000
FXUS61 KOKX 051144
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
744 AM EDT Wed Apr 5 2023
.SYNOPSIS...
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A cold front stalls out south of Long Island today. This same
front will return northward as a warm front tonight, eventually
moving north of the region by early Thursday. A cold front
approaches Thursday and moves across late Thursday afternoon
into Thursday night. High pressure will gradually build in from
the north and west late Thursday night into Friday. This high
pressure area will continue building in through the weekend,
sliding offshore by early next week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Made some slight adjustments to temperatures and dewpoints to
better match observed trends. Decreased chances of light rain
and made areas of very light drizzle the main weather parameter
for many coastal locations going through this morning. Forecast
soundings show most moisture only up through first 2kft above
ground with relatively drier air above that.
A cold front stalls to the south of Long Island today.
A very cool and increasingly damp day is expected across the
coastal and eastern sections of the region as surface flow from
the east advects in a cooler maritime airmass across the region.
Locations in Northeast NJ and the Lower Hudson Valley are
forecast to be relatively warmer compared to farther east in the
area so not nearly as damp in Northeast NJ and the Lower Hudson
Valley. Looking for temperatures to stay mostly in the 50s for
the high temperature forecast today.
Models are coherent on depicting a few hundredths of an inch of
rainfall across coastal Connecticut and Long Island. This is
where temperatures will be relatively the coolest and where more
of the light rain and drizzle will be located. Both light rain
and drizzle are mentioned this afternoon with the variance of
vertical depth of moisture indicated in the forecast soundings
between saturation of just a few thousand feet to near
saturation of up to 3 to 5 kft. Mesoscale models also depict for
eastern parts of the area, more larger discrete areas of rain in
their reflectivity fields for this afternoon.
With the increasing moisture, there will be fog especially along
the coast but more patchy away from the coast. Along the coast,
some patchy dense fog is possible this morning. As moisture
increases with any light rain or drizzle today, would expect
this fog to form farther inland this afternoon.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
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For tonight, the front south of Long Island gradually returns
north as a warm front.
The surface flow transitions from easterly to more southerly.
There will be continuing chances of light rain or drizzle, but
would expect a more expansive fog as well due to low level warm
and moist air advection occurring with the more southerly flow.
The fog could once again be potentially dense.
The warm front is expected to move north of the region early
Thursday and that will place the area in the warm sector. There
will be an increasing chance of showers and thunderstorms as a
cold front approaches and moves into the area due to growing
instability.
Temperature rebound substantially on Thursday with increasing SW
flow and increased warm air advection ahead of an approaching
cold front. This will be most pronounced across the interior
sections of the region in Southwest Connecticut, the Lower
Hudson Valley, and Northeast NJ as well as some northern and
western parts of NYC where more vertical mixing is expected.
High temperatures forecast for these aforementioned locations
are in the mid to upper 70s with some locations in Northeast NJ
reaching near 80. Meanwhile, farther east and along the coast,
more of a marine influence will be seen with forecast high
temperatures staying mostly in the 60s but a little cooler for
the Twin Forks of Long Island. Another factor leading to the
cooler temperatures farther east for the coastal sections will
also be the lingering low clouds and fog.
The cold front moves across late Thursday afternoon into
Thursday evening and will push farther offshore late Thursday
night. Showers will taper off from northwest to southeast along
with any thunder.
The forcing with the cold front has increasing bulk shear
between 0 and 6 km above the ground to near 50 kt but the
instability will be quite limited. This is also related to the
moisture content of the atmosphere as diagnosed from the
precipitable water. Both the precipitable water and instability
are higher to the south and west of the area. Model BUFKIT wind
profiles also indicate shear that is not consistent in the way
of wind direction and speed. Less organized convection may very
well be the result which is indicated by some mesoscale models.
So, some strong thunderstorms will be possible with higher
potential for severe to the southwest of the forecast region.
For Friday, high pressure gradually builds in from the north and
west. Dry conditions will remain across the region but there
will be lingering clouds as a mid level trough remains in the
Northeast but will not be that amplified.-- End Changed Discussion --
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The weekend will be dry as a 1035 mb surface high pressure
builds in from the Great Lakes. Gusty NW winds lower over the
weekend. With the northwest flow, temperatures will be cooler
during this time, generally 50s and lower 60s, with increasing
sun through Sunday.
The evolution of the large scale pattern becomes more uncertain to
start next week. The latest model consensus has the surface high
starting to move offshore, but lingering ridging may hold on during
Monday. There may be an approaching upper trough, but the timing and
amplitude continue to have little consistency. Generally stuck close
to national blended guidance for this update.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
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A slowly moving cold front remains in the vicinity, eventually
sagging just south of the terminals today. The front remains
south of the area through the evening before moving north again
tonight as a warm front.
Mainly low-end MVFR and IFR conditions expected though the day
under easterly flow. Drizzle or sprinkles are possible this
morning, especially for areas near the coast. Any slight
improvements in categories or ceilings drop again tonight back
to IFR with pockets of LIFR possible through Thursday morning.
A few showers are possible tonight after 6Z.
Winds E-NE 10 kt or less as the cold front sags southward. Winds
increase 10-15 kt during the day and remain easterly. The warm front
moves through this evening and overnight causing winds to shift out
of the SE then S after midnight. LLWS possible for easternmost
terminals, mainly KGON and KISP, for a few hours overnight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely due to uncertainty in changing flight conditions.
Moderate to high confidence in wind forecast. Low confidence in
vsbys during the day. Moderate confidence in vsbys tonight.
The afternoon KJFK haze potential forecast is YELLOW...which implies
slant range visibility 4-6SM outside of cloud.
The afternoon KLGA haze potential forecast is YELLOW...which implies
slant range visibility 4-6SM outside of cloud.
The afternoon KEWR haze potential forecast is YELLOW...which implies
slant range visibility 4-6SM outside of cloud.
...OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
Thursday-Thursday Night: IFR improves to MVFR during the day
with showers likely in the afternoon. A chance of TSRA. SW
gusts 15-20kt, becoming W-NW Thursday night.
Friday-Sunday: VFR. W-NW G20-25kt Friday morning.
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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Marine dense fog advisory had been in effect for the NY
Harbor but has been cancelled. The marine dense fog advisories
are still in effect for the ocean zones (in effect until 6PM) and
the South Shore Bays of Long Island (in effect until 12PM).
Visibilities have improved along the coast. Farther north,
there is no fog at all. The marine dense fog goes through this
afternoon for the ocean zones and for the South Shore Bays
through this morning. A lot of webcams indicate improved
visibilities along the coastline.
However, farther out across the ocean there is still some
indication of low moisture from derived GOES16 satellite
product imagery and with the ocean being relatively closer to
the front, more fog could very well get advected in later today
with the increase in easterly flow. Also, some relatively lower
visibilities are still being observed for sites near the South
Shore Bays. Therefore keeping marine dense fog for South Shore
Bays and the ocean for the time being.
Dense fog will be possible once again tonight for all the
forecast waters. This could expand from the ocean waters to the
non-ocean waters.
Sub-SCA on all waters to start today. SCA conditions then
develop tonight on the ocean and continue into Thursday. Non-
ocean waters remain below SCA thresholds through Thursday. SCA
conditions for wind gusts could spread to most waters Thursday
night with ocean SCA seas probably continuing.
SCA conditions are then possible on all waters Friday into
Friday night as high pressure builds in, potentially bringing NW
gusts around 25 kt. Sub-SCA conditions are expected on all
waters through the weekend with high pressure in control.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic concerns expected through early next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until noon EDT today for ANZ345.
Dense Fog Advisory until 6 PM EDT this evening for ANZ350-353-
355.
Small Craft Advisory from 10 PM this evening to 6 PM EDT
Thursday for ANZ350-353.
Small Craft Advisory from 10 PM this evening to 2 PM EDT
Thursday for ANZ355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JM/DR
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...DR
AVIATION...MW
MARINE...JM/DR
HYDROLOGY...JM