633
FXUS61 KOKX 171143
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
743 AM EDT Mon Mar 17 2025
.SYNOPSIS...
A cold front moves off the coast today, with a large high pressure
ridge gradually building across tonight. The high settles over the
area Tuesday and Tuesday night and remains into Wednesday. A fast
moving frontal system moves across Thursday into Thursday night.
High pressure begins to build back in on Friday.
&&
.NEAR TERM /THROUGH TONIGHT/...
The moderate to heavy rain continues to push up from the south
early this morning as most max hourly rainfall rates are at 0.4
to 0.5 inches per hour. However, some locations across Central
/ Eastern LI and Eastern So. CT did have max rates closer to
0.75 inches per hour with earlier activity. Similar rates are
expected with this next batch moving up along and off the NJ
shore. Ponding of poor drainage areas and localized urban and
poor drainage flooding will occur where the rain maxes out.
Convective elements have decreased some, but a rumble of thunder
and a few flashes of lightning remain possible, especially
further east through the morning commute.
The cold front gets through the metro this morning, then for far
eastern sections towards midday. The steadier, more moderate to
heavier rainfall is expected to get east of our far eastern portions
of the CWA by 13-15z. However, with the boundary taking on more of
anafrontal behavior and dry advection not really strengthening until
later, look for some pockets of light rain for the late morning and
into the afternoon for the majority of the area. The pressure
gradient will be much weaker throughout a good portion of the day as
waves of low pressure along the cold frontal boundary slowly pivot
through. Once the boundary gets out towards far SNE a NNW flow at
the sfc gets going some. Gusts look to return towards 19-20z or
thereabouts across the western half of the area, then shortly
thereafter across eastern portions. Clouds will hold throughout the
day with periodic shower activity with a deep upper level trough
axis still just off to the west and a strong southerly flow at 500
mb. Look for temperatures into this afternoon to run about 5 to 10
degrees above normal despite the cloud cover.
For this evening looks for the ongoing risk of showers mainly from
the metro and east, with some partial clearing attempting to being
across western portions. The upper level trough axis doesn`t really
get through until 6z or shortly thereafter. Clearing should ensue
quickly from west to east behind the passage of the trough axis.
With the trough axis being quite sharp it should serve as a good
proxy and line of demarcation with respect to clearing. With the
best cold advection taking late in the overnight into Tuesday
morning this is when dew points make more of a move downward. Dew
points by the Tue wake up will get through the 30s and mainly into
the middle and upper 20s. This results in temperatures bottoming out
primarily in the 30s across the region with clouds getting off the
east end of LI towards shortly after sunrise.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
Look for any clouds across far eastern sections to get off the coast
during the morning. A rather expansive high pressure ridge will
build in from the west. On a dry northerly flow look for complete
sunshine and mild temperatures with enough of a synoptic flow to
likely prevent any real widespread sea breeze / ocean diurnal
induced wind. Look for mainly middle 50s to lower half of the 60s
for daytime max temperatures, a good 10 degrees or so above normal
in most places.
With the high settling right over the region Tuesday night look for
clear skies and light to calm winds. This should result in a fair
amount of radiational cooling. Lows will range from middle 30s
across far northern interior and rural sections, to the middle 40s
across much of the NYC metro.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Key Points:
* Dry conditions will prevail Wednesday into Thursday morning,
and then again next weekend with temperatures mainly above
average.
* Showers become likely late Thursday and Thursday night along a
fast moving frontal system.
* Breezy and cooler conditions briefly return Friday.
The modeling has remained relatively consistent over the last few
days with the overall pattern progression into next weekend.
The upper trough that slowly moves overhead on Monday will slide
offshore Tuesday morning. This is in response to a build upper
ridge. The upper low is still expected to get trapped beneath the
ridge over the western Atlantic into Wednesday. This will not
directly impact our weather, but could enhance subsidence with the
ridging aloft later Tuesday and Wednesday. The upper ridging pushes
offshore on Thursday ahead of the next upper level trough, which
likely lifts over the area Thursday night into Friday. The ensemble
means then indicate a mostly zonal flow for next weekend.
Surface high pressure will be in control to begin the period, before
moving offshore on Thursday. The aforementioned upper trough will
send a fast moving frontal system across the area late Thursday
into Thursday night. The latest model consensus indicates most of
the daytime Thursday will be dry with just a chance of showers
late in the afternoon. The cold front sweeps across the area
Thursday night with the likelihood of showers. Low pressure may
develop along the front as it passes to our east and help add
more lift and moisture for the continuation of showers into
early Friday morning. Guidance has come into better agreement
with this scenario, but differ on the intensity of the low. The
progressive pattern would favor the low to quickly push off the
New England coast Friday morning. The NBM probabilities for
greater than an inch of rain in a 12 or 24 hour period Thursday
into Thursday night remain low and under 10 percent, consistent
with the speed of the system. The potential of low pressure on
the front may bring a possibility of some wet snow flakes mixing
in well inland as the system pulls away and draws colder air
southward.
Breezy and cooler conditions are expected on Friday under strong
cold advection and a W-NW flow. Temperatures look to remain in the
mid and upper 40s for highs which are slightly below average for
March 21st. Winds will likely gust 25-35 mph. The pressure gradient
should relax Friday night with high pressure returning for the
remainder of the weekend. Have kept the forecast dry next weekend
with a mainly zonal flow aloft.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
Cold front and wave of low pressure along it draped across the
region advances east through the day.
Generally sub VFR thru this afternoon. Conditions vary across
the region as of 11Z, but generally MVFR or IFR with SHRA. The
steadier rain pushes east into the rest of the morning, and NYC
terminals generally dry out by 18Z, though KISP and KGON likely
keep showers around thru the afternoon or early evening before
tapering. Category improvement will be slow to occur, with a
return to VFR expected for most by the early evening before
skies largely clear out overnight.
Winds have diminished as the frontal wave moved into the area
this morning, and direction will remain variable for several
hours before a NW or NNW flow becomes established into late
morning or early afternoon. Speeds increase as well, toward
15G25 kt by late afternoon. The gusts subside overnight into
Tuesday morning, though speeds linger around 10 kt into the day.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Unscheduled AMD likely to address changes in flight categories
and timing of rain and wind shifts.
LIFR cigs and vsbys possible at times this morning.
Timing of category changes may be off by a couple of hours.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday and Wednesday: VFR.
Thursday: IFR/LIFR cigs possible in the morning mainly E of the
NYC metros. Chance of showers with MVFR cond possible. S winds
10-15 kt with G20-25 kt, winds shifting W during the evening.
Friday: VFR at the NYC terminals and west, MVFR/IFR east with
showers ending late in the day, becoming VFR throughout. NW
wind 15-20 kt with G20-30kt.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds have come down for the time being, but the winds do come
back up some for this afternoon and this evening as a cold
front will push from west to east through the waters today.
Small craft advisories will be in effect for the ocean for a
prolonged period, and for a shorter time for NY Harbor later
today and this evening. The winds will switch to the NNW, with
a NNW flow prevailing later today into tonight, and into
Tuesday. With elevated seas on the ocean small craft seas are
expected to continue through much of the day Tuesday. The winds
will become rather light Tuesday afternoon into Tuesday night as
high pressure settles directly over the waters.
Winds on all waters should remain below SCA levels Wednesday and
through much of Thursday. Initially ocean seas will be around
4 ft, and then ocean seas become slightly more elevated at or
above 5 ft late Wednesday night into Thursday mainly due to
lingering SE swells. The next chance for SCA winds will be
Thursday night behind a cold front passage. There is also
potential for gales on the waters on Friday under a strong NW
flow and cold advection over the warmer waters. Seas will remain
elevated to end the week.
&&
.HYDROLOGY...
Nuisance poor drainage flooding will remain a localized concern
through this morning, especially further east. Otherwise, dry
conditions return through mid week. No additional hydrologic
concerns exist for later in the week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to midnight EDT
tonight for ANZ338.
Small Craft Advisory until 6 PM EDT Tuesday for ANZ350-353-355.
&&
$$
SYNOPSIS...JE/DS
NEAR TERM...JE
SHORT TERM...JE
LONG TERM...DS
AVIATION...DR
MARINE...JE/DS
HYDROLOGY...JE/DS