626
FXUS61 KOKX 291920
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
320 PM EDT Mon Jul 29 2024
.SYNOPSIS...
A surface low to the east today moves north of the area into
this evening. Another low pressure approaches from the west
and sends a cold front through the area Wednesday into Wednesday
night. A series of disturbances move through the area Friday
through Sunday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Current visible satellite imagery shows both the upper level
low and surface low circulations clearly. The upper level low is
centered just east of the area while the surface low can be
seen just off the southern Maine coast. Showers continue this
morning, with higher chances for the eastern half of the area.
Some embedded thunderstorms have also been able to develop
across eastern Long Island. Isolated 2 inch per hour rates have
been observed in some areas over the South Fork of Long Island
that saw training. The heaviest activity has now shifted
offshore.
There will remain a chance for showers and isolated
thunderstorms through much of the day with ample low level
moisture in place under an upper- level trough allowing for the
development of weak to moderate instability. Increasing shear
into this afternoon, with effective shear values around 25 to 30
kts may allow some storms to become strong to severe. This is
mainly for southwest of the area, but can not be ruled out for
NYC and portions of northeast NJ. The primary threat is damaging
wind gusts. Any stronger storms can also produce heavy
downpours. Again, this activity is more likely farther south,
but the marginal risk from WPC has been extended farther north
to cover the NYC/NJ metro area for the isolated chance of
excessive rainfall.
Much of the day will remain cloudy, especially for northeastern
areas. Southwestern skies may improve into the afternoon. Highs
today will be in the middle to upper 70s for the eastern half of the
area and most of southern Connecticut. NE NJ, the Lower Hudson
Valley and the NYC metro will see highs in the middle 80s. Lows
tonight will be warm with temperatures falling only into the
lower 70s to upper 60s for northern areas.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
The low that impacted the area on Monday moves well north by
Tuesday with a lingering upper level trough over the area.
Another mid-level shortwave approaches the area from the west on
Tuesday which reinforces the upper-level trough remaining over
the area. The lower heights aloft combined with a moist boundary
layer will result in the potential development of additional
showers and thunderstorms on Tuesday, though without a primary
forcing mechanism, any showers or thunderstorm activity likely
won`t be organized. The best chance to see any precipitation
will be for western areas later in the day and into Tuesday
evening as the frontal system approaches from the west. Highs on
Tuesday will be in the middle to upper 80s.
The frontal system continues its way into the area on Wednesday
with a better chance for more widespread shower and thunderstorm
activity during the day and into Wednesday evening as the cold
front moves through the area. The anticipated shower/storm
activity with mostly cloudy skies should prevent temperatures
from rising more than the low to middle 80s. Timing of the cold
frontal passage varies a bit but by late Wednesday night, the
front is expected to be east of the area with drying conditions
and clearing skies.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Key Points:
* Multiple rounds of showers and thunderstorms late week into the
weekend.
* Increasing heat and humidity will increase chances for heat
indices approaching and/or exceeding 95F for Thursday through
Sunday.
An active northern stream Friday into Sunday will send multiple
shortwave troughs across the forecast area. Weak ridging Thursday
along with warm advection will allow heat and humidity to build
across the region. There is a chance of late day and evening showers
and thunderstorms Thursday, mainly inland.
Another upper level trough will send a weak disturbance into the
area late Friday into Friday night. With a mid and upper level
trough remaining to the west of the region Saturday another
disturbance moves through the region during the timeframe. Heat, and
increasing humidity, will remain in place for Friday through Sunday.
With the possibility of multiple days reaching heat indices of at
least 95 degrees across at least northeastern New Jersey, the lower
Hudson Valley, New York City, and portions of western Long Island,
heat advisories may be needed for late in the week and into the
upcoming weekend. There will be little relief at night as
temperatures are expected to be several degrees above normal, in the
upper 60s to the lower and mid 70s.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
An upper level low over the area will linger over New England
today, with a weak inland surface trough in its wake.
Tstms are now E of the NYC metros and impacting KISP with IFR
vsby and gusty winds. Storms there should end around or shortly
after 20Z. Outside of these storms SE-S flow 10 kt or less
prevails with mainly VFR cond, and winds at the coastal
terminals especially KJFK may increase to 10-15 kt late today
for a time before sunset.
S flow 10 kt or less expected tonight, with MVFR cigs late
tonight into the early daylight hours for the NYC metros.
Outlying terminals are more likely to go IFR/LIFR during that
time.
S winds should start to increase as cigs lift during Tue
morning. Expect speeds 10-15G20kt at some terminals by
afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
AMD possible for winds deviating from fcst.
OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
Tuesday afternoon and Wednesday: Numerous showers/tstms
expected. For the coastal terminals, S winds G20-25kt
possible, along with MVFR/IFR cigs in low stratus overnight/AM.
Wednesday night and Thursday: VFR.
Friday and Saturday: Chance of MVFR or lower in
afternoon/evening showers/tstms.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds and waves will be below SCA levels today but an increase
in southerly winds on the ocean waters late this afternoon and
tonight will allow wave heights to build to around 5 feet. As
such, a Small Craft Advisory is in effect tonight and into
early morning Tuesday. Waves should subside below 5 feet Tuesday
morning. While there may be an occasional gust to near 25 kt
for the western ocean zones, it should be brief and localized
enough to not warrant an additional advisory or extension of the
existing one.
An increasing and persistent south to southwest flow will allow for
ocean seas to build to SCA levels late Friday night into
Saturday.
&&
.HYDROLOGY...
The marginal risk from WPC has been extended farther north to
cover the NYC/NJ metro area for the isolated chance of excessive
rainfall with showers/thunderstorms this afternoon. The bulk of
the showers and thunderstorms are more likely just south of the
area.
Multiple rounds of showers and thunderstorms are possible
Tuesday into Wednesday and again heading into the weekend. While
widespread hydrologic impacts are not expected, it is not out of
the question that localized urban and poor drainage flooding
occur in any heavier and more persistent downpours.
No hydrologic impacts are expected Thursday through next
weekend.
&&
.TIDES/COASTAL FLOODING...
A strengthening southerly flow Monday and Tuesday in
conjunction will a building swell will produce a moderate rip
current risk at the ocean beaches. opted to keep a moderate
risk of rip currents on Tuesday but there remains the potential
for a high risk of rip currents as the swells take on a more
southerly approach to the shore increasing the amplitude of
waves in the surf zone.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 8 PM this evening to 8 AM EDT
Tuesday for ANZ350-353-355.
&&
$$
SYNOPSIS...MET/MW
NEAR TERM...JT/MW
SHORT TERM...MW
LONG TERM...MET
AVIATION...BG
MARINE...MET/MW
HYDROLOGY...MET
TIDES/COASTAL FLOODING...