129
FXUS61 KOKX 210158
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
958 PM EDT Tue May 20 2025
.SYNOPSIS...
As high pressure noses down from the north, a back door cold
front will move through from the east tonight. An expansive low
pressure system will then approach from the west on Wednesday,
with a secondary low developing off the southern Mid Atlantic
coast Wednesday night. This second low will then pass south and
east of Long Island into New England Thursday into Thursday
night. The low will remain over the Northeast Friday and
Saturday before slowly moving toward the Canadian Maritimes on
Sunday. High pressure may return early next week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --
A back door cold front about to move into far eastern LI and SE
CT will track east to west across the area overnight with winds
becoming easterly and gradually strengthening. Low-level clouds
will also work in from the east in tandem with the boundary,
while mid and high level clouds associated with low pressure to
the southwest gradually move eastward. Precip with the low to
the west unlikely to make it into the area tonight, but a few
sprinkles are possible with the back door front as it moves
westward.
Based on latest temperature trends and increasing cloud cover,
bumped up lows a bit overnight, ranging from the upper 40s to
lower 50s, warmest along the coast.-- End Changed Discussion --
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Rain may be slow to enter the area on Wed especially out east with
upper level ridging only starting to move east, but should make
it into the western half of the CWA by afternoon and then
eastern sections by late afternoon or evening as the ridge moves
E and a lead mid level shortwave trough approaches.
Periods of rain expected throughout from Wed night into Thu,
with the heavier QPF mainly from late Wed night into Thu
morning as an easterly LLJ transports Atlantic moisture into the
area ahead of the approaching coastal low, and as a stronger
mid level shortwave trough approaches from the west. As the low
pulls east Thu night precip should become light and more
intermittent/showery.
High temps both Wed/Thu should remain in the 50s. Lows Wed night
will be 45-50 inland and in the lower 50s along the coast, and
in the 40s throughout Thu night with some CAA on N flow on the
back side of the low as it passes to the east and heads up
toward the New England coast.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Key Points:
*Unsettled conditions will continue Friday with cool temperatures
and scattered showers possible.
*Temperatures start to trend warmer Saturday and especially Sunday,
but will remain below normal for this time of year. A shower is
possible on Saturday.
*Mainly dry conditions are currently expected on Memorial Day with
temperatures slightly below normal in the upper 60s and low 70s.
Anomalous upper low and associated trough will slowly move across
the area Friday through Saturday. The upper low slowly shifts
towards the Canadian Maritimes Sunday and pushes further east next
Monday.
The proximity of the upper low and associated surface low Friday
will bring a continuation of mostly cloudy and cool conditions.
The cold pocket aloft and any surface heating should lead to the
development of scattered showers. This potential may continue into
Friday night as the upper trough axis starts to slide east of the
area. Cyclonic flow will continue aloft on Saturday with an isolated
shower possible. Skies will likely remain partly sunny to mostly
cloudy due to the lingering cold pocket aloft. Highs on Friday will
only reach the upper 50s and low 60s. Highs on Saturday will start
to warm a bit, but still remain below normal in the lower to middle
60s.
Improving conditions continue on Sunday with low pressure slowly
pushing into the Canadian Maritimes. Cyclonic flow lingers aloft,
but should see less cloud cover versus Saturday allowing
temperatures to push into the upper 60s and potentially low 70s in
the usual warmer locations. Some guidance is hinting at some energy
rotating around the low to our west, but think the atmosphere will
be dry enough to suppress any shower development.
The evolution of the large scale pattern is much less certain
heading into next Tuesday, but there are hints of another trough
developing over the eastern US. Followed the latest model consensus
(NBM) which is currently keeping conditions mainly dry on Memorial
day as high pressure returns. The next chance of showers may occur
on Tuesday, but this will be dependent on the potential evolution of
another upper trough. Highs will be in the upper 60s and lower 70s,
slightly below normal for the last week of May.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
High pressure will nose into the area from the north tonight,
then gradually gives way to low pressure approaching from the
southwest on Wednesday.
VFR to start with MVFR ceilings overspreading the area from
east to west overnight into Wednesday morning. KGON may not see
these ceilings initially persist as it resides closer to some
low-level dry air associated with the surface high. IFR conditions
likely hold off until Wednesday night, but there could be some
pockets before then, especially across the Lower Hudson Valley.
Rain will overspread the area late morning into the afternoon,
but may not reach KGON until Wednesday night.
Light NE to ESE winds across area will become more easterly
overnight as a backdoor cold front works across the area. The
easterly flow will gradually strengthen behind the front,
increasing to 10-15kt G15-20kt by late morning.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Winds will likely vary from SE to NE across the terminals the
first half of the night at less than 10 kt, becoming more
easterly after 06Z.
Timing of the rain and MVFR conditions may vary by 1-2 hours.
Pockets of IFR possible Wednesday afternoon.
.OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...
Wednesday Night-Thursday: MVFR or lower with periods of rain. E
wind gusts 20-25kt, mainly at the coastal terminals. Winds
diminishing and veering to the N/NE Thursday afternoon/night.
Friday: MVFR or lower with a chance of showers. Light/VRB winds
becoming W.
Saturday: Chance of MVFR in showers. WNW flow gusting 20-25kt.
Sunday: 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 --
Gale watch remains in effect for the ocean E of Fire Island
Inlet for late Wed night into Thu morning. As low pressure
passes to the south and then east during this time, E winds
should ramp up, with gusts to 35-40 kt possible during this
time. On the remaining waters, SCA in effect, beginning 11 AM
Wed for the ocean W of Fire Island Inlet, and for Wed night into
Thu for all but western Long Island Sound, with gusts 25-30 kt.
Seas build to 6-10 ft on the ocean during this time and also
4-6 ft on easternmost Long Island Sound.
By Thu evening winds back northerly and diminish, but seas will
still be as high as 6-8 ft on the ocean and 5 ft on the ernmost
Sound, and should gradually diminish to 4-6 ft and 3-4 ft
respectively.
SCA conditions due to lingering 5 ft ocean seas will likely be
ongoing on Friday. Seas should subside below 5 ft Friday night.
There is a chance wind gusts could approach 25 kt on Saturday.
Otherwise, conditions will remain below SCA levels Saturday and
Sunday.-- End Changed Discussion --
&&
.HYDROLOGY...
Rainfall from Wed into Thu night will range from 1-1.25 inches
for most areas, with higher amts of 1.50-1.75 inches across ern
Long Island and SE CT. Rainfall will be light to moderate, with
rates not expected to exceed 1/2 inch per hour. At worst only
nuisance impacts expected mainly from late Wed night into Thu
morning.
&&
.TIDES/COASTAL FLOODING...
A strengthening/persistent E-NE flow Wednesday through Thursday
may result in minor coastal flooding mid to late week. Water
levels should remain below minor coastal flood benchmarks during
times of high tide Wed into Thu morning, but a round of more
widespread minor flooding is possible with the high tide late
Thu afternoon into Thu evening, with tidal departures mostly 1.5
to 2.0 ft and locally as high as 2.0 to 2.5 ft out east. These
departures are actually lower than in some previous forecasts,
as it appears winds may start to back N and diminish leading
into this high tide cycle.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from midnight Wednesday night to 6 PM EDT
Thursday for ANZ331-332-340.
Small Craft Advisory from 6 PM Wednesday to 6 AM EDT Thursday
for ANZ338.
Small Craft Advisory from midnight Wednesday night to noon EDT
Thursday for ANZ345.
Small Craft Advisory from 11 AM Wednesday to midnight EDT
Wednesday night for ANZ350-353.
Gale Watch from late Wednesday night through Thursday morning
for ANZ350-353.
Small Craft Advisory from 11 AM Wednesday to noon EDT Thursday
for ANZ355.
&&
$$
SYNOPSIS...BG/DS
NEAR TERM...BG/DS/DW
SHORT TERM...BG
LONG TERM...DS
AVIATION...DW
MARINE...BG/DS
HYDROLOGY...BG/DS
TIDES/COASTAL FLOODING...