000
FXUS61 KOKX 140919
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
519 AM EDT Fri Jul 14 2023
.SYNOPSIS...
A frontal boundary will remain in the vicinity of the forecast area
today and tonight. Unsettled weather is expected much of the time
from Saturday through Tuesday as a series of frontal boundaries move
across the area. High pressure returns for Wednesday. Another
frontal system may affect the region Thursday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Flood Watch in effect through midnight for the Lower Hudson Valley
and Southern CT.
Showers and thunderstorms continue to move across portions of
the CWA early this morning. Most of the storms are across the
northern half of the CWA. Earlier this evening, portions of
Orange County saw anywhere from 2 to 4 inches of rain. A few
cities may have seen locally higher amounts. This area of heavy
rainfall, has moved east into southern CT and have weakened over
time. With PWATs currently 1.5-1.75, expect any showers that
move across the CWA to produce locally heavy rainfall.
We should get a break in the precipitation after sunrise for a few
hours, but with a frontal boundary remaining to our west and an
upper level shortwave progged to move across the region today,
additional rounds of showers and thunderstorms are expected later in
the day.
Based on the overnight models and CAMS, uncertainty remains on the
timing and placement of convection.
Any showers and thunderstorms that develop will be capable of
producing locally heavy rainfall and minor flooding of poor drainage
areas. Localized flash flooding is also a threat. WPC has maintained
the slight risk of excessive rainfall for much of the area. The one
exception is across the Lower Hudson Valley, where through
collaboration, we have decided to go with a moderate risk, based on
all the recent rainfall and the threat of additional heavy rain
today. The areas in the moderate risk have been hit hard with heavy
rain over the last week and it wont take much additional rainfall to
result in flash flooding. Have hoisted a flood watch for the
northern half of the CWA, since this area of the CWA has had the
most rain over the last 5-7 days, and are the most vulnerable for
any flooding to occur today.
In addition, SPC has also maintained the marginal risk with an
isolated threat of damaging wind gusts.
It will remain hot and humid today with temperatures slightly cooler
today than the past few days. Highs should remain in the 80s CWA
wide.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
Showers and thunderstorms are expected to continue through the
evening hours, then gradually diminish after dark with weakening
instability and loss of heating. Warm and muggy conditions will
continue Friday night.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
No significant changes in the long term period.
A closed upper low over south central Canada will drift south
through Sunday and then evolve into an open trough Sunday night.
This trough then passes through the region Tuesday night into
Wednesday. Shortwaves will be rotating into the eastern portion of
the low as surface troughs/weak low pressures pass through the area.
There is a lot of uncertainty with the timing of the shortwaves,
and the development of the surface troughs/low pressures. Any of the
showers and thunderstorms may produce briefly heavy rain, especially
during Sunday as precipitable water values increase to 2 to 2.25
inches, and warm cloud processes dominate. And WPC continues to keep
most of the CWA in a slight risk for excessive rainfall, with the
potential for flash flooding. Monday the longwave upper trough will
be moving through the area and showers and thunderstorms will be
possible once again, and may be more diurnally driven.
Closely followed the NBM for temperatures and probabilities through
the extended period. Temperatures will be near seasonal normals
through the period, with no records expected to be broken.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
A cold front within the area today will begin to slowly lift north.
Showers and thunderstorms moving across parts of NYC, Long
Island and Southern Connecticut this morning expected to be east
of all terminals by 12Z. Categories vary from MVFR to VFR. IFR
is still forecast at a few terminals with high enough potential
for lower ceilings going into this morning. More shower and
thunderstorm activity is possible late this morning through the
rest of the TAF period.
Winds light (5 kts or less) and variable direction into early this
morning across the area for most terminals. NYC terminals remain
with a southerly wind near 7-10 kt. A return S/SW flow around 8-10
kt then develops going into this afternoon.
Confidence remains low with showers and thunderstorms today.
Continued with a PROB30 between 18Z today and 01Z Saturday and
still think this is the best chance for any showers/thunderstorms.
However, an isolated shower or thunderstorm could move through
before or after this period.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Very low confidence with the timing of showers and thunderstorms.
OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
Tonight: Chance of MVFR or lower in showers/thunderstorms, mainly in
the evening.
Saturday: MVFR or lower possible in the morning, otherwise VFR with
a chance of showers/thunderstorms in the afternoon and evening.
Sunday-Tuesday: Chance of showers/thunderstorms with MVFR or
lower.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-SCA conditions are expected through early next week. However, an
increasing southerly swell Sunday into Monday may allow for ocean
seas to be near 5 feet at times Monday into Monday night.
&&
.HYDROLOGY...
A Flood Watch is in effect for the Lower Hudson Valley and Southern
CT today.
Locally heavy rain is possible from any shower or thunderstorm
through tonight. The main concern is from minor poor drainage
flooding and a low potential of small stream from reaching bankfull.
The Weather Prediction Center has placed the area in a slight risk
for flash flooding today and tonight, with the exception of the
lower hudson valley where a moderate risk exists. This area was
upgraded to a moderate risk due to all the heavy rainfall that has
fallen over the last week.
Additional rounds of moderate to locally heavy rain will be possible
Saturday and especially Sunday, with the threat of flash flooding,
nuisance, and minor flooding of poor drainage areas possible.
&&
.TIDES/COASTAL FLOODING...
There is a moderate risk of rip current development at all the
ocean beaches today and Saturday.
Southerly winds with southerly swells around 2 ft will be in place
across the ocean beaches during this time period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Flood Watch through this evening for CTZ005>012.
NY...Flood Watch through this evening for NYZ067>071.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BC/MET
NEAR TERM...BC
SHORT TERM...BC
LONG TERM...MET
AVIATION...JM
MARINE...BC/MET
HYDROLOGY...BC/MET
TIDES/COASTAL FLOODING...