Area Forecast Discussion
Issued by NWS Upton, NY-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KOKX 281720
Area Forecast Discussion
National Weather Service New York NY
120 PM EDT Fri Apr 28 2017
A series of weak fronts cross the region today through Sunday.
High pressure moves to the north of the region Sunday, shifting
east by Monday with a warm front moving northward through the
area by afternoon. A cold front moves through Monday night,
followed by weak high pressure through Wednesday. A frontal
system approaches from the southwest Thursday and moves along
the coast through late week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --The cold front was weakening or has dissipated across the
eastern zones, and with increasing subsidence as high pressure
builds into the region skies have cleared.
Temperatures have been rising a bit quicker than forecast and
made adjustments, even raising highs this afternoon a degree or
two inland. Coastal sections were cooler with more of a
southerly flow, as local sea breezes develop.
-- End Changed Discussion --
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Much of tonight night should remain dry and warm. With dew
points rising into the upper 50s and possibly into the lower
60s by7 Saturday morning, the air will feel more humid. A cold
front will approach from the northwest, giving the area a chance
for showers, mainly just before sunrise Saturday morning. Of
particular concern is the 00Z NAM, which looks to spin up an
MCS. Not totally bought into this, but needs to be monitored
with further model runs.
The cold front should push through late in the afternoon,
however, any lift with this front weakens in the afternoon, so
just a passing shower or thunderstorm is possible away from the
coast. Coastal areas may not see any activity in the afternoon
as marine influence keeps the atmosphere more stable here.
Temperatures will be even warmer on Saturday than Friday, with
highs in the upper 70s (even along much of the coast) to middle
80s (mainly in the New York City metro area). The Twin Forks of
Long Island and southeast Connecticut will see highs in the
upper 60s to lower 70s.
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
By Sunday, an upper ridge centered off the southeast coast will
build northward leading to a strengthening subsidence inversion
across the area. Although there will be elevated instability, the
strengthening inversion, in part due to low-level onshore flow, and
lack of overall forcing for ascent should generally limit
precipitation/thunderstorm chances. Onshore flow and cloud cover
will limit heating, keeping temperatures near or slightly below
climatological normals during the daytime, and slightly above normal
for night. Onshore flow will continue into Monday morning, likely
saturating lower levels and leading to increasing chances of light
rain and/or drizzle. Went with a slightly slower European solution
regarding the warm frontal passage, keeping the area cooler and
cloudier for the earlier part of the day. The front should gradually
move northward by afternoon or perhaps evening, with south flow
leading to above normal temperatures across inland areas away from
marine influence, and near normal elsewhere. The cold front moves
through Monday night with likely rain and a chance of thunderstorms,
giving way to clearing skies, gusty west winds and seasonable
temperatures by Tuesday afternoon. Gusty west flow will continue
into Wednesday, with cold advection offset somewhat by downsloping.
Went slightly above guidance for Wednesday due to downslope
component of the winds and lack of expected marine influence. By
late week, a deepening area of low pressure will approach from the
south with increasing chances of rain late into the work week.
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
A weakening cold front dissipates as it moves into western
portions of the area this morning. High pressure then builds in
from the southeast into tonight.
VFR except lingering stratus and fog eastern terminals. These
locales should improve by 11 am or noon, perhaps 1 pm at GON.
Light and variable winds become WNW-W over western terminals
and SW eastern terminals late this morning. Seabreezes likely at
KJFK/KLGA/KISP and CT terminals this afternoon. Occasional
gusts to around 15 kt are possible this afternoon
KEWR/KTEB/KHPN, mainly after 18-19Z. These locations should
settle from the W/SW.
Winds become light and variable again tonight.
VFR tonight with possible showers late. Low chance for patchy
NY Metro Enhanced Aviation Weather Support...
Detailed information...including hourly TAF wind component fcsts
can be found at:
KJFK TAF Comments: Amendments for wind direction changes are
possible, but a seabreeze is expected by 18-19Z.
KLGA TAF Comments: Amendments for wind direction changes are
possible, but a seabreeze is expected by 20-21Z.
KEWR TAF Comments: Amendments for wind direction forecast
possible. Expect winds to become west/SW by 18-20Z. Low chance
for SE seabreeze late.
The afternoon KEWR haze potential forecast is green...which
implies slant range visibility 7SM or greater outside of cloud.
KTEB TAF Comments: Amendments for wind direction changes
possible. West/Sw winds are expected by 16-18Z.
KHPN TAF Comments: Amendments are possible for low cloud
forecast. Do expected VFR conditions by 15-16Z.
KISP TAF Comments: Seabreeze is expected by 17-18Z.
.OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
.Saturday morning...Isolated-scattered showers with embedded
thunderstorms are possible.
.Saturday afternoon-Sunday...VFR. W-NW winds G15-20KT possible
.Sunday night-Monday...MVFR or lower possible. SW winds G20-25KT
.Monday night...MVFR possible along with isolated to scattered
showers and thunderstorms isolated thunderstorms. LLWS possible.
Wind waves and swells have been subsiding across the ocean
waters, particularly west of Fire Island Inlet, where seas were
below 5 feet. So, has cancelled the hazardous seas advisory for
this zone. Seas will take time to subside east of Fire Island
Inlet and will keep the advisory there.
Winds and seas will remain fairly tranquil on Sunday, though
isolated gusts to 25 kt will be possible during the afternoon
and early evening. As winds become more southerly and increase
on Monday ahead of an approaching cold front, seas will build to
5 to 9 ft Monday night. Ocean seas will linger over 5 ft into
Tuesday and Wednesday as flow becomes more westerly but remains
strong, with gusts to 25 kt possible, mainly during the
afternoon and evening. Seas will briefly diminish Wednesday
night into Thursday as weak high pressure moves though, before
increasing again Thursday night ahead of an approaching area of
No widespread hydrologic impacts foreseen through the next 7
MARINE...Small Craft Advisory for hazardous seas until 2 AM EDT
Saturday for ANZ350-353.