Scientific Forecaster Discussion
fxus61 kokx 241635
Area forecast discussion
National Weather Service New York New York
1135 am EST Fri Feb 24 2017
high pressure will remain steady over the western Atlantic
through tonight. A frontal system will approach on Saturday,
and move across Saturday night, followed by building high
pressure Sunday into Monday. A couple of fast moving
disturbances may bring unsettled conditions beginning Monday
Near term /until 6 PM this evening/...
East Coast ridging and western Atlantic high pressure control
the region today, with mostly sunny skies.
With region in warm sector, another early springlike day today,
with highs in the 60 to lower 70s. A moist air mass advecting
over cold ocean waters could lead to advection fog/stratus
developing along the New Jersey coast and working northward toward the
South Shore of Long Island late.
With SW flow aloft and plenty of sunshine, most areas from NYC
north/west should reach the lower 70s. Elsewhere, temps away
from south facing shores should climb well into the 60s. Marine
influence will likely limit temps to the 50s for most of the
South Shore areas.
Short term /6 PM this evening through 6 PM Saturday/...
East Coast ridging tonight will give way to a Central Plains
upper low shearing toward Hudson Bay on Saturday, with
associated trough and frontal system swinging toward the region
late in the day and then though Sat night.
Coastal stratus/fog development are favored in a second night
of mild/moist southerly flow tonight. Models soundings and high-
res/sref guidance strongly indicating more widespread
stratus/fog development across much of the region
tonight, which may then linger across CT/long much of the day
with low level flow backing more to the S-se. Temps will likely
be cooler on Sat with more of an onshore flow and cloud cover,
with temps ranging from well into the 60s for areas well northwest
and west of the Hudson, to 50s for south and east coastal areas.
Not much in the way of forcing or focus for rain overnight
into Sat morning, so shower threat looks isolated at most. Can't
rule our some patchy drizzle later tonight into Sat morning as
well if low levels saturate sufficiently.
Main rain activity will be along and immediately behind an
approaching frontal system. A narrow band of convection will
likely approach from PA/New York along the leading edge of the front
late Sat into Sat eve, with strong convergence of a moist (pw
2-3 std above avg) and marginally unstable air mass advecting
in via a 40-kt llj, plus lift via an approaching shortwave.
There is potential for brief heavy rain/thunder/30-40 mph wind
gusts with this line mainly west of the Hudson, where there
should be some weak surface/elevated instability. This line
should weaken as it encounters the stable marine layer along the
coast. Otherwise, expect lighter Post-frontal activity Sat eve
ahead of approaching shortwave axis, shifting offshore by
In the wake of the shortwave/cold front Sat night, a dry and
cooler air mass will build in on breezy northwest flow. With strong cold air advection
and deep mixing, wind gusts of 30-40 mph possible.
Long term /Saturday night through Thursday/...
high pressure builds towards the area on Sunday and Sunday
night. Temperatures on Sunday will be in the low to mid 40s with
low temperatures Sunday night in the low to mid 30s along the
coast and upper 20s inland.
High pressure moves offshore Monday, as a storm system moves out of
the mid Atlantic states Monday night and Tuesday. A chance of rain
and snow are possible with the storm system. Light rain is
possible again on Tuesday night and into early Wednesday as a
warm front pushes north of the region Wednesday, followed by a
cold front later Wednesday. High pressure builds behind the cold
front on Thursday.
Temperatures during this period should be 5 to 10 degrees above
Aviation /16z Friday through Tuesday/...
late Spring-like pattern with a warm front north over central
New York state and New England with convection along it. A cold front
approaches from the west on Saturday.
VFR today with a light south-southwest flow.
The forecast question of the day is the development of fog and
stratus this evening along the coast. Latest thinking is 00z or
later for this to occur.
New York Metro enhanced aviation weather support...
Detailed information, including hourly taf wind component forecasts,
can be found at: http:/www.Weather.Gov/zny/n90
Kjfk taf comments: lots of uncertainty on development of fog and
status this evening. Timing could be as early at 21z, but more
likely is around 00z.
Klga taf comments: high confidence in VFR through the day.
Uncertainty with development of fog and status late this
Kewr taf comments: high confidence in VFR through the day.
Uncertainty with development of fog and status late this
The afternoon kewr haze potential forecast is green...which implies
slant range visibility 7sm or greater outside of cloud.
Kteb taf comments: high confidence in VFR through the day.
Khpn taf comments: high confidence in VFR through the day.
Kisp taf comments: lots of uncertainty on development of fog and
status this evening.
Outlook for 12z Saturday through Tuesday...
Saturday...mainly IFR or lower in the morning before possibly
improving to MVFR or VFR.
Saturday night...MVFR or lower likely with rain.
Tuesday...possible MVFR in showers.
persistent S-SW flow around western Atlantic high pressure and
long period easterly swells should have seas hovering around 3-4
ft much of tonight, and up to 5 ft Saturday morning. Will hold
off of Small Craft Advisory due to marginal nature of hazard.
Potential for dense fog over the near shore waters late today
into Saturday morning, which may linger until a cold frontal
passage Sat evening.
Ocean seas should gradually build to Small Craft Advisory levels Saturday
afternoon ahead of a cold front, with marginal Small Craft Advisory gusts
possible. Higher confidence is in Small Craft Advisory gusts in the wake of
frontal passage Sat night, with even potential for a brief
period of gale force gusts.
Small Craft Advisory conditions expected to continue across the ocean waters on
Sunday. Winds and waves will then gradually subside Sunday night
into Monday as high pressure moves south of the area. The next
chance of Small Craft Advisory conditions will be Monday night into Tuesday as
winds strengthen following a warm frontal passage. Winds and
seas may remain at or near Small Craft Advisory conditions through late week
ahead of a cold front.
basin avg rainfall of 1/4 to 1/2 inch is likely on Saturday,
with local amounts up to an inch that could cause associated
the following are record high temperatures for today February
24, 2017 along with the forecast high temperature.
Record high temperature forecast high
Central Park........75 (1985) 70
LaGuardia...........73 (1985) 71
Kennedy.............60 (1984) 65
Islip...............59 (2000) 65* (record broken earlier)
Newark..............73 (1985) 71
Bridgeport..........60 (2016) 62
The following are record high minimum temperatures for Saturday
February 25, 2017 along with the forecast minimum temperature.
Record high min temperature forecast min
Central Park........51 (1930) 53
LaGuardia...........49 (1996) 54
Kennedy.............46 (1996) 50
Islip...............47 (1996) 50
Newark..............47 (1996) 54
Bridgeport..........44 (1996) 49