000
FXUS61 KOKX 312322
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
722 PM EDT Sun Mar 31 2024
.SYNOPSIS...
High pressure slides offshore this evening. Low pressure approaches
from the west tonight, passing to the south on Monday. A series of
lows will develop along a stalled front south of the area Monday
night into midweek. The strongest of the lows develops along it
toward midweek, traversing south of Long Island Wednesday night
and eventually off the New England coast Thursday night. High
pressure stays west of the area with low continuing to track
slowly east Friday through the weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --
Forecast on track this evening. A weak 1016 mb high slides over
the region into this evening, and offshore tonight.
Temperatures fall back into the 40s tonight as clouds stream in
and thicken ahead of the first in a series of rainmakers this
week. Light rain may break out toward daybreak in western areas
as warm air advection advances from the south and west.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
April begins on an active note, with a stalled boundary draped
over the Mid-Atlantic and multiple associated waves of low
pressure tracking near the region over the next several days.
The first of which arrives to start the period as a band of warm
air advection and frontogenetic forcing approaches the area in
the morning hours. Guidance has been shifting the axis of
strongest forcing associated with this wave south over the last
couple of cycles, cutting back the rainfall locally. For
example, 12Z HREF halved QPF at NYC from the previous run, now
progging around a quarter inch, though some guidance like the
ECM yield no measurable precip Monday. QPF has been lowered to
reflect this shift, as were PoPs, especially north and west.
Stuck with an ensemble approach and settled on around a quarter
inch for NE NJ and NYC, quickly falling to less than a tenth of
an inch north and west of this. Still, given the trends, it
wouldn`t surprise if some locales remain entirely dry, primarily
SE CT.
Regardless of where the axis ultimately sets up, this system is
a quick mover, with much of what rain there is ending by late
afternoon. Those looking for a reprieve from the wet weather
however will be disappointed as the next wave begins to enter
the picture late Monday night. Increasing PoPs toward daybreak
Tuesday, when rain redevelops from the west.
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.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
A broad area of low pressure will be stretched from the Ohio Valley
to the Mid-Atlantic on Tuesday. Moisture deepens as the day
progresses, with rain continuing to spread eastward across the
forecast area. An easterly low level jet may enhance the rain
potential over coastal and eastern areas, but generally looking at
light to moderate rainfall during the day. The system doesn`t make
too much eastward progression Tuesday night as a closed 500mb low
attempts to draw the parent surface low towards it in the vicinity
of the Great Lakes. The 500mb low will however help strengthen a
secondary surface low to our south. This low is then expected to
pass through or just SE of us Wednesday afternoon into night. This
maintains categorical PoPs Tuesday night through the daytime
Wednesday. Will leave in a slight chance of thunder for Wednesday
afternoon with models showing a little elevated CAPE and forcing
from the approaching low center. Rain during Wednesday will probably
be more on the moderate side for coastal/eastern areas with a llj
remaining in the vicinity.
Precip remains likely Wednesday night as the deepening surface low
will be slow to pull away due to the influence of the lagging 500mb
low to the west. Colder air wraps in from the north with snow in the
mix for inland areas. The low pressure system is then progged to
become stacked somewhere along the New England Coast by Thursday
evening. Precip chances remain over here through Thursday with the
cyclonic flow aloft and wrap-around moisture. PoPs highest over the
northernmost zones, and still cold enough for a rain/snow mix across
the interior in the morning. Looks like a breezy day as well with a
tight pressure gradient over the area. The storm continues to slowly
move and is expected to be off the coast of Nova Scotia on Friday.
Continued cyclonic flow aloft, and with a weak cold front/trough
with just enough moisture may trigger rain showers in the
afternoon. Maybe mixed with snow in the higher elevation N and W of
the city.
Will go with a dry forecast for the weekend as high pressure slowly
builds in from the west as this storm finally shifts far enough out
to sea.
High temperatures below normal Tuesday through Friday, a little
milder on Saturday, then back to near normal for Sunday.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
Weak high pressure builds across the area through this evening,
then gives way to a wave of low pressure that passes to the
south on Monday.
VFR through much of tonight. There continues to be decreasing
confidence with both extent of rain Monday morning and if there
will be any MVFR ceilings. There is still a chance of MVFR with
mainly light rain in the morning into the early afternoon for
mainly the NYC metro, western Long Island and potentially at
KHPN. However, model trends have continued to show the bulk of
the rain passing south of the terminals. There remains a
chance at MVFR ceilings late morning into early afternoon. VFR
appears likely in the afternoon and evening.
WSW-WNW flow will weaken this evening with most locations
becoming light and/or variable by 03z. Winds at coastal
terminals should become NE-ENE early Monday morning and then
may briefly become E-ESE before shifting back towards the NE in
the afternoon. Wind speeds will be light and generally around
5-7 kt on Monday, so there is a chance at more variability in
wind direction.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Wind direction at KJFK may be more SW through 01z, but should
become WNW-NW thereafter.
Low confidence forecast regarding the extent of -RA and any MVFR
ceilings Monday morning and early afternoon. There is also a
chance MVFR ceilings linger into early Monday evening.
OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
Monday Night: Mainly VFR early, then MVFR and rain developing
late.
Tuesday: 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 inland at night.
Thursday: MVFR or lower with lingering rain, possibly mixed
with wet snow inland. 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 are expected to remain below SCA criteria through
Monday night.
SCA conditions become more likely Tuesday and especially going
through the midweek period. There will be potential for gales
Tuesday night through Thursday night.
Winds and seas increase Tuesday leading to small craft conditions
developing from south to north across the waters. Gales may even be
possible on the ocean Tuesday night, with a better chance of this on
Wednesday as low pressure approaches the waters. Can`t rule out the
the threat of gales on some of the other waters as well on
Wednesday. Gusty offshore winds are expected on Thursday and
Thursday night with SCA conds anticipated during this period. For
Friday, winds drop off a little with SCA conditions probably limited
to the ocean waters, but still possible over the eastern Sound and
bays.
&&
.HYDROLOGY...
Rain amounts from late Monday night through Thursday may be in the
range of 1.50 to 2.50 inches. Poor drainage and low lying areas
could very well experience some minor flooding, but anything more
impactful would be a low chance, mainly because of the long duration
of time the rain amounts would occur. This also takes into
consideration current flash flood guidance. Periods of heavier
rainfall are more likely to occur Tuesday afternoon through
Wednesday afternoon.
&&
.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.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DR
NEAR TERM...DR/DS
SHORT TERM...DR
LONG TERM...JC
AVIATION...DS
MARINE...JC/DR
HYDROLOGY...JC/DR
TIDES/COASTAL FLOODING...