000
FXUS61 KOKX 242344
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
744 PM EDT Wed May 24 2023
.SYNOPSIS...
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A cold front will move south of Long Island tonight. High
pressure builds across the local region from the Great Lakes
going into this holiday weekend. High pressure weakens on
Memorial Day and into the middle of next week with weak low
pressure approaching from the south.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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Adjusted POPs for showers, removed thunder with instability
decreasing. Areas of showers along a cold front will move across the
region from north to south this evening. Dry conditions expected
overnight. Rain amounts expected to remain under a quarter of an
inch. Slight adjustments were made with hourly temperatures and
dewpoints to better match up with observed trends.
Overnight, skies look to clear quickly behind the frontal
passage with clear skies by the morning as high pressure begins
to build behind the front. Blustery conditions develop after the
front into Thursday morning with a tightening pressure gradient
as the high builds, generally gusts 20-25 mph. Went with a
blended short term model consensus for winds overnight Wednesday
into Thursday morning. Despite clearing skies, the winds will
reduce the amount of radiational cooling that we will see
tonight with lows near 50 in the NYC metro and in the mid-40s
elsewhere.-- End Changed Discussion --
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
High pressures builds into the region from the Great Lakes through
Thursday. North winds remain on Thursday due to high pressure
located to our northwest, keeping highs below seasonal in the
mid/upper-60s. Gusty winds should subside by midday on Wednesday
with sustained winds below 10 mph into the afternoon. Winds continue
to let up Thursday night as the pressure gradient relaxes and high
pressure builds further into the region. Clear skies and light winds
will lead to radiational cooling in spots allowing the LI Pine
Barrens and parts of the Lower Hudson Valley to dip into the upper-
30s. Went with a MOS consensus for Thursday night`s temperatures to
account for the radiational cooling.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
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Mid levels of the atmosphere exhibit a ridging trend as a trough
moves farther northeast of the region Friday. The mid level ridge
will continue to build in Friday night through much of the holiday
weekend. The ridge begins to weaken Sunday night into Memorial Day
but its center axis will be very close to the area. The dominant
signal from the mid level analysis conveys more of negative
vorticity advection.
At the surface, high pressure builds in from the Great Lakes for the
first half of the holiday weekend, then moves just offshore for the
second half of the holiday weekend. The high strength will be
getting weaker Sunday night into Memorial Day. Weak low pressure
begins to approach from the south towards the middle of next
week.
The ridging and dominance of surface high pressure will lead to
suppressed vertical motions, allowing for a prevalence of dry
weather Friday into the holiday weekend. The forecast introduces
slight chance POPs for rain showers south of Long Island Sunday and
Sunday night and farther north across some of the coastal areas for
Memorial Day. Mainly slight chance POPs for rain showers also in the
forecast going into the middle of next week. This will coincide
with weakening of high pressure and weakening ridging aloft
along with consecutive days of onshore flow, helping to increase
low level moisture especially along the coast.
Kept the POPs just slight chance with the closer proximity of the
upper level ridge axis for early next week. The numerical weather
prediction models diverge with the progression of evolution of an
upper level low to the south and west of the area going into the
middle of next week. So, weather is expected to remain mainly dry
for Memorial Day and into the middle of next week.
Looking at the model consensus with 850mb temperatures, there is a
coherent warming trend Friday going through the holiday weekend.
Likewise, this will mean a warming trend for surface temperatures
leaning more above normal towards the end of the holiday weekend and
into the middle of next week. More onshore flow along the coast will
moderate the warming trend there. Forecast highs are mainly in the
lower 70s on Friday, low to mid 70s Saturday, low to upper 70s
Sunday, and then mid 70s to lower 80s for Memorial Day. Tuesday next
week has forecast highs in the low 70s to low 80s and Wednesday next
week has forecast highs in the mid 70s to mid 80s.-- End Changed Discussion --
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
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A cold front passes through this evening. High pressure builds
in from the northwest late tonight and Thursday.
Any S wind ahead of the cold front, mainly KJFK and KISP for
the next hour or so, will shift to N/NNW and increase this
evening. NNW/N winds 10-15 kt with gusts 20-25 kt expected
tonight for all terminals. Winds remain steady N/NW on Thursday
but gusts should become less frequent by 14-16Z. Brisk N/NW flow
should prevent seabreezes from making much progress inland on
Thursday, but are not completely ruled out for the coastal
terminals after 18Z.
Mainly VFR but a brief period of MVFR is possible in any heavier
shower through 3Z. Showers will continue to move through the
area and should dissipate by 3-4Z.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Low chance of a seabreeze for KJFK on Thursday.
OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
Thursday night-Friday: VFR.
Saturday-Monday: VFR. A slight chance of showers on Sunday near
the coast.
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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Winds behind a cold front late this evening and overnight will
result in SCA level wind gusts across the ocean and for parts of the
other waters. However, the non-ocean waters will be more marginal
for SCA gusts, with SCA level gusts there being more
occasional.
SCA conditions are expected to continue into early Thursday
afternoon along our ocean waters with wind gusts of 25 kts and
5 ft waves. Conditions drop below SCA mid-afternoon Thursday.
With the overall dominance of high pressure, the pressure gradient
will remain relatively weak. As such, winds and seas are expected to
remain below SCA thresholds Friday through the holiday weekend.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through the middle of next
week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 11 PM this evening to 2 PM EDT
Thursday for ANZ350-353-355.
&&
$$
SYNOPSIS...JM/BR
NEAR TERM...JM/BR
SHORT TERM...BR
LONG TERM...JM
AVIATION...MW
MARINE...JM/BR
HYDROLOGY...JM/BR