000
FXUS61 KOKX 112042
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
442 PM EDT Thu Apr 11 2024

.SYNOPSIS...
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A cold front approaches tonight and moves through Friday as its
associated low pressure over southeastern Canada lifts north. A
series of surface trough moves through Friday night into
Saturday. A weak low moves through on Sunday. High pressure
takes over Monday, potentially followed by a warm front front
moving in late Tuesday into Wednesday.
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&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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The near term starts off with the area warm sectored and thus
only scattered showers expected for the first few hours.
Additionally, a dry slot moving through will help to limit the
rain and the potential for flooding. WPC has lowered their
excessive rainfall category of slight for western Orange county
to marginal. Thus, the main threat for flooding should be
limited to minor nuisance and poor drainage flooding tonight
into Friday. The chance for showers is then expected to
increase from southwest to northeast this evening into tonight
as a cold front approaches from the west. There are some signs
that a convective line forms just ahead of the cold front late
tonight around the same time as the low level jet increases (see
below) in the CAMs and forecast soundings do show some elevated
instability as dew points rise into the low to mid 50s range.
Will continue to mention an isolated thunderstorm from around 2
am to 8 am Friday. It is this line that will be associated with
some moderate to briefly heavy rainfall for western areas of the
forecast area late tonight.

A low level jet will increase tonight to 70 to 80 kt at around 925
hPa. This would normally bring some higher winds to the surface
but it is coupled with a low level inversion which will limit
some of this wind from mixing down to the surface. However, the
NBM is showing an 80% chance or higher for wind gusts of 46 mph
or higher from around midnight through 6 am Friday.
Additionally, the HRRR has been showing 10 m gust potential of
50 to 60 mph. Don`t think gusts will be that high, and this may
only be for an hour or two based on the HRRR, but it would be
enough to issue a Wind Advisory for Long Island (including
Queens and Brooklyn) and coastal Connecticut for gusts of 45 to
50 mph and an isolated gust of 50 to 55 mph is possible from
midnight tonight through 6 am Friday.

With area warm sectored and thus southerly flow established across
the area, coupled with clouds, temperatures will not drop much. In
fact, in some areas, they may rise slightly overnight. Lows are
expected to be in the 50s for much of the region.
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&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
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The moderate to locally heavier rain should push east of the
forecast area by mid morning Friday, but another round of light
showers and possibly a thunderstorm will move through western
areas at the same time in association with a surface trough.
Chances for precipitation should lower during Friday afternoon
(though it will not be completely dry) as the main forcing for
the surface trough lifts north along with the low pressure. Any
shower or thunderstorm may be associated with gusty winds.

Speaking of this low pressure which is associated with the cold
front in southern Canada, it will strengthen slightly Friday
morning as it heads into southern Canada. So, although not as
windy as Thursday night, it will be a breezy day. Gusts up to 35
mph are expected as heights lower and more ideal mixing takes
place as lower heights build across the area with steeper lapse
rates and a trough swings through. A strong SW flow will then
become more westerly Friday night and into Saturday.

Another surface trough, along with the upper level low, which
transitions into an upper level shortwave, will move approach
and move through portions of the forecast area Friday night,
bringing another round of showers, mainly for areas north and
west of New York City.
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&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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Light, isolated showers (mainly for northern zones) may still linger
in the vicinity Saturday morning as an impactful low pressure system
exits into Canada, clearing by Saturday afternoon with a cold front.
There will still be a bit of a pressure gradient around on Saturday
keeping things breezy until Saturday night when winds finally
diminish.

A second cold front on Saturday will aid in clearing clouds and any
lingering precip, as well as usher in cooler air with highs on
Saturday in the mid/low-50s. This will be supported by a strong
trough centering itself over the region.

A trough over the region exits to the east Saturday night into
Sunday morning with the upper-level pattern becoming zonal on Sunday
as surface high pressure noses in from the south. The zonal west to
east flow helps advect in higher moisture and mid-level energy,
leftovers from a weak low that moved into the Great Lakes. Unlike
yesterday, all models have now come into agreement on this solution.
We should see some scattered showers as this moves through on
Sunday. Isolated thunderstorms are also possible as there could be
some elevated instability, weak as it may be. A due north cold front
will clear clouds and precip Monday morning.

The upper-level pattern remains zonal through Monday before a strong
ridge builds Tuesday into Wednesday. This will lead to sunnier
weather and temperatures warming into the mid-70s to upper-60s,
supported by warm air advection aloft.

The ridge remains in place on Tuesday, though a strong upper-level
jet develops aloft with a warm front placing itself over the area
from a low in the northern Great Plains/Western Great Lakes. These
will act together to increase cloud cover through the day on
Tuesday, but expected warmer temperatures to remain due to warm air
advection aloft. This warm front which eventually becomes a stalled
boundary will lead to rain chances Tuesday night into Wednesday.
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&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
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A cold front passes through the area Friday.

IFR to LIFR returns tonight. Showers becoming more likely this
evening through early Friday morning. There is a period where
thunder is possible late tonight into early Friday morning, but
confidence is too low in coverage and occurrence to add to the TAF.
Marginal improvement Friday with VFR likely returning in the
afternoon but ceiling improvements expected to be slow occurring.

SE-S winds increase this evening with gusts 25-30kt later this
evening with gusts up to 40kt possible overnight. LLWS begins
tonight and peaks overnight and Friday morning. Winds slowly
diminishing as the day progresses on Friday.

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

Amendments likely, especially tonight, for ceilings and visibilities.
Low confidence in any thunder, will likely be isolated across the
area.


OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...

18z Friday: MVFR with chance of showers and SW winds G30-35kt.

Saturday: Chance of showers mainly NW of the NYC metros, mainly VFR.
W-NW winds G25-30kt.

Sunday: Mainly VFR. Chance of MVFR and showers in the afternoon.
SW-W winds G20-25kt.

Mon and Tue: Mainly VFR.

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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SSE gales are expected to develop during this evening and
spread NE across the waters late in the night, with gusts up to
45 kt. An isolated gust to 50 kt is possible. Gale conditions
should give way to small craft conditions from west to east late
Friday morning into Friday afternoon on a SW wind. Small craft
conditions will linger through Friday night with a WSW wind
gusting mainly 25 to 30 kt.

Seas will build quickly tonight with 10 to 15 ft ocean seas by
late tonight into Friday morning. Waves over the sound will
rise to 3 to 5 ft, with up to 9 ft possible for the extreme
eastern sound. Waves diminish Friday afternoon, but remain above
5 ft for the ocean waters and the eastern sound and even into
the entrance of the harbor through Friday night.
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&&

.HYDROLOGY...
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A period of moderate to briefly heavy rain is expected tonight
and into early Friday morning for eastern sections. At this
time the flooding risk from rainfall is limited despite the fact
that antecedent conditions/soil moisture remains rather high.
Due to the progressive nature of the system it is likely that
any flooding would be more of the minor, nuisance and urban-poor
drainage variety. WPC maintains a marginal risk of excessive
rainfall across the entire forecast area. Between 3/4 and 1 1/2
inches of rain is forecast, with the highest across inland
southern Connecticut.
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&&

.TIDES/COASTAL FLOODING...
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There has not been a significant change to the forecast thinking
this afternoon. Strengthening SE-S flow with a storm system tonight
into Friday morning will likely force widespread minor to locally
moderate coastal flooding. With increasing SE gusty flow, waves will
increase in height, setting up a widespread minor coastal flood
event for the forecast all area shorelines. Some localized moderate
coastal flooding is forecast, especially for some of the South Shore
Bays with tonight`s high tide cycle. Advisories are now in effect
everywhere this evening into early Friday morning`s high tide cycle.

One fly in the ointment with this forecast is the delay in the peak
surge timing relative to high tide, especially across the eastern LI
Sound and Atlantic facing south shore locations. Should peak surge
values come in a bit later, toward 06-09Z, as per the newer 12Z
guidance, some locations will not reach forecasted levels.

Winds will remain southerly through the event, becoming more
southwest toward daybreak Friday, as the surge begins to wane.
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&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Coastal Flood Advisory from midnight tonight to 5 AM EDT
     Friday for CTZ009-010.
     Wind Advisory from 2 AM to 8 AM EDT Friday for CTZ009>012.
     Coastal Flood Advisory from 11 PM this evening to 4 AM EDT
     Friday for CTZ011-012.
NY...Coastal Flood Advisory from midnight tonight to 5 AM EDT
     Friday for NYZ071-073-078-176-177.
     Wind Advisory from 2 AM to 8 AM EDT Friday for NYZ075-078>081-
     176>179.
     Coastal Flood Advisory from 9 PM this evening to 2 AM EDT
     Friday for NYZ072-074-075.
     Coastal Flood Advisory from 11 PM this evening to 6 AM EDT
     Friday for NYZ079.
     Coastal Flood Advisory from 11 PM this evening to 5 AM EDT
     Friday for NYZ080-081.
     Coastal Flood Advisory from 9 PM this evening to 3 AM EDT
     Friday for NYZ178-179.
NJ...Coastal Flood Advisory from 9 PM this evening to 2 AM EDT
     Friday for NJZ006-104-106-108.
MARINE...Gale Warning from 8 PM this evening to 4 PM EDT Friday for
     ANZ331-332-340-345.
     Gale Warning until noon EDT Friday for ANZ335-338.
     Gale Warning until 6 PM EDT Friday for ANZ350-353-355.
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&&

$$

SYNOPSIS...JP/BR
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...BR
AVIATION...IRD
MARINE...JP/BR
HYDROLOGY...JP/BR
TIDES/COASTAL FLOODING...