000
FXUS61 KOKX 071948
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
348 PM EDT Sun May 7 2023
.SYNOPSIS...
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A frontal wave passes across the area tonight. Another frontal
wave passes across the Middle Atlantic Monday night into
Tuesday. High pressure will build from the Great Lakes Tuesday
night into Wednesday, then set up off the Southeast coast from
Thursday through the weekend. A back door cold front will approach
from the north and may enter the area late Friday night into
Saturday, then lift back to the north later this coming weekend. A
frontal system will then begin to approach from the southwest on
Sunday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Surface ridge axis will continue moving offshore into the evening.
A wave of low pressure currently near the Eastern Great Lakes
will track towards to region tonight. Clouds will increase and
thicken this evening ahead of the system. There may some light
warm advection showers middle to late evening, but more
widespread showers should move across towards midnight into the
early Monday morning hours.
There is still some concern that the precip shield will split
with two areas, one passing well south across the Middle
Atlantic and one impacting portions of our area and New England.
The 12z CAMs are still not in ideal agreement for the inclusion
of categorical PoPs tonight. It appears that as the wave of low
pressure moves in towards midnight that there should be enough
coverage of showers to support likely PoPs. Current trends favor
potential of amounts reaching close to a quarter of inch across
southern CT and eastern Long Island. This rainfall should end
up along and just north of the center of the weak low pressure.
If the low ends up a bit further south, then some of these
slightly higher totals could move over the SW part of the area.
There is some limited elevated CAPE, but have left out mention
of thunder. Think this weak instability is enough to develop
some convective elements, but not enough for lightning
production.
A few showers could linger near the coast towards day break, but
should end quickly as the low pressure moves away from the region.
Lows will be several degrees above normal in the 50s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
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High pressure briefly returns on Monday. The region will lie on
the SW side of a larger upper trough over southeastern Canada
and the outer periphery of some ridging across the midwest.
Heights look to rise a bit Monday. Despite the passage of the
low pressure and associated front early Monday, the air mass
does not cool. NW flow should dominate through the day, holding
back sea breeze development. Any lingering clouds to start the
day quickly diminish with just some high clouds possible in the
afternoon. Highs will be in the lower 70s for most locations
except the NYC metro where readings in the middle to upper 70s
are forecast.
Another shortwave/vort max tracks across the Great Lakes Monday
night and then around the periphery of the aforementioned
troughing to our northeast on Tuesday. Another wave of low
pressure develops with this energy, but the most likely scenario
is for the track to be across the Middle Atlantic. This would
hold any showers with the low to our south and west. Much of the
12z model suite keeps the area dry late Monday night into
Tuesday. However, the GFS and several of its ensemble members
have some measurable precip nearing the southwestern portion of
the CWA. Will continue to indicate minimal PoPs for now, but
favor a scenario where the precip misses the areas to the south.
Lows will be close to normal Monday night in the middle 40s inland
to the upper 40s to low 50s near the coast. Highs on Tuesday are
forecast close to normal in the middle to upper 60s, largely due to
middle and high level clouds from the low passing to the south. A
light easterly flow also develops in the afternoon, which should
hold temperatures down closer to the coast.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
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NWP guidance has trended fast with the last embedded shortwave in a
departing upper trough going into mid week, meaning that high
pressure will build in earlier, and with milder temperatures than
previously forecast and close to normal on Wednesday. Above normal
temps then expected for at least Thu-Fri as the high parks off the
SE coast, with the combo of NW flow aloft and a nearby thermal
trough providing more of a downslope W rather than SW flow. Temps on
Fri likely to reach the lower 80s from NYC west and south, and ruse
well into the 70s elsewhere away from immediate south shore areas of
Long Island and SE CT.
An upper trough (or a closed low per stronger GFS) diving SE across
New England Fri night should take a back door cold front into or
through the area late Fri night into Sat morning, but with heights
aloft rising quickly in the wake of the trough passage daytime Sat,
the front appears more likely than not to wash out or lift back to
the north by Sat afternoon, so until a clearer trend becomes
established among the guidance have sided with temps remaining above
normal for Sat. Increasing clouds and shower chances with a frontal
system off to the SW should lead to increasing shower chances and
somewhat lower but still above normal temps for Sunday, with highs
mostly in the 70s.-- End Changed Discussion --
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
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Weak high pressure pushes offshore through this evening. A wave of
low pressure passes nearby tonight and moves away early on Monday.
VFR conditions prevail through 03z, and are likely to prevail until
5-6z for some terminals. Showers chances also increase towards 0z.
Chances for MVFR conditions increase after 03z. Some guidance is
suggestive of a period IFR after 04-05z as rain showers move in from
the west but have not included in TAFs at this time. MVFR conditions
should prevail at most terminals from 04-08z, with improvement
beginning first for N and NW terminals, with city and southern
coastal terminals to follow towards the AM push. VFR conditions
prevail throughout Monday.
Through early this evening the winds will be S-SW near 10-12 kt with
a few non-prevailing gusts up to 20 kt at southern coastal
terminals. Wind speeds fall below 10 kt again tonight, and gradually
shift towards the N and NW approaching the Mon AM push. On Monday
NNW winds become more pure NW towards 300-320 towards the early
afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Some uncertainty with how low cigs get towards and just after 04-05z
timeframe. Therefore confidence remains low for IFR conditions
overnight. Also, improvement to IFR early Mon morning may be off by
1-2 hours.
...OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday afternoon: VFR, with NW winds.
Monday night: Mainly VFR, with a slight chance of showers and MVFR
towards early Tue AM.
Tuesday: Mainly VFR, with a slight chance of showers for mainly
southern terminals.
Wednesday: Mainly VFR.
Thursday: VFR.
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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A few gusts up to 20 kt are possible in the ocean waters west of
Fire Island Inlet late this afternoon/early this evening. Otherwise,
a weak pressure gradient will keep winds and seas below SCA through
the end of the week.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic concerns exist through next week.
&&
.TIDES/COASTAL FLOODING...
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Water levels may approach minor coastal flood benchmarks for
tonight`s high tide cycle across western LI Sound and the south
shore back bays of Nassau. This may also occur for the next few
nights as well. This is due in combination to a recent full moon
and 1-2 ft easterly swell. However, based on latest trends no
statements are needed at this time.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BG/DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...BG
AVIATION...JE
MARINE...BG/DS
HYDROLOGY...BG/DS
TIDES/COASTAL FLOODING...