-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 271126
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
726 AM EDT Tue Sep 27 2016

.SYNOPSIS...
A weakening cold front moves through this morning and stalls just
offshore this afternoon. This boundary remains in the vicinity
during Wednesday while weak high pressure builds in from the
north. Then, low pressure over the Ohio Valley and Mid Atlantic
states will meander about this region into the weekend bringing an
extended period of unsettled weather. The low will gradually lift
through New England early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Made some minor adjustments to PoPs this morning based on latest
radar imagery...otherwise forecast is on track. Showers shift
east across the CWA this morning with a weakening cold front.
Clouds then diminish behind the front west to east. High
temperatures will be near normal but perhaps slightly above normal
for the western half of the CWA where clouds will diminish
earlier.

There is a moderate risk of rip current development at the ocean
beaches for today.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
Looks like the frontal boundary will remain not too far offshore
tonight and may begin to drift back towards the CWA by late. High
pressure will also be building in from the northeast late at night
into Wednesday. This ridging will limit moisture to the low levels.
Isentropic lift pushing in from the east could supply enough lift
for light rain or drizzle with the best overall chances appearing to
be Wednesday afternoon. Will go with slight chc pops tonight, but
only over the twin forks region...and then expand pops westward
during Wendesday, but capping them at chance. Temperatures are a
blend of Superblend, MAV and MET MOS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
NWP guidance and ensembles are in good agreement with the overall
H5 pattern across North America through the first half of the
weekend...then solutions begin to diverge with the next
trough/cutoff low entering the PacNW although this should not
impact the local area until early next week.

The long term period starts with cutoff low pres over the Ohio
Valley trapped between ridging to the east and west. This will
result in the system meandering about this area into the weekend
before the ridge to the east finally begins to break down allowing
it to track through the eastern Great Lakes and New England early
next week. Confidence decreases in the finer details...although a
frontal boundary extending from the sfc low in combination with
strengthening isentropic lift will result in much needed overrunning
rainfall Wed night into Fri morning. While the periods of heavier
rainfall remain uncertain there is a signal that Thu night could
be one timeframe where heavier pcpn does occur with mid level vort
energy passing through.

Unsettled pattern will continue into the weekend with abundant
cloud cover and perhaps a transition to more showery pcpn with mid
level ridging trying to build in from the east. Moisture transport
will still be originating from the Gulf of Mexico under this
pattern. Warm front may push through on Sun as the system begins
to lift through the Great Lakes. This will also push the heaviest
rainfall to the north as well...resulting in decreasing PoPs
through Mon.

The EC remains the western outlier...hanging tough with this soln
for the past 3 runs...although it has moved somewhat closer to
consensus. Based on the location of the system...heaviest rainfall
is expected to fall west of the area. See hydro section for more
information on expected totals locally.

Removed thunder as the lower heights associated with the deep low
are too far west...thus it remains too warm aloft for any elevated
instability.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
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A cold front moves east of the terminals this morning, and then
lingers just offshore tonight.

MVFR at most terminals to start the TAF period with improvements
to VFR from west to east through the morning. -SHRA continue
moving east of city terminals and will end by mid morning.

W flow around 10 kt this morning backs to the S-SW in the
afternoon. Winds become light and variable this evening before
becoming NE around 5 kt early Wednesday morning.

   ...NY Metro Enhanced Aviation Weather Support...

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

KJFK TAF Comments: Ceiling may fluctuate between MVFR and VFR
before prevailing VFR after 14-15z.

KLGA TAF Comments: Ceiling may fluctuate between MVFR and VFR
before prevailing VFR after 14-15z.

KEWR TAF Comments: Ceiling may fluctuate between MVFR and VFR
before prevailing VFR after 14-15z.

The afternoon KEWR haze potential forecast is GREEN...which implies
slant range visibility 7SM or greater outside of cloud.

KTEB TAF Comments: Ceiling may fluctuate between MVFR and VFR
before prevailing VFR after 14-15z.

KHPN TAF Comments: MVFR could persist an hour or two longer than
indicated in TAF.

KISP TAF Comments: MVFR could persist an hour or two longer than
indicated in TAF.

.Outlook for 12Z Wednesday through Saturday...
.WED...Becoming MVFR late morning/early afternoon. NE gusts to 20
kt possible in the afternoon.
.THU-SAT...IFR/MVFR in showers. NE winds 15-20 kt with gusts
25-30 kt possible THU-FRI.
-- End Changed Discussion --

&&

.MARINE...
Wind gusts on the non-ocean waters have been falling short of
advisory criteria and are not expected to strengthen much if any, so
have cancelled the SCA for these areas. On the ocean, marginal
advisory criteria conditions are expected today. Changes were made
east of Fire Island Inlet to shorten the SCA by a few hours based on
guidance and trends.

Sub-sca conds then prevail tonight, then the pressure gradient
tightens on Wednesday with increasing winds. Will probably need
another SCA for some of the waters, but with the current headline
up, will wait before posting any headlines for that period.

SCA conditions all waters Wed night through at least Thu night
due to a tight pres gradient across the waters. There still
remains a low probability of marginal gale force gusts during this
time...thus will continue the mention in the HWO. It may only be
confined to the ocean waters however. The GFS is indicating gusts
into the 40`s but feel this is overdone. NAM looks more
reasonable...but perhaps a tad light. Have used a compromise of
the 2 weighted more towards the NAM.

Winds subside on Fri as the gradient weakens...although seas on
the ocean will remain elevated...possibly into Sat.

&&

.HYDROLOGY...
Between 1/4 to 1/2 inch of rain is expected through this morning.
No hydrologic impacts are expected at this time other than typical
urban ponding.

The proximity of a low pressure system late in the week looks to
be too far west at the current time for the local area to fall in
the axis of heaviest QPF. Currently between 1/2 and 1 1/2 inches of
rainfall is forecast between Wed night through Sat. This is not
expected to cause any hydrologic impacts.

&&

.TIDES/COASTAL FLOODING...
A persistent moderate easterly flow during mid to late week may
combine with increasing astronomical high tides associated with
the new moon on Friday to cause minor to locally moderate coastal
flooding late this week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ355.
     Small Craft Advisory until 8 PM EDT this evening for ANZ350.
     Small Craft Advisory until 2 PM EDT this afternoon for ANZ353.

&&

$$