554
FXUS61 KOKX 291739
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
139 PM EDT Wed May 29 2024
.SYNOPSIS...
A cold front approaches today and passes through tonight with a weak
surface trough lingering nearby on Thursday. High pressure then builds
in Friday and Saturday then slowly weakens beginning on Sunday,
allowing a series of weak disturbances to approach from the west
on Monday and Tuesday.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
Scattered showers have popped up in the Hudson Valley early
this afternoon, with a few slipping south into portions of the
local area. This activity should remain relatively limited and
weak as a frontal system approaches. Cloud cover will continue
to thicken into late day ahead of the system, but the bulk of
the precipitation arrives this evening with the main shortwave.
Locally heavy downpours will be possible, mainly after 00Z, and
could bring the potential for nuisance flooding where this
occurs. Forecast remains on track.
With an upper trough axis swinging through the region tonight, a
cold front and weak low center approach us and pass through this
afternoon into tonight. The cold pool accompanying the falling
heights aloft will help create conditionally unstable mid level
lapse rates this afternoon into tonight, and SBCAPES increase to
around 500 J/kg during this time. These ingredients, combined
with moisture and the lift from the aforementioned features
passing through, result in showers eventually become likely
everywhere by the end of the night. Chances begin over western
sections around noon with chances increasing and spreading
eastward as the afternoon and evening progress. Shear profiles
are not supportive of severe weather, especially with the
limited CAPE, but thunderstorms will be possible. NBM was used
for temperatures.-- End Changed Discussion --
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
The system should be just east of us, or at least exiting early
Thursday morning. A cyclonic flow aloft and surface trough will
however still be present during the rest of the day. Slight chance
to chance PoPs during the day. CAPE will be more limited, and can`t
completely rule out a thunderstorm, but will leave the mention of it
out for now. Highs mostly in the lower 70s.
The longwave pattern aloft amplifies Thursday night, sending another
trough axis our way. This axis will be over or just east of us by
late, with ridging following it for Friday. Moisture is limited, so
it looks like it will be a dry period. Highs around normal - in the
lower and middle 70s.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
High pressure sfc and aloft will dominate this weekend, while low
pressure remains well out to sea over the western Atlantic. A series
of weak upper level disturbances approaching from the west will
weaken the ridge in place, with timing and location in question.
ECMWF shears out a weakening lead mid level disturbance early next
week, with most of the forcing passing to the north on Sunday and a
lingering weak trough passing S on Mon. GFS remains more
consolidated presumably in response to a stronger and more
consolidated western Atlantic cutoff low, with an approaching
disturbance on Mon. Both models then show a second upper level
disturbance approaching on Tue. For now have remained dry Sunday and
Monday and have no more than 20-30 PoP on Tue.
Daytime temps through the period will run at least a few degrees
above normal. Lows will be near normal Sat night, then also moderate
to above normal especially by Sunday night as a S return flow
becomes established.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
A low pressure system approaches this evening and passes
through overnight.
VFR this afternoon into this evening. Pop-up showers developing
mainly near KSWF may approach the NYC terminals this afternoon.
By 00Z, widespread SHRA with embedded TSRA becomes likely for
the NYC terminals, gradually spreading east overnight. Best
chance for TSRA from 00-06Z for much of the terminals. KGON best
chance for SHRA and TSRA after 06Z. SHRA continues through the
night and into early morning. MVFR or locally IFR conditions
become more likely late night and into the AM push. SHRA comes
to an end from 13-16Z, west to east. Improvement to VFR likely
by mid-day for the NYC terminals with additional pop-up showers
possible after 20Z.
Generally a N/NW flow around 10 kt away from the coastal
terminals where sea breezes are allowing for a more SSW flow
around 10 kt. Wind shifts N tonight for all terminals behind
the passing low pressure remaining at 10kt or less. Wind remains
N with some gusts upwards of 20kt for Thursday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled AMD expected through late this afternoon.
Amendments may be needed for timing of SHRA or TSRA this evening
into the overnight. Locally and briefly lower categories are
possible with this activity.
OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
Thursday: Mainly VFR for NYC terminals. Slight chance of
showers with MVFR cond possible in the afternoon. VFR at night.
Friday through Sunday: VFR.
Monday: Mainly VFR. Low chance of rain showers.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-advisory conditions persist through the weekend with a
light flow, generally 10 kt or less.
&&
.HYDROLOGY...
-- Changed Discussion --
Around a half inch of rain on average is expected through tonight,
but locally heavy downpours with any thunderstorms could quickly
produce an inch or two and rainfall and lead to localized
nuisance flooding.
No other hydrologic impacts are expected for the rest of the
forecast period.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
There is a moderate risk for rip current development today. The
moderate risk continues for Thursday for the southeast Suffolk
County ocean beaches, with a low risk elsewhere.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JC/BG
NEAR TERM...JC/DR
SHORT TERM...JC
LONG TERM...BG
AVIATION...MW
MARINE...JC/BG
HYDROLOGY...JC/BG
TIDES/COASTAL FLOODING...