Area Forecast Discussion
Issued by NWS Upton, NY-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KOKX 141731
Area Forecast Discussion
National Weather Service New York NY
1231 PM EST Sat Jan 14 2017
High pressure passes offshore this afternoon with a weak wave of
low pressure passing well to the south tonight. High pressure
builds over the region Sunday into Monday, then moves off the Mid
Atlantic and northeast coast Monday night and Tuesday as a frontal
system approaches to the west. A warm front moves through the
region Tuesday followed by a cold front Wednesday. High pressure
builds in Wednesday night through Thursday and moves offshore
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Mid and high clouds will continue to increase ahead of a frontal
system that will pass to the south. Some light snow may impact
southern and western portions of the area late this afternoon,
assuming sufficient low level saturation occurs. Much of this
reliant on available lift, and approach of upper jet. Best chance
will be closer to the coast.
Temperatures will remain nearly steady, and may fall a few degrees
in areas where snow occurs.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Water vapor imagery shows a short wave moving towards New
England. Stronger northwest flow as the wave moves east should
help to keep the developing low more to our south.
Despite weak warm advection in the low levels, dry air and
subsidence will inhibit much more than light snow with minimal
accumulations. However, NWP model suite continues to suggest
light precip does indeed develop, with low QPF amounts from a
trace to a few hundredths of an inch. If precip does develop,
boundary layer will cool, and wet bulb temps will remain below
freezing. As such, any precip will be in the form of snow this
Temperatures tonight will be close to climatological normals. Dry
conditions follow for Sunday as high pressure builds eastward
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Weak upper ridging builds ahead of an approaching southern stream
shortwave Sunday night into Monday night that will get picked up
in the eastern portion of a northern stream shortwave Monday night
into Tuesday across the northern plains into the upper midwest.
Surface high pressure builds over the area Sunday night into
Monday. A wide range in overnight lows Sunday night are expected
with ideal radiational cooling conditions.
A return flow develops Monday as the high begins to shift
offshore. Warmer air will be moving into the region as a warm
front develops ahead of surface low pressure. The front across the
region will be weak with weak frontal forcing. Systems have
slowed, with the ECMWF slower than the GFS. Light precipitation
develops with the front right around 12Z Tuesday. Still expecting
a brief period of wintry weather Tuesday morning with the onset of
precipitation. There is still uncertainty with the areal extent
of the wintry mix and will be dependent on how quickly the
surface cold air is scoured out. Model soundings do indicate
mostly liquid even well inland at the beginning of the
precipitation. During Tuesday morning the warm front moves through
and by late morning all liquid precipitation is expected.
With the slower progression of the upper trough, which becomes
negative Tuesday night into Wednesday, precipitation continues
until the cold frontal passage Wednesday.
Models have trended drier for Wednesday night through Friday.
There is no really cold air behind the front with warming setting
up for Friday.
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --A stationary front will remain south of the region through
tonight. High pressure will build in from the west on Sunday.
A period of light snow is expected late this afternoon and
evening. Snowfall rates are expected to be less than a half inch
Total snowfall accumulations, due to the light rates, are not
expected to exceed a half inch at this time. Only flurries may
occur at Newburgh.
Ceilings have been kept at 1000 ft in the snow, however there is a
low chance that they drop below 1000 ft after 23Z.
VFR returns quickly after the snow ends, and remains through the
remainder of the TAF period.
Light flow, generally at or below 6 kt, can be expected through
6-10Z. The flow will increase slightly out of the northwest by
.OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...
.Rest of Sunday...VFR.
.Monday night...Rain will attempt to develop resulting in MVFR or
lower. If precipitation does develop, freezing rain is possible at
.Tuesday...Rain with IFR.
-- End Changed Discussion --
Winds and seas forecast on track. Light flow this afternoon
expected, with tranquil seas.
Sub-SCA conditions are forecast through tonight. NW winds develop
late tonight behind low pressure well to the south and east. Gusts
on the ocean waters could get up to 20 kt by daybreak Sunday.
Winds and seas will remain below small craft levels from
Sunday night through Monday night as high pressure builds into
the waters, then moves east Monday night.
An increasing, and prolonged, southerly flow will develop
Tuesday around the departing high and an approach frontal system.
By Wednesday, just before a clod frontal passage, ocean seas
are expected to be at small craft levels. In addition southerly
gusts will be around small craft levels for a short period of
time, then diminish briefly as the cold front moves across the
waters. A gusty westerly flow behind the front will then increase
with small craft conditions expected once again. Small craft
winds and seas will continue into Thursday morning. The remainder
of the forecast waters are expected to remain below advisory
levels Tuesday through Thursday.
No significant precipitation is forecast this weekend into next
week. No hydrologic impacts are expected.