656
FXUS61 KOKX 210952
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
552 AM EDT Sun Jul 21 2024
.SYNOPSIS...
A surface trough remains over the area today, while a weakening cold
front approaches from the north. A series of waves of low pressure
will then pass through the region Monday night through Wednesday
night along a stalled frontal boundary. The boundary weakens
and lifts north late Wednesday into Thursday. A cold front early
on Friday. Weak high pressure should return late Friday into
next weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Showers are almost out of the area and skies have started to
clear from west to east. Clear skies are seen now over the Lower
Hudson Valley and some river valley fog can be seen on current
Nighttime Microphysics satellite imagery. Have adjusted the
forecast to capture these trends and obs.
Otherwise, a shortwave exits to the east this morning and a dry
day is expected for most. Although less aggressive than 24
hours ago, the CAMs still all show some convective activity this
afternoon around northeast NJ, NYC and western Long Island near
the surface trough axis. While a rumble of thunder can`t be
completely ruled out, thinking this activity will mainly be rain
showers like yesterday given weak CAPE profiles. Any
showers/thunderstorms associated with an approaching weakening
cold front likely fizzle out before reaching the area, but can`t
rule out some sprinkles across the interior late in the day.
Temperatures today will be back to a few degrees above normal, in
the upper 80s to low 90s.-- End Changed Discussion --
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Unsettled weather returns to the area on Monday. The region remains
on the eastern side of a broad upper level trough, with multiple
shortwaves moving through during this period. At the surface, a
frontal boundary to our south crawls back north with a series of
waves of low pressure forecast to pass near the area. This set up
will bring chances of showers/thunderstorms the whole period.
Periods of moderate to heavy rainfall are likely possible, but it
remains to early for any specifics on timing and areal coverage of
this. See hydrology section below.
Temperatures will be a bit lower than today given the cloud cover
and shower/thunderstorm activity, in the low to mid 80s.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A frontal boundary will stall and persist nearby for the mid week
period. Expect rather warm and humid conditions with some unsettled
weather at times. A few impulses of shortwave energy are suggested
by global NWP leading to chance and likely PoPs for a good duration
from Wednesday through late Thursday. PWATs are likely going to run
at or just above 2 inches. Any embedded thunderstorm activity that
occurs will likely lead to intervals of moderate to locally heavy
rainfall. See the hydrology portion of the AFD for more information.
Weak high pressure likely returns either late Thursday night or
during the day Friday and likely lasts into next weekend.
Temperatures through much of the period are likely to be near to
slightly above normal, with more of a tendency for above normal
temperatures for the night time due to high humidity and a tendency
for clouds. Cloud cover should preclude the need for any heat
headlines this week. Although, it may be close in the urban corridor
if cloud cover ends up being less than currently anticipated during
Wednesday and Thursday. The greater chance for headline heat and
humidity comes towards late next weekend.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
Weak high pressure remains in place today along with a surface
trough through this evening. A frontal boundary weakens while
drifting in from the north late tonight.
VFR prevails through the period. Any isolated to widely scattered
showers across northern and eastern terminals ends for the morning
push. A few widely scattered to isolated showers cannot be ruled out
W & N of NYC for this afternoon, but confidence in occurrence and
location remains too low to include in the TAFs.
Winds will be light and variable and light from the WSW into early
this morning. The winds then will return to S at around 10 kt
towards afternoon. Once again the winds will be light and around 5
kt for most terminals late Sunday evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments are possible for any isolated showers that pop up Sunday.
OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...
Late Sunday night: VFR.
Monday: VFR. Potential MVFR towards late afternoon and evening in
SHRA.
Tuesday through Thursday: Periods of MVFR or lower likely with
SHRA/TSRA.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
With a weak pressure gradient over the area, winds and waves will
remain below Small Craft Advisory criteria through Wednesday
night.
More marginal small craft conditions due to seas is
anticipated, especially further east on the ocean Thursday
afternoon and night.
&&
.HYDROLOGY...
The region will be in a humid and unsettled pattern towards mid week
with anomalously high PWATs. Therefore at this time there appears to
be at least a limited risk of localized flash flooding from any
thunderstorms that produce heavy rain. WPC has placed our region in
a Marginal Risk of excessive rainfall for Tuesday, Wednesday
and Thursday. It remains too soon to lock down any details
around hydrologic related impacts for the Wednesday and Thursday
time frame.
&&
.TIDES/COASTAL FLOODING...
There is a low risk for the development of rip currents at the ocean
beaches today. A SE swell increases to around 3 feet at 10s on
Monday resulting in a moderate risk of rip current development.
Minor coastal flood benchmarks may be approached along the western
south shore bays of Nassau and Queens for the Monday and Tuesday
night high tide cycles.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JE/JT
NEAR TERM...JT
SHORT TERM...JT
LONG TERM...JE
AVIATION...JE
MARINE...JE/JT
HYDROLOGY...JE/JT
TIDES/COASTAL FLOODING...JT