677
FXUS61 KOKX 111159 CCA
AFDOKX
Area Forecast Discussion...CORRECTED
National Weather Service New York NY
759 AM EDT Thu Jul 11 2024
.SYNOPSIS...
A cold front stalls over the region today. An area of low
pressure along the front tracks nearby Friday and Saturday, and
remains within the area Sunday into early Monday. Then, these
features move farther north of the area Monday into Tuesday with
another cold front approaching for the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Cold front analyzed just to the west at 10Z continues to slow
as it approaches. An associated broken line of showers ahead of
it has largely dissipated, though a few scattered showers remain
possible early this morning, mainly over eastern Long Island
and southern Connecticut where a 50 kt LLJ at 925 mb is passing
thru. Most remain dry though the rest of this morning. Otherwise,
breezy and muggy start to the day.
The remnant low of Beryl continues to lift northeast thru
Upstate NY, and the attendant cold front attempting to advance
east stalls over the region today. As it does, the axis of
deeper moisture shifts east and should keep much of any
additional wet weather focused just offshore, keeping the bulk
of the region dry this afternoon. With the subtly drier air
mass, dew pts fall back into the 60s for the western half of
the region. This should keep heat indices a bit lower than
recent days here and under advisory criteria despite temperatures
approaching 90 in NE NJ and the NYC metro once again.
Rain chances begin to rise tonight as the boundary begins to
wiggle back west, with CAMs hinting at scattered showers pushing
back onshore from west to east overnight into Friday AM.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
The front that stalls over the area on Thursday retreats back
west Friday as a wave of low pressure over the Southeast begins
to ride north along it. The main shortwave energy is progged to
pass over the region into the start of the weekend and this
will instigate more widespread showers and perhaps a few
embedded thunderstorms as it does so. Scattered showers much of
Friday increase in coverage late, becoming likely everywhere
overnight into Saturday as the associated slug of moisture
arrives. PWATs climb once again over 2 inches and heavy
downpours will be possible with this activity. Given the high
moisture content, these could lead to nuisance and minor urban
and poor drainage flooding, and present at least a low threat of
flash flooding. WPC has maintained a marginal risk of excessive
rainfall in this period, which lines up with a potential for
isolated instances of flash flooding. Total QPF thru Saturday is
generally around an inch or so, but expect locally higher
amounts in any areas of training or thunderstorms.
The shortwave lifts north by Saturday night and drier air filters
in from the west. Temperatures both Friday and Saturday, while
held down some by rain and clouds, should still achieve the 80s
regionwide, with overnight lows in the 70s. Stayed close to
guidance consensus with this update.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Main points:
* Potentially another heat wave Sunday into next week with hot and
humid conditions forecast for many locations. Max heat indices
forecast get near the 90 to 100 degree range for much of the area.
Excessive heat will be possible for some interior and urban
locations as heat indices forecast at times to reach above 100 and
could trend a few degrees higher with subsequent forecasts.
* Chances for showers and thunderstorms, mainly late afternoon into
early evening and to the north and west of NYC Monday and Tuesday.
A more widespread chance of showers and thunderstorms exists for
Wednesday into Wednesday night. Extent both spatially and
temporally appears to be greater for thunderstorms towards the
middle of next week due to more vertical forcing.
* Precipitable waters potentially in the 1.5 to 1.9 range for early
to mid next week, making heavy rain a possibility with any
thunderstorms that form.
Overall pattern from LREF depicts flattening of mid level ridge and
zonal flow establishing itself across the region Sunday into early
next week. LREF depicts a strengthening mid level trough approaching
for midweek. This gets relatively closest to the region Wednesday
night next week.
At the surface, low pressure and a frontal boundary remain near the
region Sunday into early Monday. These features then move farther
north of the region while a cold front eventually approaches from
the west. The cold front will be approaching towards the middle of
next week.
The features of low pressure and nearby frontal boundary however
appear quite weak with dry conditions expected Sunday into Sunday
night. Chances for showers and thunderstorms return to the forecast,
mainly north and west of NYC and mainly for the late afternoon into
early evening on Monday as well as Tuesday. The forcing from daytime
trough development along with the buildup of low level instability.
The chances for showers and thunderstorms grow Wednesday as a cold
front approaches and increased forcing aloft allows for greater
lifting as a result.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
A cold front will stall within the region today and then
eventually move back west tonight into early Friday.
Some MVFR stratus remains for KLGA and KHPN with some widely
scattered rain shower activity near KGON this morning. For KISP
and KGON, they still have IFR and below conditions this morning.
Otherwise, VFR conditions are expected through much of the
remainder of the TAF period.
Showers return to the forecast late tonight into Friday
morning, increasing the potential for MVFR.
Winds generally S-SW during the TAF period with wind speeds of
near 10-15 kt. Gusts up to near 20 kt are forecast, mainly
during the afternoon with peak gusts at times to near 25 kt.
Gusts subside tonight with winds generally SW near 5-10 kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of categorical changes in TAF could be off by 1-3 hours.
Uncertainty on end time of wind gusts, which also could be off by 1-
3 hours.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday through Saturday: MVFR or lower possible at times with
periods of showers/thunderstorms. Higher chances of
thunderstorms Friday night and Saturday. Otherwise VFR.
Sunday: VFR.
Monday: Mainly VFR. A chance of afternoon into early evening showers
and thunderstorms with MVFR possible, mainly north and west of
NYC terminals.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Small Craft Advisory on the local ocean waters remains in effect
through tonight with elevated seas between 5 and 8 ft and SW flow
gusts up to 25 kt. Winds subside this evening, but seas likely
hang near 5 ft thru Friday and the advisory may need an extension.
Thereafter, the pressure gradient will be weak enough to allow
for both winds and seas to stay below SCA thresholds across all
the forecast waters.
&&
.HYDROLOGY...
Showers and thunderstorms Friday and Saturday associated with a
nearby boundary and low pressure wave could produce locally
heavy downpours that lead to nuisance flooding in urban and poor
drainage areas. Isolated instances of flash flooding are possible
as well. WPC has outlined the region in a marginal risk of
excessive rainfall.
With higher precipitable waters moving into place for early to mid
next week, heavy rain will be a possibility with any thunderstorms
that develop. The precipitable waters reach between 1.5 and 1.9
inches, below the max records but at times nearing the 90th
percentile. Too early to ascertain any specific rainfall amounts,
but localized heavier rainfall can be expected.
&&
.TIDES/COASTAL FLOODING...
There is a high risk of rip current development along all ocean
beaches today and Friday with surf heights up to 5 ft and a
southwest wind between 10 and 15 kt.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents through this evening for NYZ075-080-081-
178-179.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ350-353-355.
&&
$$
SYNOPSIS...JM/DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...JM
AVIATION...JM
MARINE...JM/DR
HYDROLOGY...JM/DR
TIDES/COASTAL FLOODING...