000
FXUS61 KOKX 071141
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
741 AM EDT Sun Apr 7 2024
.SYNOPSIS...
A large low pressure system will continue to rotate southeast of
Nova Scotia today, gradually moving farther offshore tonight into
Monday. High pressure will then build in through Monday and
remain into Tuesday. A backdoor cold front crosses the region late
Tuesday. A complex frontal system then approaches midweek, with
the associated warm front lifting through Wednesday, before an
attendant cold front approaches on Thursday, moving through late
Thursday or early Friday. High pressure returns next weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
Good model agreement in offshore upper low continuing to drift east
into Western Atlantic today into tonight, with upper ridging
gradually building east into the area tonight.
At the surface, a large offshore low southeast of Nova Scotia today,
will drift east tonight, with surface high pressure gradually
building in from the west.
One more day of cyclonic flow today, gradually relenting in wake of
one final shortwave pivoting through eastern portions of the area
this aft. Partly sunny (west) to mostly cloudy (east) diurnal
cloud cover in response. With continued drying of the column,
any afternoon shower threat should be very isolated and
primarily for far SE CT and twin forks.
Clearing skies and good radiational cooling conditions likely
across outlying areas tonight with temps there falling below
freezing. Temps holding near 40 for the NYC/NJ metro area.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Pseudo rex blocking upper pattern, with upper ridging squeezing up
through the region, in between exiting western Atlantic upper low
on Monday (replaced by a Greenland low on Tuesday), and a
northern plains/SW Ontario upper low.
At the surface, elongated high pressure down the entire east
coast, builds south of the region Monday into Monday Night with
dry conditions and mild return flow Monday into Tuesday. A weak
warm front approaches from the SW Monday Night, but appears to
dissipate across western portions of the area Monday Night. This
will be followed by southeastern Canadian high pressure nosing
down towards the area late Tuesday into Tuesday Night in
response to Greenland low, with a likely backdoor cold frontal
passage late Tue aft/eve.
Dry and seasonably mild conditions for Monday with developing return
flow. Latest model trends are indicating more in the way of cirrus
and possible mid deck streaming in the afternoon as a weak shortwave
shears over upper ridge axis. The increased cloud cover may
keep temps a bit lower than max potential, but lower 60s are
likely for much of the region (a few degrees above seasonable),
except upper 50s for immediate south coasts with afternoon sea
breeze development. Outside of urban centers, particularly pine
barrens, temps could drop a couple of degrees during partial
eclipse between 3-4pm, but otherwise not anticipating any
significant sensible weather anomalies.
A shearing shortwave rounding the upper ridge and weak warm front
late Monday into Monday Night will continue to increase
cirrus/mid deck, with perhaps a few sprinkles across far western
sections. Mild conditions with lows in the 40s (near 50 NYC/NJ
metro) in waa flow and with cloud cover.
Mild start to the day on Tuesday, but quite a bit of spread on
temperatures dependent on lingering cloud cover and timing of
backdoor front in the aft/eve. Will stay close to NBM deterministic
guidance based on uncertainty, lower 70s interior and lower to mid
60s coast. If more in the way of sunshine and backdoor cold front
holds off till late, potential for temps to run several degrees
warmer than forecast.
Potential for a few showers developing across far western areas late
Tue Night as subtropical jet begins to extend eastward and
frontal system approaches from the Ohio Valley.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
-- Changed Discussion --
After a dry start to the week, rain returns to the region starting
midweek, lingering through Friday. The synoptic flow becomes more
amplified out of the southeast on Wednesday as a warm front lifts
north ahead of an approaching trough. While PoPs are high Wed and
Thu, it won`t be raining the entire period. More scattered in
coverage showers as the region becomes warm sectored into Thursday.
A steadier period of rain is likely late Thursday into Friday ahead
of the attendant cold front. It`s possible a few thunderstorms could
develop, although parameters are marginal and have opted to omit
from forecast at this time.
Ensemble means continue to print a widespread 1 to 2 inches of
QPF at this point, with the bulk late Thursday into Friday
along and ahead of the associated cold front. WPC placed the
region in a marginal risk for excessive rainfall for NYC and
Long Island, with a slight just to the north across the Lower
Hudson Valley and southern Connecticut. While localized areal or
flash flooding is possible with this system, the threat window
looks relatively brief given the progressive nature of the
system. Also cannot rule out a riverine flood threat given the
antecedent conditions and high stream flows. Typical nuisance
flooding of urban and poor drainage areas is possible as well.
Timing differences amongst the globals continue, with the GFS
tracking the front thru early Friday morning, and the ECM about 12
hours slower. Either way, the steadiest of the rain comes to an end
on Friday, although spotty showers are likely in the cyclonic flow
as the trough axis and upper low advance east over the region. Gusty
winds on the backside as the surface low deepens to the north into
Saturday. Surface high pressure then gradually builds in from the
southeast over the weekend as the trough lifts out.-- End Changed Discussion --
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
Low pressure off the New England coast tracks further offshore as
high pressure builds in from the west.
VFR.
N flow increases back to around 10-15G20kt by late this morning and
continues thru the afternoon. Flow likely goes light and variable
for a few hours toward 00Z Mon as the high builds over, then
becoming WNW into early Monday morning. Cigs remain near 5 kft
during the day, briefly clearing overnight before a high deck
develops on Monday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts later in the day may be more occasional at times.
OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
Tuesday: VFR. WNW flow up to 10 kt.
Wednesday: MVFR possible with chance of showers. E winds G15-20kt.
Thursday: MVFR or lower with showers likely. SE winds G25-30kt.
LLWS possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
High pressure builds in from w to e today into tonight. This has
conds falling below SCA on the ocean this morning, and sub-SCA
conditions through Tuesday Night for all waters. Note, a
backdoor cold frontal passage late Tue/Tue eve may bring
easterly gusts to 20 kt in its wake.
Increasing onshore flow ahead of a frontal system may bring a return
of SCA conditions on the ocean waters late Wednesday or early
Thursday. A higher likelihood Thu into Thu night, with gales
possible on the ocean, and widespread SCA conds elsewhere.
&&
.HYDROLOGY...
A period of moderate to potentially heavy rain is likely Thursday
into Friday as a frontal system moves through the region. At this
time, the most likely solution is for 1 to 2 inches of rain to fall
in this period. This will bring the potential for minor nuisance
flooding of urban and poor drainage areas, along with a riverine
flood threat. Localized flash flooding cannot be ruled out, but the
threat appears low at this time.
&&
.TIDES/COASTAL FLOODING...
Localized minor flooding likely in southern Nassau and Queens, and
coastal Fairfield and Westchester this morning. More widespread
minor flooding likely in these vulnerable spots with this
eve/tonight high tide (and isolated minor elsewhere), as tidal
departures needed for minor drop as low as 1/4 ft, and Ekman
effects from the offshore low increase water levels along the
entire coast.
Another round of localized minor coastal flooding is likely
Monday morning, and more widespread minor flooding Monday
evening.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 9 PM this evening to 1 AM EDT
Monday for CTZ009.
NY...Coastal Flood Advisory from 9 PM this evening to 1 AM EDT
Monday for NYZ071.
Coastal Flood Advisory from 6 PM this evening to midnight EDT
tonight for NYZ178-179.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DR/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...DR
AVIATION...DR
MARINE...DR/NV
HYDROLOGY...DR/NV
TIDES/COASTAL FLOODING...