504
FXUS61 KOKX 301822
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
222 PM EDT Sun Jun 30 2024

.SYNOPSIS...
A cold front will move across the region this afternoon and
evening. High pressure then builds in Monday and will remain
in control through Wednesday. A warm front lifts north of the
area on Wednesday Night followed by a cold front late in the
week which may remain nearby into the first half of next
weekend.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
*** SEVERE THUNDERSTORM WATCH UNTIL 7 PM THIS EVENING ***

Convection has been ongoing for a couple of hours now across N
and NW zones, and this activity will be going into an
increasingly unstable airmass to the immediate S and E towards
towards the northern NYC suburbs and across the more southern
interior zones. MLCAPE values of 2000+ J/kg and bulk shear
values of 40 to 45 kt will support organized and longer lived
convection. As the pre-frontal trough and trailing cold front
slide east / southeast expect the activity to become
increasingly linear in nature. This activity moves through the
rest of the afternoon and early evening. The actual cold front
will follow quickly behind the pre-frontal trough and could
initiate a few more showers and storms early in the evening
before any lingering convection pushes offshore. At this time it
remains uncertain as to how overturned the convective
environment will be, especially further east. Thus the impact of
any squall line or convection with the actual cold front still
remains uncertain. Currently the watch goes to 7 pm, but may
need to be extended, more so potentially for eastern sections if
the convection to the west can hold together and get better
organized. There is a good chance of this due to the higher dew
point air and anomalously moist environment along the coast and
for the immediate coastal zones as dew points are primarily in
the lower and middle 70s.

The main threat from the thunderstorms will be from damaging
wind gusts in excess of 58 mph. There is also a risk of hail
and an isolated tornado cannot be completely ruled out. SPC has
an enhanced risk across the entire area, something that doesn`t
occur too often for our CWA. The timing of the highest risk for
severe thunderstorms still appears to be from now until 8pm for
NW to SE, and perhaps a couple of hours later into the evening
for far eastern and southeastern sections. Another concern with
the convection will be from frequent cloud-to-ground lightning.

Highs this afternoon will be in the middle to upper 80s for
most with potential of hitting 90 in urban NE NJ. Heat indices
should reach around 90 for much of the area with close to 95 in
the NYC and urban NE NJ corridor. The cold front will push south
and east of the area this evening and should be offshore after
midnight. Some showers/storms may linger near the coast after
9pm, but most of the activity should be ending thereafter. Much
drier and cooler air will begin working in behind the front with
dew points falling into the 50s and low 60s by early Monday
morning.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
The upper trough will pivot across New England on Monday. The
progression of the trough will be slow enough that a few showers
may develop across eastern CT and the east end of Long Island
Monday afternoon. These would be associated with energy within
the trough that may attempt to close off near the New England
coast. Otherwise, high pressure will slowly build in from the
Great Lakes region. Mainly partly cloudy skies are expected
although it could trend mostly cloudy out east in the afternoon.
Highs will be a bit below normal for July 1 ranging from the
upper 70s inland to around 80 near the coast. The pressure
gradient ahead of the building high pressure will support N
gusts 20-25 mph.

The trough pushes offshore Monday night with ridging building
behind it into Tuesday. The surface high will also settle over
the area by Tuesday. Dry conditions will continue with highs
moderating to seasonable levels in the lower to middle 80s for
Tuesday.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
No major changes were made to the Long Term and closely followed
the NBM.

High pressure will remain in control on Wednesday before
shifting offshore Wednesday night as a warm front lifts to the
north. A cold front will follow, but will likely not move
through the area and may remain to our north into early next
weekend. Will have to watch the evolution of any middle level
impulses as they ride along the periphery of the ridge. These
are difficult to resolve at this time range, but they may be a
focus for showers and thunderstorms. Right now the consensus of
the modeling indicates a bit higher probability on Friday and
potentially Saturday compared to Thursday.

Temperatures remain seasonable on Wednesday. The deterministic
NBM has trended down a bit for the end of the week, but still
should reach above normal levels, with highs in the upper 80s to
lower 90s away from the coast. Similar readings are expected
through Saturday. Humidity levels will also be on the rise for
the end of the week into next Saturday.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A pre-frontal trough moving across the area this afternoon will
be followed by a cold front moving across this evening.

Some MVFR conditions linger across some of the coastal terminals
this afternoon due to low stratus. MVFR or lower conditions
will be possible with some thunderstorms this afternoon and
evening. Otherwise, VFR conditions can be expected during the
TAF period late this evening through Monday.

Two rounds of thunderstorms are forecast for this afternoon and
evening. The first of these with the pre-frontal trough should
impact the Hudson Valley terminals until near 20Z, the NYC
metros from about 19Z-21Z, and out east across Long Island/CT
from 20Z-22Z. The second round with the cold front should occur
mainly this evening, impacting the NYC metros from 22Z-23Z
until 01Z-02Z, once again about an hour earlier to the NW and an
hour or two later to the E. Stronger cells with either round
could produce strong W-NW winds, mentioned in the 1st round of
thunderstorms in TAFs with potential for 35 kt, and possibly
brief 50 kt gusts. These strong gusts are also possible with 2nd
round of thunderstorms but not explicitly mentioned in TAFs
yet.

Outside of tstms, SW winds will be around 10 kt with some gusts
near 20 kt into early this evening. After the cold front
passage, winds shift to NW and remain near 10 kt with gusts
lingering as well to near 20 kt. Winds become more NNW-N
direction Monday with wind speeds near 10-15 kt and gusts near
20-25 kt.

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

Strong wind gusts possible with any tstm directly impacting the
terminals this afternoon and evening.

OUTLOOK FOR 12Z MONDAY THROUGH FRIDAY...

Monday through Wednesday: VFR. S wind gusts 15-20 kt Wednesday
afternoon into Wednesday early evening.

Thursday: MVFR or lower possible with any late day or nighttime
showers/tstms.

Friday: MVFR or lower possible with a chance of showers and
tstms.

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

&&

.MARINE...
A severe thunderstorm watch is in effect across all waters
through 7 pm this evening.

Thunderstorms develop this afternoon across the western most
waters, and should push east and south through the afternoon and
into this evening for the eastern most waters. Strong, gusty, to
potentially damaging winds, and frequent lightning can be
expected, and hail with any storms. The storms push further
offshore late this evening into the overnight.

The SCA on the ocean remains in effect through midnight. A cold
front will approach the waters this afternoon and move across
this evening. Showers and thunderstorms may bring locally higher
winds and seas. Conditions will subside below SCA levels
overnight behind the front.

Winds and seas should remain below SCA levels through the week.
However, late day winds in the NY Bight area just E of Sandy
Hook could gust close to 25 kt each afternoon Wed through Fri.

&&

.HYDROLOGY...
Showers and thunderstorms are likely this afternoon and evening
with locally heavy downpours. The main hydro threat with this
activity is from minor urban and poor drainage flooding. There
is a low risk for localized flash flooding.

Locally heavy rainfall is also be possible the end of the
upcoming week.

&&

.TIDES/COASTAL FLOODING...
A high rip current risk continues into this evening with swells
of 5-6 ft and 7 second period. Seas and swells subside a bit on
Monday with the flow becoming N. Have gone with a moderate rip
current risk for Monday, which is supported by the latest RCMOS
guidance.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ075-
     080-081-178-179.
NJ...None.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ350-353-
     355.

&&

$$

SYNOPSIS...JP/DS
NEAR TERM...JE/DS
SHORT TERM...DS
LONG TERM...JP/DS
AVIATION...JM
MARINE...JP/DS
HYDROLOGY...JP/DS
TIDES/COASTAL FLOODING...