000
FXUS61 KOKX 011810
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
210 PM EDT Mon Apr 1 2024
.SYNOPSIS...
Low pressure passes to the south this morning and early afternoon.
High pressure briefly takes hold late afternoon-evening before
another low approaches and passes tonight into Tuesday. The
front remains south of Long Island with lows continuing to move
along it for Tuesday night. A stronger low developing along it
approaches on Wednesday and eventually moves south of Long
Island Wednesday night. The low moves northeast to just east of
Long Island by early Thursday and will move into the Gulf of
Maine Thursday into early Friday. The low will gradually makes
its way to the Northwestern Atlantic going into the weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
Lowered POPs with this update as much of the rain has pushed
offshore. There remains a slight chance, mainly for western
areas through mid to late afternoon, then dry conditions
expected.
April begins on an active note, with a stalled boundary draped over
the Mid-Atlantic and a wave of low pressure tracking along it
and to our south this morning.
A band of warm air advection and frontogenetic forcing approaches
the area this morning. However, the latest CAMs suppress the axis of
highest forcing to our south along with the rain and center of low
pressure. We`ll likely see rain in NE NJ, NYC metro and LI for a
brief period on this morning as the northern edge of precipitation
skirts our area. Rainfall totals will be less than 0.1" with heavy
rain looking unlikely in our area an more likely to our south. Any
lingering rain will clear in the early afternoon.
High pressure will briefly take hold later in the day today with a
brief break from the rain in the afternoon. The rain, clouds, and
light onshore flow Monday will allow for a bit cooler conditions
than recent days. Afternoon highs should get into the lower 50s for
most, or just a few degrees below normal for early April. The
exception looks to be interior CT, which may be able to achieve mid
50s.-- End Changed Discussion --
&&
.SHORT TERM /TUESDAY NIGHT THROUGH 6 PM TUESDAY/...
Another wave of low pressure arrives overnight and tomorrow.
Rain chances increase in our western zones by daybreak Tuesday
then overspread the rest of the area later in the morning. Rain
will continue into the afternoon. Just like today`s system, it
is riding west to east along a stalled boundary.
AN ENE wind will pick up in the afternoon, strongest along coastal
areas with gusts of 20-25 mph. Rain and cloud cover along with the
change in wind direction will keep highs below average on Tuesday in
the upper-40s.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Main points
* Strong coastal low developing Wednesday, moving south of Long
Island Wednesday night and east of Long Island Thursday.
* This low will bring moderate to occasionally heavy rainfall
with a marginal flood threat.
* For more northern portions of the Lower Hudson Valley,
interior Northeast NJ, and interior Southern Connecticut, the
precipitation will likely transition to a mix of rain and
snow. Some light snow accumulations will be possible.
* Winds will increase and become gusty Tuesday night through
Wednesday night. This will be out of the east Tuesday night
into Wednesday and then become more northerly Wednesday night.
Period of highest winds forecast Wednesday afternoon through
Thursday morning, with gusts forecast near 35 to 40 mph. Some
higher gusts will be possible, reaching up to near 50 mph.
* Coastal flooding will be possible starting Tuesday night and
becoming a higher chance Wednesday into Wednesday night. The
flooding looks to be mostly minor but some moderate coastal
flooding will be possible for parts of Western Long Island
Sound shoreline as well as along parts of the South Shore Bays
of Long Island.
The upper level jet pattern becomes more active towards the middle
of the week coinciding with a diving strong mid level shortwave
from South Central Canada. Left front quad of the jet gets closest
to the area on Wednesday. This cutoff low approaches the area
Wednesday into Thursday and eventually moves east of the area
Friday into Friday night, gradually making its way east to the
NW Atlantic going into the weekend.
At the surface, there will be a stalled front south of Long Island
with multiple lows developing and traveling along it into the
middle of the week. The low Wednesday into Wednesday night looks
to be the stronger one according to the consensus of forecast
model guidance. This low eventually moves northeast of the area
going into latter half of this week.
For Tuesday night through Wednesday the development and southward
push of the 500mb closed low from South Central Canada into the
Great Lakes will be main factor in the evolution of cyclogenesis for
that time period and into the proceeding day.
Models indicate an overall increase in warm air advection at 850mb
Tuesday night into Wednesday. SE flow increases at the 850mb
level. At the surface, waves of low pressure move along front
south of Long Island. Models overall indicate increasing
easterly flow and the developing of another main low to the west
along northern Appalachians into Mid-Atlantic. This low is
going to move to right off Mid-Atlantic coastline by early
Wednesday evening.
For Wednesday night there will be a closed mid level strong low in
Ohio Valley, with strengthening SW mid level flow from Southeast US
into the local area. For Wednesday night into early Thursday, there
will be mid level strong positive vorticity advection. The 850 mb
winds are higher over Long Island and extending offshore, up to
near 45-50 kt.
Some strong 850mb cold air advection Wednesday night into early
Thursday allowing for precipitation to transition to a mix of
snow and rain across parts of the interior. Elsewhere, mainly a
plain rain event is expected.
Some elevated instability will allow for a slight chance of
thunderstorms along parts of the coast late Wednesday into
Wednesday night as well as early Thursday.
Forecast high temperatures remain mainly in the 40s Wednesday,
Thursday and Friday. A warming trend for high temperatures is
forecast for the weekend, getting closer to normal values.
Mainly dry conditions are anticipated Thursday night through the
following weekend with the return of high pressure.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
Weak low pressure passes to the south today. High pressure
briefly takes hold this evening before another wave of low
pressure arrives on Tuesday.
VFR today. Light rain that was around this morning has pushed
offshore and dry conditions are expected for remainder of the
day. Conditions should decline across the board Tue AM as
steady rain returns, MVFR cigs likely toward 12Z or just
thereafter in the city, spreading east to other terminals by
18Z. IFR likely for most terminals by early afternoon.
Light flow generally out of the NE and E today. Direction may
be variable at times. A more sustained ENE direction becomes
established Tuesday AM as speeds increase to btwn 10 and 15 kt
by late morning. Gusts 20-25 kt thereafter thru the day.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Light winds will allow more variability in direction today.
Timing of category declines on Tuesday may be off by a few hours.
OUTLOOK FOR 18Z TUESDAY THROUGH FRIDAY...
Tuesday PM: IFR in rain. E-ENE G20-25 kt.
Wednesday: IFR in rain. E-ENE G20-30 kt. The rain could be mixed
with wet snow at KSWF.
Thursday: MVFR or lower with lingering rain, possibly mixed with
wet snow at KSWF. NW gusts 25-35 kt.
Friday: Mainly VFR. Slight chance of showers inland. NW G20-25kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds and waves will remain below SCA criteria through Monday.
SCA conditions will start with 5-7 ft waves and 25-30 kt gusts
starting Tuesday late afternoon/early evening.
Higher chances of SCA conditions Tuesday night with gales
possible Wednesday into Wednesday night. Gales are possible
Thursday as well. Conditions lower Thursday night into Friday,
but SCA conditions will remain probable for most waters.
&&
.HYDROLOGY...
No hydrologic impacts are expected Monday through Tuesday
afternoon.
Around 2 to 3 inches of rain is forecast from late tonight
through Wednesday night. This will be spread out over a long
enough time period so the mode of this rain will be light to
moderate stratiform rainfall. Some heavy rain will be possible
though especially Wednesday into Wednesday night and there will
be marginal threat for flooding, mainly for minor flooding
within poor drainage and low lying areas.
&&
.TIDES/COASTAL FLOODING...
Astronomically, by the middle of this week, we will be past the
halfway point between the full and the new moon cycles. There
will thus be an increase in the tidal levels around high tide.
This combined with a long period and increasing easterly flow
early to mid week will lead to more fetch and piling of water.
For some shorelines, particularly across the lower NY Harbor,
South Shore Bays, and Western Long Island for late Tuesday
night into Wednesday around the times of high tide, minor
coastal flooding will be possible. The chances for minor
coastal flooding increase Wednesday night into early Thursday.
This is when minor coastal flooding could become more widespread
with some localized moderate coastal flooding possible for parts
of the Western Long Island Sound shoreline as well as for parts
of the South Shore Bays of Long Island.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JM/BR
NEAR TERM...JM/JP/BR
SHORT TERM...BR
LONG TERM...JM
AVIATION...DR
MARINE...JM/BR
HYDROLOGY...JM/BR
TIDES/COASTAL FLOODING...