148
FXUS61 KOKX 162015
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
415 PM EDT Fri May 16 2025
.SYNOPSIS...
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A warm front draped over portions of the Mid Atlantic lifts north
through the region tonight into early Saturday. An attendant cold
front follows, with the passage expected Saturday evening. A
secondary cold front passes Sunday night. Low pressure lingers in
New England and the Canadian Maritimes Sunday through Monday. High
pressure takes control Monday night into early Tuesday night.
Another frontal system impacts the area Wednesday into Thursday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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Digging trough and upper low over the Upper Midwest swings east
across the Great Lakes region, sending an associated frontal
system toward the region. Warm front analyzed to the southwest
over the Mid Atlantic begins to approach and lift through
tonight.
Remnant MCS that had been advancing east through Pennsylvania
has weakened substantially as it reached the local region, with
only a few lingering showers over parts of LI late this
afternoon. Largely dry conditions expected thru the remainder
of the day, with perhaps a few isolated showers popping up as
forcing and instability remain weak with the boundary still to
the south, and parent low well off to the west.
With multiple spokes of vorticity rounding the trough, CAMs
have been signaling another MCS potentially developing well to
the west along the boundary tonight, before working east with
the outflow. Should this occur, it`s possible the remnants work
into the region overnight, though this is far from a guarantee,
and any local severe risk from this potential activity is low.
Otherwise, likely see areas of fog development once again into
the night with light flow and abundant surface moisture. The fog
may become locally dense depending on the evolution of any
convective system(s) to the west.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
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Upper level low and trough over the Great Lakes pivots east on
Saturday, as a vigorous shortwave tracks across the Mid Atlantic.
A warm front lifts thru by the morning, as the associated
surface low slides into Quebec. The attendant cold front looks
to move through locally in the early to mid evening.
A challenging convective forecast with uncertainty on timing and
coverage of any morning activity. The approaching cold front
adds more in the way of forcing as the day progresses, and
breaks in the clouds should develop by the afternoon. 12z HREF
is progging MLCAPE values as high as 1500 J/kg, along with bulk
shear values 30 to 40 kt. That said, cloud cover could limit
this instability, and subsidence behind any previous MCS could
help to cap the low levels as well. It now appears the core of
the shortwave energy passes north and west by mid afternoon,
and could help limit any organized severe threat locally. With
this, SPC has lowered their threat locally from a slight to a
marginal, which seems reasonable based on the above and
continued uncertainty.
CAMs aren`t overly aggressive in depicting convective
development, but should initiation occur, damaging wind gusts
would be the primary threat, though large hail and even an
isolated tornado cannot be ruled out in the environment.
Coverage looks isolated to scattered, especially across the
LoHud Valley and southern CT.
Cold frontal passage progged around 00Z Sun, and behind it winds
veer westerly into the overnight, with drying conditions
overnight as dew pts fall back into the lower 50s by daybreak.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
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Key Messages:
* Mainly quiet & pleasant weather Sunday through Tuesday.
* A frontal system may will bring rainfall Wednesday, possibly into
Thursday and Friday.
A surface low w/ an associated upper-level low will be located over
New England Sunday. This low will exit into the Canadian Maritimes
by Monday.
This low will bring a second cold front through on Sunday night
helping clear out partly to mostly cloud skies and advecting in
drier air. This leaves late Sunday night into Monday mostly
clear/sunny. A few showers are possible in the northern interior,
closer to the periphery of the low Sunday afternoon/evening, but
chances look quite low.
A quick moving shortwave will pass over or just to the north of the
area Monday afternoon/evening. This may lead to a few clouds, but
otherwise, we will remain clear and sunny late Sunday night through
most of Tuesday.
An increased pressure gradient from the low to our northeast will
lead to breezy W/NW flow Sunday and Monday. As the low exits farther
away, the gradient weakens, leaving light winds by Monday night. It
remains this way with high pressure at the surface through Tuesday.
12Z guidance still varies in timing and track of a frontal system
for the middle of next week. A low over TN/KY late Tuesday will
approach the area Tuesday night and pass near or to the south of the
area Wednesday into Thursday, pushing more north and/or east of the
area on Friday. This will bring a period of wet weather. There is
higher confidence in showers on Wednesday, but confidence is lower
Thursday and especially Friday and models diverge on a solution.
Sunday and Monday will see highs in the upper-60s to mid-70s, right
around the climatological average. Temperatures will be much cooler
from a passing frontal system on Wednesday with highs in the low-60s
under E/NE flow.-- End Changed Discussion --
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
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Weak low pressure with a surface trough near the area today,
followed by a warm front moving through Saturday. Cold front
follows for Saturday evening.
Mainly dry conditions expected through early this evening.
Potentially 3 additional rounds of rainfall in the TAF period.
Next one is coming up late this evening into overnight, just mainly
showers within and around NYC terminals with VCSH in TAFs. Next
round after that is Saturday morning but too low confidence to
include in TAFs. After that is Saturday afternoon into early
Saturday evening which is when showers and thunderstorms will be
possible with PROB30s in the 30 hour TAF sites.
Outside of some brief VFR early this evening and late in the TAF
period, mainly IFR to LIFR conditions expected. Some coastal sites
already have redeveloped IFR stratus this afternoon. LIFR expected
overnight into Saturday morning with clouds lowering and fog forming.
Category forecast is of low confidence with amendments likely. There
could be fluctuation between categories during the TAF period.
Southerly flow near 5-10 kts expected through much of the TAF
period. Southerly winds pick up to near 10-15 kt with some gusts
up to 20 kt Saturday afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of IFR, MVFR, and LIFR changes could be a few hours off
from TAF.
VLIFR possible early Saturday, 08-12Z.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday: Mainly VFR but MVFR possible in the afternoon with
chance of showers and thunderstorms with MVFR or lower conditions
possible.
Sunday: Mainly VFR. Slight chance of showers inland with MVFR
possible. W winds G20-25kt.
Monday - Tuesday: VFR. Monday NW winds G20-25kt day into evening.
Wednesday: MVFR or lower with showers likely, mainly at night. E
wind gusts 15-20 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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Areas of fog likely return tonight, potentially becoming dense
and persisting into mid Saturday morning. A Dense Fog Advisory
may be needed, with the potential for vsbys to fall to less than
1 nm at times overnight into Saturday AM.
Winds and waves remain below Small Craft Advisory (SCA) criteria
through at least Saturday night.
Sunday afternoon and evening, wind gusts may marginally reach SCA
criteria for the NY Harbor, western Sound and western Ocean.
Otherwise, sub SCA conditions are expected on all waters thereafter
through Wednesday. A passing frontal system will lead to ocean seas
climbing 5-7 feet Wednesday night through Thursday night.-- End Changed Discussion --
&&
.HYDROLOGY...
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Locally heavy downpours are possible with any thunderstorms
through Saturday aft/eve. While the overall flash flood threat
is low, the brief heavy rainfall could lead to minor nuisance
flooding in urban and poor drainage areas.
There are no other hydrologic concerns through the end of next
week.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BR/DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...BR
AVIATION...JM
MARINE...BR/DR
HYDROLOGY...BR/DR