659
FXUS61 KOKX 211505
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1105 AM EDT Wed May 21 2025
.SYNOPSIS...
A complex frontal boundary approaches today, with coastal low
pressure developing late tonight into Thursday morning. The low
moves north of the area Thursday night and tracks along the New
England coast Friday and Friday night, and into the Canadian
Maritimes Saturday. Weak high pressure returns for Sunday into
early next week, as a low passes to the south.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
The forecast has been updated for PoPs and temperatures. Rain
has already spread into NYC, but should have a tough time
advancing eastward over the next few hours as there is still
some dry air in the low-mid levels to overcome. Most of the
forecast area likely sees some rainfall by sundown.
In any event, it will be an overcast day. An easterly flow
increases today, and will be more noticeable this afternoon.
Look for below average temperatures today with temperatures not
getting out of the 50s.
Tonight, synoptic scale forcing increases with positive
vorticity advection increasing through the night and peaking
into early Thu morning. Simultaneously the best warm air
advection takes shape from 0z to about 12z Thu. The LLJ gets to
30-40 kt out of the SE and E, and thus the steadiest rain takes
shape tonight and carries into Thu morning. Temperatures will
average near to slightly below normal tonight despite moisture
and cloud cover due to a cool strong onshore flow. Winds will
gust 20 to 25 mph in many locations, with coastal sections
gusting to around 30 mph at times.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
The 700 mb lobe of low pressure / shortwave pivot through slowly
during Thu morning. Carlson conveyor belt brings in the moisture off
the Atlantic with rain through the morning and into the early
afternoon. But by later in the day the 700 mb low consolidates and
starts to get further north. This likely shuts off the steady rain,
especially further south across the area with northern interior
sections perhaps holding on to steady rain for much of the day. With
the sfc reflection getting a bit further east and north the winds
are expected to get more of a northerly component and be more out of
the northeast Thu afternoon. Coastal locations once again will
see gusts close to 30 mph at times. With the cloud cover and
ENE flow regime look for temperatures once again to run below
average and not get out of the 50s region wide as rain tapers
most likely from south to north during the second half of the
day. Event rainfall totals should average 1 to 2 inches across
the region. For more details with respect to the rain and any
hydrologic response please refer to the hydrology section.
Cyclonic flow continues into Thursday night, however the best
forcing slowly pushes north of the area and into New England. Look
for periods of light shower activity with any additional rainfall to
be on the light side as the system becomes vertically stacked.
Mainly cloudy skies persist with temperatures averaging a bit below
average with lows mainly in the 40s, to around 50 in the NYC
metro.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
Key Points:
* Unsettled conditions will continue Friday with cool
temperatures and scattered showers possible.
* Temperatures start to trend warmer Saturday and especially
Sunday. Showers possible inland on Saturday.
* Chance of showers Memorial Day with temperatures near to
slightly below normal.
* Unsettled weather remains into Tuesday with a chance of
showers.
An upper trough, with an enclosed low, lingers across the northeast
Friday and Saturday, and moves into Northern New England Sunday.
Another shortwave rotates into the trough Sunday night into Monday,
with unsettled weather continuing into Memorial Day. The elongated
upper trough then remains across the Great Lakes region and into the
northeast into the middle of next week. Meanwhile surface low
pressure tracks along the New England coast Friday and into the
Canadian Maritimes Saturday.
Weak surface high pressure may briefly build into the region for
Sunday into Monday. Then low pressure tracks south of the area later
Monday into Tuesday with the potential for additional rainfall.
Followed the NBM guidance through the extended period.-- End Changed Discussion --
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Low pressure will approach from the west today. Another low will
develop off the Carolina coast this evening and track northeast
tonight into Thursday.
MVFR cigs over most of the area (KBDR should follow suit by
17Z), with light rain slowly expanding eastward from the NYC
metros to the lower Hudson Valley and most CT/Long Island
terminals during this afternoon, but not reaching KGON until
evening. Have trended more optimistically with cigs/vsby going
into this evening, with most terminals not seeing IFR until late
evening or overnight. LIFR cigs may br possible along the coast
toward Thu morning.
E winds 10-15kt, with G15-20kt also look to remain fairly steady
through the day, then start to increase by a few kt this
evening. Winds back to the NE late tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled AMD expected.
.OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
Thursday: IFR, possibly LIFR, with periods of rain. E winds
G20-30kt, highest E of the NYC metros. Winds gradually
diminish and back to the N Thur afternoon/night.
Friday: MVFR or lower with chance of showers.
Saturday: Mainly VFR. Slight chance of MVFR at times in showers.
Sunday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Small craft conditions develop today on the ocean waters as gusts
get to 25 kt for the most part and ocean seas get closer to 5 ft
late in the day. During this evening small craft conditions develop
on the near shore waters mainly from west to east. Gale watches
continue late tonight into a portion of the day on Thursday for the
ocean waters, and have added the eastern nearshore waters to the
Gale Watch through the day Thursday. During Thursday night sub
advisory conditions return from west to east on the near shore
waters as the winds turn more NW and gradually diminish into
early Friday morning. Small craft seas linger on the ocean
waters throughout Thursday night.
Small craft conditions will be possible on the ocean waters Friday
morning, with seas falling below advisory levels by the
afternoon as a northwest flow backs to the west. Winds and seas
will then remain below advisory levels across the forecast
waters through Monday night.
&&
.HYDROLOGY...
No hydrologic impacts are anticipated with the coastal system for
mid week. Flooding overall is not a concern as max rainfall rates
should stay below a half inch per hour. The rain is expected to fall
over a long enough duration to preclude flood impacts. Some minor
nuisance urban related flooding cannot be completely ruled out, but
overall impacts should be low to none. There are no hydrologic
concerns Friday into early next week.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
An increasing E-NE flow develops and persists into Thursday. Later
in the day Thursday and into Thursday evening the winds take on more
of a northerly component. This could very well limit any coastal
flooding for the Thursday evening high tide cycle, and the Friday
evening high tide cycle for coastal SW CT appears to be trending
down.
At this time it appears the main high tide cycle to monitor for the
south shore bays of Queens, Nassau, and portions of the south shore
of Suffolk is Thursday evening. Tidal departures in these spots look
to be mainly 1.5 to 2 ft, and locally as high as 2.0 to 2.5 ft out
east. The latest Stevens, ETSS, ESTOFS blend yields pockets of minor
benchmarks being touched or exceeded. There is a low probability
that Staten Island and portions of NE NJ may also approach and
barely touch minor benchmarks Thursday evening. Otherwise the area
along the coast to monitor is SW CT as Bridgeport an
inland with MVFR.d Stamford may
touch or slightly exceed minor benchmarks for the Thursday evening
cycle, with the Friday cycle looking less likely now for SW CT.
Trends along the NW LI gauges has come down with minor benchmarks
likely not being met.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from midnight tonight to 6 AM EDT
Thursday for ANZ331-332-340.
Gale Watch from Thursday morning through Thursday afternoon
for ANZ331-332-340.
Small Craft Advisory from 6 PM this evening to 6 PM EDT
Thursday for ANZ335-345.
Small Craft Advisory from 6 PM this evening to noon EDT
Thursday for ANZ338.
Small Craft Advisory until midnight EDT tonight for ANZ350-353.
Gale Watch from late tonight through Thursday morning for
ANZ350-353.
Small Craft Advisory until noon EDT Thursday for ANZ355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JE/MET
NEAR TERM...JC/JE
SHORT TERM...JE
LONG TERM...MET
AVIATION...BG/MET
MARINE...JE/MET
HYDROLOGY...JE/MET
TIDES/COASTAL FLOODING...