000
FXUS61 KOKX 082309
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
709 PM EDT Sun Oct 8 2023
.SYNOPSIS...
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Low pressure deepens and occludes to the north of the area in
eastern Canada and then gradually weakens through the middle of
the week. High pressure across the region Wednesday weakens into
Wednesday night. A warm front slowly approaches from the south
Thursday and Friday. Low pressure impacts the area next weekend.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Latest HRRR and MOS guidance not indicating any chances of
precipitation higher than 10% across the interior this evening,
so lowered probabilities. A few sprinkles are still possible and
replaced the showers with slight chance sprinkles. Also updated
cloud cover this evening with clouds increasing across portions
of southern New Jersey and over the ocean in response to a
surface trough.
Cloud cover is scattered to broken across western and central
portions of the CWA from overspreading cumulus and stratocumulus
enhanced by and along a surface trough that extends down from a
stacked occluded low in Canada to our north. This cloud cover
has helped keep Central Park below 60 today. This is the first
time Central Park has failed to reach 60 degrees since May 4th.
Cloud will persist into the evening, eventually clearing late
overnight as the surface trough clears the area.
Isolated showers are possible over the eastern end of Long
Island and possibly into SE Connecticut as the surface trough
moves east, developing a line of showers along it over the
ocean. The best timing for this is this evening and early
tonight, though chances and confidence in either areas of
isolated showers remains low as model soundings show a layer of
drier air between the surface and 900 to 850mb. Observed
dewpoints have also been running a little drier than forecasted
in some areas.
The pressure gradient will gradually weaken through the evening
and tonight leading to decreasing winds as the low in Canada
retrogrades from Quebec to Ontario and weakens. SW to WSW winds
will continue at 10-15 mph for the first few hours this evening
becoming 5-10 mph overnight.
With winds weakening and cloud cover expecting the mostly clear
late tonight, there remains a few hours before sunrise where
temperatures could further cool. Overnight lows are forecasted
to be in the mid- 40s to low-50s for coastal areas while
interior areas should drop into the low-40s to upper-30s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
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A stacked occluded low to our north with a large trough will
remain influencing our weather Monday and Tuesday. We`ll see dry
conditions for the start of Monday as we sit at the base of the
trough with W/SW flow. Temperatures will once again be below
average with highs maxing out around 60.
As pieces of energy rotate around the base of the trough and
the cut off low with minor warm air advection at 850mb, some
additional cloud cover with possible shower development will
become possible Monday night and into Tuesday. Capped
precipitation at a low- end chance as there is uncertainty in
the development of any showers late Monday night and through the
day Tuesday. Some 12Z CAMs show almost no showers developing
while others show spotty coverage, with the best chances across
E LI and SE CT. Either way, PWATs will likely only top off
around 0.8" based on the 12Z GFS and 12Z NAM. This could hint
that any showers that do develop will not have enough moisture
to cause any significant rainfall, likely remaining only light
in nature.
Otherwise, Tuesday is expected to be closer to average with
highs in the low/mid-60s. Shower chances diminish by Tuesday
night as the piece of energy moves to the northeast.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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An upper level closed low meanders across southeastern Canada
Tuesday night through Wednesday night, while slowly weakening.
The low shifts eastward in response to a longwave trough that
moves onshore of the Pacific northwest during Tuesday and moves
into the western states through Wednesday night. A low closes
off in this western trough and becomes slightly negative
Thursday, and then tracks east into next weekend. The near zonal
flow will keep a developing surface warm front associated with
the western trough and surface low to the south of the region,
and may even become nearly stationary south of the region
Thursday into Friday as the low remains well to the west, and
the southeastern Canada low remains in place. There is also some
uncertainty as to the strength of ridging that amplifies into
the region between the two lows late Thursday into Friday. This
ridge may also keep the front well to the south and slow the
eastward progression of the low. While there are minimaL chances
to slight chances of precipitation with weak warm advection
Thursday and Friday confidence in anything occurring is low as
better forcing remains to the south and moisture is limited.
Better agreement comes with the upper trough/closed low and
surface low impacting the region for next weekend. with the slow
movement of the systems a prolonged period of precipitation is
looking more likely.
Temperatures are expected to be near seasonal normal Tuesday
night through Thursday night, and then likely below normal for
next weekend with limited heating with extensive cloud cover and
precipitation.-- End Changed Discussion --
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
Low pressure over eastern Canada will become nearly stationary
to start the week, gradually weakening with time.
VFR. SCT-BKN040-060 each afternoon/early evening. A brief
isolated shower is possible at KSWF through early this evening,
and at KGON the first half of tonight.
WSW winds 10-15 kt with gusts 20-25 kt will diminish this
evening with sustained speeds falling below 10 kt overnight.
Winds back to the SW on Monday at around 10kt with G17-20kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
End time of gusts this evening may be off by 1-3 hours.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday: Mainly VFR. Low chance of showers at night. SW winds G15-
20kt possible in the afternoon.
Tuesday...Mainly VFR. Low chance of showers in the morning.
Wednesday...VFR.
Thursday and Friday...Mainly VFR with a low chance of showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
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Frequent wind gusts to around 25 kt have ended across the Long
Island Sound and the Long Island bays, along with New York
Harbor, do the SCA has been cancelled.
Ocean seas have been running 1 to 2 feet lower than forecast and
NWPS guidance, and have lowered accordingly mainly across the
western ocean forecast zones. The SCA remains on the ocean
waters into Monday night as winds remain gusty around 25 kt
through this evening, diminishing overnight. Seas will be slowly
subsiding to below 5 ft after late Monday night.
Winds and seas are expected to remain below SCA levels across the
forecast waters Tuesday night through Friday night.-- End Changed Discussion --
&&
.HYDROLOGY...
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No hydrologic impacts expected through Friday.
There is the potential for 1 to 2 inches of rainfall next
weekend.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 2 AM EDT Tuesday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BR/MET
NEAR TERM...BR/MET
SHORT TERM...BR
LONG TERM...MET
AVIATION...DW
MARINE...BR/MET
HYDROLOGY...BR/MET