FXUS61 KOKX 252116

Area Forecast Discussion
National Weather Service New York NY
516 PM EDT Tue Jun 25 2019

A cold front moves across the region tonight. Weak high
pressure briefly builds in Wednesday before giving way to
another cold front Wednesday night. Thereafter, high pressure
will dominate into the late week, though weak surface troughs
will develop each afternoon across the interior. A weak cold
front then passes through Saturday, followed by a stronger cold
front Sunday, with a return to high pressure thereafter.


A cold front is approaching from the west and will move across
late this evening into the overnight. The pressure gradient is
weak so winds will switch to a more northerly direction but will
remain light.

Aloft, upper level low moves northward towards Hudson Bay with
an associated jet streak moving in. Left front quad will enable
for extra lift this evening. A few models such as the HRRR and
NAM as well as GFS depicting some light precipitation so kept a
slight chance to low chance of showers along with a slight
chance of thunderstorms. Instability will be decreasing this
evening. Much of the rainfall is done and any additional
rainfall is not expected to amount to much, around a quarter of
an inch or less.

There will be patchy fog into tonight, particularly for
Southern CT and Long Island with moisture laden boundary layer
from recent rain and not much mixing within boundary layer.

Lows are a blend of MAV/MET which are in pretty good agreement,
ranging from the low 60s to near 70.

There remains a moderate risk of rip current development at the
Atlantic Ocean beaches into early this evening.


There will be ridging aloft with those westerlies translating
farther north of the region. Weak high pressure briefly builds
in Wednesday. Another cold front moves in Wednesday night. There
will be another weak shortwave aloft moving in Wednesday night
to accompany the front.

Mainly dry conditions are expected outside of a possible shower
or thunderstorm late Wednesday afternoon into Wednesday
evening. More efficient mixing is expected with downslope
westerly flow Wednesday. This will both promote greater daytime
instability but also slightly lower dewpoints so the instability
will be limited. High temperatures forecast are from the ECS
guidance with warmer values for the coastlines, getting well
into the 80s for most of the coast, and close to 90 degrees
within urban northeast NJ and NYC. For Wednesday night, a blend
of ECS/MAV/MET was used for low temperatures with winds becoming
light once again and some radiational cooling late to promote a
more vast range of lows, ranging from upper 50s to lower 70s.


A Bermuda high will persist into the late week, with a deeper upper
level trough over the Hudson Bay. Our region will remain between the
two systems, with subsidence and generally offshore flow, with the
exception of afternoon sea breezes, leading to above normal
temperatures and increasing humidity into Saturday. Shower and
thunderstorm coverage and locations will be less certain, and likely
more reliant upon weak upstream vorticity maximums, some of which
will be convectively induced and heavily dependent upon what occurs
well to the west. These vorticity maximums will then interact with
daily thermal troughs and sea breezes for at least isolated coverage
of thunderstorms each day.

By the weekend, the pattern begins to shift as ridging strengthens
across the central U.S., allowing the Hudson Bay trough to move
southeastward into the region in response. Although the timing of
the trough remains uncertain, the past few runs of the deterministic
guidance have become more consistent in the closed upper low moving
into the Northeast Sunday during the day. If the timing is
maintained, the trough and attendant surface front will be favorably
timed with peak diurnal heating and instability, which combined with
the strengthening deep layer shear could lead to severe weather
potential. Will need to monitor closely in subsequent updates.

Thereafter, a marked decrease in humidity and return to seasonable
to slightly below normal temperatures will occur as a Canadian high
builds into the region.


A cold front gradually moves across the terminals through

VFR for the city terminals and Lower Hudson Valley terminals.
MVFR/IFR east of the city across Long Island and southern
Connecticut, but improvement to VFR is possible through sunset.
There could be a return to lower conditions east of NYC

Winds mostly under 10 kt into this evening, shifting NNW behind
the cold front towards midnight.

     NY Metro Enhanced Aviation Weather Support...

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

KJFK TAF Comments: Wind direction could shift to the W this
evening but remain under 10 kt.

KLGA TAF Comments: Winds could shift towards the south 22-23z,
but remain under 10 kt.

KEWR TAF Comments: A gust to 15 kt possible through 23z.

KTEB TAF Comments: No unscheduled amendments expected.

KHPN TAF Comments: Low confidence forecast after 00z.
Uncertainty in flight category. Conditions could be VFR through
the night.

KISP TAF Comments: Low confidence forecast. Low conditions may
improve to MVFR through 23z. LIFR or IFR may return after
01-02z, but uncertain on the extent and duration.

.Wednesday through Friday...VFR.
.Saturday and Sunday...Mostly VFR. Chance of a tstm with MVFR
or lower conds.


The conditions on the waters are expected to remain below small
craft advisory criteria through Wednesday night as the pressure
gradient remains relatively weak.

A generally weak pressure gradient under high pressure will maintain
sub-SCA levels on all waters through the late week. A cold front is
then expected to pass through the waters on Saturday, followed by a
stronger front on Sunday. Wind gusts to near 20-25 kt may be
possible, with an increasing threat for a few showers
and thunderstorms over the waters as well.


There are no hydrologic concerns into the weekend.


NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off
the air.





NWS OKX Office Area Forecast Discussion