393
FXUS61 KOKX 141342
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
942 AM EDT Tue May 14 2024

.SYNOPSIS...
A warm front will be well northeast of the region with a
stalled front well west of the region through today. Low
pressure develops along the front and another low approaches
from the south tonight into Wednesday. The low to the south of
the area gets close Wednesday night into Thursday before moving
farther offshore Thursday night. Weak high pressure on Friday
will be followed by a frontal system that impacts the area
through the weekend. Brief high pressure may once again move in
by early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Mid level ridging becomes more of a troughing pattern today as
an embedded shortwave moves across the region today.

Expecting increasing clouds through the day with steady
southerly surface flow.

GFS depicts surface CAPE of a few hundred J/kg across interior
locations today into early this evening. NAM depicts more
surface CAPE (near 500 to 900 J/kg) than the GFS across the
interior today into early this evening.

CAMs show some shower and possible thunderstorm activity moving
in to mainly western parts of the region mid part of this
afternoon into early this evening.

Expecting much of the day to be mainly dry for most locations.
The chances for showers and a slight chance of thunderstorms is
forecast for the latter half of this afternoon to the north and
west of NYC.

Forecast high temperatures a blend of MOS and blends of
guidance, well into the 70s for highs away from the coast.
Temperatures more in the mid 60s to near 70 range along the
coast.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Low pressure approaching brings more showers tonight and
eventually a transition to more stratiform rain is expected
Wednesday into Thursday as low pressure moves south of the
region. Low levels look to remain stable enough to not include
any mention of thunderstorms.

The SREF indicates some low to mid level Q vector convergence so
increased POPs for rain showers tonight. The mid level trough
will continue to approach from the west with an additional wave
of low pressure forming south and west of the region. This more
southern low will move south of Long Island Wednesday and get
to close proximity to Long Island Wednesday night into Thursday.

Model changes in solution are quite drastic regarding the 00Z
NAM versus the 12Z NAM where the 00Z solution depicts hardly any
measurable rain through Thursday night. This has trended drier
than previous runs.

It appears overall the low has shifted farther south compared to
previous forecast, shifting a bulk of the rain farther south
compared to the previous forecast as well. If the trend to the
south with this low continues, look for a trend downward with
respect to POPs and rainfall in subsequent forecasts.

The low appears to moves farther southeast of the region
Thursday night, allowing for chances of rain to decrease.

During this timeframe, expecting less of a diurnal temperature
range with a more maritime airmass developing. Highs Wednesday
and Thursday mostly in the 60s while lows each night are mostly
in the 50s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Brief upper level ridging remains in place over the area on Friday
between an occluded low being reintroduced to the large-scale flow
and an approaching trough. This will likely result in mainly dry
conditions for Friday. By Friday night, the area will begin to feel
impacts of the approaching low pressure system to the west. Onshore
S/SE flow will allow for the increase of moisture and result in the
beginning of showery activity into Saturday.

The low pressure approaching from the west will become cut-off from
the flow over the East Coast. Global models differ greatly in the
positioning of the cut-off low and resulting unsettled conditions.
the CMC and GFS have the low spinning over the area through the
beginning of next week with unsettled weather and on and off showers
through the period. The ECMWF suppresses the low to the south with
high pressure from the northeast nosing in, resulting in mainly dry
conditions. The extended forecast remains low confidence but the
variability in the handling of the surface low pressure will result
in unsettled weather through at least the weekend, so a chance of
showers exists through the entire long term period.

Temperatures will be at or slightly below average, despite generally
cloudy and showery conditions. Highs each day will be in the middle
60s to the middle 70s. Lows will generally be in the middle to upper
50s.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
High pressure remains offshore this morning, then moves into the
Atlantic as low pressure slowly approaches from the southwest into
the afternoon and tonight.

VFR through this evening. There is a slight chance of showers late
this afternoon at KSWF, however, confidence on timing and
occurrence is low. There is also a low chance of thunder.
Chances for showers increases slightly into the NYC metro
terminals during the evening and tonight but handled with a
PROB30 for now. MVFR cigs move into the terminals (western
terminals initially) tonight and into early Wednesday morning.
Widely scattered light showers will be possible through tonight.
Cigs continue to lower such that IFR condition will be possible
by Wednesday morning, but confidence in timing is low.

Southerly flow under 10kt continues into this morning before
increasing to 10-15kt by early afternoon. Any gusts that do occur
this afternoon will be occasional. Winds gradually become SE
overnight into Wednesday morning.

 ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

No unscheduled amendments expected through this afternoon. Low
confidence in timing and occurrence of SHRA/TSRA this afternoon
and IFR cigs tomorrow.

OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...

Wednesday: MVFR or lower likely with SHRA. SHRA chances
diminishes late at night. NE winds G15-20kt.

Thursday: Mainly VFR. A chance of showers. NE winds G20kt.

Friday: VFR. Slight chance of a shower late.

Saturday: MVFR possible. Chance of showers. SE winds G15-20kt.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
Conditions are forecast to remain below SCA thresholds on all
waters through Wednesday. For Wednesday night, SCA conditions
are more probable on the ocean while non-ocean waters will
probably remain below SCA. For Thursday, most waters could
receive SCA level gusts and by this point the ocean seas are
forecast to build to SCA levels as well. The ocean zones are
probable to have SCA level conditions Thursday night while non-
ocean zones are probably below SCA.

Marginal wind gusts near 20-25 kt persist on the ocean Friday with
wave heights 5-7 feet, so SCA condition appear likely. Wave heights
drop below SCA threshold by Saturday night and remain below SCA
conditions through the weekend.

&&

.HYDROLOGY...
No hydrologic problems are expected through the beginning of
next week.

The rain in the short term is expected to be mostly light and
prolonged. Total rainfall forecast is generally between 0.25
and 0.75 inch tonight through Thursday with the possibility that
some locations may not receive rain.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...JM/MW
NEAR TERM...BC/JM
SHORT TERM...JM
LONG TERM...MW
AVIATION...MW
MARINE...JM/MW
HYDROLOGY...JM/MW