387
FXUS61 KOKX 011951
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
351 PM EDT Tue Oct 1 2024
.SYNOPSIS...
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High pressure slides northeast of the region tonight as
an area of low pressure passes well to the south. A weak cold front
approaches on Wednesday and dissipates west of the area. High
pressure builds on Thursday and remains in control through
Friday. A weak cold front will pass through the area sometime on
Saturday followed by high pressure to end the weekend. A
stronger cold front looks to move through early next week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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Mid level shortwave shears out into an open wave as it heads through
the area this afternoon. At the surface, high pressure remains
anchored well to the north across eastern Canada while developing
low pressure was located well to the south off North Carolina. That
places the region between systems under a predominately
easterly/northeasterly flow, with shallow moisture trapped under an
inversion.
Dry conditions are expected into the overnight, though an isolated
sprinkle cannot be completely ruled out across the far northwest
zones. Cloud cover today has varied between completely overcast to
the southwest to clear/scattered to the northeast, which is a
function of a layer of dry air aloft, per 12Z KOKX RAOB. Expect this
trend to continue into the overnight, with more clouds to the south
across NYC, Long Island and NJ. This will keep lows tonight a bit
warmer in these areas, in the upper 50s and low 60s. Elsewhere in
CT and the Lower Hudson Valley, with lighter winds and dewpoints in
the 50s, some good radiational cooling may allow minimum
temperatures to approach the dewpoint by early Thursday.-- End Changed Discussion --
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
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High pressure to the northeast sags a bit southward while the low to
our south heads further east. Another weak mid level shortwave
approaches from central PA by Wednesday morning, allowing a weak
cold front to approach from the northwest by afternoon. While the
front looks to stall and/or dissipate to the west, another day of
partly to mostly cloudy skies are in store with no real change in
airmass. Midlevel dry air remains in place and so low confidence in
any shower activity making it far enough east by Wednesday
afternoon. Highs will be similar to Tuesday, seasonable, in the mid
60s to near 70.-- End Changed Discussion --
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
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Surface high pressure will build over the region on Thursday with
heights building aloft from a building ridge. This will lead to
warmer temperatures with highs in the low/mid-70s under mostly sunny
skies.
High pressure at the surface (with a weakening ridge aloft) remains
in control to start the day Friday, but at this point it is exiting
east giving way to a weak trough from the Great Lakes. A surface low
with a cold front is likely to develop just to our north along the
passing trough, but most forcing including positive vorticity
advection associated with the trough will be focused to our north.
Only a few light showers are possible (but unlikely) for northern
interior locations along the weak frontal passage Friday night into
Saturday morning.
Following the weak low and frontal passage, high pressure will
settle in for most of the weekend leading to mostly sunny skies and
continually warmer temperatures on Saturday with highs in the
mid/upper-70s.
Things change late on Sunday. High pressure weakens as an upper-low
and shortwave deepen over the Great Lakes. This low and associated
frontal system approach the area on Sunday and will likely impact us
late Sunday through Tuesday. First, a warm front will move in ahead
of the cold front late Sunday which will increase cloud cover and
moisture. PWATs currently peak around 1.5-1.6" among global guidance
Sunday night. Then the low will move over the area or just north of
us, bringing a cold front Sunday night/Monday morning (timing
subject to change given variance in global guidance). A line of
showers is likely to develop along the cold front given ample
moisture and forcing.
Following the frontal passage, things get a little tricky in the
Monday-Tuesday timeframe. Guidance varies on what happens with the
low when it passes us. Some guidance, such as the 12Z GFS deepen the
low over over area on Monday then linger it just off the New England
coast through Tuesday. Should this solution come to pass showers
could persist into Tuesday along with reinforced northerly flow and
lower heights aloft leading to temperatures becoming cooler than
currently forecast. However, other guidance, such as the 12Z ECMWF,
keep the low on an eastward trajectory followed by high pressure,
leading to a sunnier and drier Tuesday.
Regardless of which solution comes to pass, two things are likely.
Showers along a frontal passage followed by cooler air under
northerly flow. Highs on Monday are forecast in the low to upper-60s
followed by the mid/low-60s on Tuesday with overnight lows in the
mid-40s to mid-50s.-- End Changed Discussion --
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
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High pressure remains anchored along the New England coast through
Wednesday morning, while weak low pressure tracks east off the
Mid Atlantic coast. A dissipating cold front approaches from the
west late Wednesday.
Any MVFR this afternoon will be brief, otherwise VFR. Cigs then
lower to MVFR again from east to west late this evening and
overnight. Brief IFR possible outside of the NYC terminals. VFR
returns mid to late morning Wednesday.
Winds remain generally easterly through much of the TAF period
near 5-10 kts. A few gusts of 15-20 kt are possible this
afternoon, mainly along the coast.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
MVFR overnight may be more occasional or even brief versus
prevailing.
OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
Wednesday Afternoon through Friday: Mainly VFR.
Saturday: Mainly VFR. A slight chance of showers with MVFR possible.
Sunday: 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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Ocean seas continue to hover around 5ft this afternoon, with wind
gusts around 25 kts. As the surface low to the south continues
to slowly head east, expect the elevated seas to continue for
the first half of Wednesday. Thus, the SCA has been extended
through 18Z Wednesday, with winds around 20kts but seas around 5
ft continuing.
Sub SCA conditions are likely on all waters through the weekend.
There is potential for 25+ knot gusts and 5+ ft seas with a cold
frontal passage early next week.-- End Changed Discussion --
&&
.HYDROLOGY...
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No significant hydrologic issues are expected through the middle of
next week.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
Astronomical tides will be increasing with the approach of a new
moon Wednesday afternoon. This combined with a persistent easterly
wind may push levels right up to minor flooding benchmarks for the
Wednesday morning high tide cycle. A statement may eventually be
needed to address this for the south shore back bays of Nassau and
Queens.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 3 PM EDT Wednesday for ANZ350-353-
355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DBR/BR
NEAR TERM...DBR
SHORT TERM...DBR
LONG TERM...BR
AVIATION...BC/DW
MARINE...DBR/BR
HYDROLOGY...DBR/BR
TIDES/COASTAL FLOODING...