Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 280850

Area Forecast Discussion
National Weather Service New York NY
450 AM EDT Fri Oct 28 2016

High pressure builds in today and tonight and slides offshore on
Saturday. A cold front moves into the area Saturday night, then
stalls just south of Long Island with a wave of low pressure
moving along it from Sunday into Sunday evening. High pressure
then builds in through Monday night, then slides offshore through
Tuesday night. A cold front pushes through Wednesday, followed by
high pressure building in through Thursday.


A trough axis and shortwave aloft will be right over us this
morning. The flow aloft then turns anticyclonic as the trough shifts
east through the day. High pressure will therefore be building in at
the surface with a gusty NW flow. Expecting a mostly to partly sunny
day for the most part, but there could be periods where its mostly
cloudy as some mid level moisture will be around.

High temperatures for the day have already occurred across many locations
over Long Island and SE CT. Based on mixing up to 900mb and good
downsloping winds...expecting afternoon temperatures across the
entire forecast area to reach the upper 40s to lower 50s.
There Could even be some mid 50s across the city and urban
corridor of NE NJ.


The surface ridge shifts into the region tonight. There could be some
cirrus moving in late at night, but it should be mostly clear with
light to calm winds for a long enough time for decent radiational
cooling conditions. Will therefore add some frost to the forecast
for some of the interior suburbs.

Saturday looks like its shaping up to be another mostly to
partly sunny day overall with maybe a little more in the way of
clouds during the afternoon versus the morning. Subsidence from
high pressure will greatly limit the mixing depth. Preferred the
cooler side of guidance for high temps, so used an even mix of
MET MOS and SuperBlend. Highs in the upper 50s to lower 60s.


Northern stream ridging passes over the area Saturday night, keeping
things dry until maybe late at night, when some rain could build
into far western zones ahead of the next system.

A deepening northern stream trough builds in Sunday and Sunday
night, with increasing low level warm advection. As a result rain
should build in from W to E Sunday, then taper of Sunday night as
the low levels begin to dry in response to drier air advecting in
from the NW.

Deep layer ridging builds in Monday/Monday night then slides
offshore on Tuesday. Subsidence associated with the ridge should
keep things dry. Cloud cover should be at a minimum from Monday into
Tuesday morning, then increase later Tuesday ahead of the next
shortwave building in behind the ridge.

A northern stream shortwave trough passes to the north Tuesday
night, at this time it appears that any significant forcing should
pass far enough north to keep things dry.

Northern stream ridging then builds in Wednesday and Wednesday
night, with once again associated subsidence keeping things dry.

The ridge axis exits to the east early Thursday with a 700-500 hPa
trough approaching from the west. This warrants slight chance pops
over NW zones Thursday afternoon.

For temperatures Saturday Night-Thursday...

Lows Saturday night were based on a blend of MAV/MET/ECS guidance
and NAM 2-meter temperatures and should be around 10-15 degrees
above normal.

Highs on Sunday were based on a blend of MAV/MET guidance, NAM 2-
meter temperatures and a mix down from 975 to 925 hPa per BUFKIT
soundings. Highs should be around 10 degrees above normal.

Lows Sunday night were forecast using a blend of
MEX/MEN/ECE/ECM/EKD/WPC guidance and NAM 2-meter temperatures and
should be within a couple degrees of normal.

Temperatures Monday-Thursday were based on the Superblend, blended
towards a blend of MOS Monday and Wednesday night, when there is the
potential for decent radiational cooling. Temperatures start out
below normal Monday, recover to near normal by Tuesday and then
should be above normal Wednesday and possibly Thursday.


Low pressure centered just east of Long Island will continue to
shift east, followed by building high pressure. Lingering LIFR
conditions at KSWF should improve to MVFR or VFR by daybreak.
Gusty NW flow will then develop, right around 310 magnetic at
most sites, with sustained winds 15-25 kt and gusts 25 kt to just
over 30 kt, highest at the NYC metros especially KJFK. Winds
should also stay up until 00Z, longer than MOS guidance which has
been too quick to diminish winds at sunset in other recent gusty
NW flow events. BKN035-040 VFR cigs should also develop by
afternoon and persist until around 00Z.

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

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

KJFK TAF Comments: High confidence on wind speeds and general
direction, but low confidence on exactly which side of 310
magnetic wind direction will fall today.

KLGA TAF Comments: High confidence on wind speeds and general
direction, but low confidence on exactly which side of 310
magnetic wind direction will fall today.

KEWR TAF Comments: High confidence on winds.

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

KTEB TAF Comments: High confidence on wind speeds and general
direction, but low confidence on exactly which side of 310
magnetic wind direction will fall today.

KHPN TAF Comments: High confidence on winds.

KISP TAF Comments: High confidence on wind speeds and general
direction, but low confidence on exactly which side of 310
magnetic wind direction will fall today.

.Late tonight...Diminishing NW winds. Patchy fog possible at
KSWF, otherwise VFR.
.Saturday...VFR. SW winds G20kt in the afternoon and early evening
NYC metro/coast.
.Sunday...Rain likely with MVFR conditions, especially in the
afternoon and early evening. Becoming VFR later at night, with N
winds G20kt possible, highest NYC metro/coast.
.Monday...VFR. N winds G20kt possible in the morning.


Winds will increase today as high pressure builds in behind
a departing low pressure system. Gale Warnings will remain on
the ocean waters east of Fire Island Inlet, and have been
extended into the evening hours of tonight. SCA conds are then
likely to follow into the overnight hours here. All other waters
will be under a SCA through this evening. There could however be
occasional gusts to Gale force on the ocean west of Fire Island
Inlet. Sub- SCA conditions then expected on all waters for most
of Saturday with a high pressure ridge shifting offshore. Winds
and seas on the ocean then build to marginal advisory criteria
late in the day.

A moderate pressure gradient over the waters Saturday night will
allow for winds up to 20 kt, with gusts up to 25 kt possible, mainly
on the coastal ocean waters. Seas on the coastal ocean waters should
remain at SCA levels Saturday night and possibly into Sunday.

The pressure gradient slackens early next week, with winds up to 15
kt from Sunday into Monday, then 10 kt or less late Monday and


No significant (0.5 inches or more) widespread precipitation is
expected through Thursday.


MARINE...Small Craft Advisory until 2 AM EDT Saturday for ANZ330-335-
     Gale Warning until 10 PM EDT this evening for ANZ350-353.


LONG TERM...Maloit
HYDROLOGY...JC/Maloit is the U.S. government's official web portal to all federal, state and local government web resources and services.