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867
FXUS61 KOKX 021132
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
732 AM EDT Thu May 2 2024

.SYNOPSIS...
A warm front moves through this morning, followed by a cold front
this afternoon. High pressure otherwise controls the weather through
most of Saturday. A cold front then moves through Sunday night
into Monday morning, then stalls south of the region. The front
moves back north as a warm front Tuesday into Wednesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
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Patchy dense fog is being observed, mainly over southern CT,
Long Island and portions of the Lower Hudson Valley and NYC. An
SPS has been issued through 13z. After 13z visibilities should
generally be above a quarter of a mile.

A warm front will pass through during this morning, followed by
a cold front this afternoon while a shortwave dives SE through
New England. Moisture is limited with both fronts, and although
eastern portions of the forecast area will have deeper lift this
afternoon, would have liked to have seen deeper moisture on
time-heights to introduce a chance of showers.

The high temperature forecast will be a little tricky as there`s
some uncertainty surrounding how quickly low stratus dissipates,
especially for coastal areas. Thinking is that it should eventually
turn out to be a mostly sunny afternoon for most spots. Based on
progged 850mb temps, up to where mixing occurs for most areas by the
end of the afternoon, deterministic NBM numbers seem reasonable.

Continued dry for tonight as high pressure builds in from the north.
Low temperatures a few degrees above normal.
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&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure continues to build in from the north while a ridge
axis aloft shifts towards us. Dry and cooler as winds arrive from
the east, limiting the mixing depth. Went slightly cooler than NBM,
which is close to its 25th percentile, and still might be a little
too warm based on progged 925mb temps of 7-8C.

Dry for Friday night and at least Saturday morning, but generally
lowering and thickening clouds are expected during this period. The
ridge axis aloft will be right over us during Saturday and slow to
move, so even Saturday afternoon stands a good chance of remaining
dry. Will maintain slight chance PoPs west of the Hudson River in
the afternoon. Mixing depth is limited once again for Saturday with
an onshore flow and the ridge axis aloft. Went slightly cooler than
the NBM again for high temps.

A cold front slowly approaches from the west Saturday night as it
runs into ridging aloft. Associated rainfall with the front will
also have a tough time pushing into the forecast area. Rain
probabilities remain below likely through the night.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
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Upper level ridge axis shifts offshore early Sunday and the flow
becomes near zonal by early next week. A longwave upper trough
across eastern Canada amplifies into the northeast Tuesday and moves
off shore Wednesday as another upper ridge builds to the west of the
area and moves into the region Wednesday. At the surface, a cold
front tracks across Sunday night into Monday, and becomes nearly
stationary as the flow becomes parallel to the boundary. A period of
some heavier showers will be possible Sunday as precipitable water
values increase to 1.3 inches. NBM QPF probabilities remain similar
to 24 hours ago. Probabilities of seeing 1 inch or more with this
event are 20 to 15 percent from west to east, with the 90th
percentile PQPF over 48 hours showing 1 to 1.5 inches, with the
higher values over the western half of the area.

Tuesday into Wednesday high pressure builds south from the Hudson
Bay region of Canada into the eastern Great Lakes. With a deep low
tracking northward from the northern plains into southern Canada
Tuesday into Wednesday the stalled cold front will move slowly
northward as a warm front. There is uncertainty as to the movement
of the front as high pressure, and an upper ridge will be in place.
Temperatures Friday night through Sunday will be around 5 degrees
above normal, and then Sunday night into Wednesday 5 to 10 degrees
above normal. For highs and lows Monday through Wednesday used a
blend of NBM and NBM 75th percentile to raise temperatures a few
degrees above the NBM. Depending on the movement of the warm front
next week, there is a chance that a few locations will have a record
high low Monday night into Tuesday morning.
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&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
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A weak frontal system moves through the area today. There is some
uncertainty as to how quickly the associated cold front gets
through the area, which could lead to wind timing and intensity
issues. The front may struggle to get east of the coastal
terminals.

Mainly IFR to LIFR through the early morning hours. Improvement
to VFR is expected later this morning, 14-16z for NYC terminals.
It may take until the afternoon across the far eastern
terminals to see a return to VFR.

S winds under 10kt early this morning, then gradually veering
from east to west as a frontal system attempts to work across
the area. The westerly wind shift may remain west of the KLGA
and KJFK for much of the day, before going around in the early
evening. There is fair amount of uncertainty as to how far east
the west winds. W/NW winds 10-15kt G20kt are possible for those
locations that do come around. By late day/early evening, all
the terminals should become more N/NE and E by Friday morning.
MVFR cigs could return briefly overnight from east to west.


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

AMD expected early this morning as conditions slowly improve.

The timing of the wind shift to the W/NW today could be delayed
significantly, especially at KLGA and KJFK where a southerly flow
may hold on longer. In turn, improvement to VFR could also be an
hour or two later than the TAF.

OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...

Friday: VFR.

Saturday: Mainly VFR. Slight chance of showers and MVFR
conditions in the afternoon, increasing chances overnight.

Sunday...Likely showers, with MVFR or lower conditions. ESE
winds G15-20kt.

Monday...VFR.

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

.MARINE...
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A Dense Fog Advisory has been issued for all waters this morning
as widespread visibilities below 1 miles are being observed on
coastal ASOS and area cameras. The fog will clear up for the
western waters first late this morning and then for the eastern
waters this afternoon.

Winds will be at around 10 kt or less through the day today, but
will increase out of NE behind late tonight as high pressure builds
in behind a departed cold front. NE-E winds 10-15 kt Friday morning
with gusts below 25 kt diminish in the afternoon. A weak pressure
gradient then maintains sub-advisory conditions across the waters
Friday night through the middle of next week.
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&&

.HYDROLOGY...
There are currently no hydrologic concerns through early next
week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until 1 PM EDT this afternoon for ANZ331-
     332-340-345-350-353.
     Dense Fog Advisory until 11 AM EDT this morning for ANZ335-338-
     355.
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&&

$$

SYNOPSIS...JC/JT
NEAR TERM...JC/JT
SHORT TERM...JC
LONG TERM...MET/JT
AVIATION...JT
MARINE...JC/MET/JT
HYDROLOGY...MET/JT