499
FXUS61 KOKX 291440
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1040 AM 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 /THROUGH TONIGHT/...
-- Changed Discussion --
Another pleasant start to the day with sunshine prevailing over
scattered cu. Temperatures top out in the 70s regionwide as cloud
cover thickens this afternoon ahead of an approaching frontal
system that moves through this evening, bringing showers and a
few thunderstorms with it. Can`t rule out a few of these
developing into the western portion of the local area by mid to
late afternoon, but the bulk of this activity looks to arrive
early this evening. Locally heavy downpours will be possible,
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 /THURSDAY 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 TUESDAY/...
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 /15Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
A cold front approaches today and passes through tonight.
VFR to start with NW flow 5-10 kt, followed by sea breeze
development at KBDR/KGON late this AM and KJFK/KISP this
afternoon.
Pop-up showers become possible as early as 20Z but more
widespread SHRA likely not until closer to 00Z for the NYC
terminals. TSRA also becomes possible, mainly from 23-05Z, and
handled with a Prob30 for the time being. SHRA continue into the
night before ending late in the night. Any of this SHRA or TSRA
activity can result in MVFR or locally lower categories for a
brief time this evening into the first half of the overnight
period.
...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 12Z THURSDAY THROUGH SUNDAY...
Thursday: Chance of showers with MVFR cond possible in the
morning E of the NYC metros. Otherwise, an isolated shower
possible into the afternoon.
Friday through Sunday: VFR.
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 today into
tonight, but locally heavy downpours with any thunderstorms
could quickly produce up to an inch or two, leading 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...BG/MW
MARINE...JC/BG
HYDROLOGY...JC/BG
TIDES/COASTAL FLOODING...