360
FXUS61 KOKX 060009
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
809 PM EDT Sat Oct 5 2024

.SYNOPSIS...
High pressure builds across the area into Sunday morning, then
gives way to a frontal system approaching from the west. The
associated warm front lifts through the area Sunday night,
followed by the cold frontal passage on Monday. A series of
weak cold fronts moves through the area midweek as an upper
level disturbance slides through the northeast U.S. Meanwhile a
large Canadian high pressure system then builds in west of the
area midweek and south of the area late in the week.

&&

.NEAR TERM /THROUGH SUNDAY/...
Surface high pressure and upper ridge will remain over the region
through Sunday. Meanwhile, an upper level closed low, and associated
trough will move through southern Canada and the Northern Plain
states tonight, and move into the Great Lakes region on Sunday. Lows
tonight will fall into the 40s and 50s. Sunday, highs will be in the
upper 60s and lower 70s.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
High pressure over the area slides east Sunday night. This will
allow a frontal system to impact the region late Sunday night into
Monday. First, a warm front will lift north across the region Sunday
night, then a cold front will follow on Monday.

Expect POPs to gradually increase Sunday night with showers becoming
likely after midnight and continuing into Monday morning. With
some CAPE and instability, along with the forcing, isolated
thunder cannot be ruled out. With the warm air moving in, Sunday
night`s lows will be in the middle 50s to lower 60s.

The upper closed low opens Monday as the upper trough become
negatively tilted, slowing the eastward progression of the
associated cold front. Showers and isolated thunder will continue
much of the day before the cold front moves east by Monday evening.
Highs will be in the upper 60s to lower 70s.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Good model agreement on Hudson Bay upper low on Monday, gradually
sliding east into northern New England mid next week, before
gradually lifting NE Friday into next weekend. Model spread increase
for late week on how quickly the upper trough lifts.

Deep NW flow continues to bring in a fall airmass through mid-week
(coolest of the early fall season so far) as high pressure gradually
builds to the west of the region, and a series of reinforcing cold
fronts move through the area Tue Night and Wed Night, bringing heart
of cool airmass Wed into Thu. Mainly dry conditions during this
period, but as southern periphery of upper low moves overhead and a
couple of embedded shortwaves rotate through sct-bkn instability cu
likely, and even isolated instability shra/sprinkle activity across
the interior Wed and Thu aft/eve.

Highs Tue are likely to run slightly to a few degrees below
seasonable, and then several degrees below seasonable Wed/Thu (Upper
50s to 60 F interior, lower 60s to 65F city/coast) as heart of cool
airmass descends on the region. Bias corrected NBM deterministic
continues to run close to NBM 75-95th percentile of raw ensemble
during this period (highest for the coast), so potential that the
deterministic could be running a bit high considering this regime
change and persistent caa. Have blended NBM deterministic and NBM
50th based on above, with potential for diurnal temps to trend
down a few degrees from current forecast.

Mixed low-levels should keep overnight lows from bottoming out
thru much of the time period, but far outlying areas would be
several degrees cooler than forecast Mon Night thru Thu Night if
able to decouple, bringing a low potential for frost,
particularly Wed and Thu Night. MOS guidance will provide a
better picture within a 72 hr window on this threat.

NBM spread increases for Friday into the weekend based on how quickly
upper trough lifts ne, but overall a moderating trend signaled for
Fri into the weekend as upper low (cold core) likely lifts.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
High pressure builds into the area through Sunday morning, then
gives way to an approaching frontal system. The associated warm
front lifts through the area Sunday night, followed by the cold
frontal passage on Monday.

Mainly VFR. Chance of MVFR in showers after 06Z Monday.

N/NE winds less than 10 kt overnight will veer around to the
S/SE on Sunday.

...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

No unscheduled amendments expected.

OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...

Sunday Night through Monday: MVFR likely in showers late Sunday
night into Monday. Becoming VFR Monday afternoon with showers
ending from west to east. Chance of NW G15-20kt Monday
afternoon.

Tuesday: VFR.

Wednesday and Thursday: VFR. W-NW G15-20kt, mainly late morning
into the afternoon.

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

&&

.MARINE...
Sub-SCA conditions remain across the forecast waters through
Sunday. Ocean seas are expected to build to SCA levels Sunday
night as long period swells from Hurricane Kirk (see NHC for
forecast details) move into the waters. Long period swells from
Hurricane Kirk peak at 5 to 6 feet Monday, gradually subsiding
below SCA late Monday night into Tuesday morning.

Generally sub-SCA NW gusts through midweek, but low potential for
brief nocturnal marginal SCA gusts over the ocean in wake of
reinforcing cold fronts Mon Night thru Thu Night.

&&

.HYDROLOGY...
No hydrologic issues are expected throughout the forecast
period.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from midnight Sunday night to 8 AM EDT
     Tuesday for ANZ350-353-355.

&&

$$

SYNOPSIS...BC/NV/DW
NEAR TERM...BC/NV
SHORT TERM...BC
LONG TERM...NV
AVIATION...DW
MARINE...BC/NV
HYDROLOGY...BC/NV