000
FXUS61 KOKX 230552
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
152 AM EDT Mon Oct 23 2023
.SYNOPSIS...
Strong low pressure over the Canadian Maritimes will gradually
move farther out into the north Atlantic overnight as high
pressure build from the west. The high will be along the coast
on Tuesday, then shift just offshore and allow a warm front to
pass to the north late Tuesday into Tuesday night. The high will
remain in place through Friday, then drift southward this
weekend as low pressure passes well to the north and drags one
weakening cold front toward the area this weekend. Another weak
cold front approaching from the west may get close enough to
bring the next chance of rain late Sunday or Sunday night.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Steep pressure gradient between low pressure northeast of the
region across the Canadian Maritimes and high pressure near the
western Great Lakes will be gradually weakening overnight, and
gusty NW flow will subside as a result.
A mid-level vorticity maximum was tracking south of Long Island.
The associated cyclonic flow aloft will keep cloud cover with
us tonight. At the surface, a trough moves across at night,
allowing for the winds to take on a more northerly component.
The pressure gradient weakens tonight with the low moving
farther away from the local region and the high pressure area to
the west getting closer. Less cyclonic flow is expected by late
tonight, allowing for clouds to decrease. With the winds
staying up though, radiational cooling will be mitigated.
Forecast low temps are in the 40s.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
For Monday, high pressure will be more of an influence in the
region with greater subsidence and a further decrease of the
pressure gradient. Less gusty winds and more sun will lead to a
relatively warmer day. Forecast high temperatures are more in
the upper 50s to lower 60s, which will be closer to normal for
this time of year.
For Monday night, while surface high pressure builds overhead,
models depict a weak shortwave moving in at night. Most guidance
agrees with an increase in cloud cover at night because of
this. The 12Z HREF member mean is showing max cloud cover Monday
night between 40-50%, building west to east along the track of
the shortwave. The increased cloud cover may inhibit significant
radiational cooling. Took a blend of MOS and did not take the
coldest of the MOS because of this. Forecast lows still range
mainly in the mid 30s to upper 40s. Forecast lows still have
outlying areas and interior locations in the lower 30s. Frost
with low level saturation is forecast for north and west of NYC
and parts of the Pine Barrens but confidence is not high due to
uncertainty in the maximum extent of cloud coverage Monday
night. Parts of the Lower Hudson Valley have forecast
temperatures near freezing.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
A significant warmup expected going into mid week after sfc
high pressure along the coast shifts offshore on Tue, and a warm
front passes well to the north late Tue into Tue night.
Expecting near record warmth mid to late week, as H5 heights
reach 588 dm on Thu with H5-10 thicknesses at least 567 dm Thu-
Sat. For temps took a 12Z GFS MOS/00Z ECMWF MOS blend which for
the most part was even warmer than the NBM 75th
percentile...with some modest downslope component to the flow
(WSW) can`t see why some spots west of NYC wouldn`t push 80 for
highs on at least Thu.
Thicknesses remain high into Sat but heights fall aloft, and
guidance does show a mostly dry cool front sagging southward
toward the area this weekend, so it is possible that Fri/Sat may
be not quite as warm. Meanwhile GFS likely too fast with cold
frontal approach from the west on Sunday and lowering heights
aloft too quickly, while other guidance is slower. As a result
have kept most of the weekend dry, with chance PoP holding off
until Sunday night.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
High pressure builds in from the west through Monday.
VFR. There is a low chance of high end MVFR ceilings at KSWF
late tonight.
A gusty NW flow continues until around 06Z, and then both
sustained winds and gusts gradually diminish. Gusts may become
more occasional after 04Z before ending 06Z to 09Z. Monday winds
become more northerly. A light north to northeasterly flow
develops Monday night, with the possibility of winds becoming
light and variable everywhere, but especially outside the metro
terminals.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments expected.
OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY...
Monday night through Friday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA remains in effect through tonight for all waters for wind
gusts 25-30 kt, and through noon Monday on the ocean where
residual 5+ ft seas are still likely through the morning.
Quiet conditions expected thereafter with high pressure in
control. Persistent SW flow 15 kt on Wed could build ocean seas
up to 4 ft during that time frame. Swells from distant Tammy
could start to arrive on the ocean waters very late in the fcst
period (Fri night).
&&
.HYDROLOGY...
No hydrologic impacts expected through the week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT early this morning for
ANZ331-332-335-338-340-345.
Small Craft Advisory until noon EDT today for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/BR
NEAR TERM...BG/BR/MET
SHORT TERM...BR
LONG TERM...BG
AVIATION...JP
MARINE...BG/BR
HYDROLOGY...BG/BR