000
FXUS61 KOKX 301146
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
746 AM EDT Sat Sep 30 2023
.SYNOPSIS...
Offshore low pressure will continue to track out into the western
Atlantic, while high pressure builds in through the middle of
next week. The high may start to move offshore at the end of
the week as the next frontal system approaches from the west.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The inverted trough that brought the flooding rain to the area
in conjunction with an upper trough has dissipated and offshore
low pressure has taken over. However, with the upper trough/closed
low moving through the area today, areas of mainly light rain
will overspread the area from the east this morning. The best
chance will for LI and southern CT. The rain will then work
offshore during the afternoon into early evening hours from
west to east. An additional quarter to half inch is possible for
portions of LI and CT, with lesser amounts elsewhere. This
should have minimal impacts on area rivers and streams that are
in flood.
N-NE winds today will gusts up to 20 mph, mainly at the coast.
Some clearing can be expected late this afternoon for western
sections, mainly from NYC and areas north and west.
Highs today will top out in the lower to middle 60s, which is
about 5 degrees below normal.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
The upper low/trough departs to the east this evening with a
anomalously (+2SD) strong upper ridge building in from the west
for the upcoming week. This will lead to unseasonably warm, dry
conditions.
For highs on Sunday, took a blend of the NBM and its 90th
percentile as a middle ground to account for the warmer MOS.
Highs will top out mainly in the middle and upper 70s, but
cooler across eastern LI. This is also above normal by about 5
degrees. Near normal lows Sunday morning will warm several
degrees as well heading into Monday morning.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
There has not been much change to the overall forecast thinking for
the upcoming week. The deterministic global models and ensemble
means are in good agreement with the large scale pattern across the
CONUS through much of the week with deep-layered ridging over the
central and eastern states and troughing over the west. Differences
start to arise late in the week with the timing of the ridge
breaking down/shifting to the western Atlantic and the approach of a
larger upper trough at the end of the week.
A strong high pressure will dominate through Thursday with dry
conditions. The high is progged to shift offshore at the end of the
week in response to the ridge breaking down/shifting offshore and
the approaching upper trough. An associated cold front is progged to
approach on Friday, but there is a large amount of uncertainty on
the timing. A faster timing of the front would bring some showers to
the area next Friday. A slower timing would delay the passage and
any showers until next Friday night or next Saturday.
A warming trend in temperatures is expected next week with highs
above normal. Highs on Monday look to be in the lower to middle 70s,
then increase to the upper 70s on Tuesday. Model consensus has
Wednesday as the warmest day of the week with highs in the upper 70s
to potentially the lower 80s in the normal warmer spots of NE NJ and
the NYC metro. Highs to end the week should be in the lower to
middle 70s.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Offshore low pressure will continue to track out into the western
Atlantic. As it does so, rain with IFR cond over the Long Island
and CT terminals will move back into the remaining terminals and
hang on until early afternoon. Gradual improvement to VFR
expected late this afternoon into early this evening.
Winds should be NNE to start either side of 10 kt, with some
places gusting up to 20 kt especially east of the NYC metros.
Winds should then back N late this afternoon as the rain ends
and diminish.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
AMD possible to address changes in flight cat deviating from
fcst.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Expect SCA conditions to end across the non-ocean waters later
this morning with occasional gusts up to 25 kt possible
for a brief time thereafter. For the ocean waters, SCA
conditions in a N-NE flow around 20kt, with gusts around 25 kt,
and seas of 6 to 8 ft today, will gradually subside tonight
into Sunday. SCA seas may linger into Monday morning.
Sub-SCA conditions are forecast Monday through the middle of
the week with a weak pressure gradient in place over the waters.
&&
.HYDROLOGY...
Additional .025 to 0.50 is possible today as rain works across
much of LI and southern CT, with lesser amounts to the west.
Outside of any residual flooding and rivers that are elevated,
no additional significant rainfall is expected.
No hydrologic impacts are expected next week.
&&
.TIDES/COASTAL FLOODING...
High astronomical tides combined with a persistent NE flow, and an E-
SE wind wave/swell should restrict tidal drainage and prolong minor
coastal flood potential into Sunday and possibly Monday, mainly for
the AM high tide cycles. Advy was extended into Sunday for the south
shore of Queens/Nassau and the western shores of CT including
Westchester. Statements cover most of the remaining shorelines for
the upcoming high tide cycle only.
In addition, continued beach erosion will continue through at least
Saturday due to elevated water levels, 4-6 ft breaking surf, and a
strong E-W longshore current. Dune erosion potential looks to be
localized, with overwashes not expected.
NOTE: The Peconic River at Riverhead tidal gauge is out of service
(had been reading too high). The gauge is being looked into by our
partners at the USGS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 11 AM this morning to 3 PM EDT
Sunday for CTZ009.
NY...Coastal Flood Advisory from 11 AM this morning to 3 PM EDT
Sunday for NYZ071.
Coastal Flood Advisory until 1 PM EDT Sunday for NYZ178-179.
NJ...Coastal Flood Advisory until 1 PM EDT Sunday for NJZ006-106-
108.
MARINE...Small Craft Advisory until 8 PM EDT Sunday for ANZ350-353-355.
&&
$$
SYNOPSIS...DS/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...DS
AVIATION...BG
MARINE...DS/DW
HYDROLOGY...DS/DW
TIDES/COASTAL FLOODING...