178
FXUS61 KOKX 021445
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1045 AM EDT Thu May 2 2024
.SYNOPSIS...
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A warm front will struggle to pass east of Connecticut and Long
Island today, followed by a cold frontal passage this afternoon
into this evening. 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.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
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Back edge of clearing along the Hudson River and south into the
NYC metro. Expect gradual erosion of the clouds/fog along the
western edge, translating east into the afternoon. The main
change with this update was to adjust temperatures down a few
degrees along coastal locations, mainly east of the NYC metro.
This will be a challenging temperature forecast due to the
timing of the clearing and how much time the area has to heat
up. Thus, the trend has been to adjust LI and coastal CT down a
few degrees. Highs across these areas will be in the lower 60s
to around 70. Locations from NYC north and west still look to
get into the upper 70s and lower 80s.
Patchy dense fog mainly across CT and LI will also continue to
lift the next couple of hours. Visibilities will generally be
greater than a mile, but some patchy dense fog is still being
noted, especially along the immediate coast.
Warm front struggles to pass east of the area today, followed
by a cold frontal passage this afternoon/evening. 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.
Continued dry for tonight as high pressure builds in from the
north. Low temperatures a few degrees above normal.-- End Changed Discussion --
&&
.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/...
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.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
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A weak frontal system moves through the area this afternoon.
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.
Improvement from IFR/LIFR to VFR is expected by early this
afternoon around 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 gradually veering to west as a frontal
system attempts to work across the area. Gusts to 20 kt
possible. Coastal areas may remain onshore.
By late day/early evening, all the terminals should become more
N/NE and E by Friday morning. MVFR cigs could return overnight
from east to west.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments are likely 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-- End Changed Discussion --
&&
.MARINE...
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A Dense Fog Advisory remains in effect 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.-- End Changed Discussion --
&&
.HYDROLOGY...
There are currently no hydrologic concerns through early next
week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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.
&&
$$
UPDATE...DW
AVIATION...IRD