659
FXUS61 KOKX 191721
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
121 PM EDT Wed Mar 19 2025
.SYNOPSIS...
High pressure will remain in place today before pushing offshore
tonight into early Thursday. A complex frontal system with
developing low pressure approaches Thursday and impacts the region
Thursday night before moving out on Friday. High pressure briefly
builds in Friday night into Saturday before a weak area of low
pressure passes through Saturday night. High pressure then returns
Sunday, with another frontal system expected to move through early
next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Main update was to account for quicker timing of stratus and fog
observed offshore, which should move into eastern portions of
the area this evening in light ESE flow. Given the development
of a surface inversion between the subsidence from ridging
aloft, diurnal cooling, and the onshore flow, expect the stratus
to spread across the area, with drizzle and fog also possible
overnight.
Max temperatures will be reached earlier in the day along
coastal locations prior to the onset of sea breezes. There will
be a fairly large spread in temperatures by late afternoon with
some middle 60s further inland, to near 50 for the immediate
coast.
Minimum temperatures will likely range from the upper half of
the 30s well inland, to the middle 40s towards the NYC metro.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
With any ridging getting off the coast the flow will be primarily
onshore out of the SE. This should keep low clouds in place for the
most part. The breeze should pick up later in the day as the
pressure gradient increases some ahead of an approaching frontal
system off to the west. Temperatures have trended a bit cooler for
Thursday with more cloud cover expected ahead of the boundary and
more certainty with a bit more of an easterly component to the sfc
wind. Temperatures may not get out of the upper 40s for some eastern
coastal communities, with upper 50s to near 60 for far western most
locations. With the trend continuing in sharpening the approaching
longwave trough, the arrival of rain / showers ahead of the boundary
has slowed. PoPs begin to increase late in the day and for the early
evening for western sections (mainly slight chance to low end chance
PoPs).
Much of the rain / shower activity out ahead of the frontal boundary
should hold off until about 2-3z Fri for the NYC metro. Much of the
area should see most of the rain from 3 to 9z, and 6 to 12z further
east. This frontal system is not going to draw up as much lower
latitudinal air as the frontal system from a few days ago with
moisture related standard deviations / anomalies not as great this
time around. There should be enough mid level dynamics and warm
advection to generate a good 0.5 to 0.75 inches of water equivalent.
Much if not all of the precipitation will be in the form of rain. As
a secondary low forms along the boundary and heights begin to fall,
colder air does eventually pour in from the west and northwest
towards Friday morning. Because the system remains progressive and
will not cut off over the area, any changeover to wet snow will be
brief across N and NW interior zones. It does not appear that there
will be any accumulation, with perhaps a light dusting / coating
across the highest elevations to the N and NW for Friday morning.
Strong dry and cold advection ensues by mid to late morning on
Friday. As the system deepens as it pulls away the pressure gradient
increases quickly. NW winds will increase quickly for the late
morning and afternoon. Gusts to around 40 mph are likely across the
entire area with strong cold advection and deep layer mixing. Skies
will clear from west to east during the late morning and into the
afternoon. Temperatures will max out in the middle 40s to around
50 on a gusty and strong NW wind.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Key Points:
* A few showers possible Saturday evening, otherwise remaining dry
thru the weekend
* Frontal system moves through Monday and brings next widespread
rainfall to the region
Brief ridging builds in Friday night, helping clear skies and lower
winds as the gradient relaxes. Tranquil conditions persist thru
Saturday afternoon, before a weakening shortwave advancing east thru
the Great Lakes approaches and may instigate a few isolated to
scattered rain showers into Saturday evening, especially across the
interior. QPF, where it does precipitate, just a few hundredths at
most. Conditions dry out Saturday night as ridging begins to build
in once again. Behind the associated fropa Saturday night winds veer
NW and usher in a colder air mass to close the weekend. Temperatures
Saturday in the mid to upper 50s fall about 10 degrees for Sunday,
which is closer to typical for this time of year.
Attention then turns to the next system which guidance progs moving
through the region Monday and Monday night. Closed low trough swings
thru the Lakes, with associated warm front lifting thru Monday, and
the attendant cold front Monday night. Some solutions do include the
possibility of wintry precip initially with the overrunning, but this
is likely limited to the interior if it were to occur with limited
cold air in place and timing issues. Otherwise, rain develops Monday
morning and likely persists much of the day before tapering Monday
evening as the cold front sweeps east and dries the area back out
for Tuesday.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
High pressure gradually moves offshore through this evening. A
cold front then approaches through Thursday.
VFR through 22z. Low stratus and fog will likely begin moving
in from the E and SE this evening generally between 23z and 02z
at most terminals, taking longest to reach KSWF (03-06z). Flight
categories are expected to fall to IFR and then LIFR once the
stratus/fog overspread the terminals. LIFR will likely persist
through day break with gradual improvement to IFR and then MVFR
Thursday morning. Some patchy drizzle is also possible overnight
and early Thursday morning. Mainly MVFR conditions with local
IFR expected Thursday afternoon with a chance for VFR.
SE winds around 10 kt or less will continue through the rest of
the afternoon. Winds will weaken this evening and back towards
the E, becoming light and variable outside of the NYC metro
terminals. SE winds increase again Thursday morning, with gusts
around 20 kt possible, mainly in the afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for timing of IFR/LIFR this evening.
Visibilities could lower to around 1/2SM several hours faster
than currently indicated.
Timing of improving ceilings/visibilities Thursday morning may
be off by 1-3 hours.
.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
Thursday Afternoon: MVFR-IFR possible. SE winds G20kt.
Thursday night: IFR likely in rain. Precip could mix with snow
late at KSWF. NW winds G20-25kt late from the NYC metros
north/west.
Friday: Chance showers and MVFR early, becoming VFR. NW winds
G30-40kt morning and afternoon. NW gusts 20-25 kt in the
evening.
Saturday: Mainly VFR. Slight chance showers NW of NYC. SW winds
G20kt in the afternoon at the NYC metros.
Sunday: VFR. NW winds G20kt.
Monday: IFR with rain likely. S-SW winds G20 kt possible.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub small craft conditions will be in place today as high pressure
resides over the waters with a SE flow developing, especially for
this afternoon into tonight. Ocean seas begin to gradually increase
during the day Thursday. Small craft seas should prevail by
afternoon with a SE wind around 15 kts late in the day and evening.
Low pressure and its associated frontal system pivot through Friday
morning as the winds quickly switch to the NW. The winds increase
quickly, within a couple of hours for the mid to late morning on
Friday. Gale force gusts will prevail through the day, with the
winds diminishing and gales giving way to small craft conditions for
a brief time during Friday night.
Winds and seas lower below Small Craft Advisory (SCA) conditions on
all waters Friday night into Saturday morning, then generally sub
SCA conditions are expected through Sunday. Possible some ocean
waters near 5 ft Saturday night, especially east of Moriches Inlet.
A frontal system moves thru Monday and ocean seas may build to over
5 ft once again as it does so.
&&
.HYDROLOGY...
At this time no hydrologic impacts are expected throughout the
forecast period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Gale Watch from Friday morning through Friday afternoon for
ANZ331-332-335-338-340-345-350-353-355.
Small Craft Advisory from noon Thursday to 6 AM EDT Friday for
ANZ350-353-355.
&&
$$
SYNOPSIS...MD/JE/DR
NEAR TERM...MD/JE
SHORT TERM...JE
LONG TERM...DR
AVIATION...DS
MARINE...JE/DR
HYDROLOGY...JE/DR