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523
FXUS61 KOKX 061908
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
308 PM EDT Thu Jun 6 2024

.SYNOPSIS...
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A cold frontal passage will occur tonight. A broad area of low
pressure meanders nearby over southeast Canada Friday and into early
next week. High pressure follow for the middle of next week. A
broad area of low pressure meanders nearby over southeast Canada
Friday and into early next week. High pressure should follow
for the middle of next week.
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&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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A warm front over the area will continue to advance north through
this evening before a cold front passes tonight. At the same, a
strong mid/upper-level low moves into the northern Great Lakes this
evening into tonight.

Convection has already been initiated for western portions of the
area and coverage of showers and thunderstorms is expected to
increase over the next few hours and last until 8-9 pm as they push
eastward. Based on the latest CAMs and SPC`s mesoanalysis,
thunderstorms will likely stay sub-severe, but there is some severe
potential for stronger wind gusts in areas of the Lower Hudson
Valley and perhaps parts of SW CT and NE NJ. 0-6km bulk shear
appears sufficient for for some areas west of NYC and particularly
areas north of NYC with 30-40 kts. SBCAPE also appears more than
enough with 12Z CAMs and later providing values between 2000-3000
J/kg. Effective SRH also appears to reach around 100 m2/s2 in the
Lower Hudson Valley. Hodographs look much better north of our CWA as
do other parameters for rotating storms. Should we see severe
weather, it will likely remain isolated with the best chances for
seeing such in the Lower Hudson Valley, Passaic Co, and Fairfield
Co. General thunderstorms, however, appear likely for areas north
and west of the city with other areas having a chance for
thunderstorms. Rainfall today has the potential to be efficient
with PWATs topping around 2 inches with warm temperatures up
the column. Some of the showers and thunderstorms today have the
chance for bringing moments of moderate to heavy rainfall, but
overall, total rainfall amounts should stay under an inch. Most
will see rainfall of 0.25 to 0.5". The flooding potential will
be limited due to the expected speed of the showers and
thunderstorms. With a high freezing level, hail growth potential
will be low.

After the storms clear tonight, cloud cover will gradually begin to
clear, west to east as winds shift from southerly to westerly and
northwesterly as the cold front passes. This will also lead to
lowering dewpoints at the surface, but overall, weak winds are
expected.
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&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
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The upper low moves into the eastern Great Lakes and into Upstate
New York Friday. Scattered showers are possible Friday afternoon
under west/northwest flow, but primarily for northern interior
locations closer to the periphery of the flow of the upper-low. The
latest CAMs and HREF agree with this outcome. Thunderstorms look
unlikely due to a more stable airmass. Did not include thunder
chances in the forecast, but an isolated rumble could still be
possible.

Westerly flow should keep temperatures in the 80s for most, but with
dewpoints in the mid and upper 50s, it will feel less humid than
Thursday. A well-mixed boundary layer may also allow for some
westerly wind gusts near 20mph.
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&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
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There are no significant changes to the forecast thinking this
weekend through much of next week.

*Key Points*

*Broad low pressure will meander over Northern New England and
southeast Canada this weekend through early next week.

*Dry conditions on Saturday will be followed by a chance of showers
late Saturday night into Sunday with a cold front passage.

*A few weak fronts or surface troughs may pass early next week, but
conditions should remain mainly dry.

*Temperatures likely end up a few degrees above normal this weekend,
trend near normal early next week, then edge above normal middle of
the week.

Anomalous upper low will slowly move across Northern New England
Saturday and then meander over southeast Canada Sunday. The upper
low should shift towards the Maritimes early next week.
The flow aloft over the region will be nearly zonal on Saturday and
this will prevent any development of afternoon/evening showers. A
stronger vortmax will swing around the upper low towards the area
Saturday night into early Sunday. This will help send a cold front
across the region and bring a chance for showers. Instability looks
limited given the timing and have left mention of thunder out of the
forecast for now. The upper trough axis associated with the upper
low then lingers over the region Monday. The guidance indicates the
trough axis could shift offshore Tuesday, but it may also remain
nearby. While moisture and lift are limited, an isolated shower is
possible Monday afternoon and evening and then again on Tuesday.

The trough should be replaced with a middle level ridge Wednesday,
but the modeling does not agree on if it will remain overhead or
push offshore quickly with the approach of the next shortwave. Have
followed the NBM which yields a slight chance PoP Wednesday and
Thursday given the uncertainty. A faster shortwave could introduce a
higher chance for shower Wednesday. A slower trough would lead to
dry conditions for the mid week period.
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&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
A cold front through upstate New York into central Pennsylvania
moves east and passes through the terminals around 00Z west and
toward Friday morning east. Otherwise, the associated low
remains to the north through Friday afternoon.

Scattered showers and thunderstorms will precede the frontal
passage with the best chance of thunderstorms from the NYC
terminals and west and north, while to the east mainly showers
are expected. Some of the thunderstorms, mainly across the lower
Hudson Valley and into northeastern New Jersey may produce wind
gusts 30-35kt.

Conditions vary from mainly VFR at the NYC terminals and west,
to MVFR to the east, with KGON at LIFR. Improvement to VFR east
is expected late afternoon, with timing uncertain, as some
clearing was already occurring. VFR is expected with the
frontal passage.

Winds are mainly light, less then 10kt, and from the SW,
although a few locations are variable. A general SW flow is
likely ahead of the front, with a few gusts up to 20kt, and
then winds shift to W/NW behind the cold front.


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

Amendments possible this afternoon for timing of thunderstorms
and MVFR conditions.


OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...

Friday afternoon: VFR.

Saturday-Sunday. VFR, MVFR possible with a chance of showers
late Saturday night through Sunday.

Monday-Tuesday: VFR. A slight chance of showers Tuesday.

Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
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SCA continues for the ocean waters through tonight. Marginal seas 4-
5ft and southerly gusts 20-25kt look to continue until early Friday
with the frontal system in the vicinity.

Conditions are expected to remain below SCA levels this weekend into
early next week.
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&&

.HYDROLOGY...
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Rainfall amounts of 0.50 to 1.00" with localized higher amounts are
expected through tonight. Minor nuisance poor drainage flooding will
be the primary threat especially in urban and low lying areas. The
flooding potential will be limited due to the expected speed of the
showers and thunderstorms.

No hydrologic impacts are expected this Friday and weekend into
early next week.
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&&

.TIDES/COASTAL FLOODING...
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Have continued the ongoing Coastal Flood Advisory for coastal
Fairfield, Westchester, and S Nassau counties for this evening`s
high tide cycle. Elevated astronomical high tides associated with
the new moon combined with onshore flow will continue to support
water levels touching or just surpassing minor flood benchmarks in
these areas.

Water levels may just touch or slightly exceed minor benchmarks for
the same locations with Friday evenings high tide cycle.
Guidance appears to have come down with the latest data. Prefer to
hold off on issuing any statements or advisories until this evenings
high tide passes and we can assess the latest data tonight.

There is a high rip current risk at the Suffolk County ocean beaches
into this evening, with a moderate risk elsewhere. This is due to
building seas, southerly swell, and a strengthening southerly flow.
There is also a moderate rip current risk Friday and Saturday at all
Atlantic beaches due to 3-4 ft seas and lingering southerly swell.
This is supported by the latest RCHMOS.
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&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
     Friday for CTZ009.
NY...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
     Friday for NYZ071.
     High Risk for Rip Currents until 9 PM EDT this evening for NYZ080-
     081.
     Coastal Flood Advisory from 8 PM to 11 PM EDT this evening for
     NYZ179.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ350-353-355.

&&

$$

SYNOPSIS...BR/DS
NEAR TERM...BR
SHORT TERM...BR
LONG TERM...DS
AVIATION...MET
MARINE...BR/DS
HYDROLOGY...BR/DS
TIDES/COASTAL FLOODING...