000
FXUS61 KOKX 091149
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
649 AM EST Sat Dec 9 2023
.SYNOPSIS...
High pressure over the western Atlantic will continue to gradually
move eastward, while a strengthening frontal system over the mid
section of the country tracks east. A strong cold frontal passage
will occur late Sunday night into Monday morning, 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.
&&
.NEAR TERM /THROUGH TONIGHT/...
No significant changes with the forecast update this morning.
The biggest change was to update the morning temperatures which
were cooler than forecast. Otherwise, we are looking at a
fairly quiet weather day, with dry conditions. Any early
morning fog across the region will gradually dissipate with
warming temperatures. Southerly winds today will result in some
warm air advection. This will allow temperatures to warm into
the 50s across the entire region. While there may be some sun in
the morning, clouds will gradually increase through the day as
an upper level trough approaches from the west. Can not rule out
breaks of sun throughout the day. If more sun occurs than
forecast, temperatures may need to be adjusted upwards.
For Saturday night, upper level ridging moves east with troughing to
the west moving into the region. Clouds will continue to lower and
thicken. With abundant low level moisture, will once again include
patchy fog in the forecast. The fog may be more widespread than
Friday night. Most of the night will be dry, however will have some
slight chance/chance POPs enter the CWA from the west very late
tonight. Anything that falls before sunrise will be light. A warmer
night is expected tonight with warm air advection continuing. Lows
tonight will remain in the 40s for much of the CWA. The only
exception will be across Orange county where temperatures may fall
into the middle to upper 30s.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A significant storm system is expected to impact the forecast area
during the short term period. For now, No changes to the current
forecast headlines.
A flood watch remains in effect for all but the Twin Forks of LI. A
high wind watch remains in effect for all of LI, along with Brooklyn
and Queens. Both watches start at 4 pm Sun.
A deepening upper level trough and strong cold front will approach
the region on Sunday. There will be lots of moisture with this
system as the upper trough digs deep into the south, tapping into
the moisture over the Gulf of Mexico. Winds will gradually increase
on Sunday as this system starts to run into the high over the
Atlantic as the pressure gradient increases. Also, an area of low
pressure is expected to develop along the front on Saturday and
travel northward along the front as if moves from the middle
Atlantic into New England. Most of the rain on Sunday will generally
be light to moderate, however by late Sunday afternoon and evening,
the rainfall will increase in coverage and intensity. Periods of
moderate to locally heavy rainfall will continue through much of
Sunday night for the entire region as the front moves across the
area. Will continue to mention the slight chance of thunder with the
frontal passage as well. Overall, rainfall amounts will range
between 2-3 inches across the entire region, with locally higher
amounts possible. Forecast guidance showing a good chance that the
highest rainfall totals could end up in CT as the front does slow
down a bit as the front exits the region, as the upper trough starts
to become negatively tilted.
Also, a rather windy period is expected with the front. A strong low
level jet is forecast to move over the eastern sections of the CWA.
Both the NAM and GFS shows the jet really intensifying after 06z
east of NYC. As a result a high wind watch will remain in effect.
The GFS is showing 925mb winds around 70kt. Forecast will continue
to call for 40-50mph gusts early Monday morning across Long Island,
Brooklyn and Queens.
The front moves east of the region on Monday. As the front moves
east winds will quickly shift around the NW with a shot of colder
air working into the region. Can not rule out some parts of orange
county seeing some snowflakes as the precip comes to an end.
Right now, little to no accumulations are expected.
Dry weather is expected for Monday night as high pressure starts to
build back into the region. It will remain gusty as the gradient
remains tight between the departing low and arriving high.
Highs on Sunday will be in the upper 50s and lower 60s, with highs
on Monday in the 40s for much of the region.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
No significant changes for the long term period and stuck largely to
the NBM.
A large, strong high pressure system sets itself up over the East
Coast by Tuesday morning under fairly zonal mid-level flow. This
high pressure system becomes reinforced by an approaching mid-level
ridge moving in from the west through the middle of the week. This
high pressure will keep conditions dry through the week. Despite dry
conditions for the area, conditions may be a bit breezy as
disturbances pass by to the north. This will allow for a tight
pressure gradient with generally W to NW winds through the week.
While global models disagree on the details of the next system, all
are consistent in developing a low pressure system somewhere in the
vicinity of the East Coast next weekend.
The W/NW winds through the period will allow for temperatures to be
at or just below normal for this time of the year with highs
generally in the low to middle 40s through the middle of the week
with a subtle warm up to the upper 40s by the end of the
week.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
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 day. THis morning
there may be pockets of MVFR or localized IFR, mainly for KHPN
and KSWF. Low stratus and fog may attempt to work in toward the
city terminals from the west this morning but not expecting to
result in sub-VFR conditions. MVFR/IFR condition expected late
tonight for most terminals with the approach of the frontal
system. SHRA possible as early as 10Z Sunday but more likely by
15Z Sunday.
Light flow is forecast through the evening with wind speeds
below 10 kt. Light S-SE winds into the afternoon. The light
southerly flow will begin to gradually increase toward daybreak
Sunday, especially at the coastal terminals.
...NY Metro(KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Very localized MVFR visibilities/cigs possible before 15Z.
Light winds this morning could vary significantly in direction.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
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 rain, possibly heavy at times. 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. Chance of LLWS.
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-- End Changed Discussion --
&&
.MARINE...
Conditions are expected to remain below SCA criteria from tonight
through Saturday night as a weak pressure gradient remains in place.
Strong southerly winds develop Sunday into Sunday night. A storm
watch remains in effect for most of the waters. The exception is
portions of the Sound and Harbor, where a gale watch remains.
NW gales will remain possible on Monday as the gradient remains
tight with the departing low and arriving high to the west.
Small craft advisory conditions appear likely during the Tuesday
through Thursday timeframe, mainly on the ocean zones. Seas Tuesday
remain elevated and don`t look to drop below 5 feet until early
Thursday morning. Additionally, breezy W/NW winds will result in
gusts 25-30kt on the ocean and possibly the sheltered waters Tuesday
through early Thursday.
&&
.HYDROLOGY...
There are no hydrologic concerns through Saturday night.
Between 2 and 3 inches of rain is likely Sun into Monday morning.
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 remains in
effect 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.
Surge guidance has come to more of a consensus that much of the area
should remain below minor flooding thresholds, but any changes in
the forecast timing of the developing low may result in
significant changes to the coastal flooding forecast.
&&
.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...BC/MW
NEAR TERM...BC
SHORT TERM...BC
LONG TERM...MW
AVIATION...MW
MARINE...BC/MW
HYDROLOGY...BC/MW
TIDES/COASTAL FLOODING...