000
FXUS61 KOKX 031054
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
554 AM EST Wed Jan 3 2024
.SYNOPSIS...
High pressure south of the area shifts offshore tonight with a
weak frontal system moving through on Thursday. High pressure
starts to build in Thursday night and remains in control into
Saturday morning. A storm system impacts the area Saturday evening
through Sunday. High pressure builds in to start next week,
followed by another storm system for the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
The forecast is on track this morning. Temperatures have
flattened out in many areas with high and mid level clouds
moving overhead. Otherwise, dry and cool conditions are
expected to continue today with high pressure positioned south
of the area gradually sliding offshore during the day. Highs
today will be around average with temperatures in the low to
middle 40s. Mostly clear skies in the morning and early
afternoon will become mostly cloudy and overcast into the
evening and overnight as a cold front approaches the area from
the west.
Mid-level troughing associated with the cold front will force a weak wave of
low pressure to develop to the south of the area. This may result in the
development of some light snow showers late in the night, mainly along the
coast, though dry low levels may prevent any precipitation from reaching the
surface. Lows tonight will be in the middle 20s to lower 30s.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
The weak low pressure system to the south continues to shift offshore during
the day on Thursday with any light showers along the coast dissipating by early
afternoon. There may be some additional light rain or snow showers with the
FROPA during the morning and early afternoon on Thursday, though there is only
a slight chance.
The mid-level troughing pushes the front and low pressure offshore by Thursday
night with a strong 1030 high pressure building into the area from the west.
The tight pressure gradient between the departing low and the approaching high
will bring breezy conditions Thursday evening and into the first half of the
overnight with NW winds 10-20 mph with gusts upwards of 30 mph along the coast.
Gusts diminish by Friday morning with mostly clear skies and cold conditions
with highs only in the middle to upper 30s.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
*Key Points*
* A coastal storm is expected to impact the area Saturday evening
through Sunday. Too early to be specific with potential snow
amounts and precipitation types. Wind and coastal flooding impacts
will be possible as well.
* Another area of low pressure for the middle of next week may bring
wind and flooding impacts.
There has not been much change from the previous forecast. Quiet
weather is expected Friday night through early Saturday as high
pressure remains in control as it shifts offshore.
Attention then turns to the first of two strong systems to impact
the area in the long term. Deterministic and ensemble guidance
continue to be in agreement on an area of low pressure passing close
enough to our south and east to bring impacts this weekend.
Differences still exist in exact center track which is expected this
far out. This will impact what precip types are seen across the
area. The latest ECMWF and Canadian have the low tracking right near
the 40N/70W benchmark, with the GFS quite a bit farther south and
east. The trend in the ECMWF Ensemble and the GEFS has been slightly
farther southeast, with the GEPS actually trending slightly closer
to the coast. With this event still several days away, small wobbles
in model tracks will continue run to run. Something to note though
is the weakening trend in the GFS. This has to do with the shortwave
lifting out of the southwest CONUS becoming almost flat by the time
it reaches the northeast. This can be blamed on the interaction with
a piece of energy behind the trough moving into the northwest CONUS
Thursday night. This trend is something that needs to be watched
over the next few days and would lead to less impacts. As mentioned,
it is too early to talk specific precip types, but confidence in
accumulating snow is highest across the Lower Hudson Valley and
southern CT given a blend of current model tracks. The Weather
Prediction Center has a 50 to 70% chance of these areas
exceeding .25 inches of liquid equivalent of snow/sleet. This
lowers to about 10 to 30% for the NYC/NJ metro area and Long
Island. Winds with this system could briefly touch advisory
level, mainly across Long Island. There may also be minor
coastal/shoreline impacts, including scattered dune erosion.
There is another area of low pressure that will impact the area in
the long term during the middle of next week. There continues to be
very good agreement with the guidance with this system as well,
especially for being this far out. A closed upper level low and
associated surface low will lift from the southern CONUS and track
west of the area. The main concerns with this system at this time
are the strong winds and heavy rain. The area could potentially be
in between roughly a ~980mb low and ~1034mb high. This very tight
pressure gradient brings the potential for strong winds. This system
also brings plenty of moisture with it and the potential for heavy
rain. The flooding threat would be greatest over the interior
sections where, even outside of the amount of rain that falls, an
existing snowpack may be present and rapidly melt on top of already-
saturated soils. The LREF currently has a an 85% chance across the
whole area of seeing greater than 1 inch of rain in any 24 hour
period with this storm and a 25 to 40% chance of seeing greater than
2 inches.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
High pressure remains centered SW of the region thru this morning. A trough of
low pressure preceding a cold front approaches this evening.
Mainly VFR through the day. The exception is KSWF where BKN MVFR ceilings are
expected to prevail towards midday. MVFR ceilings start to become more likely
for the 30 hr city terminals towards 0z Thu. MVFR ceilings may prevail sooner
but confidence of occurrence during the day remains low. Uncertainty remains
around the coverage and duration of any MVFR ceilings for this evening / night.
The winds will be mainly out of the W at 5 to 8 kt overnight, and below 5 kt
for the non-city terminals. The winds then increase to around 10 kt at most
terminals during the day, then decrease to closer to 5 kt tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments expected through this morning. Amendments may be
needed this afternoon for possible MVFR ceilings. Confidence is lower than
average around MVFR ceilings occurrence.
OUTLOOK FOR 09Z THURSDAY THROUGH SUNDAY...
Wednesday night: MVFR to VFR, with MVFR more likely for the western most
terminals the first half of the night.
Thursday: Chance of MVFR or lower cond in rain/snow showers early, improving to
VFR. NW winds 10-15G20-25kt.
Thursday night: VFR. NW winds 10-15G20-25kt.
Friday: VFR. NW winds G20kt possible for the AM push.
Saturday: VFR becoming IFR or lower Sat ngt in snow and/or rain.
Increasing E/NE winds.
Sunday: Rain/snow ending as snow. IFR or lower possible. Winds becoming N.
Detailed information, including hourly TAF wind component forecasts, can be
found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Quiet conditions over the waters through Thursday afternoon. Winds increase
late Thursday as low pressure passes well offshore and high pressure builds in
from the west. Small Craft Advisories look likely on all waters Thursday
afternoon through Thursday night with 25 to 30 kt wind gusts. Wind gusts on the
ocean waters may briefly approach or exceed 35 kt. Ocean seas will also likely
reach 5 to 6 ft.
Winds should begin weakening on Friday, but some lingering 25 kt gusts are
possible on the ocean. Seas should subside below 5 ft by Friday afternoon.
Conditions are then expected to be below SCA levels on Saturday.
A storm system impacting the waters Saturday evening through Sunday
will bring a chance of gales across all waters during the this
period. HWO mention of this potential continues. Ocean seas during
this time could reach 10 ft. After the system moves east, 5 ft waves
could linger on the ocean waters through Monday.
Another storm system is expected during the middle of next week.
This also has the potential to bring gales to the waters and
possibly even storm force gusts to the ocean waters. It is too
far out in time and confidence is too low for a mention in the
HWO.
&&
.HYDROLOGY...
There are no hydrologic concerns through the end of the week.
A liquid-equivalent 0.75 to 1.50 inches of precipitation is
anticipated from Saturday evening through Sunday. Since some of this
may be in the form of snow, impacts may be minimal.
A greater flooding threat (especially rivers) may exist starting
next Tuesday. This will partially depend on what materializes this
weekend. Regardless, soils will remain nearly saturated leading up
to the event.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JT/MW
NEAR TERM...JT/MW
SHORT TERM...MW
LONG TERM...JT
AVIATION...MW
MARINE...JT/MW
HYDROLOGY...JT/MW