000
FXUS61 KOKX 011443
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1043 AM EDT Fri Sep 1 2023
.SYNOPSIS...
High pressure settles over the northeast today and will remain
in control through much of next week. Low pressure may impact
the area late next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Forecast remains on track for the remainder of the late morning
and into the early afternoon, with no real changes in database
through the next several hours. Sprawling high pressure is the
main weather story to start September 2023. The region will lie
on the outer periphery of upper ridging that remains centered
over the middle of the U.S. The atmospheric column is quite dry
with forecast soundings showing PWATs close to the 10th
percentile on the SPC Sounding Climatology for OKX. Skies will
be clear with highs below normal for this time of year in the
middle to upper 70s.
Another cool night is in store with good radiational cooling
conditions. Lows will range from around 50 degrees inland to the
middle and upper 50s most elsewhere. The NYC metro will be a
bit milder in the lower 60s.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
The northeast will continue to lie on the outer periphery of
the larger upper ridge over the central states. A shortwave
trough will traverse across southeast Canada and approach New
England on Saturday. This will allow heights to fall a bit
through the day, with the core of the surface high shifting just
offshore. Upper level moisture increases somewhat with the
heights falling. This will lead to a slight increase in cirrus
clouds, but overall another mostly sunny day is expected on
Saturday. The air mass moderates compared to recent days with
highs likely a few degrees warmer. Highs will be in the upper
70s to around 80 degrees, warmest in the NYC metro.
The axis of the shortwave will pass across the region Saturday
night. The most notable sensible weather change will be in an
increasing clouds overnight yielding mostly cloudy skies. The
low levels will remain dry and lift is weak. No precipitation
is forecast with lows falling closer to normal levels in the
60s.
Heights rise behind the shortwave as the ridge tries to build
back towards the area on Sunday. Middle and upper level clouds
will diminish in the morning with mostly sunny skies for much of
the day. 850 mb temperatures increase through the day reaching
16-18C. Southwest flow around the high will boast temperatures
well into the middle and upper 80s for the NYC metro, NE NJ, and
Lower Hudson Valley. A more onshore flow component further east
across Long Island and southern Connecticut will likely cap
highs off in the lower 80s. Heat indices will approach 90 in the
warmest locations as dew points increase into the middle 60s by
afternoon.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
No significant changes to the long term forecast. Stuck closely
to the NBM.
The long term is largely dominated by a large high pressure system
that traverses the area through the middle of next week.
A weakness in the high pressure system on Sunday may give way to
a very weak cold front that likely pushes through without any
precipitation. High pressure then builds back into the area from
the southwest as an upper level ridge moves back into the area
by the middle of the week.
There will be a significant warmup during this period with the
warmest day possibly being early in the period on Monday as a
ridge sets up over the area. Meanwhile, TC Idalia will get
trapped in the upper level ridge and become cut off from the
flow over the Western Atlantic. This may result in the system
retrograding toward the East Coast by the middle of the week. At
a minimum this will keep mid- level height lower and will limit
the temperatures from becoming excessively hot. Despite this,
temperatures through the middle of the week are expected to be 5
to 10 degrees above average with highs in the middle 80s to
lower 90s through Thursday.
There remains substantial uncertainty in the strength and
positioning of TC Idalia and how it interacts with an approaching
shortwave toward the end of the week as it becomes reintroduced
to the flow. This interaction will impact the sensible weather
for late in the week. However, an approaching trough from the
west likely brings a low pressure system near the area by late
in the week or for next weekend. This looks to be the next best
chance for precipitation for the area.
For the latest official forecast information on Tropical Cyclone
Idalia, please monitor the National Hurricane Center at
https:/www.nhc.noaa.gov or https:/www.weather.gov/okx/tropical.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
A large high pressure system settles over the area through the
TAF period.
VFR. NE winds 5 to around 10 kt into early afternoon when winds
gradually shift to E/SE, and then sea breezes are expected for
all terminals, except KSWF where winds likely remain light and
variable. Winds remain light out of the S tonight or become
light and variable for outlying terminals.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments are expected. Timing of the wind
shifts to SE and then to sea breeze directions may be off around
an hour.
OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
Saturday-Tuesday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Elevated seas at or above SCA levels will continue on the ocean
waters this morning with lingering SE swells. Have not made any
changes to the SCA at this time, but it may need to be extended
into the afternoon if seas are slower to subside. Otherwise,
the pressure gradient will weaken this morning with winds
remaining below SCA levels through the weekend. Seas will begin
to subside this afternoon into tonight and should remain below
SCA levels into the weekend once they fall below 5 ft later
today. Sub-SCA conditions will then continue into the middle of
next week.
&&
.HYDROLOGY...
No hydrologic impacts are expected through next week.
&&
.TIDES/COASTAL FLOODING...
Lingering long period SE swells from TC Franklin continue on the
ocean front. This will lead to a high risk of rip currents at
all ocean beaches through this evening. 3-4 ft seas are forecast
on Saturday, but long period swells should still linger. Have
forecast a moderate risk for now, but may need to be increased
to high risk.
Astronomical tides remain high from the recent full moon.
Widespread minor coastal flooding is not anticipated as was the
case the last few nights across the south shore back bays. It
appears that any minor coastal flooding will be isolated and
have gone with a coastal flood statement that includes both the
morning and evening high tide cycle. Elsewhere across the Lower
NY Harbor and coastal Fairfield County CT, water levels are
likely going to fall just short of minor benchmarks and have
held off on any statements. The threat for minor coastal
flooding diminishes further on Saturday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents until 8 PM EDT this evening for NYZ075-
080-081-178-179.
NJ...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ350-353-355.
&&
$$
SYNOPSIS...DS/MW
NEAR TERM...JE/DS
SHORT TERM...DS
LONG TERM...MW
AVIATION...MET
MARINE...DS/MW
HYDROLOGY...DS/MW
TIDES/COASTAL FLOODING...