000
FXUS61 KOKX 101938
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
338 PM EDT Sun Sep 10 2023
.SYNOPSIS...
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A stationary front remains to our north and west through early tonight,
then slowly heads east as a cold front. The front will pass
offshore or dissipate over the area Monday night. Another slow
moving frontal passage occurs during the middle of the week. High
pressure then builds in behind the system.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Widespread rain continues over the eastern third of the area,
with embedded heavy showers/thunderstorms along the leading edge
of the outflow boundary. This activity should be leaving the CWA
shortly. The outflow boundary has moved west to east across the
entire area, originating from the earlier batch of showers and
thunderstorms this morning that moved into our area from the
southwest. Given the widespread showers so far and placement of
the front to our north and west, not expecting anymore
convection firing up during the rest of the afternoon and
evening hours over western locations. However, seeing widely
scattered showers on the regional radar and can not completely
rule this out. Given the nature of this moist airmass (pwats
1.7-1.9 inches), any showers have the ability to produce heavy
rainfall. Isolated flooding can not be completely ruled out, but
confidence in this has decreased.
The CAMs did not perform too well today, but they continue to hint
at showers/thunderstorms moving in from the west during the
overnight period as the stalled front sags southward and a shortwave
moves overhead. Slow moving and training storms could lead to
isolated flooding. See hydrology section below.
Lows will be above normal, in the mid 60s to low 70s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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The stationary front starts to move slowly east as a cold front
early Monday. The shortwave aloft continues to flatten in
response to a digging upper level trough coming down from
central Canada. Another day of showers and thunderstorms is
expected as the front makes its way through the area. The front
eventually passes offshore or dissipates over the area. At the
same time, a weak frontal wave passes to the south. Instability
looks more limited than today. No severe storms are expected at
this time.
Highs will be in the 80s on Monday. Dewpoints remain in the
upper 60s and low 70s.
Brief ridging builds in Monday night and the area should be free
of any showers/thunderstorms by the second half of the night.
Some clearing is also expected, but overall it will likely be a
partly cloudy night. Lows will be a few degrees cooler than
Sunday night.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
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Weak flow across the area on Tue, with h85 winds only around 10kt.
It is likely there will be some residual boundaries across the cwa,
which could trigger a few shwrs in a low instability environment. In
addition to a lack of strong forcing, dry mid lvl air is modeled to
be traversing the area as well. For all of these reasons, only have
slight chances for shwrs on Tue.
The models were in good agreement for a shrtwv passage on Wed, but
the 12Z NAM came in slower and dry for which adds uncertainty. As a
result, limited the NBM pops to 60 percent for Wed. The 12Z GFS and
ECMWF both support the sys moving thru Wed with rain and embedded
tstms.
The airmass dries out significantly on Thu and thru the remainder of
the extended. In the absence of any impacts from Lee, fair wx can be
expected.
The NBM with local adjustments was used for temps thru the period.
Monitor https:/www.weather.gov/okx/tropical or
https:/www.nhc.noaa.gov for the latest NHC forecasts on Hurricane
Lee and others.-- End Changed Discussion --
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
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A stationary front to the NW of the area this afternoon will work
slowly east tonight and approach the area around daybreak Monday.
The front will then dissipate while moving slowly through the area
Monday.
Mainly VFR for the remainder of this afternoon into early this
evening with widely scattered showers and/or thunderstorms. MVFR to
IFR conditions will develop tonight, as early as 00Z at KGON.
There is low confidence on the timing and areal extent of showers
and thunderstorms tonight into Monday. For the time, this is being
addressed with VCSH and PROB30. The most likely time looks to be
after midnight (04Z), then working west to east through the morning
hours. Scattered showers and thunderstorms are also possible Monday
afternoon/early evening.
Winds will generally be light, becoming more E/SE this evening and
then light and variable overnight into Monday. Sea breezes are
possible Monday afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
There is low confidence on timing and areal extent of additional
showers and thunderstorms tonight into Monday.
Timing of MVFR may vary by several hours. Locally IFR possible.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday Afternoon/Night: Mainly VFR with chance of showers and
thunderstorms through evening.
Tuesday: Mainly VFR. Isolated showers possible.
Wednesday: Showers likely with MVFR to IFR possible. Chance of a
thunderstorm.
Thursday and Friday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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With a weak pressure gradient in place, winds and seas will remain
below SCA thresholds through Monday night.
Winds will remain blw sca lvls Tue-Fri. Winds will increase on Sat,
with speeds dependent on the track of Lee. 25kt possible especially
ern waters. Swell from Lee will produce sca seas lvls by Wed, with
seas around 15 ft possible Fri-Sat.
Monitor https:/www.weather.gov/okx/tropical or
https:/www.nhc.noaa.gov for the latest NHC forecasts on Hurricane
Lee and others.-- End Changed Discussion --
&&
.HYDROLOGY...
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Scattered showers and thunderstorms are possible in the
overnight hours. Isolated flooding can not be completely ruled
out, but mainly minor nuisance flooding is expected. Given the
airmass, any shower or thunderstorm has the potential to produce
heavy downpours.
Moderate to locally hvy rain on Wed could lead to some areas of
mainly minor flooding. Otherwise, no hydrologic impacts are expected
in the long term.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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High surf and dangerous rips are possible on the the oceanfront Fri
and Sat.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JMC/JT
NEAR TERM...JT
SHORT TERM...JT
LONG TERM...JMC
AVIATION...DW
MARINE...JMC/JT
HYDROLOGY...JMC/JT
TIDES/COASTAL FLOODING...JMC