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Area forecast discussion 
National Weather Service New York New York
352 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/...
deep upper trough continues to track southeast 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 New Jersey.

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
including a deep plume of moisture across the central states where
it is currently located. Pwats are forecast to range between 1.5
and 2 South Dakota above normal. Some moderate to heavy rain is possible
as the front moves across. 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 /07z Sunday through Thursday/...
VFR plus !

Kewr wind direction this afternoon will vary either side of 310
magnetic, but gusts do not appear likely to occur with the speed
averaging below 10 knots.

Kjfk wind direction may back more to west or even west-southwest for or during
the international departure bank.

Outlook for 06z Monday through Thursday...
Monday...VFR.
Tuesday...MVFR W/areas of IFR in the morning. Becoming VFR from west to
east midday.
Wednesday...VFR.
Thursday...potential IFR/MVFR ceilings with rain. NE wind 15-20 knots.

&&

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
southeast swells from distant tropical cyclone Karl will continue to
impact the ocean waters with seas right 4 to 5 ft. The Small Craft Advisory 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
Small Craft Advisory may be cancelled earlier if seas do not build to 5 ft this
morning.

Sub-Small Craft Advisory conditions are likely on Monday with Small Craft Advisory conditions
Monday night into Tuesday on ocean waters ahead of a frontal
system. The possibility also exists for Small Craft Advisory 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
relatively quick.

&&

Okx watches/warnings/advisories...
CT...none.
New York...none.
New Jersey...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

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