826
FXUS61 KOKX 231454
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1054 AM EDT Tue Jul 23 2024
.SYNOPSIS...
Multiple weak areas of low pressure will pass near the area through
Wednesday night. A cold front approaches during Thursday and moves
through Thursday night into early Friday morning. High pressure
builds in from the west Friday and Saturday, then remains into the
beginning of next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
The area remains on the eastern side of a broad upper level
trough, with multiple embedded shortwaves expected to move
overhead. A stalled frontal boundary will be lingering over the
area, with multiple waves of low pressure moving through.
A mostly cloudy day is expected, but some breaks of sun are
possible late in the day with slight height rises possible in
between shortwaves. Even with the cloud cover, the HREF mean
SBCAPE values peak around 750-1000 J/kg again today. CAMs
continue to signal isolated to scattered convective activity
during the afternoon, primarily across the Lower Hudson Valley
and southern CT in vicinity of weak surface wave and to the
north of sea/breeze warm front. Severe thunderstorms are not
likely, but an isolated strong thunderstorm with strong wind
gusts and heavy downpours are possible in a weakly capped nut
modestly unstable and sheared environment.
High temperatures will be right around normal, low to mid 80s.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
The next shortwave and associated surface wave of low pressure is
expected to pass near the area late tonight into Wednesday. The
placement of the heaviest precip has shifted south slightly in
the latest guidance and looks to be mostly offshore at this
time. However, showers and thunderstorms are still expected for
at least the southern half of the area and given the moist
environment with pwats around 2 inches, any shower or
thunderstorm could contain heavy downpours. The thinking remains
the same that flash flooding is an isolated risk and poor
drainage and urban flooding is more likely. The heaviest showers
and thunderstorms will exit east in the late morning hours.
We then once again destabilize Wednesday afternoon and scattered
showers and thunderstorms are possible the rest of the day given
multiple disturbances passing overhead. Highs on Wednesday will
be a couple of degrees below today`s highs.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
An upper level trough remains from the upper midwest into the
northeast Wednesday night as a weak wave of low pressure will be
moving just north or through the region Wednesday night. With
high precipitable water values remaining across the region any
thunderstorms will be capable of producing briefly heavy
rainfall. And, while the storms are expected to be rather quick
moving, with previous days of heavy rainfall, and convection
potentially tracking over the same regions, the area remains in
a marginal risk for excessive rainfall Wednesday night. The
upper trough amplifies into the mid Atlantic region Thursday as
a cold front moves southeastward. The upper trough axis shifts
east of the region Thursday night into friday morning with the
passage of the cold front. The marginal risk for excessive
rainfall will continue into Thursday with additional rounds of
moderate to heavy rainfall possible, however, precipitable water
values will be lowering slightly.
As the trough moves into the north Atlantic Friday into the
weekend, a highly amplified, and full latitude ridge will builds
into the mid section of the country and track to the east coast
through the weekend and off the coast Monday. With the chance
of a shortwave moving through the periphery of the ridge Monday
have increased probabilities to slight chance across the inland
areas Monday afternoon.
Daytime high temperatures Thursday through Sunday will be near
seasonal normals, and may be slightly above normal for Monday as
high pressure begins to shift off the northeast and mid
Atlantic coast. Overnight lows will be slightly above seasonal
normal Wednesday night, and then near normal for Thursday night
into Saturday night.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
A frontal system remains just south or in the vicinity through
Tuesday night.
MVFR to IFR conditions expected through much of the day, with a
return to VFR by this afternoon. A brief respite before MVFR or
lower comes back in at the tail end of the forecast period with
the next wave of low pressure bringing in another round of
SHRA. SHRA may also develop across the interior (KSWF) this
afternoon, but is less likely across much of the rest of the
terminals. SHRA move back into the area again late tonight,
which may be heavy at times, bringing conditions briefly lower
than what is forecast. Very low chance of TSRA.
Large uncertainty in wind direction given uncertainty in
position of weak lows, position of the frontal boundary over
the next 24 hours, and the overall general light flow. E to NE
flow shifts to the S to SE by late this afternoon at 10 kt or
less, then become light and variable for most terminals once
again Tuesday night. Sea breeze development will allow for a
shift to the S earlier than other terminals.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely with flight categories changes. Large
uncertainty in wind direction given track of weak lows, frontal
boundary position, and overall general weak flow.
OUTLOOK FOR 15Z WEDNESDAY THROUGH SATURDAY...
Wednesday through Thursday: MVFR or lower in SHRA/isolated
TSRA.
Friday: MVFR or lower possible in the morning with SHRA,
otherwise VFR.
Saturday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
With a weak pressure gradient over the area, winds and seas/waves
remain below Small Craft Advisory criteria through the weekend.
Periods of moderate to heavy showers and thunderstorms will be
possible with multiple waves of low pressure passing near the area
through Wednesday night.
&&
.HYDROLOGY...
-- Changed Discussion --
With a frontal boundary expected to linger over or near the
area and multiple waves of low pressure passing through, a
period or two of moderate to locally heavy rain, interspersed
with scattered diurnal shower and thunderstorm activity, will be
possible through Thursday.
Rainfall rates of 1 to 2"/hr are possible in stronger
convection, but at this point convective coverage appears to be
limited and predictability on boundary placement as a focus for
training showers and thunderstorms is low. So overall, the
primary threat is for scattered minor urban and poor drainage
flooding, with a localized flash flood threat. This is outlined
by the marginal risk of excessive rainfall through Thursday.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
A moderate risk of rip current development at the ocean beaches
will remain through Wednesday as a 3 to 4 ft S/SE swell at 7 to
8 seconds continues. Rip activity could be locally high due to
the Spring tides.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$