Area Forecast Discussion
Issued by NWS Upton, NY-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KOKX 261529
Area Forecast Discussion
National Weather Service New York NY
1129 AM EDT Mon Sep 26 2016
High pressure will move off the coast today as a cold front
approaches from the west. The front passes across the region after
midnight into early Tuesday morning accompanied by showers. The
front will likely linger just offshore through the end of the
week...resulting in a period of rather unsettled weather.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Forecast remains on track. Only minor adjustments were made to
cloud coverage, temperatures, and dewpoints to account for latest
obs and trends. The high slides off shore causing winds to veer to
south with warm advection this AFTN. Some thin cirrus through the
day which thickens late. Overall, a mostly sunny day.
Not much spread in the MOS - Seasonable.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
NWP remains consistent with timing of FROPA and PCPN.
Rain will quickly traverse the region from West to East after
midnight into the early morning on Tuesday. Rain should actually
end by 12Z in the NY Metro. Have lowered PCPN totals back to
around 1/2" based consensus. Latest GEFS also agreeing on this.
Temps on Tuesday reach the mid 70s - with some upper 70s in the NY
Metro. Used the warmer NAM MOS as thinking we should get partial
sun with W-SW flow in the wake of the front.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Models are in good agreement with a cutoff low pressure system
over the Great Lakes Tue night dropping into the Ohio Valley on
Wed/Wed Night. From this point forward...uncertainty increases on
the track of this system due to blocking both to the east and
west. However...it does appear to linger in this general vicinity
through the remainder of the week. The 00z EC remains a western outlier
with the upper low but has trended slightly closer to the general
consensus. This setup is pointing towards a more unsettled
weather pattern for the mid to late week period.
At the surface...cold frontal rains expected to be S/E of the
local area by 00z Wed. Dry and seasonable weather into Wed
morning...although a piece of vort energy lifting up the east
coast and resulting in a weak wave of low pres at the sfc may
trigger some showers during the aftn.
Have maintained the combination of a ensemble/operational
forecast approach mid to late week. This will bring the potential
for additional waves of low pressure to develop along the cold
front just offshore. Periods of rain will be possible mid to late
week with a frontal boundary extending from sfc low pressure W-SW
of the region.
Temps on Wednesday are expected to be slightly above normal.
Thereafter...temps should be near seasonable under a maritime
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --High pressure moves offshore this afternoon with a cold front
approaching the terminals tonight.
S Winds increasing to 10-15 kt this afternoon with gusts around
20 kt. The strongest winds are expected at KJFK and KISP. S gusts
20-25 kt may continue at KJFK and KISP into the evening.
Otherwise, S winds around 10 kt are forecast overnight veering to
the SW towards day break Tuesday.
VFR through around midnight, then SHRA move in from the west with
the cold front lowering conditions to IFR until early Tuesday
morning. Ceilings should gradually become MVFR/VFR from west to
east after 14-15z on Tuesday but latest guidance shows unsettled
conditions remaining into early afternoon.
...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: Winds may be variable between S and SE early
KLGA TAF Comments: No unscheduled amendments are expected.
KEWR TAF Comments: No unscheduled amendments are expected.
The afternoon KEWR haze potential forecast is GREEN...which implies
slant range visibility 7SM or greater outside of cloud.
KTEB TAF Comments: No unscheduled amendments are expected.
KHPN TAF Comments: No unscheduled amendments are expected
KISP TAF Comments: No unscheduled amendments are expected.
.Outlook for 12Z Tuesday through Friday...
.TUE...IFR in SHRA early morning, then becoming VFR from west to
east mid to late morning.
.THU and FRI...Potential IFR/MVFR in showers RA. NE winds 15-20 kt
with gusts 25-30 kt possible.
-- End Changed Discussion --
Winds and seas forecast on track. Winds veer to the south this
afternoon and gradually increase from west to east as a cold front
approaches. SCA is up for the overnight on the Ocean and the south
shore bays. Winds subside with the frontal passage on Tuesday, but
seas on the ocean remain elevated.
Sub SCA conditions likely return for Tue night into Wed...then
potential for SCA conds to develop once again with persistent
easterly flow for remainder of the week. There is still a great
deal of uncertainty regarding the specifics of the forecast during
this time period...however there is a low probability of gale
force winds...mainly on the ocean.
Around an 1/2" from midnight into early Tuesday morning expected.
Additional bouts of rain are possible during the mid to late
No hydrologic impacts are expected at this time for overnight into
Tuesday morning other then the typical urban ponding. The PCPN
later in the week may pose urban flood issues with the potential
for a couple of inches of rain.
Astronomical tides will be increasing through the week due to a new
moon on Friday. A persistent moderate easterly flow during mid to
late week may result in coastal flooding concerns. At this
time...it appears that minor to locally moderate coastal flooding
is a possibility late in the week.
MARINE...Small Craft Advisory from 8 PM this evening to noon EDT
Tuesday for ANZ355.
Small Craft Advisory from 8 PM this evening to 8 AM EDT
Tuesday for ANZ345.
Small Craft Advisory from 11 PM this evening to 8 PM EDT
Tuesday for ANZ350-353.