000
FXUS61 KOKX 191802
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
202 PM EDT Thu Oct 19 2023
.SYNOPSIS...
High pressure along the Northeast and Mid Atlantic coast moves
into the western Atlantic Ocean as a frontal system approaches
to the west through tonight. A secondary low develops along the
Delmarva late Friday into Friday night and deepens through
Saturday night while tracking to the northeast. The low departs
to the northeast Sunday as high pressure builds in from the west
and settles over the region early next week. A frontal boundary
approaches late next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A convergent band of cloud cover and spotty showers has
stubbornly persisted across portions of Suffolk Co and into
southern CT. Adjusted sky and PoPs in these areas to allow for
a rogue sprinkle, but otherwise, forecast remains on track.
Today will be dry and tranquil as upper ridging builds into the
northeast with the ridge axis moving to the east this afternoon
and off the northeast coast by this evening. Meanwhile, surface
high pressure moves into the western Atlantic. Temperatures
will be near seasonal normals with a light return flow, with dew
points gradually rising.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
An amplifying trough digging into the central US today will
track east tonight into Friday. A northern stream frontal system
will be slowly deepening and tracks through the Great Lakes
region tonight into Friday afternoon. With a strong vort max
rotating into the upper trough, which becomes negative tonight,
will spin up a surface low along the mid Atlantic coast tonight.
There is still some guidance differences as to how far off the
coast the low will deepen and track to the northeast.
Precipitation with the developing coastal low will move up
along the coast tonight with chances of precipitation increasing
by late night across the southern portion of the forecast area,
and early Friday morning precipitation overspreads the area.
Late Friday night lift increases across eastern Long Island and
southeastern Connecticut as the mid level low of trough tracks
across this region. There will be developing instability along
with elevated CAPE, and a few thunderstorms will be possible
late night and toward Saturday morning, and have maintained the
chance for thunder. Model guidance suggests that there may be a
brief break, or the precipitation becoming light, Saturday
morning, and then increase again during the afternoon as the mid
and upper level low with the northern stream system tracks
across the region and merges over New England. Then Saturday
night with the upper trough and low lifting to the northeast the
precipitation winds down again.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Low pressure continues to depart to the northeast on Sunday, with a
lingering upper level trough remaining over the area. Conditions
will be mainly dry on Sunday, however, a fairly tight pressure
gradient over there area between the departing low and high pressure
to the west will make for a rather gusty day. NW winds are expect to
gust up around 30-35 mph. Highs on Sunday will be in the middle and
upper 50s, but will feel a bit cooler with the gusty winds.
The gradient relaxes Sunday night, with gusts diminishing. A
shortwave in the upper trough will swing through the region late
Sunday night and Monday, which may result in some additional rain
showers, mainly east of NYC. Have bumped up POPs a bit to account
for this, but will keep POPS limited to just chance at this time.
Surface high pressure and upper level ridging then build into the
region Monday night and remain through Wednesday. As the high and
upper ridge move east late late Wednesday, a frontal boundary slowly
approaches from the west. There are some timing differences with
this boundary, so expected some possible changes late in the week
with respect to a chance of precipitation during the second half of
next week.
Temperatures each day next week gradually rise. Monday - middle
and upper 50s, Tuesday - upper 50s to lower 60s, Wednesday - lower
to middle 60s, and Thursday - middle to upper 60s. Lows overnight
will be in the 30s and 40s, with the coldest night expected to be
Monday night. There will be a chance of some frost Monday night,
especially across the usually colder spots in the forecast area.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
High pres will continue to drift east of the region thru tngt.
A low pres sys approaches on Fri.
VFR thru this eve. CIGS lower aft 6Z, becoming MVFR or lower by
12Z most areas. Rain in the mrng, tapering of from S to N by
18Z. Additional shwrs possible aft 18Z, but coverage and exact
timing/placement are uncertain attm. Regardless of shwrs, some
-ra/dz may linger thru 00Z Sat.
KGON may stay VFR thru the TAF period.
S winds thru tngt, backing to the SE Fri mrng and remaining thru
00Z Sat.
....NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of MVFR CIGS may be a little later than fcst, closer to
10Z.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday night through Saturday: MVFR/IFR possible with showers.
Sunday: MVFR possible with CIGS around 3000 ft. W to NW wind
gusts 25-30 kt.
Monday: VFR with gusty NW flow.
Tuesday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
A south to north oriented line of weak showers across portions
of the ocean and south shore bays may produce a funnel cloud or
weak waterspout this afternoon. Marine Weather Statement is in
effect in these areas for this potential.
Otherwise, with a weak pressure gradient across the waters
today and tonight, winds and seas remain below advisory levels
across the forecast waters.
Southerly flow increases Friday into Friday night as a low
pressure system approaches the waters to the west. And, during
Saturday ocean seas will be building, reaching SCA levels in the
morning. Then with a deepening low passing to the northeast of
the waters Saturday night SCA gusts become likely across all the
forecast waters.
The pressure gradient over the area waters tightens on Sunday,
bringing the best chance for gales to the ocean waters. While
the chances for gales are lower on the non-ocean waters, can not
rule out a few gust to gale force. Winds and seas with then
gradually diminish Sunday night, with the non-ocean waters
falling below SCA conditions, however the ocean will continue to
see seas at or above 5ft through Sunday night. The seas on the
ocean waters are forecast to fall below SCA levels Monday
morning. By Monday afternoon or early evening, sub-SCA
conditions are then expected on all the waters and should remain
below SCA levels through Wednesday.
&&
.HYDROLOGY...
Rainfall of 0.75 to 1.25 inches is possible from late tonight
through Saturday night, with most of the rainfall occurring
Friday into Friday night. There are no flooding concerns at this
time. And there are no hydrologic concerns Sunday through next
week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BC/MET
NEAR TERM...DR/MET
SHORT TERM...MET
LONG TERM...BC
AVIATION...JMC
MARINE...BC/MET
HYDROLOGY...BC/MET