000
FXUS61 KOKX 241949
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
349 PM EDT Wed May 24 2023
.SYNOPSIS...
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A cold front is beginning to move through the area and should clear
out by 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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A cold front is beginning to track through the area from a trough
digging south from Canada into New England. The front will bring
likely POPs to the Lower Hudson Valley, western Passaic county and
Fairfield county. The line of showers will weaken as they aproach
the NYC metro early this evening and eventually dissipate over
eastern LI and SE CT. Most CAMs and global models are in agreement
on the progression and deterioration of the line of showers as the
cold front pushes through. HREF mean SBCAPE values are sitting
around 500 J/kg for Orange county with parts of Putnam, western
Passaic counties getting close to these values. Only isolated
thunderstorms are expected. The window for thunderstorms will be
brief late this afternoon and early this evening, before showers
weaken as they push south with the front. Totals will be around or
below 0.15" in Orange and Putnam counties with some isolated higher
totals possible in any stronger individual showers or thunderstorms.
These totals drop under 0.10" in NYC, dropping to only a trace on
eastern LI.
Tonight, 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/...
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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.-- End Changed Discussion --
&&
.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.
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.
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 /20Z WEDNESDAY THROUGH MONDAY/...
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A cold front approaches from the north and passes through this
evening around 00z. High pressure builds in from the northwest late
tonight and Thursday.
S-SW winds around 10-15 kt shift abruptly after 23z from NW to SE
across the region following Fropa. Winds should also increase into
the evening and overnight with gusts 20-25kt possible behind the
front.
VFR with a chance of showers this evening. There is a low chance
of brief MVFR ceilings with the showers, but confidence too low
to put in the TAFs. The exception is KSWF where showers are
likely, as well as MVFR ceilings. There is a chance of a
thunderstorm with briefly gusty winds until 23-00z
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Low chance of amendments due to brief MVFR ceilings and showers.
Timing of wind shift with cold frontal passage may be off +/- 1-2
hours. There may be occasional northerly gusts with the showers.
OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
18z Thursday-Friday: VFR. N wind G20-25kt Thursday early morning
then diminishing. Afternoon sea breeze likely coastal terminals.
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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SCA conditions are expected late Wednesday evening following a
cold front into early Thursday afternoon along our ocean waters
with wind gusts of 25 mph 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...
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There are no hydrologic concerns through the middle of next
week.-- End Changed Discussion --
&&
.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...BR
SHORT TERM...BR
LONG TERM...JM
AVIATION...IRD
MARINE...JM/BR
HYDROLOGY...JM/BR