000
FXUS61 KOKX 311830
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
230 PM EDT Sun Mar 31 2024
.SYNOPSIS...
-- Changed Discussion --
Weak high pressure settles in today. Low pressure approaches
from the west tonight, passing to the south on Monday. A stalled
front south of the area Monday night into midweek will have
lows developing along it. The relatively strongest low develops
along it in the Mid-Atlantic toward midweek. This low traverses
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 into
Saturday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Forecast remains on track early this afternoon. The region has
climbed into the 50s with plenty of sunshine through the
scattered cloud cover. The day comes to an end on a tranquil and
dry note. Previous discussion follows.
A weak 1016 mb high over Michigan quickly slides east over the
region today. This will keep dry conditions in place through
this evening, with varying degrees of clouds streaming east in
W/NW flow.
The final day of the month will feature temperatures running
about 5 degrees above normal, with most areas topping out in the
mid to upper 50s, and the lower 60s in the urban metro.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Another wave of low pressure swings by tonight into Monday.
Clouds become overcast Sunday evening. A band of strong 850mb
warm air advection and forcing approaches the area Monday
morning and afternoon. It has a northwest to southeast
orientation to it and will likely lead to higher rain totals
with periods of moderate to heavy rain. In addition, the area is
located under the left exit region of an upper-level jet
streak. Totals will range between 0.10" to 0.5" with the higher
totals concentrated in NE NJ, NYC metro and LI. PWATs will reach
around 0.9" during the peak period of forcing which is around
the 90th percentile for this time of year per SPC`s Sounding
Climatology page. Should the band of stronger forcing shift
north or south, the area of heavier rainfall and higher totals
will shift with it. This too will be a fast system, with much of
the rain ending by early afternoon. As a result, flood
benchmarks will not be reached.
Temperatures will remain above normal tonight due to the cloud
cover, but with the easterly flow and rain Monday, temperatures
will budge little. Highs Monday will be around 50, which is
several degrees below normal.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Long wave ridge in the mid levels will be starting place for
the local region Monday night into Tuesday. The upper level jet
pattern will be zonal. The 250mb jet streak SW to NE Pacific
into Mexico extends northeast to South Central US and then
branches into Great Lakes as well as Carolinas.
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 for late Tuesday night into early Wednesday. This
cutoff low approaches the area Wednesday and eventually moves
into the Northeast Thursday into Friday, gradually making its
way east to the NW Atlantic going into next weekend.
At the surface, there will be a stalled front south of Long Island
with multiple lows developing and traveling along it Monday night
into the middle of the week. The low Tuesday night into Wednesday
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.
Rain is in the forecast Monday night through Thursday. Conditions
then trend drier Thursday night with dry conditions expected Friday
into Saturday. Potentially the rain could be heavy at times
especially for midweek. Elevated instability will present a
slight chance of thunderstorms as well around the middle of this
week, particularly near the coast. Wintry precipitation remains
possible as well for the interior while for the coast this
precipitation will be mainly plain rain.
Temperatures average below normal overall during the long term.
Forecast highs stay in the 40s Tuesday, Wednesday and Thursday.
Forecast highs trend higher Friday into next weekend and get
relatively closer to normal values. Winds will become quite
gusty Tuesday night through Thursday night but at this time,
forecast values are below wind advisory thresholds.
More detailed analysis focused on the low pressure storm system
for mid to late week as well as surface winds is discussed
below.
The main feature at the surface will be the origin of cyclogenesis
Tuesday night and its subsequent evolution through mid to late week.
The models have a general consensus of depicting this low to move
northeast from the Mid-Atlantic towards New England going from mid
to late week and then slowly moving the low farther offshore.
Models have exhibited large differences from each other as well as
from the same model but from an earlier run. The low position and
movement has widely varying depictions amongst large scale
numerical weather prediction models of the GFS, ECMWF, and
Canadian models for Thursday.
An example of a significant change is within the ECMWF model which
has trended relatively weaker with this storm system for the middle
of the week. The rainfall within a 24 hour period according to the
grand ensemble still has differences between extremes amounting to
near 2.5 inches which is a half inch less than where the differences
were looking at the same grand ensemble the previous night. The same
grand ensemble also continues to convey the possibility of
measurable snow especially for interior areas.
Regarding winds, there is forecast to be an extended period of
easterly winds, building fetch and seas. There will be some minor
coastal flooding heading into midweek. See tides/coastal flooding
section for more details. Winds are forecast to become more
northeast to north Wednesday night and then northwest Thursday into
the start of next weekend. Highest forecast gusts are forecast in
the Tuesday night through Thursday night time period, with
gusts along the coast getting near 35 to 40 mph.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
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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. Guidance has trended farther south
with the axis of rainfall, thus there is decreasing confidence
on seeing MVFR or lower ceilings. There is a chance of MVFR in
rain, mainly in the morning Monday with the exception of KGON.
However, did go with prevailing MVFR for KTEB, KHPN, KSWF as
low-level moisture is more prevalent at this time. Should this
southward trend continue, VFR conditions may become more likely
on Monday.
WNW flow as is typical in these parts appears to be overachieving
this afternoon based on vertical wind profiles. Gusts though
should average around 20 kt, but a few higher gusts will be
possible. Winds quickly diminish this evening and become light
and variable. An ESE wind at less than 10 kt develops Monday
morning.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Winds mainly left of 310 magnetic with a few gusts up to 25 kt
this afternoon.
Confidence is decreasing for MVFR conditions on Monday.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday Afternoon: Chance of MVFR, mainly north and west of the
NYC terminals.
Tuesday: IFR in rain. E-ENE G20-25 kt. The rain could be mixed
with wet snow inland Wednesday night.
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 showers possible, possibly mixed with
snow inland. NW gusts 25-35 kt.
Friday: Mainly VFR. Chance of showers. 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.
Winds and waves will trend higher Monday night but are forecast
to stay below SCA criteria.
SCA conditions become more likely Tuesday and especially going
through the midweek period. There will be potential for gales
Tuesday night through Thursday night.
&&
.HYDROLOGY...
A brief period of moderate to heavy rainfall is possible Monday
morning with totals of 0.25"-0.5" for NE NJ, NYC metro and LI. The
rain quickly exits Monday afternoon, so flood benchmarks will not be
reached.
An extended forecast period of rainfall is forecast Monday night
through Thursday. It will not rain the entire timeframe but the
bulk of the rainfall can be expected Tuesday through Wednesday
night. Heavy rainfall will be possible at times but exact
rainfall amounts cannot be determined at this time due to low
confidence. Poor drainage and low lying areas could very well
experience some minor flooding with an overall marginal flood
threat.
&&
.TIDES/COASTAL FLOODING...
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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.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JM/BR/DR
NEAR TERM...JM/BR/DR
SHORT TERM...BR
LONG TERM...JM
AVIATION...DW
MARINE...JM/BR
HYDROLOGY...JM/BR
TIDES/COASTAL FLOODING...//