Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 181831

Area Forecast Discussion
National Weather Service New York NY
231 PM EDT Tue Jun 18 2019

A frontal boundary will remain nearby this afternoon as a wave
of low pressure approaches from the west. This low will move
near or just south of the area late this afternoon into this
evening. Additional waves of low pressure will move along the
front later this week, bringing periods of unsettled weather.
The front will then move offshore late Friday, with high
pressure returning this weekend. Another frontal system may
approach early next week.


There has been a steady light to moderate rain across the Lower
Hudson Valley and Connecticut today with a few embedded heavier
cells. Movement has been to the east at about 30 mph, thus
negating any flood threat. Rainfall amounts from the ECMWF and
NAM Nest have been overdone with the magnitude of the frontal
forcing to the north of the boundary. Farther to the south,
across the NYC/NJ Metro and Long Island, in the vicinity of the
warm front, there have been some embedded heavier cells as well,
but rainfall amounts have been less than an inch an hour. The
area of greatest interest at this time is along the SW flank of
the line across north central NJ. This activity is an area of
decent deep-layer shear and modest instability, but is likely to
take a track just south of the forecast area. Latest HRRR also
redevelops additional convection later this afternoon with a
similar track. This will be closely monitored due the close
proximity of the boundary. The activity across CT and the Lower
Hudson Valley will diminish in coverage while working to the
south and east.

Conditions are favorable at the very least for some heavy
rainfall and localized flash flooding with PW values near 2
inches. Main area of concern is the NYC/NJ metro.

Any showers/possible tstms should end early this evening. High
temps should range from the upper 60s to mid 70s, possibly
getting closer to 80 in NE NJ if the warm front enters the area.
Lows tonight will be in the 60s.


A break in precip appears likely to continue for the morning,
then as the next wave of low pressure approaches from the SW,
chances of showers will increase in the afternoon. High temps
expected to range from the lower/mid 70s across eastern
sections, to the upper 70s/lower 80s from the NYC metro area
north/west and in the interior CT River valley.

There will be a low rip current risk for Atlantic Ocean beaches
on Wednesday.


The frontal boundary that has been with us for the last several days
continues to be in place Wednesday night. There does not appear to
be any appreciable wave or focus so do not anticipate anything more
than a few showers or isolated thunderstorms in the evening. The
last in the series of frontal waves looks to move through late
Thursday into Friday morning. Model performance with this feature
has not shown much continuity with overall strength and track. The
one factor that does appear to be in better agreement is with a more
well defined shortwave accompanying the frontal wave. However, there
are still differences with the amplitude of this shortwave. As has
been the case the last few days, convection in the models could be
throwing off the low pressure track and intensity. Cannot be
confident with specific details for late Thursday into Thursday
night, but it does appear there is a likelihood of showers and
possible thunderstorms. The shortwave trough should provide enhanced
lift as well, especially Thursday night. Bulk shear would support a
severe weather threat, but amount of instability is the biggest
question and will ultimately depend on the track of the frontal
wave. The track of the wave will also determine where the heaviest
rain occurs. Will continue with likely PoPs from Thursday afternoon
through Thursday night with the hope that more specific details will
come into better agreement in the next day or so.

The shortwave axis shifts offshore Friday morning. If the low tracks
over or to the south of the region, then some showers could linger
in the morning. If the low track is further north, then conditions
should begin to dry out Friday morning. The passage of the shortwave
axis will take the frontal boundary offshore.

The upper level pattern across the CONUS is progged to amplify later
Friday into Saturday with a cutoff upper low/trough over the
Canadian Maritimes, a ridge over the central States and another
cutoff upper low/trough. The upper low/trough across the Maritimes
will move out into the Atlantic by Sunday with the ridge moving over
the east. Sensible weather across the region this weekend looks dry
with temperatures near seasonable levels. The ridge may begin to
flatten early next week allowing for the approach of the next
frontal system, but this could be too fast as models have a tendency
to break ridges down too quick.


A front stalled near the region will keep moisture and light
and variable winds around 10 kts or less through the TAF
period. Varying flight categories this afternoon with stratus
and fog...worst conditions east of NYC terminals.  LIFR
returning again for tonight.

Showers will occur from time to time throughout the TAF period.
There is a slight chance for thunderstorms this afternoon. For
now, just VCTS through about 21Z...confidence is very low on
placement and occurrence. There could be significant changes in
category within a small distance and the changes in category
could occur quite rapidly so forecast confidence is low to

     NY Metro Enhanced Aviation Weather Support...

Detailed information, including hourly TAF wind component fcsts,
can be found at: http:/

KJFK TAF Comments: Varying flight categories this afternoon
with stratus and fog.

KLGA TAF Comments: Varying flight categories this afternoon
with stratus and fog.

KEWR TAF Comments: Varying flight categories this afternoon
with stratus and fog.

KTEB TAF Comments: Varying flight categories this afternoon
with stratus and fog.

KHPN TAF Comments: Limited improvement this afternoon in
stratus and fog.

KISP TAF Comments: Limited improvement this afternoon in
stratus and fog.

.18z Wednesday-Thursday...MVFR or lower. Possible Showers and
.Friday...VFR. Chance of showers.
.Saturday and Sunday...VFR.


Areas of fog will likely persist across the waters today and
possibly into tonight as warm, moist air moves across the cool
waters. Showers and a few thunderstorms are likely to provide
enough mixing to keep dense fog more patchy in nature.

Marginal SCA conditions are possible late Thursday night into
Friday mainly due to 4-5 ft ocean seas. There could also be a
brief period of wind gusts approaching 25 kt Fri
afternoon/evening on a NW flow.


Basin average QPF to 1-2 inches from NYC north/west, with
locally higher amts over 3 inches possible. The potential of
training cells poses at least a low threat of flash flooding.
Areas farther east more likely to see avg QPF of 1/2 to 1 inch
with local amts 1-2 inches.

Another wave of low pressure may bring showers and possible
thunderstorms for Thursday into early Friday. Rainfall amounts
will ultimately depend on the track of the low, which remains
uncertain at this time. Minor urban and poor drainage flooding
appears to be the main threat.


Astronomical tides will be relatively high over the next couple
of days due to the recent full moon. This will bring a chance of
localized minor coastal flooding benchmarks being touched
along the South Shore back bays of Nassau and Queens during the
evening high tide cycles occurring tonight through Thursday
night. Guidance appears to be running a bit high with recent
high tides, so have held off on issuing a coastal flood
statement for this evening`s high tide.


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





NEAR TERM...Goodman/DW
SHORT TERM...Goodman
EQUIPMENT...// is the U.S. government's official web portal to all federal, state and local government web resources and services.