Hudson Valley, and southern CT,
expect 5 to 7 inches with a Winter Storm Warning in effect.
Winds through the event are expected to be under 10 mph, so
blowing and drifting unlikely.
Temperatures on Saturday get up into the lower and middle 30s,
then fall into the upper 20s and lower 30s in the evening with
the onset of the snow, fluctuating little overnight.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
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Key Points:
* Increased confidence for accumulating snow late Tuesday night into
early Wednesday.
* Uncertainty remains high for accumulating snow Wednesday through
Thursday as additional low pressure systems possibly impact the
area.
* Daytime high temperatures will be below normal for much of the
week, with the exception of Thursday, with near normal overnight
low temperatures.
The fast and nearly zonal flow aloft will continue Sunday through
Wednesday with a more amplified trough approaching the east coast
Thursday and passing through Thursday night. High pressure briefly
build into the area late Sunday through late Monday. With another
high likely building to the north late Tuesday through Wednesday
cold air will remain in place. And with a couple of lows passing to
the south precipitation with these lows late Tuesday into Wednesday
will be all snow across the region. The track of the lows are a
little uncertain and will be determined with the strength of the
high to the north.
There is increased confidence for an accumulating snow late Tuesday
into Wednesday, however, amounts are uncertain with the track of the
low, and have trended lower.
There may be a brief break in the precipitation later Wednesday into
Wednesday evening, however with the uncertainty with the timing of
the lows will maintain at least chance probabilities.
With the next low pressure system quickly approaching late
Wednesday, and being more amplified and a deeper surface low, chances
remain high for additional snow accumulations at least across the
inland areas. There will be increased moisture with this system as
the low takes a southerly track and Gulf moisture entrains. With the
inland system and a strong southerly flow with strong warm air
advection, frozen precipitation will likely transition to rain along
the coast, and mixed precipitation inland. And with the warm
advection temperatures Thursday may be near to above normal. High
pressure and upper ridging build behind the low to end next week.-- End Changed Discussion --
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
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High pressure builds towards the terminals through tonight.
VFR.
WNW-NW winds 15-20 kt with gusts 25-30 kt. Frequent gusts should end
00-02z, with NW-WNW winds less than 10 kt late tonight. Light NW
winds for Saturday morning becoming variable late in the morning,
then SE-S in the afternoon under 10 kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Winds average around 310 magnetic through into this evening,
probably favoring north/right of 310 magnetic into this evening.
Occasional gusts 30-35 kt still possible before 23-00z.
End time of gusts may be off by 1-2 hours.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday Afternoon: VFR.
Saturday night: Snow developing, with LIFR/IFR at times. Precip
transitions to a wintry mix for the NYC metros/KISP around midnight.
Accumulations around 4-7 inches possible at KSWF/KHPN/KBDR/KGON.
Accumulations of 3-5 inches possible at the NYC metros/KISP.
Sunday: MVFR early, bcmg VFR by noon. NW wind gusts 20-25 kt.
Monday: VFR.
Tuesday: Chance of snow in the afternoon, becoming likely at night.
IFR/LIFR conditions possible at night.
Wednesday: Chance of sub-VFR and light 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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Sub-SCA conditions are expected to return to all the waters
later this evening into tonight as high pressure builds in from
the west. Winds and seas will then remain below SCA through
Saturday night until low pressure deepens east of the area
Sunday.
A strong and gusty northwest flow develops behind departing low
pressure Sunday with small craft seas likely on the ocean waters
with marginal advisory gusts. Winds diminish Sunday night with
building high pressure, however, ocean seas will remain elevated
until late Sunday night. With a weak pressure gradient force
Tuesday into Wednesday winds and seas remain below advisory
across all the forecast waters. Then with an increasing
northeast flow with low pressure impacting the waters Wednesday
night marginal SCA conditions will be possible across the ocean
waters.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through the forecast period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Winter Storm Warning from 5 PM Saturday to 11 AM EST Sunday
for CTZ005>012.
NY...Winter Storm Warning from 5 PM Saturday to 11 AM EST Sunday
for NYZ067>070.
Winter Weather Advisory from 5 PM Saturday to 11 AM EST Sunday
for NYZ071>075-078>081-176>179.
NJ...Winter Storm Warning from 5 PM Saturday to 11 AM EST Sunday
for NJZ002-103.
Winter Weather Advisory from 5 PM Saturday to 11 AM EST Sunday
for NJZ004-006-104>108.
MARINE...Small Craft Advisory until 1 AM EST Saturday for ANZ331-332-
335-338-340-345-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...MET/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...MET
AVIATION...JC
MARINE...MET/DW
HYDROLOGY...MET/DW