000
FXUS61 KOKX 210051
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
851 PM EDT Sat May 20 2023
.SYNOPSIS...
Low pressure approaches along the coast and passes through the
region this evening. Meanwhile, a cold front approaches from
the west and moves through tonight. High pressure builds to the
west Sunday. A pair of cold fronts swings through from the
northwest on Monday and late Wednesday into early Thursday,
otherwise high pressure will be in control through the week.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
A surge of moisture associated with weak low pressure ahead of
an approaching cold front continues to produce moderate to
locally heavy rainfall. The swath of precip is now east of
Nassau and Fairfield County. The Flood Watch for the NYC metro
and surrounding areas has been cancelled. The heaviest rainfall
is producing mainly 1/4 to 3/4 inch per hour rates over eastern
locations with an additional ~1 inch total expected.
The cold front draped across PA will cross the area by 06Z
Sunday. As the front and weak coastal low slowly shift east
through tonight rain chances decrease with the moderate and
heavy rain coming to an end from west to east. By 12Z Sunday the
precipitation should be east of the area as the cold front
passes to the east.
Temperatures tonight will be in the low to mid 50s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
A large scale upper trough will remain over the northeast and
eastern Canada Sunday and Sunday night as surface high pressure
builds to the west, with the center of high pressure to the
north. Clearing is expected as weak subsidence increases.
High temperatures Sunday will be near seasonal levels, in the
lower 70s.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
A cold front should be getting offshore on Monday, with high
pressure in control for much of the upcoming week. A second cold
front is progged to come down from the northwest towards Wed night.
At this time it appears there will be no sensible wx with this
feature as well with shower activity likely staying north of the
area. High pressure will follow once again for the late week period.
Went with a consensus approach with regard to temps throughout. A
pair of dry cP air masses with fairly low dew points should lead to
a strong diurnal curve throughout. Night time temps are expected to
be around normal, with day time temps anticipated to be near to
slightly above normal. Inland locations will experience warmer
temperatures overall compared to coastal locations, in line with the
time of year. The question is whether temps may actually be cooler
than currently progged for Thursday and Thursday night behind a cold
front. Current thinking has the air mass modifying quite a bit as it
presses south, therefore stayed close to the NBM with the NBM
deterministic being on the lower end of the member spread.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
A frontal wave will exit the area to the NE over the next 2 to 3
hours, followed by a cold frontal passage quickly on its heels.
High pressure then builds in from the west on Sunday with a
trough moving through the area in the afternoon.
LIFR/IFR and in some case VLIFR conditions will continue until
a cold frontal passage occurs later tonight. VFR conditions are
then forecast within 1-2 hours of the cold frontal passage. The
cold front will pass through the Lower Hudson Valley and NYC
terminals 05-06Z, and the eastern terminals 07Z-09Z. Much of the
rain will be to the east, primarily impacting KGON through
about 04Z. There could be a few showers accompanied by the
actual cold front. An isolated thunderstorm also cannot be
ruled out at KGON, but confidence is too low to mention in the
TAF at this time.
S winds primarily from KHPN to KJFK and east will be around 10
kt at the coast, but weaker inland. Winds will be light and
variable to the west. Winds will gradually veer to the SW this
evening, then shift to the W/NW at 10kt or less following the
cold frontal passage. For Sunday, winds will be W-NW around
10kt with G15-20kt. There is a low chance of a late day
seabreeze with the passage of a surface trough.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of the cold frontal passage tonight could vary by about
an hour.
Low chance of a late day seabreeze on Sunday at KJFK.
OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
Sunday afternoon through Thursday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA levels across the ocean waters as a weak low pressure along
the coast approaches and moves through the area. Seas levels
will be slow to subside and do not fall below 5 feet until
Sunday evening. The non ocean waters will remain below advisory
levels through Sunday night.
Sub small craft conditions are anticipated with ocean seas running
at 3 to 4 ft much of the time through mid week. High pressure to the
north is expected to result in a relatively weak pressure gradient
for the first half of next week with only a residual east to
northeast wind much of the time.
&&
.HYDROLOGY...
-- Changed Discussion --
Storm totals east of NYC were generally 1 1/2 to to 2 1/2 inches
with localized higher amounts possible. An additional quarter
to half inch is expected across eastern LI/SE CT the next 1-2
hours. Due to dry antecedent conditions, any flooding has been
limited to minor, of the urban and poor drainage type.
No hydrologic impacts are anticipated in the extended timeframe
with another period of dry weather taking place.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT Sunday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...
NEAR TERM...JT
SHORT TERM...
LONG TERM...
AVIATION...DW
MARINE...
HYDROLOGY...