000
FXUS61 KOKX 090004 CCA
AFDOKX
Area Forecast Discussion...CORRECTED
National Weather Service New York NY
704 PM EST Fri Dec 8 2023
.SYNOPSIS...
-- Changed Discussion --
High pressure offshore will continue to track away from the area
through Saturday. At the same time, a weak warm front will stall
in the area and head northeast on Saturday. A strong frontal
passage will occur Sunday night, with low pressure deepening along
it as it tracks into Canada on Monday. A broad area of high
pressure then builds in through the rest of next week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
The fcst is on track. Upper level ridge will move over the
Northeast tonight as the center of surface high pressure slides
off the East Coast. The main forecast challenges tonight will be
if there will be any fog and/or stratus developing late
tonight. NAM forecast soundings show a low level inversion late
tonight well inland with abundant low level moisture trapped
underneath. Other models show a hint of this inversion, but not
nearly as deep. Meanwhile, ensembles show high probabilities of
fog and stratus, mainly well the aforementioned well inland
areas. Therefore, opted to continue mention of patchy fog and
increasing clouds late. This will mean that temperatures in
these areas will likely drop fairly quickly once sun sets
tonight, but then remain steady and then slowly increase through
the rest of the night, mainly sometime after 3 am. There is
also the possibility of freezing fog in the areas well north of
the area, but with even more uncertainty, did not mention in the
actual forecast. If this does occur, then an SPS may need to be
issued later tonight.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Any fog burns off early in the morning Saturday as the lower layers
warm. Weak warm advection and rising heights will mean warmer
conditions, with highs rising into the 50s region-wide. More in the
way of clouds are expected as a weak surface trough moves toward the
area, but if clouds break out a bit, even warmer temperatures are
possible. Saturday night will see a slight chance to low end chance
for light rain with the warm front still in the forecast area. The
only areas the might not see any precipitation will be eastern
areas. With continued abundant low level moisture, patchy fog will
once again be possible, though a bit more widespread than the
previous night. Lows will also be warmer given continued weak warm
air advection, ranging from the 30s well inland to the middle 40s
across the metro area.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A flood watch has been issued for all but the Twin Forks of LI,
and a high wind watch has been issued for all of LI, along with
Brooklyn and Queens. Both watches start at 4 pm Sun.
A cold front approaches on Sun, with strong moisture transport ahead
of it. High pres over the Atlc will allow for a strong pres
gradient, so increasing winds can be expected on Sun. The upr trof
is still modeled to be near Lake Erie 00Z Mon, so the heaviest
rainfall should hold off until late Sun aft/eve and ngt with
the upr support, and only light to mdt rain for the most part
during the day on Sun.
By Sun eve, rainfall increases in coverage and intensity across the
region. With the strong, deep lift displayed in the modeled omega
fields, isold tstms possible. The rain tapes off from W to E after
midnight as the cold front sweeps thru. There is a good chance
that the highest rainfall totals end up in CT with this event
due to speed convergence on sly flow.
It is important to note that rainfall timing may change depending on
the exact track and timing of the sys overall, and this far out it
is entirely possible. There is already some spread in the models,
which is why the consensus approach has been taken attm.
Any timing changes would impact the wind fcst as well. Based on
the current consensus however, peak sly winds develop Sun eve
and end with the fropa. The most significant winds occur as the
low begins to intensify Sun ngt. For fcst gusts, generally mixed
down 80 percent of the h95 winds from the 12Z NAM12. This
method yields peak gusts around 60 mph. With 55kt or higher
modeled around 1000 ft, these numbers seemed reasonable.
As the sys exits Mon, gusty NW flow but speeds blw advy lvls attm.
There could also be a brief changeover to snow, particularly across
the interior, early Mon before ending. Little to no accumulations
are expected attm.
High pres builds S of the region thereafter, keeping fair weather
locked in place for the rest of the week. The NBM yields temps
close to or slightly blw normal Tue-Fri.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
High pressure offshore will continue to slowly track away from
the area, while a strengthening frontal system over the mid
section of the country tracks east.
Mainly VFR conditions are forecast through the TAF period. The
only exception is the potential for MVFR to IFR fog late tonight
into early Saturday morning, mainly for KSWF and KHPN.
Light flow is forecast through the TAF period with wind speeds below
10 kt. S-SE winds into early this evening become light and/or
variable tonight. Wind gradually become S-SE again late
Saturday morning into the afternoon.
...NY Metro(KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
MVFR visibilities possible early Saturday morning.
Light winds on Saturday could vary significantly in direction,
especially during thee morning hours.
OUTLOOK FOR 00Z SATURDAY THROUGH WEDNESDAY...
Saturday Night: Chance of MVFR or lower by 12Z. A few showers
may be around as well.
Sunday: MVFR or lower in developing showers from west to east
through the day. S winds 15-20 kt with gusts 25-30 kt in the
afternoon.
Sunday Night: IFR in showers. Isolated thunderstorms possible. S
winds 20-30 kt with gusts 25-45 kt, strongest near the coast. A
few gusts up to 55 kt possible near the coast.
Monday: MVFR or lower early in showers, then VFR. W-WNW winds 15-20
kt with gusts 25-35 kt.
Tuesday: VFR. SW gusts 15-20 kt in the afternoon.
Wednesday: VFR. W gusts 15-20 kt in the afternoon.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Conditions are expected to remain below SCA criteria from tonight
through Saturday night as a weak pressure gradient remains in
place.
Strong sly winds develop Sun into Sun ngt. A storm watch has
been issued for all but portions of the Sound and Harbor, where
a gale watch has been issued. NW gales possible behind the sys
on Mon, then winds drop blw sca lvls on Tue. Winds are likely to
remain blw sca lvls Wed and Thu, but seas on the ocean may
linger aoa 5 ft.
&&
.HYDROLOGY...
There are no hydrologic concerns through Saturday night.
Around 2 inches of rain is likely Sun and Sun night. Locally
higher amounts in excess of 3 inches are possible. Adjustments
to the fcst are possible based on changes in the overall track,
timing, and intensity of the system. A flood watch has been
issued for all by the Twin Forks. Widespread urban and poor
drainage flooding is likely, with some areas of more significant
flooding possible, including the flooding of some rivers and
streams.
&&
.TIDES/COASTAL FLOODING...
A strong cold front will bring increasing southerly flow late
Sunday into Sunday night. The system brings potential for minor
coastal flooding with the Monday morning high tide cycle.
However, the strongest southerly flow is most likely to occur
between high tide cycles. Winds will quickly shift to the west
early Monday morning, which will help keep water levels down
during times of high tide.
There remains a large amount of spread in the surge guidance.
The highest chance for minor coastal flooding at this time
appears to be for the south shore back bays and over the western
Long Island Sound along the Westchester and Fairfield coasts.
If the higher end of the surge guidance and stronger onshore
winds linger closer to high tide, then minor coastal flooding
would be more widespread, and a localized moderate coastal
flooding threat would exist.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Flood Watch from Sunday afternoon through late Sunday night
for CTZ005>012.
NY...Flood Watch from Sunday afternoon through late Sunday night
for NYZ067>075-078-080-176>179.
High Wind Watch from Sunday afternoon through late Sunday
night for NYZ075-078>081-176>179.
NJ...Flood Watch from Sunday afternoon through late Sunday night
for NJZ002-004-006-103>108.
MARINE...Gale Watch from Sunday afternoon through late Sunday night for
ANZ331-335-338.
Storm Watch from Sunday afternoon through late Sunday night
for ANZ332-340-345-350-353-355.
&&
$$
SYNOPSIS...JMC/JP
NEAR TERM...JMC/JP
SHORT TERM...JP
LONG TERM...JMC
AVIATION...DW
MARINE...JMC/JP
HYDROLOGY...JMC/JP
TIDES/COASTAL FLOODING...