000
FXUS61 KOKX 102145
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
545 PM EDT Wed Apr 10 2024
.SYNOPSIS...
A stationary boundary will remain south of the area tonight and
then lift north as a warm front on Thursday. A strong low pressure
system lifts west of the area and sends a strong frontal system
through the area Thursday night into Friday. A second cold front
moves through Saturday. A weak low moves through on Sunday. High
pressure takes over Monday with a warm front front moving in late
Tuesday into Wednesday.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
Only minor changes have been made to the forecast in this
update to account for current observations. The forecast
remains on track.
A southern branch storm system over the Lower Mississippi
Valley will lift northeast tonight ahead of a digging northern
branch shortwave trough. The latter of which will phase the two
steams with a rapidly deepening low that lifts up into the
Tennessee and Ohio Valleys overnight. Upper level ridging along
the eastern seaboard will continue to gradually translate east.
A stationary front will also remain poised to the the south
overnight as low-level ridging maintains its last gasp across
the area. A light easterly flow and weak warm advection will
continue to gradually moisten the airmass. Areas of fog will
likely develop overnight. Any showers will be spotty overnight
with the best chance toward daybreak. Latest CAMs show a band of
warm advection showers approaching from the SW toward 12Z
Thursday, with the best chance being across the western third
of the forecast area (NE NJ, Lower Hudson Valley, NYC metro).
Overnight lows will be mild in the mid 40s to lower 50s. This is
about 7 to 10 degrees above normal.-- End Changed Discussion --
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
Deepening low pressure tracks up through the Tennessee and Ohio
Valleys Thursday and into the lower Great Lakes region by
evening, then north of the Lakes on Friday. This will send a
stationary front to the south of the area north across the
region Thursday afternoon, aided by a strengthening LLJ working
up the Mid Atlantic coast. Some warm advection showers will be
possible, mainly in the morning Thursday before more widespread
showers move in from the south during the evening hours. Warm
conveyor belt processes in the warm sector will be the primary
lifting mechanism Thursday night. Showers will be of moderate to
occasionally heavy intensity. In addition, highly anomalous
precipitable water values will be available for the system
increasing to around 1.50 inches. Fortunately, this is not a
deeply convective system with only marginal instability and the
surface boundary to the north. Hourly rates during the heaviest
rain look to be between 0.25 to 0.50 inches. SPC HREF shows PMM
of 0.75 to 1" 3hr QPF across interior southern CT. This location
looks to be the most favored for the highest rainfall amounts
due to the orientation of the LLJ and orographics. Storm total
rainfall amounts range from 0.75 to 1" along the coast and far
western sections of the Lower Hudson Valley, to 1-1.50" across
interior southern CT. Localized higher amounts are possible in
any thunderstorms. These rainfall amounts and rates should
mainly confine flooding to the minor nuisance variety. WPC has
most of the area in marginal risk for isolated flash flooding,
with a slight risk across interior NE NJ and western Orange
County in NY. We would need to see amounts closer to 2 inches
in 3-6hr across NE NJ to see minor flooding on the Saddle River
at Lodi, but some of the quicker responding streams, like the
Ho-Ho-kus Brook need less to exceed bankfull.
As for the wind forecast, there is a fair amount of uncertainty
with how much of the southerly LLJ is mixed down to the surface
Thursday night with a strong low-level inversion developing.
The base of the inversion will have winds in the 40-50kt range,
so currently expect surface winds to be in the 25-35 kt range,
highest at the coast. A few 40-kt gusts are possible along the
coast, but confidence is too low at this time for wind advisory
headlines. This will continue to be evaluated as we draw closer
to the event.
The showers become more scattered in coverage on Friday with
the cold front moving through during the late morning/early
afternoon hours. Wind gusts diminish a bit as winds veer to the
SW, but still expect gusts to around 30 kt through the day.
Temperatures will remain on the mild side with highs in the 50s
to lower 60s on Thursday, warmest away from south facing coastal
locations. Friday will be even a few degrees warmer as the flow
becomes SW and cold air advection lags behind the cold front.
Lows Thursday night likely stay in the 50s, which is well above
normal.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
An impactful low pressure system exits into New England on Friday
night. Light, spotty showers (mainly for northern zones) may still
linger in the vicinity through Friday night, clearing by Saturday
afternoon. Winds will continue to diminish into Friday night and
Saturday morning as the pressure gradient weakens.
A second cold front on Saturday will aid in clearing clouds and any
lingering precip, as well as usher in cooler air with highs on
Saturday in the 50s. This will be supported by a strong trough
centering itself over the region.
A trough over the region exits to the east Saturday night into
Sunday morning with the upper-level pattern becoming zonal on
Sunday. The zonal west to east flow helps advect in higher moisture,
leftovers from a weak low that moved into the Great Lakes. At the
same time, some models indicated mid-level energy being ejected
through our area from the trough as it rises into Canada and the
weak low over the Great Lakes. Not all models agree on this
solution, but odds are we should see some scattered showers as this
moves through on Sunday. Isolated thunderstorms are also possible as
there could be some elevated instability, weak as it may be.
The trough exits east Sunday night with a strong ridge building over
the northeastern US and Canada Monday and Tuesday. This will lead to
sunnier weather on Monday and temperatures warming into the mid-70s
to upper-60s, supported by warm air advection aloft. Its important
to note that not all models agree with the ridge building on Monday,
with some guidance not showing a building ridge until Tuesday.
The ridge remains in place on Tuesday, though a strong upper-level
jet develops aloft with a stalled/warm front placing itself over the
area from a low in the northern Great Plains/Western Great Lakes.
These will act together to increase cloud cover through the day on
Tuesday, which will keep high temperatures a few degrees cooler on
Tuesday compared to Monday, but still reaching the 70s. This front
may lead to rain chances Tuesday night into Wednesday.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
Mostly VFR then MVFR cigs develop with IFR for some this evening
especially eastern terminals (KISP, KBDR and KGON). More of a chance
for IFR cigs tonight, along with MVFR vsby in BR. Included TEMPO
groups mainly between 09z to 12z to capture this. Some locations
could even briefly see LIFR cigs and IFR vsby, the best chance for
this will again be for eastern terminals. Some light showers or
drizzle possible for coastal areas.
On THU...some periodic improvements possible mid-morning but
conditions go downhill again Thu afternoon. While some light
rain is possible, widespread rain develops toward evening.
Regarding wind, E/SE winds around 10 kt continue tonight.
Isolated gusts possible. Winds pick up Thu afternoon and
increased gusts to 25 kt are possible especially along the
coast. LLWS is also being added to TAF for some as strong low-
level jet develops along with a weak inversion.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments possible this afternoon as cigs lower to MVFR and
then potentially IFR.
Higher confidence in cig forecast tonight. Cigs could lower to
MVFR and then to IFR a few hours later than what is shown in
current TAF.
OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
18Z Thursday: MVFR to IFR with chance of showers AM, then
showers likely with IFR/MVFR PM. SE winds G20-25kt LLWS
developing.
Thursday night: IFR with showers. SE winds G30-40kt with LLWS.
Friday: IFR cond with showers and S winds G30-35kt AM. MVFR
with chance of showers PM and SW winds G30-35kt.
Saturday: Slight chance of showers mainly NW of the NYC metros,
mainly VFR. W-NW winds G25-30kt.
Sunday: Mainly VFR. Chance of MVFR and showers in the afternoon.
SW-W winds G20-25kt.
Monday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Sub-SCA conditions are on tap overnight and through much of the
daytime hours on Thursday. However, SSE winds will steadily
ramp Thursday afternoon and evening ahead of low pressure
deepening to the west of the area. Gale force gusts are likely
across all waters overnight with gusts up to 40kt. Winds will
then veer to the SW on Friday with marginal gale gusts still
possible. Seas on the ocean build to 10 to 13 ft during this
time, with 3 to 6 ft on LI Sound.
SCA conditions will likely linger on all waters through Saturday as
wind gusts remain around 25 kt. Sub-SCA conditions are expected
thereafter, except on the ocean waters where 5-7 ft seas could
linger through Monday.
&&
.HYDROLOGY...
There are no hydrologic concerns through the day on Thursday. A
period of moderate to heavy rain is expected Thursday night, and
potentially lingering into a portion of Friday morning for eastern
sections. At this time, the flooding risk from rainfall is
limited despite the fact that antecedent conditions remain
rather wet. Due to the progressive nature of the system it is
likely that any flooding would be more of the minor, nuisance
and urban-poor drainage variety. WPC maintains a marginal risk
of excessive rainfall across most of the area with western
sections of NE NJ and the Lower Hudson Valley under a slight
risk.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
Astronomical high tides remain elevated with the new moon /
spring tide set up from early this week. An additional round of
minor coastal flooding is expected tonight, with water levels
likely coming in a few tenths short of last night`s high tide
cycle. A Coastal Flood Advisory remains in effect for southern
Westchester, southern Fairfield and southern Nassau. A Coastal
Flood Statement is in effect for Hudson, Staten Island,
Brooklyn, Queens, northern Nassau and northwestern Suffolk.
Strengthening SE-S flow with a storm system late Thursday into
Friday morning will likely force more widespread minor to
locally moderate coastal flooding. With increasing SE gusty
flow, waves will increase in height, setting up a widespread
minor coastal flood event for the forecast area shorelines. Some
localized moderate coastal flooding is forecast, especially for
some of the South Shore Bays.
The minor coastal flooding is also expected to occur along the
tidally fluctuating areas along rivers in Northeast NJ going
into eastern parts of Union, Essex and Bergen Counties. Coastal
flood advisories are in effect Thursday night into early Friday
morning for all coastal zones as well as the eastern portions of
Union, Essex and Bergen counties.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
Thursday for CTZ009.
Coastal Flood Advisory from midnight Thursday night to 5 AM
EDT Friday for CTZ009-010.
Coastal Flood Advisory from 11 PM Thursday to 4 AM EDT Friday
for CTZ011-012.
NY...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
Thursday for NYZ071.
Coastal Flood Advisory from midnight Thursday night to 5 AM
EDT Friday for NYZ071-073-078-176-177.
Coastal Flood Advisory from 9 PM Thursday to 2 AM EDT Friday
for NYZ072-074-075.
Coastal Flood Advisory from 11 PM Thursday to 6 AM EDT Friday
for NYZ079.
Coastal Flood Advisory from 11 PM Thursday to 5 AM EDT Friday
for NYZ080-081.
Coastal Flood Advisory from 9 PM Thursday to 3 AM EDT Friday
for NYZ178-179.
Coastal Flood Advisory until midnight EDT tonight for NYZ179.
NJ...Coastal Flood Advisory from 9 PM Thursday to 2 AM EDT Friday
for NJZ006-104-106-108.
MARINE...Gale Warning from 6 PM Thursday to 6 PM EDT Friday for ANZ331-
332-335-338-340-345-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BR/DW
NEAR TERM...BR/DW
SHORT TERM...DW
LONG TERM...BR
AVIATION...IRD
MARINE...BR/DW
HYDROLOGY...BR/DW
TIDES/COASTAL FLOODING...