961
FXUS61 KOKX 190133
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
933 PM EDT Sun Aug 18 2024
.SYNOPSIS...
A frontal system with its associated low pressure center continues
to approach the area tonight. The central low moves slowly
within the region Monday, shifting east of the area by early
Monday evening. The frontal system continues to shift east of
the region Monday night into Tuesday morning. High pressure
builds in thereafter through the remainder of the week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --
A slow moving frontal system continues to move across the area.
Early mesolow has weakened and lifted NE of CT. There is likely
another weak low that has formed nearby to the NYC metro as
winds have gone NE there, which occurred from strong convection
that has now moved into western LI.
The Severe Thunderstorm Watch has been cancelled as the threat
has now transitioned to a continued heavy rain threat into the
overnight. No changes were made to the watch.
Several reports of rainfall rates of 3-3.5"/hr in NE NJ which
has caused widespread, significant flooding. This area has moved
eastward fairly quickly and is now producing 1-2"/hr. Will be
continuing to monitor rainfall trends in CT as the areas in
Fairfield and New Haven do not need much rain to cause more
problems.
There will likely be additional showers overnight, but the heavy
rain threat should become a bit more localized with an overall
slow weakening trend into the early morning hours as activity
progresses eastward.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Mid level trough continues to approach with its axis arriving within
the region by early Tuesday. About another 30 meter drop with the
500mb height is expected within the region. Once again, multiple
areas of higher positive vorticity advection move across the area
for Monday and Monday night. Vertical forcing will remain in place
to easily allow for the development of showers.
The numerical weather prediction models convey low pressure
passing east of the area early Monday, followed by a cold front
slowly moving across for afternoon into early evening. They are
coherent in their model solutions showing the low pressure
moving east of the area Monday night.
The rain on Monday could very well be more intermittent with more
lulls in the activity. However, thinking here that numerous
showers will pop up and develop throughout the afternoon with a
lingering frontal boundary acting as a focus for low level
convergence. Although the axis of higher precipitable waters is
forecast to be more east of the region, heavy rain will still be
possible at times.
Regarding thunderstorms, low level CAPE forecast to be more, up to
near or a little above 1000 J/kg, so more potential. Will
include chance of thunderstorms. Enough factors to have more
than just slight chance or isolated thunderstorms. Lowering
chances for showers and thunderstorms Monday night, mainly dry
overnight into early Tuesday morning.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
After a secondary frontal passage, any residual showers across S CT
and Long Island should end in the morning. This will set the stage
for drier and cooler conditions to take hold into midweek. Behind
the fropa, high temps on Tuesday could be some of the coolest since
late May, generally in the upper 60s to mid 70s.
The drier, cooler pattern will continue into mid week behind the
frontal system as dry air advects south, with surface high pressure
building in. Lingering upper trough over the Northeast may persist
into late week, reinforced by a closed low dropping south out of
Canada.
This high will be accompanied with primarily N-NW winds and a much
cooler regime. Highs temps Wed will be in the 70s, with low temps
Wed AM and Thu AM in the 50s to near 60. Some interior spots as well
as in the Long Island Pine Barrens could bottom out in the upper 40s
by daybreak Thu depending on the strength of any radiational
cooling. Temperatures will gradually moderate into late week and the
weekend with highs reaching the upper 70s to lower 80s by Fri, and
well into the 80s next weekend.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
A frontal system slowly moves across the terminals through
Monday evening.
Showers and thunderstorms are expected this evening into
tonight. Flight categories will fluctuate from MVFR to IFR
through tonight and there could be some periods of brief VFR.
The bulk of the showers/thunderstorms should push east of the
NYC metro after midnight. Showers should begin tapering off
early Monday morning, but could linger across southeast CT.
Conditions should improve to VFR late Monday morning into Monday
afternoon with the potential of another round of showers and
thunderstorms late afternoon and evening.
Winds will be S to SE through tonight. Winds begin to shift
toward the SW during Monday morning. Winds shift to the W and NW
behind the cold front passage Monday evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for both showers/thunderstorms and for flight
categories.
Timing of showers and thunderstorms Monday afternoon/evening may
be off by 1-3 hours.
OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
Monday Night: Scattered showers and thunderstorms ending in the
evening. VFR.
Tuesday: Mainly VFR. A chance of showers, mainly in the
morning, with MVFR possible. NW wind gusts 15-20 kt.
Wednesday-Friday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Rough ocean seas and long period swells remain through tonight
and into Monday. Seas decrease more Monday afternoon into Monday
night. SCA for ocean remains in effect for the ocean through
Monday night.
Winds are expected to remain below SCA thresholds outside of
thunderstorms. Non-ocean zones are expected to remain below SCA
thresholds for winds and seas through Monday night.
The rough ocean seas and long period swells come from distant
tropical cyclone Ernesto as it passes well northeast of the
area in the open Atlantic. This is also leading to rough
conditions around inlets. Please refer to the National Hurricane
Center for official forecasts regarding Ernesto.
Thereafter, elevated wave heights on the ocean zones will allow
for SCA conditions to possibly continue into the day on
Tuesday. By Late Tuesday, wind diminish and wave heights should
fall below 5 feet. Sub-SCA conditions are then expected with
high pressure moving into the area by midweek.
&&
.HYDROLOGY...
-- Changed Discussion --
Additional locally heavy rainfall is possible tonight.
Widespread flooding continues across portions of Fairfield and
New Haven Counties in CT and urban NE NJ. Rivers and streams may
still exceed bankfull in these areas into the overnight.
Additional rain Monday into Monday night looks to be more
localized, with just a marginal flash flood threat. Otherwise,
minor flooding in low lying and poor drainage areas.
No hydrologic concerns expected thereafter Tuesday through next
weekend.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
A high rip current risk is in place through Monday due to elevated,
long period swells from Ernesto.
Ocean seas are forecast to be highest through Monday, and with surf
heights up to 6 ft, local beach erosion is possible.
A full moon on Monday as well as swell from distant Ernesto will
also elevate total water levels this week. Have continued the
advisory for the back bays of Nassau and Western Sound along the
southwest CT and S Westchester coast for this evening`s high tide,
and the statement for areas along Jamaica Bay and lower NY Harbor.
Additional minor flooding is possible with the high tide cycles
(especially the evening/nighttime cycles) through much of this week.
Additional advisories/statements will likely be needed.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Flood Watch until 2 AM EDT Monday for CTZ005-006-009-010.
Coastal Flood Advisory until 1 AM EDT Monday for CTZ009.
NY...Flood Watch until 2 AM EDT Monday for NYZ067>071.
Coastal Flood Advisory until 1 AM EDT Monday for NYZ071.
High Risk for Rip Currents through Monday evening for NYZ075-080-
081-178-179.
Coastal Flood Advisory until 10 PM EDT this evening for NYZ179.
NJ...Flood Watch until 2 AM EDT Monday for NJZ002-004-006-103>108.
MARINE...Small Craft Advisory until 6 AM EDT Tuesday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/JM
NEAR TERM...JM/DS
SHORT TERM...JM
LONG TERM...BG
AVIATION...DS
MARINE...BG/JM
HYDROLOGY...BG/JM
TIDES/COASTAL FLOODING...