459
FXUS61 KOKX 151502
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1102 AM EDT Thu May 15 2025
.SYNOPSIS...
Low pressure continues to weaken as it approaches today. An
associated frontal boundary looks to stay just south of the area
through the day and may push through late. Another frontal system
impacts the area Friday through Saturday. High pressure will
gradually return early next week as low pressure lingers just east
of New England. A frontal system may approach during the middle of
next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Minor adjustments made to POPs for showers. Thunderstorms in
forecast remain slight chance POPs/isolated coverage. Fog still
across the area, patchy with larger areas across the waters.
Still some localized dense fog. Expecting the fog to diminish
into early this afternoon. Forecast highs were lowered by a
degree.
The previous upper level low that lingered over the Gulf states for
several days has now opened up into a trough, with the axis just
west of the area currently. At the surface, a weakening low is
centered over the Mid-Atlantic coast, with a frontal boundary
extending to just south of our area. Convective activity is now
limited to eastern CT and eastern LI, likely with the help of a 500-
1000 J/kg MUCAPE axis and nose of a weakening LLJ. This activity
will continue to weaken and shift east gradually. See Hydrology
section below.
The upper level trough moves through today. The boundary at the
surface stays to our south, but may push through late in the
day. The area destabilizes today, with latest CAMs showing about
500-1000 J/kg of MLCAPE. This is due to an increase in moisture
and temperature at the surface today. With very weak lift
available, some pop isolated to scattered pop up convection is
possible. The chances for any thunder are greater across the
interior, as any capping will be greater towards the coast. Very
slow storm motion could result in some localized longer lasting
downpours, but with weak shear no organized convection is
expected. This activity diminishes after sunset.
The pressure gradient really slackens by this evening and
expecting calm to light winds across the whole area. Fog likely
returns given this and the onshore component of the past few
days.
For highs today, went a bit cooler than NBM, mainly across LI
and coastal CT where clouds and an onshore flow should keep
temps down in the upper 60s for the most part. Stuck with NBM
for lows. The pressure gradient really slackens by this evening
and expecting calm winds across the whole area. Fog likely
returns.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Unsettled weather continues through the short term period.
Brief zonal flow aloft follows the departing trough, but another
upper level low approaches. The associated surface low will
impact the area through Saturday night. There is quite a bit of
uncertainty as far as PoPs and thunder during this period. The
most uncertainty is with Friday morning and afternoon as
guidance continues to show a decaying line of showers and
thunderstorms approaching tonight into Friday morning. If this
activity does make it, the best chances will be for northeast NJ
and the Lower Hudson Valley. There may be additional chances
for showers and thunderstorms in the afternoon, but confidence
in this is decreasing as lift looks weak.
The upper level low gets closer on Saturday and moves overhead
Saturday night. A cold front also moves through Saturday night.
While conditions may become more conducive to showers and
thunderstorms on Saturday there is still uncertainty and the
mesoscale setup will become better resolved over the next few days,
which should help give more confidence on the evolution of potential
convection. If the current timing holds, any showers/thunderstorms
will likely be out of the area or dissipate by around midnight.
Warmer temps are expected on Friday and Saturday, highs in the
70s and potentially lower 80s for northeast NJ on Saturday.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Key Points:
* Temperatures will mainly run above normal through the weekend
before trending closer to normal early next week.
A blocky synoptic pattern will continue through the middle of
next week.
The system that impacts the area Friday and Saturday will push
east of the area on Sunday and then remain near or just off the
New England coast early next week. Lingering cyclonic flow aloft
Sunday may be enough to produce a diurnally driven isolated
shower well inland in the afternoon. Upper ridging will build
just to our west early next week with another trough amplifying
over the western states. The proximity of the ridging and upper
low just offshore should keep conditions dry Monday into
Tuesday. The NBM indicates an increase in precip probabilities
on Wednesday which may be overdone given the nearby ridging
which may take some time to break down. Will indicate a low
probability for now with potential of another frontal system
attempting to approach mid next week.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
Low pressure weakens and passes south today.
Visibilities have improved to P6SM at most locations, otherwise
visibilities weer generally MVFR. And, visibilities may improve
to P6SM at the other terminals this afternoon. However,
ceilings remain IFR to LIFR.
Improvement to MVFR possible by late afternoon from KLGA and
points N and W, with the highest probability of MVFR conditions
for KSWF (there is a moderate chance for brief VFR here).
However there is a good deal of uncertainty in the forecast for
these areas, with IFR to MVFR conditions possible this
afternoon. Coastal terminals likely remain IFR this afternoon,
with a chance of brief MVFR. Conditions are expected to
deteriorate once again tonight to IFR or lower for all
terminals.
E to ESE winds at less than 10 kt through the TAF period become
light and variable overnight tonight.
With low pressure nearby, there is a low chance for showers
mid morning through the afternoon. A passing thunderstorm is
also possible.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments expected for changing flight categories throughout
the TAF period.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday: IFR/LIFR early in the morning, then MVFR mid-morning
onward with slight chance of tstms.
Saturday: MVFR cond expected, IFR possible, with showers likely
and chance of tstms.
Sunday...Mainly VFR.
Monday...VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
A Dense Fog Advisory remains in effect for all waters. Dense
fog will likely lower visibilities to less than 1 NM through the
much of the morning. Ocean and South Shore Bays marine zones
have dense fog until 12PM, with other OKX marine zones having
dense fog until 11AM.
The Small Craft Advisory has been adjusted to have the ocean waters
from Sandy Hook to Fire Island Inlet end at 4 PM as seas will
likely decrease there sooner than previously forecast. The SCA
for the rest of the ocean waters expires at 6 PM.
Conditions then remain below SCA levels through next Monday with a
relatively weak pressure gradient over the waters.
&&
.HYDROLOGY...
Additional heavy downpours expected with any thunderstorms that
develop today. Localized minor flooding possible with not much
steering flow. This activity is not expected to reach flash
flooding levels and should diminish as we head towards sunrise.
Shower and thunderstorm coverage will likely increase this
afternoon and heavier downpours are possible again. At this
time, flash flooding is not expected with that activity either.
There are currently no hydrologic concerns Friday through early
next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until 11 AM EDT this morning for ANZ331-332-
335-338-340.
Dense Fog Advisory until noon EDT today for ANZ345-350-353-355.
Small Craft Advisory until 6 PM EDT this evening for ANZ350-
353.
Small Craft Advisory until 4 PM EDT this afternoon for ANZ355.
&&
$$
SYNOPSIS...DS/JT
NEAR TERM...JM/JT
SHORT TERM...JT
LONG TERM...DS
AVIATION...MET
MARINE...JM/DS/JT
HYDROLOGY...DS/JT