822
FXUS61 KOKX 261442
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1042 AM EDT Thu Sep 26 2024
.SYNOPSIS...
High pressure weakens and gives way to a frontal system that
moves through today and tonight. High pressure will then
gradually build in from the north on Friday and remain across
the region Friday night through Monday. An area of low pressure
passes to the south early next week with high pressure to the
north. A frontal system will then approach from the west Tuesday
into Wednesday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Some subtle adjustments made for primarily PoP and Wx with this
update to account for the latest radar and high res model trends.
Shower activity continues to move primarily SW to NE, with far
eastern / southeastern sections primarily dry for a bit, before
some showers move through for the early afternoon. Enough
instability may develop this afternoon that thunderstorms may
develop, but probably more so along the cold frontal passage
towards this evening and a portion of tonight. Thus have
maintained primarily slight chance thunder for a good portion of
the area, especially further NW for today. Towards late in the
day, approaching 21z have PoPs dropping off some and the current
shower activity gets further north and northeast.
Temperatures today will be near average with highs primarily in
the 70s, with a few upper 60s in a couple of spots across No.
CT.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A line of convective showers may develop this evening to the
north of the area, as indicated by the CAMs. This potential
convective line will shift southward over southern CT this
evening and into the overnight. Showers should gradually
dissipate overnight and become much more widely scattered by
Friday morning as the front pushes offshore.
High pressure builds into the region from the north Friday night
and through the weekend as the large upper low over the Ohio and
Mississippi Valley absorbs what is left of Tropical Cyclone
Helene. Global models indicate that while the primary low will
be well outside of our CWA, some residual showers may approach
the area from the southwest during the day on Saturday. Widely
scattered showers remain possible, mainly for extreme southern
areas as the upper level low gradually shifts offshore.
Temperatures during this time frame will be generally in the
upper 60s to low 70s each afternoon with lows in the upper 50s
to low 60s.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
There is quite a bit of uncertainty during this time period and thus
stayed very close to a consensus forecast using the NBM.
Trends over the last few days have been for a weaker high over the
Northeast for the weekend into early next week with the cutoff low
over the Tennessee Valley trending farther north and east. The 00Z
GFS takes the upper low to the south with a coastal low developing
along the Mid Atlantic on Monday that also passes to the south
through Wednesday. On the other hand, the ECMWF and Canadian attempt
to build a ridge over top of the upper low ahead of a northern
branch shortwave trough racing east out of the Northern Plains,
resulting is less progression. Players include the magnitude of the
offshore ridge and wavelength separation between multiple pieces of
energy riding over top the eastern ridge and the cutoff low to the
south. Right now, not confident in either solution because of the
subtleties that drive them.
For the time, plan on keeping showers just off to the south Sunday
into Monday with high pressure just strong enough to the north.
However, cloud cover from north to south could vary quite bit,
impacting temperatures as well. Chances for showers then increase
late Monday into Tuesday ahead of the frontal system. Part of this
is also because some of the ensemble members, like the ECMWF, bring
what is left of the shearing out upper low across the region. Bottom
line, this a low confidence forecast.
Temperatures during this time will be close to normal.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
A warm front moves through today, followed by a cold front
tonight.
Mostly MVFR/IFR into early afternoon with showers, then
improvement to mainly MVFR and potentially VFR later in the
afternoon for the city terminals and perhaps some of the other
terminals. Categories lowering to mostly IFR tonight with more
showers possible. Can`t rule out a TSTM this aftn and evening,
but not high enough chance to include in TAFs.
SE winds around 10kt will veer to the south later this morning
into early afternoon, eventually becoming SSW later this
afternoon. As the cold front settles south across the area winds
are likely to go light and variable for a time before becoming
light northerly. Southerly gusts 15-20kt possible for the NYC
and eastern terminals during the late morning and afternoon
hours.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Unscheduled amendments likely for changing flight categories due to
timing of cigs and presence of -SHRA through TAF period.
Brief window of VFR is possible late afternoon.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday: MVFR or lower in the early AM with low stratus, becoming VFR
by late morning.
Saturday: Possible MVFR in slight chance of -SHRA
Sunday-Monday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Wave heights remain fairly elevated through late morning, so
the SCA remains on the ocean waters through the day, as wave
heights should remain around 5 ft, to perhaps as high as 6 ft.
Wave heights gradually fall below SCA tonight resulting in sub-
SCA conditions for all waters.
As the low to the southwest approaches the area on Saturday
night, the pressure gradient tightens possibly resulting in
brief SCA conditions on the waters for marginal gusts near 25kt
and wave heights of near 5 ft for Saturday and Saturday night.
A continued easterly flow Sunday looks to keep winds and seas just
below marginal SCA conditions for the ocean.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through the middle of next
week.
&&
.TIDES/COASTAL FLOODING...
A high risk for the development of rip currents continues through
today due to continued long period easterly swells. Swells
begin to slowly diminish Friday and Saturday. The rip current
risk is expected to also diminish to moderate for Friday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
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 6 PM EDT this evening for ANZ350-
353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DW/MW
NEAR TERM...JE/MW
SHORT TERM...MW
LONG TERM...DW
AVIATION...JC/DW
MARINE...DW/MW
HYDROLOGY...DW/MW
TIDES/COASTAL FLOODING...