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000
FXUS61 KOKX 230040
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
840 PM EDT Mon Apr 22 2024

.SYNOPSIS...
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Weak high pressure builds across the area overnight and then
offshore on Tuesday as a frontal system approaches from the
Great Lakes. A surface trough followed by a cold front moves
through Wednesday. Behind the frontal passage, high pressure
builds into the region Wednesday night and Thursday, shifting
offshore on Friday. A warm front may lift through the area this
weekend and the associated frontal system may linger nearby into
early next week.
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&&

.NEAR TERM /THROUGH TUESDAY/...
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Another relatively quiet, but cool night is in store with
lightening flow as high pressure settles into the region.
Forecast remains on track and previous discussion follows.

For tonight look again for clear skies and light winds. Dew point
readings will likely be a shade higher with a little air mass
modification in all likelihood. With light to eventually calm winds
more of a certainty for the duration of the night and the lack of
any cloud cover the chances for more coverage in terms of frost, and
perhaps minor agriculture impacts does increase some. Thus,
continuing current Frost advisories for late tonight. There is
uncertainty around frost formation but with temperatures down into
the 30s across much of the northern zones and SE rural Suffolk on LI
agricultural interests will have to take note. Also Orange County,
or at least the western half to 2/3rds of the county should get to
or just below freezing. Thus continuing the Freeze Warning for
Orange County. Lows will be primarily in the lower and middle 30s
once again further away from urban locales, otherwise mainly upper
30s closer to most of the coast, with 40s in the more urban
locations. Went with MAV guidance for min temp and dew points as it
is the coldest of the guidance and wasn`t as cold as the previous
night which makes sense with slightly higher dew points and not
quite as dry at the bottom of the column.

During Tuesday high pressure begins to get further east and should
be primarily offshore later in the day. A return flow gets
established quickly during the early portions of the afternoon with
the winds primarily off the colder ocean and out of the S and SSE.
This wind direction should result in a fairly wide temperatures
spread across the region for the afternoon as areas further west and
inland won`t get the entrainment of the wind off the colder ocean
compared to places further east and closer to the coast. Look for a
fair amount of sunshine across the region, with perhaps a few mid
level clouds encroaching into western sections later in the day.
Went a few degrees warmer than NBM for temps across western third of
the area and into far northern CT zones, with some manual
adjustments based on climo for this time of year further east.
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&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
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For Tuesday night with the high getting further east and the
approach of the next system from the west look for the winds to veer
more to the S and perhaps the SSW towards Wed AM. The column will
undergo more of a deep layered SW flow. Thus, clouds will increase,
especially above 5 kft or thereabouts. A lot will depend on the
speed and the timing of the approach of the frontal boundary, but
the column may moisten enough that some light showers or sprinkles
could very well break out before daybreak Wed, especially across
western most locations. Went slight chance to chance PoPs during the
pre-dawn hours towards sunrise.

For Wednesday the pre-frontal trough pushes through resulting in
widespread shower activity, with the higher PoPs across mainly
northern sections for the morning and for the early portion of the
afternoon. The winds will become more SW for the first half of the
day, then become due W and eventually NW during the afternoon as
drier air wraps in quickly, especially at the lower levels. The
NAM3km indicates some CAPE in the 5 to 15-20 kft level, but this may
be overdone as the HRWFV3 has virtually no CAPE. For now kept out
any chance of thunder with chances appearing too low as the column
will likely be dry enough to preclude any meaningful convection. The
sun should start to break through with a strato-cumulus deck
for the later in the afternoon as a W to NW breeze develops.
Only looking for up to a tenth of an inch or so of rain with
PWATs not even getting to an inch on most guidance. Temperatures
will get into the 60s with good mixing later in the afternoon
and likely some breaks of sun. A few spots inland could get into
the lower 70s if the system moves to the east faster than
progged which would result in a longer period of at least
partial sunshine in the afternoon.
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&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
The region dries out Wednesday night behind the fropa as the trough
axis shifts east and surface high pressure builds in from the Great
Lakes. The high remains over the region Thursday, before slipping
offshore Friday and setting up southerly flow. Meanwhile, ridging
gradually amplifies and builds over the East Coast through the
remainder of the week. Into the weekend, a shortwave over the
Central US will attempt to ride up and over the amplified ridge and
may send an associated warm front through Sat night or Sunday, but
precipitation appears limited as the surface low passes well to the
north and west. Forecast confidence lowers after this point with
diverging solutions, but lots of time to fine tune.

Temperatures average near, to just below, normal for late April. The
coolest day looks to be Thursday, with northerly flow helping to
lower H85 temps to as low as -3C. This should translate to afternoon
highs in the 50s across the region, or about 10 degrees below
normal. In addition, frost/freeze headlines will likely be needed
Wed and Thu night, at least for portions of the local area as
temperatures outside the urban metro fall into the 30s. Only slight
moderation Fri/Sat, before the warm front attempts to lift through,
and the resultant SW flow should warm the air mass into the 70s,
particularly west of the Hudson and away from maritime influence.
With only subtle adjustments, stayed closed to national blended
guidance for this update.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
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Weak high pressure builds across the area overnight and then
offshore on Tuesday as a frontal system approaches from the
Great Lakes.

VFR. Southerly flow weakens this evening and in some cases
becomes light and variable. Winds then increase on Tuesday to
10-15kt with a chance of afternoon gusts 15-20kt. Gusts may be
more occasional. Southerly flow gradually weakens at night.

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

Gusts on Tuesday may be more occasional and late in the
afternoon.

OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...

Tuesday night: VFR. A chance of showers late, mainly at the NYC
metro terminals, and northwest.

Wednesday: Chance of MVFR in showers, mainly in the morning. An
isolated thunderstorm is possible in the afternoon. SW winds
10-15G15-20kt, becoming W-NW in the afternoon, then northerly at
night.

Thursday-Friday: VFR.

Saturday: Mainly VFR. Chance of showers. S winds G15-20kt.

Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
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&&

.MARINE...
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Primarily 2 ft ocean seas prevail through tonight with high pressure
in control and a relatively weak pressure gradient overall. Sub
small craft conditions will prevail across the coastal waters
through at least the first half of Tuesday, followed by small
craft conditions becoming more likely later in the afternoon and
evening for the Harbor and the western half of the ocean as a
hybrid Ambrose jet induced wind attempts to develop. The
prevailing southerly flow should result in small craft
conditions developing further east on the ocean later Tuesday
night and into Wednesday as ocean seas increase primarily to 5
to 6 ft. Ocean seas gradually subside late Wednesday night with
weakening NW flow, falling below advisory levels by Thursday
morning. Winds and seas then remain below advisory levels on all
forecast waters into the start of the weekend.
-- End Changed Discussion --

&&

.HYDROLOGY...
No hydrologic concerns attm.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Frost Advisory from midnight tonight to 8 AM EDT Tuesday for
     CTZ005>008-011-012.
NY...Frost Advisory from midnight tonight to 8 AM EDT Tuesday for
     NYZ068>070-079-081.
     Freeze Warning from midnight tonight to 8 AM EDT Tuesday for
     NYZ067.
NJ...Frost Advisory from midnight tonight to 8 AM EDT Tuesday for
     NJZ002.
MARINE...Small Craft Advisory from 4 PM Tuesday to midnight EDT Tuesday
     night for ANZ338.
     Small Craft Advisory from 5 AM to 6 PM EDT Wednesday for
     ANZ350.
     Small Craft Advisory from midnight Tuesday night to 6 PM EDT
     Wednesday for ANZ353.
     Small Craft Advisory from 6 PM Tuesday to 6 PM EDT Wednesday
     for ANZ355.

&&

$$

SYNOPSIS...JE/DR
NEAR TERM...JE/DR
SHORT TERM...JE
LONG TERM...DR
AVIATION...DW
MARINE...JE/DR
HYDROLOGY...JE/DR