922
FXUS61 KOKX 291156
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
756 AM EDT Sat Jun 29 2024
.SYNOPSIS...
-- Changed Discussion --
A warm front moves north of the area this afternoon and evening.
A cold front then approaches tonight and moves across Sunday
afternoon and evening. High pressure then follows Monday and
lasts into Wednesday. A weakening cold front may impact the area
Wednesday night. A more robust frontal system may impact the
area from late day Thursday into Friday.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Updated to add in slight chance of showers for Long Island and
coastal CT early this morning. Warm advection has developed
some mainly light showers. Otherwise, clouds have lowered and
thickened and anticipate this trend to continue this morning as
a warm front approaches. Some showers may also glance Orange
county, but the morning hours should largely remain dry.
Chances for showers slowly increase into the afternoon north
and west of the NYC metro as the warm front begins to lift
through the area. Forcing is generally weak and there is limited
instability aloft. A consensus of the latest CAMS indicates a
line of showers with embedded thunderstorms should approach from
the west this evening. Some of the CAMs actually dissipate the
line as it enters the area while others slowly weaken it. The
forcing remains weak and instability is elevated. The warm front
should continue lifting north through the rest of tonight, but
a pre-frontal trough settles nearby early Sunday morning. Some
weak energy aloft may be enough to regenerate showers and a few
thunderstorms early in the morning, with the higher probability
across the eastern two thirds of the region.
Not anticipating a severe thunderstorm threat through early
Sunday morning given the weak forcing and little to no surface
based instability. However, deep subtropical moisture will be
in place with PWATs approaching 2-2.25 inches on average. This
will lead to the potential of locally heavy downpours. Minor
flooding is the main threat as the activity should have enough
forward speed, but cannot completely rule out a localized flash
flood occurrence tonight.
Strengthening onshore flow will lead to wind gusts 20-25 mph,
especially near the coast this afternoon. There will also be a
good deal of cloud cover so temperatures will not rise much
above the upper 70s for most with lower 80s in NE NJ. It will
become increasingly more humid as dew points rise into the upper
60s by this afternoon and evening and then into the lower 70s
tonight.-- End Changed Discussion --
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
-- Changed Discussion --
Main concern for Sunday will be the potential for severe
thunderstorms and locally heavy downpours, mainly in the
afternoon and evening.
There remains potential for some showers and a few thunderstorms
to be ongoing to start the day along and ahead of the pre-
frontal trough. This looks to align itself closest to the coast.
Some of the guidance pushes any of this activity to our east
shortly after 12z. The uncertainty with how any morning
convection evolves may ultimately impact the environment in the
afternoon and evening, especially if lingering clouds are slow
to clear. The pre-frontal trough does look to remain near Long
Island/Southern CT with the actual cold front to the northwest
into the early afternoon. The cold front should then make its
way from northwest to southeast across the area in the evening.
Deep subtropical moisture should remain in place ahead of the
cold front, although there may be a slight decrease behind the
pre- frontal trough. Overall, PWATs look to average around
2-2.25 inches, so the threat for locally heavy downpours
continues. The flow aloft will be strengthening through the day
as the middle and upper level shortwave moves over New England.
These increasing winds bring bulk shear values to 40-45 kt.
MLCAPEs may range from around 1500 J/kg near the coast and
upwards of 2500-3000 J/kg inland. The flow is mainly
unidirectional, but there may be some backing of the low level
flow immediately ahead of the cold front.
SPC has continued to place the entire region in a slight risk
for severe thunderstorms Sunday afternoon and evening. The
main severe thunderstorm threat appears to be from damaging wind
gusts. Some hail is possible, especially if the higher CAPE
values aloft materialize. There is also a risk for an isolated
tornado.
The threat for flash flooding remains low and localized, with
minor urban/poor drainage flooding the main concern.
The other story for Sunday will be brief heat and humidity.
Despite varying levels of cloud cover, there should be enough
warming to push temperatures into the upper 80s to around 90 for
the NYC metro and NE NJ with middle to upper 80s most
elsewhere. These temperatures combined with dew points in the
lower 70s will yield heat indices in the low 90s for much of the
area, with NYC metro and NE NJ in the middle to upper 90s.
The cold front pushes offshore Sunday evening bringing an end to
the severe thunderstorm threat. Drier and cooler air will work
in behind the front and skies will clear through the night. The
upper trough axis moves across Monday morning with high
pressure at the surface and aloft beginning to build in from the
west Monday afternoon. Highs will be near seasonable levels in
the upper 70s and lower 80s.-- End Changed Discussion --
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
High pressure sfc and aloft will be3 mostly in control through
mid week, with a warm front passing to the north Tue night into
Wed. A weakening cold front may touch off a shower or tstm Wed
night, but a more important frontal system as heights fall aloft
and shortwave energy streams eastward from the Plains states,
with chances for more widespread showers/tstms during that time.
Temps will be near to slightly above normal during of of that
time, with highs mostly in the 80s. Thu should be warmer, with
highers in the lower 90s in the NYC metro area and NE NJ, and
heat index values in the mid/upper 90s in those areas and parts
of the Hudson Valley and nearby SW CT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
High pressure will move farther offshore today. A slow moving
frontal system will approach tonight.
MVFR cigs over most of the area should lift around or shortly
after midday. Then S winds into the AM push should increase to
G20-25kt at most terminals this afternoon. A few gusts closer
to 30 kt possible at KLGA/KJFK.
Cigs lower to MVFR this evening and then to IFR at outlying
terminals tonight. IFR conds with tstms possible mainly after
midnight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled AMD expected attm.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
Showers/tstms tapering off early, then becoming likely again in
the afternoon with MVFR/IFR cond and gusty winds.
Monday 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...
-- Changed Discussion --
S-SE winds increase today as a warm front lists north of the
waters. Near shore gusts to around 25 kt are likely this
afternoon and will be followed by ocean seas building to 5-6
ft this evening into tonight. Have left the start of the SCA for
the ocean and South Shore Bays to 2 pm this afternoon. The most
widespread wind gusts 25- 30 kt looks to occur tonight into
Sunday morning with winds diminishing below SCA levels Sunday
afternoon and evening. There is a threat for severe
thunderstorms which could locally increase winds Sunday
afternoon and evening. Elevated seas continue into Sunday
evening. The passage of the cold front Sunday evening will bring
weakening winds and subsiding seas into Monday morning.
Conditions will then remain below SCA levels Monday through
Wednesday. Late day winds in the NY Bight area just E of Sandy
Hook could gust close to 25 kt both Wed and Thu afternoons.-- End Changed Discussion --
&&
.HYDROLOGY...
A round of showers and thunderstorms are expected tonight
into early Sunday morning with potential of locally heavy
downpours. Another round of showers and thunderstorms will
accompany a cold front passage Sunday afternoon and evening
with a continued chance for locally heavy downpours. The most
likely threat will be from minor urban and poor drainage
flooding. The risk for flash flooding is low and localized.
Locally heavy rainfall may be possible Thu night into Fri with a
passing frontal system.
&&
.TIDES/COASTAL FLOODING...
The rip current risk this morning is moderate, but quickly
increases to high this afternoon and evening with strengthening SE
winds and building seas.
The high risk continues into Sunday with swells of 5-6 ft and 7
second period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents through Sunday evening for NYZ075-080-
081-178-179.
NJ...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 8 PM EDT
Sunday for ANZ345-350-353-355.
&&
$$
SYNOPSIS...BG/DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...BG
AVIATION...BG
MARINE...BG/DS
HYDROLOGY...BG/DS
TIDES/COASTAL FLOODING...