Area Forecast Discussion
Issued by NWS Upton, NY-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KOKX 180530
Area Forecast Discussion
National Weather Service New York NY
1230 AM EST Wed Jan 18 2017
Weak low pressure and a warm front pass nearby tonight into
Wednesday morning with high pressure slowly building in behind
it into Friday. This is followed by a weak wave of low pressure
passing to the south Friday night. High pressure then returns
this weekend before the next low pressure and associated frontal
system impacts the area early next week.
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
The forecast remains on track this evening. Rain continues
tonight as a triple-point low and warm front approach. Models have
the low passing just south of Long Island. The warm front may
briefly lift through some of the southern sections tonight, but
even north of the front, expecting surface temperatures to be
above freezing. There is however some uncertainty with the amount
of cooling aloft over much of the CT zones early this evening in
response to better lift and relatively drier low level air. Will
go with a chance of sleet mixed in with the rain for these areas
during this period.
Moisture above around 800mb dries out somewhat after midnight, so
lighter rain or drizzle is expected. Fog is expected for the
overnight hours, and although MAV and NAM MOS guidance doesn`t hint
at it, there could be a chance of dense fog formation as the low
center moves just south of Long Island, causing very light to calm
winds for at least a few hours. At least the time-lagged NARRE has
been showing an upward trend for the chance of dense fog as the
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
High pressure slowly builds in behind the departing low during
Wednesday and Wednesday night. Models in good agreement regarding a
good amount of low level moisture lingering during the day. Fog
probably lingers into part of the morning, and with a few weak
shortwaves passing through, cannot rule out some light rain or
drizzle. High temperatures will be above normal. Remaining cloudy
Wednesday night, and outside of a low chance of light rain or drizzle
over eastern LI and SE CT, it should be dry with above-normal
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
High pressure builds across the area through Friday. A weak wave
of low pressure will move into the upper Great Lakes Friday and
its associated warm front will approach the area Friday night into
Saturday. Expect a period of showers with the passage of this
front but overall rainfall amounts will be light. High
temperatures Thursday and Friday will be in the middle and upper
40s for most locations and near 50 degrees in the NYC and NE NJ
High pressure builds down from southeast Canada for the weekend with
high temperature in the low to mid 40s and lows in the lows to mid
A stronger system will move slowly across the Ohio Valley region
Sunday with its associated frontal system gradually approaching the
area early next week. As the system moves across the central states
it will pull moisture from the Gulf of Mexico, resulting in a
possible significant rainfall event. Confidence in specific details
is low at this time.
High temperatures for the beginning of the week through Tuesday will
be in the mid to upper 40s. Low temperatures will be in the upper
30s to lower 40s.
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --Low pressure tracks to the south of Long Island early this morning
and to the southeast of Long Island into this evening.
LIFR early this morning with improvements to IFR around 12-14z
mid morning, then conditions slowly improve to MVFR from W to E
into the afternoon and evening.
NE winds veer to the N this morning and then NW through the
afternoon. Speeds generally under 10KT, except speeds around 10KT
at city/coastal terminals.
.OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.Late Tonight...Becoming VFR.
.Friday night...Chance of MVFR or lower in -RA.
.Sunday...Chance of MVFR of lower, with best chance at CT/Long
-- End Changed Discussion --
Sub-SCA conditions continue on the waters tonight as a weak low
center shifts through the local ocean zones overnight. With very
light winds for a few hours and plenty of low level moisture, might
need to go with a dense fog advisory at some point for tonight into
tomorrow morning. Not enough confidence to issue one at this time.
The low center shifts farther offshore through the day Wednesday,
but strengthens as it does. Gusts to 25 KT with 5 FT seas are
expected over the ocean waters east of Moriches Inlet starting in
the afternoon. Will go with a SCA only through the afternoon for
now, and let subsequent shifts expand it in time and area as
needed as there is a chance that a swell brings seas to 5 FT to
the other ocean zones starting Wednesday night.
Winds and seas on all waters are forecast to be below SCA levels
Thursday into the weekend.
No hydrologic impacts are anticipated with the additional rainfall
occurring through Wednesday morning.
Potential exists for a significant precipitation event early next
-- Changed Discussion --CT...None.
MARINE...Small Craft Advisory from noon today to 5 PM EST this
afternoon for ANZ350.
-- End Changed Discussion --