Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 251922
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
322 PM EDT Sun Sep 25 2016

.SYNOPSIS...
High pressure over the Northeast will slowly drift off the coast
on Monday. A frontal system moves through on Tuesday. The front
will likely linger near or just offshore through the end of the
week...resulting in an unsettled weather.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Clear skies tonight with the high pressure ridge building over the
forecast area. As a result, winds should quickly decouple this
evening and temperatures will drop through the 40s. Some patchy
frost has been included in the forecast for portions of the Long
Island Pine Barrens and the northern extremities of Orange county
with reading likely falling at or below 36 degrees.

There is a moderate risk for rip currents through this evening.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
After a sunny start to the day, high clouds will overspread the
area from the west as a 500 millibar trough over the Northern
Plains advances towards the area. Southerly winds will increase,
especially along the south shore of Long Island, as the center of
the high sets up over the Atlantic. The models progress the
associated front eastward at around 20 kt, so the front will
supposedly not delay its arrival. Based on this speed and timing,
rain chances begin after dark, with the best chance for rain
coming during the overnight period. The ribbon of moisture ahead
of the front is progged to translate into about 1.8 inches of
precipitable water, so max rainfall with the steadily moving
system is expected to be capped at around an inch and a half at
this time.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Models in good agreement with a deep closed low sitting over the
Great Lakes/Southern Ontario on Tuesday. Then models coming into
better agreement with the upper low slowly sinking se into the
Ohio/Tennessee River Valley through the end of the week...and
possibly meandering around through the weekend. This setup is
pointing towards a more unsettled weather pattern for the mid to
late week period.

At the surface...a cold front associated with the stacked Great
Lakes low approaches the region Monday Night...and crosses the
region Tuesday. Continued good agreement in deep layered lift
interacting with southern moisture (1 to 2 std PWAT) bringing a
soaking rain during the late Monday night to Tuesday morning period.
An isolated tstm is not out of the question Tue morning with some
weak elevated instability and strong lift ahead of the cold
front...but prob is quite low. Appears the cold front pushes far
enough east late Tue/Tue eve for rain to taper off.

Confidence is increasing in an unsettled mid to late week period
based on ensemble/operational trend towards a less progressive and
cutoff upper level scenario as described earlier. This will result
in potential for additional waves of low pressure to develop along
the cold front just offshore as well as broad low pressure to sit sw
of the region...affecting the region with periods of rain mid to
late week. Forecast has been further weighted towards the unsettled
scenario.

Temps on Tuesday will likely be above seasonable with offshore flow
in wake of cold front and with any partial clearing.
Thereafter...temps should be nears seasonable under a maritime
airmass.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR as high pressure builds across the area tonight, then
offshore on Monday.

N-NW winds 5-10 kt with occasional gusts to around 15 kt this
afternoon, especially east of the NYC terminals. Winds may vary 10
to 20 degrees, but generally expected to stay right of 310
magnetic.

Light NE flow tonight then veers around to the SE by late Monday
morning.

Mid and high level clouds begin to work into the area on Monday
ahead of an approaching frontal system

.Outlook for 18Z Monday through Friday...
.MON...VFR...MVFR w/areas of IFR in showers late at night.
.TUE...MVFR w/areas of IFR in the morning. Becoming VFR from West to
East midday.
.WED...VFR.
.THU and FRI...Potential IFR/MVFR CIGS with RA. NE Wind 15-20 KT.

&&

.MARINE...
Seas have remained just below 5 ft this afternoon. As a result,
the small craft advisory for hazardous seas has been cancelled.
Southerly winds will increase Monday ahead of a cold front, but
speeds will not reach 25 kt until Monday night. A small craft
advisory will likely be required on the ocean as a result, and
possible elsewhere.

SCA conditions likely Tuesday morning on ocean waters...and possibly
eastern nearshore waters...ahead of an approaching frontal system.
Winds will fall below sca behind the front Tue afternoon...with
ocean seas gradually following suit.

Sub sca conditions likely return for Tues night into Wed...then
potential for sca seas to develop once again with persistent
easterly flow for remainder of the week. There is still a great deal
of uncertainty regarding the specifics of the forecast during this
time period.

&&

.HYDROLOGY...
Around an inch of rain is possible Monday night into Tuesday. Some
locally higher amounts are possible. Additional bouts of rain are
possible during the mid to late week. No significant hydrologic
impacts are expected at this time.

&&

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

&&

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


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