Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
1007 PM EDT Sat Oct 3 2015
high pressure builds down from southeastern Canada through
Sunday...then builds into the Canadian maritime provinces through
Monday night. At the same time Hurricane Joaquin will stay well
offshore. A weak cold front moves through on Wednesday followed by
another high building in from the west Tuesday through
Thursday. The high slides to the east Thursday night. Low
pressure approaches from the west on Friday.
Near term /until 6 am Sunday morning/...
forecast remains on track. Minor updates to hourly temperatures
and dew points. Weak returns still seen on radar...bit not much in
observations. Mesoscale models showing low coverage for light
rain or drizzle. Adjusted weather grids slightly. Cloudy
conditions with chilly temperatures will be the norm overnight.
Strong northeast flow gusting up to 35 miles per hour at times will continue
overnight as a result of the tight pressure gradient between
strong high pressure to the north and low pressure to our south.
Short term /6 am Sunday morning through Monday/...
high pressure ridging will continue to build in from the north on
Sunday resulting in a drier day. Would not be surprised to see
some sunny breaks during the afternoon hours as drying takes place
in the column...especially in the north. Can/T rule out a few
sprinkles or a bit of drizzle on the coast from time to time...but
the bulk of the day should be dry even there. Northeast winds
should remain gusty...but momentum algorithms suggest that it
will not be quite as windy as Saturday.
Same old story for Sunday night as cool...mostly cloudy...perhaps
some drizzle or a little light rain. Northeast winds will remain
Long term /Monday night through Saturday/...
high pressure continues to build into the region Monday through
Tuesday as Hurricane Joaquin passes hundreds of miles offshore. The
pressure gradient will continue relaxing on Monday as the high
builds in from the north. Any lingering low level moisture
diminishes through Monday with drier air working its way in from the
north and west. Skies likely start out mostly cloudy...but then
become partly cloudy late in the day. Temperatures will be held a
few degrees below normal in the lower and middle 60s. More sunshine
is expected on Tuesday with just a few-scattered clouds around. Highs will
reach the upper 60s. Night time temperatures Monday and Tuesday fall
into the lower and middle 40s inland to the lower and middle 50s
near the coast.
A weak cold front will move through on Wednesday. Not much lift with
this front and moisture will be very limited with precipitable waters falling to
between 0.5 and 0.75 inches. Ahead of the front temperatures will
be able to rise into the upper 60s and lower 70s. Another high
builds into the region behind the front Wednesday night into
Thursday. Highs will return to near seasonable levels for
The forecast for the end of the week into the start of next weekend
becomes much more uncertain. A shortwave trough is forecast by the
models to dig into the Great Lakes on Thursday and approach on
Friday. There is decent agreement among the deterministic models and
ensembles with the occurrence of this system...but differences
exist with its associated surface low and amplitude of the
shortwave trough. The surface low would end up moving across
Friday into Saturday. With this about a week away...have only
included low chance probability of precipitation for showers for now.
Aviation /02z Sunday through Thursday/...
high pressure builds down from southeastern Canada through Sunday.
Gusty NE winds continue through the overnight and through the day
Sunday. There may be a slight decrease in speeds and gusts later
For coastal terminals including NYC metropolitan...mainly MVFR ceilings are
anticipated...although cannot rule out VFR ceilings at times.
For terminals north of NYC including CT terminals...ceilings may
fluctuate between MVFR and VFR through the overnight and into
Sunday morning before VFR prevails.
On and off light rain or drizzle is possible...but do not foresee
much of a visibility restriction tonight.
Outlook for 00z Monday through Thursday...
Sun night and Monday...VFR with diminishing NE winds.
a Gale Warning remains up on all waters for freq gusts 35-40 knots.
The pressure gradient loosens up a bit across the sound and the
bays/harbors so the Gale Warning GOES until noon Sunday there.
Otherwise...gales remain up on the ocean waters through the day
Sunday...and may have to be extended for a little while longer
depending on the strength of the northeasterly low level jet.
Small Craft Advisory conditions are likely on the ocean waters on Monday with seas
remaining between 8 and 11 feet. Wind gusts will be diminishing
through the day Monday as the pressure gradient relaxes. Seas on
the ocean will slowly subside Tuesday but seas will still be above
5 feet. Sub Small Craft Advisory conditions are then forecast Wednesday and Thursday
on all waters.
less than a tenth of an inch of rainfall is forecasted through
midweek...and most places may remain dry during the time period.
a strong persistent NE flow will continue between strong high
pressure over eastern Canada and a broad area of low pressure off
the southeast coast. There are likely to be multiple episodes of minor
coastal flooding during this time with perhaps some localized
Coastal flood advisories remain with water levels up to 2 feet
above astronomical tides. In addition...splash over
of northeast facing shorelines such as Fire Island and Asharoken
A high surf advisory for the South Shore of Long Island remains
in effect and was extended through Monday. Expect beach erosion
and washover to occur due to rough seas and battering waves...with
surf as high as 10 feet in spots.
CT...coastal Flood Advisory from 4 PM to 7 PM EDT Sunday for ctz009.
New York...coastal Flood Advisory from 1 am to 4 am EDT Sunday for nyz072-
Coastal Flood Advisory from 1 PM to 4 PM EDT Sunday for nyz072-
Coastal Flood Advisory from 4 PM to 7 PM EDT Sunday for nyz071-
High surf advisory until 6 PM EDT Monday for nyz080-081-178-
Coastal Flood Advisory from 3 am to 6 am EDT Sunday for nyz080.
Coastal Flood Advisory from 3 PM to 6 PM EDT Sunday for nyz080.
New Jersey...coastal Flood Advisory from 1 am to 4 am EDT Sunday for njz006.
Coastal Flood Advisory from 1 PM to 4 PM EDT Sunday for njz006.
Marine...Gale Warning until noon EDT Sunday for anz330-335-338-340-345.
Gale Warning until 6 PM EDT Sunday for anz350-353-355.