000
FXUS61 KOKX 151512
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1012 AM EST Fri Dec 15 2023
.SYNOPSIS...
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Strong high pressure will remain centered over the Mid Atlantic
region today, before being reinforced by a second high building
across eastern Canada. The high will shift off the New England
coast Saturday night. A coastal storm will impact the area from
Sunday into Monday. Another weaker low may linger nearby into
Tuesday. High pressure will then build during mid next week.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
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A 1040 mb surface high centered over the Central Appalachians
remains in control today as ridging aloft builds from the west.
Weak disturbance passing well to the north may allow for a few
20-25 mph gusts. Otherwise, sunshine prevails as subsidence
aloft limits mixing and cloud cover. Bumped afternoon temps up
per latest GFS LAMP guidance, with highs from the lower 50s
across SE CT and ern Long Island, to the mid 50s most elsewhere,
to some upper 50s in NE NJ and adjacent boroughs of NYC. Lows
tonight should range from the lower 30s across the interior, to
the lower 40s in the urban metro.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
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Flattening ridge translates east Saturday, and then offshore
Saturday night. At the surface, additional high pressure
builds in from eastern Canada.
Abundant sunshine persists, and temperatures remain above normal
with another afternoon near 50 for most. Winds gradually veer
around as the high slides off the New England coast Saturday
night, setting up onshore flow ahead of developing low pressure
over the Southeast US. No precipitation is expected through the
evening, though cloud cover quickly increases Saturday night
ahead of this next system.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
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Low pressure over the Southeast shifts north and deepens with
the help of phasing energy aloft. The center of the low passes
over us or nearby during Monday as it continues to strengthen
and head north towards SE Canada. Rain chances begin Sunday
morning with rain then likely in the afternoon. The rain could
be heavy at times Sunday night into Monday morning as a low
level jet interacts with an anomalously moist air mass. Models
show a little instability during this time as well, so with
upward forcing from both the llj and the deepening low center, a
thunderstorm with heavy downpours cannot be ruled out. See the
hydrology section for more details.
As for winds during this event, there`s an increasing chance of
at least advisory-criteria winds - particularly for coastal
sections. Winds at 925mb are progged at 60-80 kt along with
50-65 kt at 950 mb over coastal sections late Sunday night/early
Monday morning. It appears that the low level inversion will be
at least a little weaker than with this past weekend`s storm as
temps aloft would be cooler with SE winds instead of S-SW like
the previous system. Thinking there`s potential for 60-70% of
the 925mb winds to mix down to the surface, especially in
heavier downpours. Might even need to eventually consider high
wind watches over at least eastern Long Island.
Forecast confidence lowers after Monday night due to the
interaction of a northern stream trough with the departing
storm system. With cyclonic flow aloft, lingering precipitation
chances continue through Tuesday night. Stuck fairly close to
NBM. Wednesday and Thursday look dry as high pressure builds in.-- End Changed Discussion --
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
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High pressure remains in place, centered southwest of the
terminals.
VFR. W winds around 10kt through this afternoon diminish this
evening, and then veer NW towards midnight with speeds under
10kt through the night.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts at KEWR this aftn might be only occasional. Occasional
gusts around 20kt possible at KJFK and KLGA this afternoon.
Occasional gusts 15-18kt possible at KTEB this afternoon.
OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
Saturday: VFR.
Sat night through Sun morning: MVFR or lower possible in -RA.
Sunday afternoon: Rain likely with MVFR or lower cond. E winds
G20kt NYC metro/coastal terminals.
Sunday night and Monday: IFR in rain, possibly heavy at times.
Isolated thunderstorm possible. SE winds G30-45kt along the
coast and LLWS. Winds shift to S Monday afternoon with G25-30kt,
then shift SW-W and diminish Mon night.
Tuesday: Chance of rain with MVFR or lower cond. NW winds G20kt.
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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Cancelled SCA for the ocean W of Fire Island Inlet as winds and seas
have subsided. SCA continues on the ocean east of there through
6 PM for westerly gusts up to 25 kt and seas up to 6 ft. Sub-
SCA conditions then persist on all waters through at least
Saturday night.
Winds and seas increase in advance of low pressure approaching
from the south Sunday into Monday. At least gale force winds
are probable over all waters Sunday night through Monday for
most spots, and continuing into Monday evening on the ocean.
Cannot rule out gusts to storm force as well during late Sunday
night/early Monday morning for some of the eastern waters. Wave
heights on the ocean peaking at 14-19 ft Monday.
Beyond Monday night model guidance spread increases. This leads
to a low confidence win forecast Tuesday through Thursday.
Attm winds are forecast to remain below 25 kt, but SCA
conditions continue on the ocean waters with elevated wave
heights.-- End Changed Discussion --
&&
.HYDROLOGY...
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Chances of rain start as early as Sunday morning, with rain
becoming likely Sunday afternoon and continuing through
Monday. The rain is expected to be moderate, with periods of
heavy rain Sunday night through Monday morning. At this time, a
widespread 2-3 inches of rain is expected with locally higher
amounts possible. The flash flooding potential remains low at
this time, but minor urban/small stream flooding is possible.
Given the fairly recent heavy rainfall earlier this week, there
is also an elevated threat for river flooding.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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A coastal storm has potential to bring coastal flooding to the
area during the high tide cycles late Sunday night into
Monday. The forcing will be a strengthening S-SE flow that may
bring a prolonged period of gale force gusts. There still
remains some uncertainty with the timing and track of the low
which will be crucial for the extent and magnitude of the event.
Right now, there is a good chance of widespread minor to
localized moderate coastal flooding across Lower NY Harbor and
the south shore back bays of western LI. SW CT also has a good
chance of minor coastal flooding with an isolated potential
elsewhere. A limiting factor will be low astronomical tides
between full and new moon phases. This will be refined as we get
closer to the event and there is better run-to-run continuity of
the guidance.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ350-
353.-- End Changed Discussion --
&&
$$
SYNOPSIS...JC/BG/DR
NEAR TERM...BG/DR
SHORT TERM...DR
LONG TERM...JC
AVIATION...JC
MARINE...JC/BG/DR
HYDROLOGY...JC/DR
TIDES/COASTAL FLOODING...JC