Area Forecast Discussion
Issued by NWS Upton, NY-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KOKX 272143
Area Forecast Discussion
National Weather Service New York NY
543 PM EDT Thu Oct 27 2016
Low pressure over the eastern Great Lakes tracks to the northeast
tonight as another low develops over northeastern New Jersey this
evening. This lows becomes the main low tonight and tracks along
the New England coast through Friday. Meanwhile high pressure
builds to the southwest Friday and Friday night. High pressure
moves south of the area on Saturday with a cold front approaching
from the north Saturday night. The front sinks through the area on
Sunday as a weak low pressure moves along it. High pressure then
returns Monday and Tuesday followed by a weak cold front for the
middle of the week.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Temperatures were surging upward across Long Island and to the
immediate Connecticut coast at 5 pm. The forecast has been
updated as a result. Otherwise, the rain will continue this
evening as forecast, with no significant changes made.
Rain will continue through this evening and into late tonight as
the frontal system tracks through. As the southeastern
Pennsylvania low becomes the dominate low this evening lift will
increase and the warmer air will lead to destabilization. Lifted
indices along the coast and into Connecticut fall to -1 to -2, and
isolated thunder will be possible. In addition there will be a
brief period of moderate to heavy rainfall.
High temperatures will likely occur early this evening, then fall
back later tonight. With the primary low then along the eastern
New England coast by Friday morning, rain ends quickly from west
to east after 06Z.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Low pressure along the eastern New England coast early Friday
tracks east through the day. A strong and gusty west to northwest
flow develops with moderate cold advection and low level winds
around 35 KTS mix to the surface.
Weak ridging builds late in the day and into Friday night. Winds
will lighten and decouple over the western zones Friday night and
with clear conditions temperatures will fall off. However, weak
warm advection does set up at that time.
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Deep anticyclone across the southern United States will help to
build ridging towards the northeast on Saturday. Several shortwaves
will traverse across southeast Canada but the trend in the models
and ensembles has been for these shortwaves to stay well to the
north. Have continued with a dry forecast for Saturday. Some mid and
high level clouds are possible through the day, but sky conditions
should largely be partly cloudy. High temperatures are a bit tricky
on Saturday as there is some uncertainty with how warm it will get.
Increasing westerly flow around the middle and upper level
anticyclone to south will transport unseasonable warm air just above
the surface. However, BUFKIT soundings point to a subsidence
inversion around 925 hPa which will prevent mixing into the warmer
air. Have sided with the warmer MAV guidance, which yields high
temperatures generally in the upper 50s and lower 60s with urban NE
NJ and NYC metro in the middle 60s.
A cold front slowly sags south Saturday night with into Sunday with
increasing cloud cover. Heights fall during this time period with
another shortwave in the northern stream traversing across New
England on Sunday. This will help push the front through the region
Sunday and offshore Sunday night. Moisture is limited with this
system, so will not go higher than chance PoPs. There should be
enough lift from the front and an approaching upper jet for
scattered showers in the afternoon and early evening. Temperatures
are quite uncertain on Sunday and will depend the amount of cloud
cover and placement of the front. Have gone with the warmest
temperatures across southern portions of the area with highs in
urban NE NJ and NYC in the upper 60s to possible around 70.
The rest of the long term period will be characterized by ridging
building in the middle and upper levels. High pressure moves
overhead on Monday and then situates itself offshore on Tuesday.
There could be a weak cold front that moves through on Wednesday or
Wednesday night, but the timing of this will be dependent on how
quickly the ridge breaks down. Monday will be the only day with
seasonable temperatures with above normal temperatures then expected
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
Low pressure and a warm frontal boundary converge upon the area
this evening, followed by a cold frontal passage after midnight.
Widespread MVFR/IFR conditions through tonight with gradual
improvement to VFR following the cold frontal passage late tonight.
Rain may be occasionally heavy this evening with isolated thunder
possible at the coastal terminals.
Appears warm front is making progress north of the south coastal
terminals...and should see winds veer to the SE/S for the
remainder of the coastal terminals this evening. This veering of
winds should be accompanied by gusts of 20-25 kt for NYC and LI
terminals. E/NE less than 10 kt at KSWF...and possibly holding E
Following the cold frontal passage after midnight, conditions
should improve to vfr vsby/mvfr cigs with a gusty W/NW wind. W/NW
winds should gradually ramp up through Friday morning with gusts
25-30 kt on Friday.
NY 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: Conds likely vary btwn mvfr/ifr this evening in
light to moderate rain. S/SE gusts to 25 kt likely this evening.
KLGA TAF Comments: Conds likely vary btwn mvfr/ifr this evening
in light to moderate rain. S/SE gusts to 25 kt possible this
KEWR TAF Comments: Conds likely vary btwn mvfr/ifr this evening in
light to moderate rain. S/SE gusts to 20 kt likely this evening.
KTEB TAF Comments: Conds likely vary btwn mvfr/ifr this evening in
light to moderate rain.
KHPN TAF Comments: Winds may veer to the SE after 00z. Conds
likely vary between IFR and VLIFR this evening in
light to moderate rain.
KISP TAF Comments: Conds likely vary btwn mvfr/ifr this evening.
S/SE gusts to 25 kt likely.
.OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
.Friday Afternoon...VFR with strong northwest flow. Gusts
.Saturday...VFR. Gusty southwest flow possible along the coast.
.Sunday...Low chance of showers, mainly in the afternoon.
.Monday and Tuesday...VFR.
Small craft conditions remain on the ocean waters into early this
evening. Then as low pressure deepens along the coast, winds will
increase, and small craft wind gusts will be likely across the
remainder of the forecast waters through at least tonight.
As low pressure moves to the northeast of the waters by Friday
morning, winds shift to the west to northwest and with cold
advection and the strong surface pressure gradient force, winds
increase and become gusty. Wind gusts to gale force will be likely
across the ocean waters east of Fire Island Inlet through Friday,
with small craft gusts across the remainder of the water through
Friday evening. Once gale gusts diminish on the eastern ocean
waters a small craft will likely be needed into Friday night.
Conditions will briefly fall below SCA levels early Saturday, but
increasing SW flow during the afternoon and evening will bring
winds to SCA levels on all waters. Ocean seas will also build to
between 5 and 6 ft. Winds will weaken on the near shore waters
Saturday night, but may remain around 25 kt on the ocean with seas
around 5 ft. Sub- sca conditions are then forecast on Sunday as a
cold front slowly moves across the waters. Winds could gust close
to SCA levels on the ocean Sunday night as high pressure builds
behind the front. Sub-SCA conditions are then expected Monday into
Rainfall will range from around a half inch across the western
zones with near one inch across southeastern Connecticut and the
twin forks of Long Island tonight. Dry Friday and Friday night.
Widespread significant precipitation is not expected from this
weekend into early next week.
MARINE...Small Craft Advisory until midnight EDT Friday night for
Small Craft Advisory until 6 AM EDT Friday for ANZ350-353.
Gale Warning from 6 AM to 6 PM EDT Friday for ANZ350-353.
Small Craft Advisory until midnight EDT Friday night for