000
FXUS61 KOKX 280846
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
346 AM EST Thu Dec 28 2023
.SYNOPSIS...
-- Changed Discussion --
Low pressure will pass to the south and east of the area through
tonight, then just east of Nova Scotia on Friday. A broad area
of elongated low pressure will extend to the west of the low,
lifting slowly across the Northeast through Saturday. High pressure
will then start to build in for the second half of the weekend
and into the first few days of the new year.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Axis of heaviest rain continues to lift NNE across the Lower
Hudson Valley, NE NJ, and the NYC metro, with the back edge
in close proximity to these areas. Deep-layered lift associated
with the LFQ of an upper jet lifting northward from the Mid
Atlantic states appears to be the primary source of lift. This
axis will translate west to east through the morning hours,
clearing far eastern LI and SE CT by early afternoon. Heaviest
rainfall rates will mainly be 0.25 to 0.50/hr which could
persist for several hours with storm total rainfall amounts
around 2 inches across portions of the Lower Hudson Valley, but
decreasing to around an inch across far eastern LI and SE CT.
Due to continued high stream flow across NE NJ and the Lower
Hudson Valley(>75 percentile), many rivers/streams may reach or
exceed bankfull. Areal flood warnings/advisories are already in
effect for portions of the area. In addition, river forecast
points such as the Saddle River at Lodi and Ramapo at Mahwah
are now forecast to exceed their minor flood benchmarks.
Flooding to the east across CT and LI is likely to be less
impactful as the lift weakens, producing less rainfall. These
areas are more likely to experience some minor nuisance, poor
drainage flooding.
Temperatures will fluctuate little today, topping out in the
upper 40s to lower 50s.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TONIGHT/...
-- Changed Discussion --
Conditions remain gloomy, with low stratus, mist, and
occasional light rain with the closed low off to west, and
several spokes of energy rotating around it. Maintained chance
PoPs this afternoon and then increase back to likely overnight
as a trough of low pressure lifts across the area from south to
north QPF will be light with minimal additional hydro concerns.
Mostly cloudy to overcast skies persist.
Temperatures remain well above normal, about 10 to 15 degrees
above normal for late December. Lows overnight will only
manage to fall into the 40s.-- End Changed Discussion --
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
No significant changes made to the long term and stuck close to
the NBM for this update.
*Key Points*
* Rain chances continue Friday and into early Saturday, before
drying out on Sunday and into New Year`s Day.
* A cooldown to more seasonable temperatures Saturday through
Wednesday.
Large-scale upper level troughing remains in places through much of
the end of the week and into the weekend. This is paired with
surface waves of low pressure and troughs that will likely make for
a continued unsettled end of the week and beginning of the weekend.
A mid-level vorticity max rounds the base of a trough over the Ohio
Valley into the Southeast US. This forces a more recognizable low
pressure south of the area off of the East Coast Friday night and
into Saturday. The surface low pressure likely quickly merges with
the departing low to the northeast resulting in mainly a chance for
showers through Saturday morning. As the low departs, slight
subsidence in its wake will dry out the mid-levels and likely shut
off precipitation into Sunday.
Though an upper level trough remains in place with mid-level energy
sheared throughout it, some surface ridging to the south may nose
into the area on Sunday and into Monday with mainly dry conditions.
Global models diverge on how they handle another round of mid-level
energy approaching from the west, embedded in the trough. It may
develop a quickly developing low pressure to the south of it but
with little blocking downstream, the low may quickly move offshore
with minimal if any impact to the area. As of now, kept it dry
through much of the beginning of next week, but subsequent updates
will need to be watched for any changes.-- End Changed Discussion --
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
Low pressure approaches tonight and eventually moves east of
Long Island Thursday.
Still have a vast range of conditions within the forecast
region this evening, ranging from LIFR to VFR. Expecting mainly
LIFR tonight with steadier rainfall moving in from the west and
becoming more widespread going into overnight. Occasionally
locally heavy rainfall can be expected for most terminals.
Low level moisture after main steady rainfall ends will keep IFR
to LIFR conditions in place. Also, more rain showers are
forecast to develop during the day, especially in the afternoon.
Winds generally ENE 5-10 kt during the TAF period, becoming more
northerly late in the TAF period.
Occasional gusts to near 15 kt will be possible Thursday
afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Fluctuation between categories possible. Timing of LIFR and IFR
could vary a few hours from TAF.
OUTLOOK FOR 18Z THURSDAY THROUGH SUNDAY...
Thursday afternoon / night: MVFR possible with chance of showers.
N winds.
Friday: MVFR possible with chance of showers. Light WSW to W winds.
Saturday: Mainly VFR. W winds 10-15kt G20kt. Gusts subside at
night.
Sunday: VFR. W winds.
Monday: Mainly VFR. W / NW winds G20kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
A SCA has been issued for the ocean waters due to a building SE
swell associated with low pressure passing to the south and
east today. Seas are expected to build to 4 to 7 ft by early
this evening. Seas will then gradually lower tonight into Friday
as winds become westerly and low pressure east of New England
lifts up into the north Atlantic. Elsewhere, sub SCA conditions
are expected through Friday.
Marginal SCA conditions are expected on the ocean waters Saturday
morning. SCA conds become likely over the eastern ocean zones
with developing low pressure to the south late Saturday into
Sunday, with 5-7ft seas. Sub SCA conditions return by late
Sunday.-- End Changed Discussion --
&&
.HYDROLOGY...
-- Changed Discussion --
Storm total rainfall of 1 to 2 inches is likely through early
this afternoon, highest to the north and west of NYC. Due to
recent heavy rainfall, minor flooding along a few quick
responding rivers in NE NJ is likely. Otherwise, minor urban and
poor drainage flooding should be the main hydrologic impact,
though isolated flash flooding cannot be ruled out.
There are no hydrologic impacts expected tonight through early
next week.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
Minor coastal flooding now looks more likely later this morning
with possible impacts for vulnerable coastal communities. This
is associated with a passing low pressure system with onshore
flow and an astronomically high tide. A coastal flood advisory
remains in effect for the the south shore of Nassau and Queens,
with tidal departures of between 1.3 and 1.8ft. High tide peaks
from about 7-10am. Statements are in effect for parts of
Brooklyn and southwestern Suffolk, where minor benchmarks are
not expected to be reached, but some inundation (less than
0.5ft) is possible during high tide.
Elsewhere, coastal flood statements have been issued for
the SW CT coastline on the Western Sound. Tidal departures of
1.25-1.50 ft are needed for minor flooding, which is possible
during this afternoon`s high tide between about noon and 4pm.
Localized minor flooding is possible in these areas.
The threat for dune erosion appears to be low and isolated with
this event.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...Coastal Flood Advisory from 6 AM to 11 AM EST this morning for
NYZ178-179.
NJ...None.
MARINE...Small Craft Advisory from 9 AM this morning to 11 AM EST
Friday for ANZ350-353.
Small Craft Advisory from 6 AM this morning to 6 AM EST Friday
for ANZ355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...MW
AVIATION...JM
MARINE...DW/MW
HYDROLOGY...DW/MW
TIDES/COASTAL FLOODING...//