000
FXUS61 KOKX 082142
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
442 PM EST Fri Dec 8 2023
.SYNOPSIS...
-- Changed Discussion --
High pressure will slowly move offshore tonight through Saturday. At
the same time, a 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/...
Upper level ride 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/...
-- Changed Discussion --
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 chances 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.-- End Changed Discussion --
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
High pressure will slowly move offshore through Saturday.
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 SE again late Saturday
morning into the afternoon.
...NY Metro(KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
MVFR visibilities possible early Saturday morning.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday Afternoon-Night: VFR.
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 15-25 kt with gusts 25-40 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. S-SW wind gusts 30-
40 kt eastern Long Island and Southeast Connecticut early.
Otherwise, W-WNW 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...
-- Changed Discussion --
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 late Sun and 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.-- End Changed Discussion --
&&
.HYDROLOGY...
-- Changed Discussion --
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
stream.-- End Changed Discussion --
&&
.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...JP
SHORT TERM...JP
LONG TERM...JMC
AVIATION...DS
MARINE...JMC/JP
HYDROLOGY...JMC/JP
TIDES/COASTAL FLOODING...