okx-afd on 2025-05-22

796
FXUS61 KOKX 221126
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
726 AM EDT Thu May 22 2025

.SYNOPSIS...
A developing coastal low pushes just east of the area by this
afternoon, and lifts north into New England tonight into Friday.
The low will linger across northern New England during the first
half of the weekend as high pressure builds in for the second
half of the weekend into early next week. Low pressure then
heads toward the region by Tuesday-Wednesday of next week.

.NEAR TERM /THROUGH TONIGHT/...
As the coastal low develops this morning look for the steady rain to
continue until about midday or so for the southern half of the
region, and into the afternoon some further north. The primary low
begins to fill in with an occluded front slowly pushing towards the
area. The 700 mb lobe of low pressure forms over the eastern half of
the area during the day so this should begin to shut off the Carlson
conveyor belt of Atlantic moisture as warm advection decreases into
the afternoon. Late in the day the 700 mb low consolidates and
starts to get further north. This eventually completely shuts off
the more organized wet weather, although mainly lighter showers will
pivot through into tonight with the upper level portion of the
system lingering. With the sfc reflection getting a bit further east
and north the winds are expected to go to more of a northerly
component and be more out of the northeast this afternoon, followed
by more of a true northerly flow tonight. With the cloud cover and
more of a NE flow regime look for temperatures to run well below
average. Temperatures have been continued to be lowered from
previous forecast cycles and are likely to not get out of the upper
40s inland to the NW, and the lower half of the 50s elsewhere across
the region and closer to the coast. As the coastal low develops the
winds should increase further, especially closer to the coast where
gusts get to around 30 to 35 mph in some spots. Event rainfall
totals should end up averaging 1 to 2 inches across the region, with
the highest totals across the eastern third of the area in closer
proximity to the strongest mid level warm advection and warm tongue
from the LLJ. For more details with respect to the rain and any
hydrologic response please refer to the hydrology section.

Cyclonic flow continues into tonight, however the best forcing gets
north of the area and into New England with deepening of the coastal
system, especially in the mid levels. By mid to late evening the
winds should begin to decrease as the wind direction becomes more
out of true north, then more NW late. Look for periods of light
shower activity with any additional rainfall to be on the light side
with the highest RH in the lowest 10kft as the system becomes
vertically stacked. Mainly cloudy skies persist with temperatures
averaging below average with lows mainly in the 40s region wide.

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
The cool weather regime continues as the upper level low more or
less temporarily stalls over Northern New England and Upstate NY
Friday into Friday night. Cyclonic flow continues in the column with
a good deal of cloud cover remaining. Somewhat drier air begins to
work in down lower in the column on a W flow. This should get
temperatures a bit warmer, but still running below average with a
good deal of cloud cover with mainly upper 50s and lower 60s for max
temperatures. Another spoke of mid and upper level energy pivots
through into the afternoon and this looks to yield another round of
at least some scattered shower activity. The activity is likely to
linger into Friday night as well with the relatively higher chance
of showers further N and NW. Minimum temperatures Friday night will
mainly range from the middle 40s inland to the north, to around 50
or in the lower 50s for the metro and coast.

For Saturday the upper level low slowly pushes northeast into Maine
and Nova Scotia. A deep WNW flow will reside in the column keeping
the region primarily dry with only the slightest chance of a shower
or a few sprinkles mainly across northern most sections as the cold
pool aloft lingers with mainly broken cloud coverage. With the upper
level low slowly lifting out and more of a land component to the
wind temperatures may be able to get a few degrees warmer, but still
average below normal as max temperatures should get into the lower
and middle 60s. This would still be around 10 degrees below normal
for this time of the year.

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
**Key Points**

* Dry conditions for the area Sunday and Monday, with shower chances
returning by late Monday and Tuesday.

* Slightly below normal temperates expected generally, with
Memorial Day the warmest of the period; near normal.

Decent model agreement on a slow-moving, closed mid-level low east
of the area over New England to start the period. The local area
thus resides under a deep cyclonic/NW flow aloft, with a few weak
shortwaves rounding the base of the closed low through Tuesday.
Ridging aloft then build over the area on Tuesday, while another
deep low approaches from the Great Lakes region by midweek.

Have kept the forecast dry for Sunday with the cold pool aloft and
fairly dry airmass, but can`t rule out an afternoon shower
especially with some shortwave energy passing over the area in the
afternoon (model guidance consensus still hinting at this
possibility) along with more favorable mid level lapse rates. This
looks most likely for the interior, LoHud and Southern CT. At a
minimum, an increase in cloud cover Sunday afternoon looks likely
for the whole area, with below normal high temperatures in the mid
to upper 60s.

By Monday the surface flow becomes more westerly/southwesterly, as
high pressure/upper ridging builds in. With some waa, expect a
warmer day than on Sunday, with mainly dry conditions for the much
of the day. Clouds will be on the increase, however, by Monday
afternoon/evening as surface low pressure originating over the
southeast US heads northeast toward the region. This system will
have some moisture to work with given its origin, with mean PWATS
from the LREF (NAEFS/GEFS) of around 1" by early Wednesday. Usual
model timing differences this far out, so have used the ensemble
approach for PoPs and Wx, increasing the precip potential by Tuesday
morning and keeping chances in through Wednesday. Given the
increased cloud cover and shower activity, temperatures will remain
slightly below normal in the mid and upper 60s.

.AVIATION /11Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --Low end MVFR to nearly IFR cigs are widespread across the
terminals this morning as rain becomes moderate to locally
heavy in intensity through midday. Gusts have been more
occasional than frequent thus far, ENE 15G20-25kts. A return to
high end MVFR may occur later this afternoon, with a lowering
of cigs again early Friday and toward the end of the TAF period.

...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Amendments likely mainly for changes in flight categories.
Gusts may be more occasional than frequent.

.OUTLOOK FOR 00Z FRIDAY THROUGH SUNDAY...

Thursday night: Improvement to MVFR likely and potentially low end
VFR. Winds backing NE-N 15G20-25kt.

Friday: Chance of showers with MVFR cond at times. N winds 10-
15G20kt E of the NYC metros Thu evening.

Saturday and Sunday: Mainly VFR. NW winds G15-18kt.

Monday: 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 for all waters heading into tonight. Winds increase
overnight with gales on the eastern ocean waters late at night, then
over the eastern half of LI Sound as well as the eastern bays
starting Thursday morning. Gale warning now in effect for these
spots through Thursday afternoon. May need to extend the warning a
few hours into the evening based on trends of a stronger low passing
just east of the waters during Thurs evening. All current SCAs may
needed to be extended by few hours as well. Gusts to 35 kt possible
even over the ocean waters west of Fire Island inlet, but not
widespread enough for warning consideration.

A SCA will likely be needed on the ocean Fri-Sat, mainly for
seas. All waters look to be blw SCA lvls Sun and Mon. Seas may
then build on the ocean to SCA lvls late Tue.

.MARINE...
Gale warnings continue today for the ocean waters and the eastern
nearshore waters, with small craft conditions elsewhere. During
tonight sub advisory conditions return across the nearshore water
from west to east as the winds turn more NW and gradually diminish
into early Friday morning. Ocean seas will remain near small craft
criteria through tonight, followed by more marginal small craft
conditions with mainly 4 to 5 ft seas during the day Friday. Small
craft conditions are then likely for much of the ocean Friday night,
followed by sub advisory conditions becoming increasingly likely
late Saturday into Saturday night with a lighter W to NW flow
regime. SCA criteria is not expected to be met Sunday and
Monday.

.HYDROLOGY...
Rainfall event totals are to average generally 1 to 2 inches,
but with higher amounts of over 2 inches possible across eastern
most portions of the area, especially into eastern portions of
southern CT. This is where more nuisance urban poor drainage
related flooding is more likely, but overall flood concerns
remain low with the rain expected to fall over a long enough
duration. Thereafter there remain no significant hydrologic
issues through the remainder of the forecast period.

.TIDES/COASTAL FLOODING...
-- Changed Discussion --A prolonged E-NE flow continues into this afternoon, backing
N/NE toward evening. This backing of winds should help limit
the magnitude of coastal flooding for most areas, but
potentially enhance impacts along Peconic and Gardiners Bay and
north shore of LI.

The latest forecaster adjusted Stevens (75th percentile
weighting), ETSS, PETSS STOFS guidance blend signals widespread
minor coastal flooding for the south shore of Nassau County, the
twin forks of LI (localized moderate impacts possible for north
facing areas along the bayfront), and along much of LI Sound.

Localized minor coastal flooding likely for NY/NJ harbor where
winds will back to the N/NNE earlier. Magnitude of coastal
flooding for central and eastern great South Bay, Moriches, and
Shinnecock bays will depend on tidal piling trends, but looks to
be localized here.

For Fri evening high tide, coastal flooding looks to be more
localized for the Fri eve high tide cycle, to southern Nassau
and SW CT, in response to offshore flow and subsiding onshore
swells.

Potential for localized coastal flooding Sun into early next
week with approach of new moon, causing areas to need as little
as 1/4ft of tidal departure for minor coastal flooding.

As far as shoreline impacts, along the north shore of the south
fork of Long Island, breaking waves of 1 to 3 ft may cause dune
erosion and localized washovers, as well as enhance splashover
and flooding onto shoreline roads and properties. Along the
ocean front and Orient Point, breaking waves of 4 to 6 ft on an
east to west sweep will result in beach erosion and beach
flooding during the times of high tide. Localized dune erosion
is possible. Along the north shore of Long Island, breaking
waves of 3 to 4 ft will cause dune erosion, localized washovers,
as well as enhance splashover and flooding onto shoreline roads
and properties.-- End Changed Discussion --

.CLIMATE...
Record minimum maximum (coldest high temperatures) are possible
for Thursday, May 22nd. Here are the records and forecast high
temperatures for the date:

NYC: 54/1894, forecast high: 53
JFK: 55/1967, forecast high: 53
LGA: 57/2003, forecast high: 53
EWR: 56/2003, forecast high: 53
BDR: 54/2005, forecast high: 51
ISP: 54/2003, forecast high: 54

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --CT...Coastal Flood Advisory from 6 PM to 10 PM EDT this evening for
CTZ009>012.
NY...Coastal Flood Advisory from 6 PM to 10 PM EDT this evening for
NYZ071-073-078-176-177.
Coastal Flood Advisory from 2 PM this afternoon to 11 PM EDT
this evening for NYZ079>081-179.
Coastal Flood Advisory from 2 PM this afternoon to 7 PM EDT
this evening for NYZ178.
NJ...None.
MARINE...Gale Warning until 6 PM EDT this evening for ANZ331-332-340-
350-353.
Small Craft Advisory until midnight EDT tonight for ANZ335-345.
Small Craft Advisory until 6 PM EDT this evening for ANZ338.
Small Craft Advisory until 6 AM EDT Friday for ANZ355.-- End Changed Discussion --

SYNOPSIS...JE/DBR
NEAR TERM...JE
SHORT TERM...JE
LONG TERM...DBR
AVIATION...DBR
MARINE...JE/DBR
HYDROLOGY...JE/DBR
TIDES/COASTAL FLOODING...NV/DBR
CLIMATE...