144
FXUS61 KOKX 051520
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1120 AM EDT Wed Jun 5 2024
.SYNOPSIS...
-- Changed Discussion --
High pressure moves farther out into the Atlantic today as a warm
front approaches from the south. This warm front moves in tonight
and then eventually northeast of the region Thursday followed
by a cold frontal passage Thursday night. A broad area of low
pressure meanders nearby over southeast Canada this weekend and
into early next week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Low clouds continue to dissipate slowly across the area. Fog has
not been a problem with enough spread at the surface with temps
and dew points. Temps will be the tricky part. Based on current
trends, it could be cooler, especially at coastal locations.
Onshore flow coupled with a subsidence inversion all should cap
temps from getting much higher than forecast.
In the afternoon, any remaining low clouds scatter out for most
locations with the possible exception of the immediate
coastline.
Only other weather feature for the afternoon into this evening
will be pop up showers and thunderstorms. These will be forming
well ahead of an approaching warm front. With combination of
where surface based CAPE will be relatively highest (up to a few
hundred J/kg) and where low level winds will exhibit more
convergence, that will be the western extremes of the region.
Expecting any convective activity to stay primarily to the
north and west of NYC.
With mainly a dry day expected, high temperatures away from the
coast are forecast to rise into the low to mid 80s with the
rest of the area in the 70s.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
Upper level ridge axis moves across tonight and then will shift
east of the region Thursday. It will be weakening as it does so.
An elongated NW to SE oriented upper level trough eventually
moves into the region Thursday night through Friday night.
With warm front and trough of low pressure moving in from the
south and west tonight, would expect rain showers to increase in
coverage. The passage of the warm front will make for a warm and
humid airmass to incorporate the area.
The forcing is not too strong and along with marginal elevated
instability, just left the thunderstorm mention of slight
chance. Low level omega increases more Thursday and with more
CAPE (up to around 1000 J/kg), will have a greater chance of
thunderstorms. Otherwise, showers are expected for much of
Thursday. For Thursday night, the shower and thunderstorm
activity is expected to decrease with the low and storm system
passing farther east of the region.
Mainly dry conditions expected for Friday and Friday night.
There could be a pop-up shower or thunderstorm across the
interior Friday afternoon into early Friday evening with upper
level disturbance aloft with the cutoff mid level low and its
associated cold pool. Mid 70s to lower 80s for max temperature
forecast Thursday and nearly same range for Friday, but a
greater fraction of the region has lower 80s compared to the
previous day.
High PWAT airmass still indicated by models with values up to
near 2 inches for late tonight into Thursday. This will make
for heavy downpours at times. See hydro section for more
details. These high PWATS are above the 90th percentile and even
the max according to the OKX sounding climatology from SPC.
Models indicate the PWATS to considerably lower across the
region Thursday night to around 0.7 to 1.2 inch. PWATS stay
under an inch thereafter through Friday night.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
A relatively unsettled period this weekend into early next week with
an upper low cutting off and meandering over the Great Lakes region
and southeast Canada much of the time, with multiple vorticies
rotating around it that may periodically enhance rain chances
locally.
The broad low nearby likely instigates diurnal shower activity with
varying coverage each day, especially inland. As the cold pool moves
aloft, also can`t rule out the possibility of thunderstorms with
added instability. Global guidance continues to offer differing
solutions with any potential vorticies however and this will need to
be resolved for further clarity on when rain chances will be
highest.
Temperatures, while hampered by cloud cover and rain at times,
should still manage to get into the 70s and lower 80s most
afternoons, or about typical for this time of year. For now,
continued to cap PoPs at 50%, otherwise, national blend was followed
with subtle adjustments.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
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High pressure shifts farther offshore today ahead of an approaching
warm front from the southwest. The front lifts through the region
Thursday morning.
Lingering MVFR and IFR currently for most terminals. This could
last until about 16/17z. VFR is then expected for most, with the
potential for MVFR to continue at KJFK and KISP. Conditions
likely decline to IFR or lower once again tonight with showers
developing. Embedded thunder can`t be ruled out overnight into
Thursday morning, but chance is too low to include at this time.
Steadiest of the showers exits by mid morning Thursday, but
improvement may take until late morning or early afternoon.
Southerly flow persists into Thursday, speeds generally at or
under 10 kt.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
While VFR is expected at KJFK around 17z, there is potential
for MVFR to continue or become intermittent this afternoon.
Timing of category declines and SHRA late this evening may be off by
a few hours.
Isolated thunder possible overnight into Thursday morning.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
Thursday: IFR early, improvement into afternoon. MVFR or lower
possible in showers and thunderstorms.
Friday: Chance of MVFR with showers and possible thunderstorms.
Saturday/Sunday: Chance of MVFR in showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Fog may become an issue tonight as high dew point air moves
across the waters.
Conditions on the forecast waters remain below SCA thresholds
through tonight. For Thursday through Friday night, conditions
could become marginal for SCA on the ocean. Otherwise, non-
ocean waters look to remain below SCA thresholds.
Conditions are expected to remain below SCA levels through the
weekend.-- End Changed Discussion --
&&
.HYDROLOGY...
Rainfall amounts of 0.50 to 1.00" with localized higher amounts
are expected tonight into Thursday. Minor nuisance poor
drainage flooding will be the primary threat especially in urban
and low lying areas. The flooding potential will be limited due
to the expected speed of the showers and thunderstorms which
with a progressive pattern aloft, should be a relatively faster
steering flow.
&&
.TIDES/COASTAL FLOODING...
With a new moon this week, astronomical levels are elevated. An
onshore southerly flow will also support increasing surge and should
be sufficient to continue to get some of the vulnerable locations
along the western LI Sound and the South Shore Bays at or just above
minor flood benchmarks. A Coastal Flood Advisory has been issued
once again for coastal Fairfield, Westchester, and Nassau for this
evening`s high tide, with a Coastal Flood Statement in place for
coastal Queens, where the most vulnerable spots may see brief minor
flooding.
The persistent flow and astronomically high tides will likely lead
to additional minor flooding in subsequent evening high tides into
late this week.
There remains a moderate rip current risk on the ocean beaches
through Thursday due to building seas and a strengthening
southerly flow. The rip current threat magnitude is expected to
be higher on Thursday compared to today.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 9 PM this evening to 1 AM EDT
Thursday for CTZ009.
NY...Coastal Flood Advisory from 9 PM this evening to 1 AM EDT
Thursday for NYZ071.
Coastal Flood Advisory from 6 PM to 10 PM EDT this evening for
NYZ179.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JM/DR/DW
NEAR TERM...JM/DW
SHORT TERM...JM
LONG TERM...DR
AVIATION...DR/JT
MARINE...JM/DR/DW
HYDROLOGY...JM/DR
TIDES/COASTAL FLOODING...