Area Forecast Discussion
Issued by NWS Upton, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KOKX 251123
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
723 AM EDT Sun Sep 25 2016

.SYNOPSIS...
High pressure settles over the area through tonight. The high
slides offshore on Monday followed by a frontal system moving
through on Tuesday. The front may linger near or just offshore
through the end of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Forecast remains on track this morning.

Deep upper trough continues to track SE across far eastern Canada
today with high pressure settling over the area at the surface.
Northerly flow will continue to usher in an autumn airmass with
dew points in the 30s today under clear skies. These dew points
will combine with temperatures in the middle and upper 60s for
most locations. A few readings near 70 are likely in the NYC metro
and Urban NE NJ.

There is a moderate risk of rip current development at ocean
beaches today.

Excellent radiational cooling conditions tonight with high
pressure overhead, nearly calm winds, and mostly clear skies.
Coldest locations across the interior and Long Island Pine Barrens
fall into the upper 30s. Elsewhere, lows will generally be in the
lower and middle 40s with readings in the upper 40s and lower 50s
closer to the NYC metro.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
Deep layered ridge axis moves over the region on Monday as the
surface high begins to slide offshore. This will set the stage for
another seasonable autumn day with temperatures in the upper 60s
and lower 70s.

Models continue to come into better agreement with the evolution
of a deep upper low settling over the Great Lakes/Southern Ontario
late Monday into Monday night. A frontal system associated with
the upper low approaches Monday night with increasing warm
advection and moisture. Overall, deterministic and ensembles agree
on the front moving across on Tuesday morning/early afternoon.
However, there are some members that are a bit slower. Have
increased PoPs to categorical Tuesday morning, decreasing to
chance in the afternoon. This system already has shown signs of
a deep plume of moisture across the central states where it is
currently located. PWATs are forecast to range between 1.5 and 2
SD above normal ahead of the front with moderate to heavy rain
possible. A low amount of elevated CAPE is noted on NAM BUFKIT
profiles, with more stable profiles on the GFS. An isolated rumble
of thunder cannot be ruled out, but the chance appears very low at
this time to include in the forecast.

Some clearing is expected Tuesday afternoon as much drier air
begins to work in behind the front.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
There remains a general agreement on the upper low sitting near or
over the Great Lakes/Ohio Valley region through midweek...before
models diverge in evolution and opening on the low for the late
week period.

With this in mind, forecast uncertainty continues for the mid to
late week on evolution of the closed low and how quickly it opens
up and move through the east coast. A more progressive scenario
would allow high pressure to return for the late week with mainly
dry and seasonable conditions. Meanwhile a less progressive or
cutoff scenario would result in potential for additional waves of
low pressure to develop along the cold front and affect the region
mid to late week. The forecast continues to be weighted towards a
dry solution, but have noted the 00z models have indicated the
more unsettled solution may hold a little more weight. Rainfall
chances may need to be increased in subsequent forecasts as
confidence increases in the outcome.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
VFR Plus !

KEWR wind direction this AFTN will vary either side of 310
Magnetic, but gusts do not appear likely to occur with the speed
averaging below 10 KT.

KJFK wind direction may back more to W for or during the INTL
Departure Bank.

.Outlook for 12Z Monday through Thursday...
.MON...VFR.
.TUE...MVFR w/areas of IFR in the morning. Becoming VFR from West to
East midday.
.WED...VFR.
.THU...Potential IFR/MVFR CIGS with RA. NE Wind 15-20 KT.

&&

.MARINE...
Northerly winds will continue across the waters through Sunday
night with wind gusts around 20 kt still possible, mainly on the
ocean this morning. A gust to 25 kt is also possible. Long period
SE swells from distant tropical cyclone Karl will continue to
impact the ocean waters with seas right around 4-5 ft. The SCA
will remains up on the ocean through the day today. Have noted
that seas have stayed closer to 4 ft and the NWPS guidance may be
a foot too high on seas. Will continue to monitor trends, but the
SCA may be cancelled earlier if seas do not build to 5 ft this
morning.

Sub-SCA conditions are likely on Monday with SCA conditions
Monday Night into Tuesday on ocean waters ahead of a frontal
system. The possibility also exists for SCA winds on near shore
waters.

Sub sca conditions likely return for Wednesday and Thursday as
the pressure gradient weakens although there is a great deal of
uncertainty regarding the forecast during this time period.

&&

.HYDROLOGY...
A frontal system moves through Tuesday with a general 1/2 to 1 inch
of rain likely...with locally higher amounts possible. Any
hydrologic impacts will be minor as the system will move through
quickly.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ350-
     353-355.

&&

$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...DS/NV
AVIATION...Tongue
MARINE...DS/NV
HYDROLOGY...DS/NV


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.