000
FXUS61 KOKX 272017
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
417 PM EDT Fri Oct 27 2023
.SYNOPSIS...
High pressure remains across the southeastern states tonight as low
pressure tracks through eastern Canada. An associated cold
front will cross the area early Saturday evening, stalling
south of the area Saturday night as high pressure builds to the
north. The front lifts back over the area on Sunday. A stronger
cold front moves through Sunday night into Monday. High
pressure begins to build in on Tuesday. A wave of low pressure
could impact the region Tuesday night into Wednesday before the
high pressure settles over the area to end of the week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Nearly zonal upper flow will continue tonight as a longwave
trough tracks across southern Canada, reaching eastern Canada by
Saturday morning. Meanwhile, the upper ridge will remain across
the southeastern states. Surface flow will be rather weak, with
winds decoupling overnight. Mid and upper level moisture, and
cloudiness was shifting to the south and east, and with clearing
conditions radiational cooling will set up. There may be areas
of valley fog developing late overnight, however, confidence too
low to include at this time. While outlying areas will be
cooler, temperatures will still be 10 to as much as 15 degrees
above normal.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
High pressure to the south will be weakening and drifting south
and west Saturday as a cold front, associated with low pressure
moving through eastern Canada, moving into and through the
region early Saturday evening. A westerly flow will continue
ahead of the front with a warm and rather humid airmass in
place. With little moisture through the atmospheric column
nearly clear skies are expected with plenty on incoming solar
heating. High temperatures are expected to be 15 to nearly 20
degrees above normal, and several record high temperatures are
expected to be broken at the climate sites. See the climate
section for current record highs for Saturday October 28th.
Again, with little moisture, and limited lift along the cold
front, no precipitation is expected. High temperatures,
especially inland, may occur midday to early afternoon,
depending on the timing of the cold frontal passage.
Saturday night the southeastern ridge remains over, and off
shore of the southeastern states. This will keep the cold front
from pushing too far south of the area Saturday night, and allow
the front to stall. The placement of the front will also be
dependent on the strength and movement of high pressure that
builds in to the north behind the cold front. A weak shortwave
and vorticity will be moving rather quickly through the deep
west to southwest flow, and by 12Z sunday light precipitation
will be possible, mainly across the western and southern
sections of the forecast area. There is a chance that the area
does remain dry through 12Z Sunday if the front is stalled
farther to the south and the approaching shortwave is slower to
reach the mid Atlantic areas. Overnight low Saturday night will
be closer, but still a few degrees above, normals.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
The highlights for the long term are:
* A weak frontal wave will bring showers on Sunday, mainly in the
afternoon and evening. This would continue to the streak of
weekends with measurable rainfall.
* A stronger cold front passes through Sunday Night into Monday
with continuing chances for showers.
* Much colder conditions return Monday night through the end of the
week.
* Uncertainty remains high with potential of a low pressure over or
along the Middle Atlantic coast Tuesday night into Wednesday.
There is still a chance that high pressure will remain in control
with any system passing well offshore.
An upper level trough will continue to slowly shift east Sunday into
early next week. Heights will fall aloft in response to the trough.
A weak front that settles south of the area Saturday night will
gradually lift back to the north on Sunday as a frontal wave moves
across the area. Main thermal gradient remains to the west on
Sunday, but clouds and showers will hold temperatures down near to
slightly below normal. Showers will likely remain light with some
pockets of moderate rain, but not anticipating any hydro issues as
average rainfall amounts through Sunday evening are generally under
a half inch.
The frontal wave remains in the vicinity Sunday night with the main
thermal gradient and strong cold front approaching from the
northwest. Showers remain possible, but some guidance hints at a
relative min in activity until the front moves through the region on
Monday. The timing of the frontal passage based on a consensus of
the latest guidance is during the morning inland and early afternoon
at the coast. Any showers should quickly end by Monday evening as
the the atmosphere begins to dry out behind the front. There
continue to be no hydro concerns with any of the additional showers
that Sunday night into Monday. Temperatures on Monday will be near
to slightly below normal. A sharper drop in temperatures is expected
Monday night with temperatures ranging from the mid 30s inland to
low 40s at the coast.
Forecast confidence is much lower Tuesday through Wednesday. The
models have continued to signal a potent vort max/shortwave diving
south out of Canada early next week and then amplifying the trough
over the east Tuesday into Wednesday. There are significant
amplitude differences among the guidance. A more positively tilted
trough (GFS,GEFS) should result in any low pressure remaining well
offshore or just glancing the region. A more amplified solution such
as the ECMWF and to some degrees the CMC may result in at least some
impacts from a fast moving wave of low pressure sometimes Tuesday
night into Wednesday. Have elected to stick with the NBM for
continuity as the modeling will likely fluctuate back and forth the
next few days. The main energy originates from the Arctic Circle and
should be sampled better by Sunday and ensemble sensitivity analysis
highlights the timing and intensity of the energy to be key
contributors to the ongoing uncertainty.
A persistence forecast yields a chance for rain late Tuesday into a
portion of Wednesday. Much colder air nearby supports a continued
mention of some wet snow well inland Tuesday night. However, if the
trough amplifies more significantly than currently modeled, the low
would track closer to the coast and bring warmer air limiting any
wet snow potential.
High pressure will otherwise build towards the eastern seaboard late
in the week. The main story will be the much colder air with highs
running on average about 10 degrees below average for the end of
October into early November.-- End Changed Discussion --
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
High pressure remains centered to our south today.
VFR. SW winds under 10kt this afternoon and tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments expected.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday: VFR. NW gusts 15-20kt late afternoon.
Sunday: Rain likely, especially in the afternoon. MVFR/IFR
likely in the afternoon.
Sunday night: Rain with IFR.
Monday: Rain with IFR in the morning. MVFR with showers still
possible in the afternoon.
Tuesday: VFR.
Tuesday night-Wednesday: Chance MVFR or lower with -shra. North
gusts around 20kt Wednesday afternoon.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Winds and seas remain below SCA levels across the forecast waters
tonight through Sunday night. Marginal SCA conditions are
possible on the ocean late Monday into Monday night as a strong
cold front pushes offshore. Conditions should remain below SCA
levels Tuesday before another chance of SCA conditions if low
pressure impacts the waters Tuesday night into Wednesday.
&&
.HYDROLOGY...
No hydrologic impacts expected tonight into the middle of next
week.
&&
.TIDES/COASTAL FLOODING...
Astronomical tides will continue to increase through the
weekend into early next week due to a full moon on Saturday. The
latest guidance continues to show water levels just touching
minor coastal flooding benchmarks across the South Shore Back
Bays of Queens and Nassau and the Western Sound across S
Fairfield and S Westchester with high tide Saturday morning.
Have issued a coastal flood statement across these locations.
Additional minor coastal flooding appears likely for the
morning/early afternoon high tides into Monday. The minor
coastal flooding could spread into the NY/NJ harbor as well as
more of coastal Suffolk County, specifically across the
southeast shores.
&&
.CLIMATE...
Here are the daily record high temperatures for the local
climate sites through Saturday.
FRI OCT 27TH RECORD HIGH/YEAR
Newark NJ 81/1963
Bridgeport CT 75/1963
Central Park NY 82/1963
LaGuardia NY 79/1963
Kennedy NY 78/1963
Islip NY 80/1963
SAT OCT 28TH RECORD HIGH/YEAR
Newark NJ 82/1984
Bridgeport CT 72/2010*
Central Park NY 83/1919
LaGuardia NY 80/1984
Kennedy NY 76/2010
Islip NY 75/1971
* Also occurred in previous years
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DS/MET
NEAR TERM...MET
SHORT TERM...MET
LONG TERM...DS
AVIATION...JC
MARINE...DS/MET
HYDROLOGY...DS/MET
TIDES/COASTAL FLOODING...
CLIMATE...