000
FXUS61 KOKX 101001
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
601 AM EDT Wed Apr 10 2024
.SYNOPSIS...
A stationary boundary will remain nearby through tonight and then
lift north as a warm front on Thursday. A strong low pressure system
lifts west of the area and lifts a complex frontal boundary through
Thursday night into Friday morning. A series of cold fronts will
follow into the early part of the weekend. High pressure will
then briefly nose in from the south into Sunday. Another frontal
system could move through on Monday.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Forecast continues on track with just a few adjustments in the
hourly forecast database to better align with latest
observations and trends.
A weak mid level shortwave passes through or just south of the
area this morning. This may trigger a few showers across the
area. With forcing weak and pockets of relatively dry layers in
the profile any shower activity is expected to be rather light.
For this afternoon and this evening higher res guidance
including HREF shows little in terms of QPF. In all likelihood
it will be dry much of the time this afternoon and into this
evening. Low end chance to slight chance PoPs should suffice for
this time period. Later tonight with height falls ensuing and
the frontal boundary just south of the area beginning to inch
north closer to daybreak, look for a relatively higher chance of
light shower activity late in the overnight / early Thu AM. Any
precip will be light during this period with both instances on
the order of a few hundredths. With the cloud cover and an
onshore wind out of the east today look for temperatures to be a
couple of degrees below normal on average. For the same reasons
temperatures tonight will be above normal by about 5 degrees or
so. As the front begins to nudge north late at night some
patchy fog may form, possibly areas of fog towards daybreak.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
The stationary boundary in place lifts north as a warm front
Thursday morning. The higher res guidance is indicating some showers
along and just ahead of the boundary, especially for western
sections. Thus, chance to likely showers for Thursday morning,
followed by a period of more overcast and predominantly dry
conditions during the remainder of the day on Thursday as BUFKIT
soundings indicate some mid level drying. With a wind mainly out of
the south and a marine influence for a good 2/3rds of the area, the
atmosphere down low should be relatively stable, with some elevated
instability aloft as the area gets increasingly in the warm sector
throughout the day. Due to cloud cover temperatures should be close
to normal, even a few degrees below normal further east due to a
wind off the colder ocean. Further west temperatures should get into
the 60s, and if some sun can break through it would get even warmer
but current thinking maintains cloud cover.
The ECMWF and NAEFS SATs (Situational Awareness Tables) indicate an
anomalously high plume of moisture working in from the south Thursday
night. At 850 mb there are 3 to 4 Standardized Anomalies with
respect to specific humidity / moisture values, and 3 Standardized
Anomalies with respect to PWATs. PWAT values are expected to get to
around 1.5 inches Thursday night. The NAM and GFS continue to
indicate a 70 kt LLJ centered around the 2z to 12z timeframe, with a
subtle timing difference between the two. As usual the NAM and GFS
differ on inversion height and strength, which will be the deciding
factor as to how much momentum can get down to the surface in terms
of peak winds / wind gusts. Forecast wind gusts currently fall just
below wind advisory criteria for all zones, although confidence in
the wind / wind gust is below average due to uncertainty around
inversion on how far down momentum transfer goes. Subsequent
forecast packages may adjust this. Strong forcing will be in place
with PVA and WAA with the strong LLJ, look for these ingredients to
produce about a 9 hour period of moderate, to heavy rainfall at
times. Three quarters of an inch to an inch and a half of rain
is expected on average across the CWA. See the hydrology
sections for further details. Temperatures Thursday will average
near normal, perhaps a few degrees above for western most
sections. For Thursday night look for temperatures to average
well above normal with the surge of warmer air and higher
moisture moving up from the south.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Currently forecasting peak gusts of up to 45 mph or thereabouts
early Friday morning along Long Island and other southern
coastal areas as the front swings through. Showers become
scattered and lighter Friday afternoon, then end for the most
part Friday evening and Friday night as the low exits to the
north with a second cold front on Saturday. Winds will remain
breezy through early Sat afternoon as the pressure gradient
gradually weakens. A deeper trough will center itself over the
region during this time frame, becoming zonal and weakening
Saturday into Sunday. At the same time, high pressure will
briefly nose in from the south leading to dry conditions
Saturday night through most of Sunday. Model guidance disagrees
on Monday, but will likely see the trough to our north begin to
drop with some mid-level energy swinging in on Monday which may
provide a chance for scattered showers on Monday along with a
cold front.
High temperatures will be in the mid 60s to the west and in the
mid 50s to the east on Thursday with temperatures more uniform
on Friday near 60. Saturday will be cooler in the 50s due to a
cold front then warm into the mid 60s to mid 70s by Monday.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
A very slow moving/stalled frontal boundary remains south of
the area today.
VFR early this morning. Even less confident in aforementioned
possibility of MVFR/IFR cigs approaching from the south as
latest obs do no support this. E/SE winds increase to near 10 kt
after daybreak. MVFR cigs develop in the late morning/early
afternoon and then lower to IFR for some, especially eastern
terminals. Any afternoon showers will be light and have kept in
a PROB30.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments possible today as cigs lower to MVFR and then
potentially IFR.
OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
Wednesday night: IFR cond developing with chance of showers.
Thursday: IFR with chance of showers AM, then showers likely
with IFR/MVFR PM. SE winds G20-25kt.
Thursday night: IFR with showers. SE winds G30-35kt 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: Chance of MVFR in showers mainly NW of the NYC
metros, otherwise VFR. W-NW winds G30-35kt.
Sunday: Mainly VFR. Chance of MVFR and showers in the afternoon.
SW-W winds G25kt.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
An easterly flow takes shape today with sustained winds generally
around 10 kt. Sub small craft conditions take place through tonight,
and into the first half of Thursday. Out ahead of an approaching
frontal boundary look for the winds and seas to increase Thursday
afternoon as small craft conditions develop. SSE gales are then
likely to develop Thursday evening and spread NE across the waters
Thursday night. Gusts of storm force out on the ocean cannot be
ruled out towards daybreak on Friday. Seas will build quickly
Thursday night with 10 to 15 ft ocean seas by Friday morning. Gales
conditions should give way to small craft conditions from west to
east Friday afternoon and evening on a SW wind. Small craft
conditions will linger through Saturday with a W wind.
SCA cond will likely linger on all waters through Saturday as
wind gusts remain around 25 kt. Sub-SCA conditions expected
thereafter, except on the ocean waters where 5-7 ft seas
could linger.
&&
.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 the 2/3rds of the CWA, with a slight risk into
western portions of the area (mainly west of NYC and the Hudson
River).
&&
.TIDES/COASTAL FLOODING...
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 is in effect for southern
Westchester, southern Fairfield and southern Nassau. A Coastal
Flood Statement was issued 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.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
Thursday for CTZ009.
NY...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
Thursday for NYZ071.
Coastal Flood Advisory from 8 PM this evening to midnight EDT
tonight for NYZ179.
NJ...None.
MARINE...Gale Watch from Thursday evening through Friday afternoon for
ANZ331-332-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...JE/JT
NEAR TERM...JE
SHORT TERM...JE
LONG TERM...BR
AVIATION...JT
MARINE...JE/BR
HYDROLOGY...JE
TIDES/COASTAL FLOODING...