800
FXUS61 KOKX 211128
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
728 AM EDT Mon Apr 21 2025
.SYNOPSIS...
High pressure anchored north of the area this morning slides east
and offshore today. A warm front approaches the area this
evening followed by a cold front on Tuesday into Tuesday night.
High pressure then builds back in for Wednesday. High pressure
remains over the region through Thursday night, followed by a
frontal system Friday into Saturday. High pressure returns for
the second half of the weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
Quick update to adjust temperatures across the area as forecast
was running too cool. This is especially true across eastern
Long Island and SE CT where winds have stayed up, limiting
radiational cooling. Previous discussion follows.
Good model agreement on mid and upper ridging located over much of
the northeast shifting east, and flattening as an upper low
dives out of the Northern Plains and heads over the Great Lakes.
The ridging aloft allows surface high pressure to move over the
area then offshore this afternoon. Mainly dry conditions
expected under the subsidence aloft, with surface winds becoming
easterly, then southeasterly by this afternoon as the sfc high
works east. Clouds will be on the increase during the afternoon
as low and mid level moisture increases and a warm front
approaches from the southwest. A few of the CAMs (eg, 00Z HRRR)
are depicting some shower activity across eastern LI, and
interior CT Monday afternoon in advance of the warm front, but a
dry subcloud layer should limit any shower activity.
Under the easterly flow, highs at the coast should be in the mid and
upper 50s, with perhaps a few degrees higher for NYC and points
across the interior.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Winds become southerly then southwesterly overnight Monday into
early Tuesday as moisture advection commences and the warm front
shifts through, then north, of the area. Aloft, the flow becomes
more zonal in nature, as the upper low heads toward Quebec. Guidance
has been fairly consistent showing the core of light precipitation
with this system associated with a pre-frontal trough, which looks
to work through late Monday into early Tuesday morning, clearing the
coast by mid to late morning. Given that the best forcing is
north of the region and PWATS are generally less than 1",
precipitation amounts look light (around 0.1-0.25"), with
highest amounts over CT and the Lower Hudson Valley. Highs on
Tuesday will be in the 70s, to near 80 across the urban NYC
corridor. The cold front then passes through the area by Tuesday
afternoon, and winds become westerly by Tuesday night. Adjusted
the NBM temperatures up toward the 75th percentile, in line
with the previous forecast, given that much of the day Tuesday
the cold front slowly works east.
High pressure then builds over the northeast on Wednesday,
resulting in another dry day locally, with highs in the lower
70s under weak northerly flow.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
No significant changes in the long term and stuck fairly close to
the previous forecast/NBM.
The long term period starts off with high pressure over the region
with dry conditions and mostly clear skies for Wednesday night and
Thursday. The high starts to slide east Thursday night and Friday,
with another shortwave/low pressure system approaching for Friday
into Saturday. The surface low is expected to pass north of the
region with its associated cold front moving across the area during
the day Saturday. 00z ECMWF is slightly faster than the 00z GFS
timing of the front for Saturday afternoon, but only by a difference
of a few hours.
Overall, expected clouds to gradually increase Thursday night and
early Friday, with POPs gradually increasing Friday afternoon. For
now, looking at just some chance POPs Friday afternoon and into the
first part of Friday night. POPs increase further after midnight
Friday night into Saturday as a cold front approaches and moves
across the region. POPs gradually taper off Saturday night with
drier conditions expected for Sunday.
Temperatures remain at or above normal for this time of year.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
High pressure over the terminals will push east today. A warm front
approaches tonight and lifts north of the terminals Tuesday
morning.
VFR today. MVFR/IFR conditions tonight, along with some showers.
Light and variable winds this morning become SE after 13z and
increase through the day. Wind speeds around 10-13 kt expected
in the afternoon. Gusts up to 20 kt are possible, mainly at NYC
and coastal terminals. Tonight, winds diminish, falling below
10kt. Wind become more southerly tonight, then SW to W with the
passage of a warm front early Tuesday morning.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts this afternoon/evening may be occasional.
Timing of potential showers and MVFR this evening/overnight may be
off by 1-2 hours.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday: Lingering shower possible early, mainly east of NYC
terminals. Becoming VFR in the morning. SW-W wind gusts 15-20
kt possible.
Wednesday and Thursday: VFR.
Friday: Chance of MVFR and showers, mainly in the late afternoon
into the night.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-SCA conditions are expected on all waters through Wednesday.
Occasional gusts to 25kts are possible for a short period on the
ocean waters in advance of a frontal system on Tuesday.
Conditions are expected to remain below SCA levels Wednesday night
through Friday. SCA conditions will then be possible Friday night
into Saturday with a frontal system moving across the area
waters.
&&
.HYDROLOGY...
There are no hydrologic issues through next weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BC/DBR
NEAR TERM...DBR
SHORT TERM...DBR
LONG TERM...BC
AVIATION...BC
MARINE...BC/DBR
HYDROLOGY...BC/DBR