Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 241954
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
254 PM EST Fri Feb 24 2017

.SYNOPSIS...
High pressure will remain steady over the western Atlantic
through tonight. A frontal system will approach on Saturday,
and move across Saturday Night, followed by building high
pressure Sunday into Monday. A couple of fast moving
disturbances may bring unsettled conditions beginning Monday
night.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 out of 6 Climate Records Broken - see Climate Section.

East coast ridging and western Atlantic high pressure control
the region today, with mostly sunny skies.

With region in warm sector, another early springlike day today,
with highs in the 60 to lower 70s. A moist air mass advecting
over cold ocean waters could lead to advection fog/stratus
developing along the NJ coast and working northward toward the
south shore of Long Island late.

With SW flow aloft and plenty of sunshine, most areas from NYC
north/west should reach the lower 70s. Elsewhere, temps away
from south facing shores should climb well into the 60s. Marine
influence will likely limit temps to the 50s for most of the
south shore areas.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
East Coast ridging tonight will give way to a Central Plains
upper low shearing toward Hudson Bay on Saturday, with
associated trough and frontal system swinging toward the region
late in the day and then though Sat night.

Coastal stratus/fog development are favored in a second night
of mild/moist southerly flow tonight. Models soundings and high-
res/SREF guidance strongly indicating more widespread
stratus/fog development across much of the region
tonight, which may then linger across CT/Long much of the day
with low level flow backing more to the S-SE. Temps will likely
be cooler on Sat with more of an onshore flow and cloud cover,
with temps ranging from well into the 60s for areas well NW
and W of the Hudson, to 50s for south and east coastal areas.
Not much in the way of forcing or focus for rain overnight
into Sat morning, so shower threat looks isolated at most. Can`t
rule our some patchy drizzle later tonight into Sat morning as
well if low levels saturate sufficiently.

Main rain activity will be along and immediately behind an
approaching frontal system. A narrow band of convection will
likely approach from PA/NY along the leading edge of the front
late Sat into Sat eve, with strong convergence of a moist (PW
2-3 std above avg) and marginally unstable air mass advecting
in via a 40-kt LLJ, plus lift via an approaching shortwave.
There is potential for brief heavy rain/thunder/30-40 mph wind
gusts with this line mainly west of the Hudson, where there
should be some weak surface/elevated instability. This line
should weaken as it encounters the stable marine layer along the
coast. Otherwise, expect lighter post-frontal activity Sat eve
ahead of approaching shortwave axis, shifting offshore by
around midnight.

In the wake of the shortwave/cold front Sat night, a dry and
cooler air mass will build in on breezy NW flow. With strong CAA
and deep mixing, wind gusts of 30-40 mph possible.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
High pressure builds towards the area on Sunday and Sunday
night. Temperatures on Sunday will be in the low to mid 40s with
low temperatures Sunday night in the low to mid 30s along the
coast and upper 20s inland.

High pressure moves offshore Monday, as a storm system moves out of
the mid Atlantic states Monday night and Tuesday. A chance of rain
and snow are possible with the storm system. Light rain is
possible again on Tuesday night and into early Wednesday as a
warm front pushes north of the region Wednesday, followed by a
cold front later Wednesday. High Pressure builds behind the cold
front on Thursday.

Temperatures during this period should be 5 to 10 degrees above
normal.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
Late spring-like pattern with a warm front north over central
NY State and New England with convection along it. A cold front
approaches from the west late Saturday afternoon with convection.

VFR this afternoon with south-southwest flow. Winds along Long
Island are gusting 20-25 KT as cool ocean comes on shore.

Sea Fog is moving north along the Jersey coast as of 20Z. The
forecast question of the day remains how will this expand and
affect the terminals?

Status and some fog remain likely for Saturday Morning with
IFR.

     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: Lots of uncertainty on how sea fog will
affect VSBY and cigs this evening. Fog is moving quickly north
along the Jersey Coast and will reach the Terminal by 2130Z.
Vsby may be slow to drop - but could drop rapidly as sunset.

KLGA TAF Comments: High confidence in VFR into the early evening.
Uncertainty with development of fog and stratus very late this
evening.

KEWR TAF Comments: High confidence in VFR into the early
evening. Uncertainty with development of fog and status very
late this evening.

KTEB TAF Comments: High confidence in VFR into the early
evening.

KHPN TAF Comments: High confidence in VFR into the early
evening.

KISP TAF Comments: Lots of uncertainty on development of fog and
stratus late this evening.

.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
.SAT AFTN...Mostly IFR through sunset...though CIGS may lift to
MVFR.
.SAT NGT...Improving to VFR with a COLD Frontal Passage around
00Z that will included at least SCT Convection. WNW Wind G25 KT
after the front.
.SUN...VFR. NW WND G25KT
.MON...VFR.
.TUE...MVFR with areas of IFR in showers.
.WED...Improving to VFR. W WND G20KT.

&&

.MARINE...
Persistent S-SW flow around western Atlantic high pressure and
long period easterly swells should have seas hovering around 3-4
ft much of tonight, and up to 5 ft Saturday morning. Will hold
off of SCA due to marginal nature of hazard.

Potential for dense fog over the near shore waters late today
into Saturday morning, which may linger until a cold frontal
passage Sat evening.

Ocean seas should gradually build to SCA levels Saturday
afternoon ahead of a cold front, with marginal SCA gusts
possible. Higher confidence is in SCA gusts in the wake of
frontal passage Sat Night, with even potential for a brief
period of gale force gusts.

SCA conditions expected to continue across the ocean waters on
Sunday. Winds and waves will then gradually subside Sunday night
into Monday as high pressure moves south of the area. The next
chance of SCA conditions will be Monday night into Tuesday as
winds strengthen following a warm frontal passage. Winds and
seas may remain at or near SCA conditions through late week
ahead of a cold front.

&&

.HYDROLOGY...
Basin avg rainfall of 1/4 to 1/2 inch is likely on Saturday,
with local amounts up to an inch that could cause associated
nuisance ponding.

&&

.CLIMATE...
The following are record high temperatures for today February
24, 2017 along with the forecast high temperature.

Record High Temperature          Forecast High
-----------------------------    -------------
Central Park........75 (1985)    70
LaGuardia...........73 (1985)    71
Kennedy.............60 (1984)    61 (record broken)
Islip...............59 (2000)    63 (record broken)
Newark..............73 (1985)    74 (record tied)
Bridgeport..........60 (2016)    61 (record broken)

The following are record high minimum temperatures for Saturday
February 25, 2017 along with the forecast minimum temperature.

Record High Min Temperature      Forecast Min
------------------------------   ------------
Central Park........51 (1930)    53
LaGuardia...........49 (1996)    54
Kennedy.............46 (1996)    50
Islip...............47 (1996)    50
Newark..............47 (1996)    54
Bridgeport..........44 (1996)    49

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$
SYNOPSIS...Fig/NV
NEAR TERM...Goodman/NV
SHORT TERM...NV
LONG TERM...Fig
AVIATION...Tongue
MARINE...Fig/Goodman/NV
HYDROLOGY...Fig/NV
CLIMATE...



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