000
FXUS61 KOKX 081142
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
742 AM EDT Fri Sep 8 2023
.SYNOPSIS...
A slow moving frontal system will impact the area through the
weekend. The associated cold front eventually moves east of the
region late Monday, followed by another frontal system for the
middle of the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Only minor adjustments made with the latest update as the
forecast is mostly on track. Hourly temps, dewpoints and cloud
cover were updated based on the latest obs and trends.
Surface high pressure builds to our east while under a ridge aloft.
To our NW, confluence aloft will promote high pressure building over
the Great Lakes. We`ll be in between with surface troughing /
stalled boundary over us. Moisture convergence along and near this
boundary will promote primarily afternoon and evening showers with a
chance of thunderstorms. Models imply this boundary drifts to the
west this afternoon and evening, shifting the highest threat of
showers along with it. Thunderstorms can be strong to severe with
the main threat being gusty winds as 0-6km bulk shear will be 25-30
kt along with plenty of CAPE. Large hail cannot be ruled out either,
particularly in the strongest thunderstorms. SPC has most of the
city and areas N and W of the city with a slight risk for severe
weather. See the hydrology section below regarding the flooding
threat.
More cloud cover and lower temps aloft as compared to the past few
days will lead to lower high temperatures today. Dewpoints however
will end up in the lower and middle 70s. Heat Advisories have
therefore been expanded into western LI and most of the CT zones.
Heat indices in the advisory area are expected to range 95-100.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
The pattern doesn`t change much on Saturday with a stalled boundary
and enhanced moisture convergence over the region. Showers will be
more likely in the afternoon and night along with the threat of a
thunderstorm. Overall higher chances will be from around the city to
points N and W where moisture convergence will be greater in the
vicinity of the surface boundary. No concerns for severe weather at
this time, largely due to relatively weak winds aloft. High
temperatures Saturday in the lower and middle 80s. Not anticipating
any extension of heat advisories at this time.
More of the same for Sunday as the boundary remains over the Tri-
State Area. Models are in agreement with somewhat deeper moisture
through the column this time around. Higher chances of showers
overall as compared to Saturday. High temperatures in the low 80s.
The flash flooding threat for Saturday and Sunday remains low, but
will also depend on how much rain we end up seeing beforehand. See
the hydrology section for more details.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
The boundary finally shifts east on Monday as an upper level
shortwave approaches from the W. The front should finally move east
of the region sometime late Mon evening or overnight. While much of
Mon carries at least chance PoP, still thinking that it won`t be a
complete washout as the timing of any individual piece of energy and
associated lift remains uncertain. Continued with diurnal timing for
likely probabilities.
Some drier air will finally move back into the region on Tue,
however there is a second frontal system on its heels with an
amplifying upper trough digging south and east across the Great
Lakes. Chances for convection will be on the increase ahead of this
system Tue night into Wed, perhaps lingering into Thu.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
High pressure remains offshore, meanwhile a cold front slowly
approaches from the west.
Flight categories across the NYC terminals range from LIFR to
VFR. Improvement to VFR is anticipated around 15z. NW and East
of the NYC terminals, conditions remain below VFR and slow
improvement is expected there as well during the morning hours.
Thinking VFR prevails this afternoon for a few hours, then
conditions fall back to IFR or lower tonight.
Winds are generally light and variable to start. Winds then
become S-SE and increase to around 8-12 kt in the afternoon and
early evening, before becoming light and variable once again
tonight.
Showers and thunderstorms are possible this afternoon and
evening. Will carry a TEMPO group from about 20-00. Probabilities
are lower for terminals east of NYC and have left mention out
of the TAF for now.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of improvement to VFR today may be off by 1-2 hours.
Amendments likely for potential showers/thunderstorms this
afternoon and evening.
OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
Saturday through Sunday: Showers likely and possible thunderstorms
each afternoon and evening, particularly NYC and points N&W on Sat,
possibly more widespread Sunday. MVFR or lower conditions each night
and early morning.
Monday: Possible early morning MVFR/IFR conditions. Showers and
thunderstorms, more likely across the northern and western areas.
Tuesday: Slight chance of showers with MVFR possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
A weak pressure gradient will lead to sub SCA conditions for the
rest of the week. Winds and seas will remain below SCA levels for
the weekend despite the approach of a slow moving cold front.
Ocean seas are forecast to build to 5 ft early next week and may
continue for much of the week. For the non-ocean waters, sub SCA
conditions will continue.
&&
.HYDROLOGY...
Periods of showers and thunderstorms today through Sunday are
expected to produce 1 to 3 inch rain totals for most the of
area. Lighter amounts will be generally across Long Island and
Southeast CT.
The risk for flash flooding will be low through Sunday, but
confidence is not high due to the uncertainty of how much and where
rain occurs each day. Best overall chances for any level of flooding
will be generally from around the city to points north and west,
with the highest chances over the typically more susceptible
basins across NE NJ. The threat for at least minor flooding
continues into Monday with more of the Tri-State Area included
in this chance as a frontal boundary slowly shifts east through
the region.
&&
.TIDES/COASTAL FLOODING...
A moderate risk of rip currents is anticipated at the Atlantic
beaches today and Saturday.
&&
.CLIMATE...
Daily Record High Minimum Temperatures...
Sep 8
Central Park..76(2015)
LaGuardia.....76(2015)
JFK...........73(1983)
Islip.........76(2015)
Newark........73(1999)
Bridgeport....74(2015)
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 6 PM EDT this evening for CTZ005>010.
NY...Heat Advisory until 6 PM EDT this evening for NYZ069>075-078-
080-176>179.
NJ...Heat Advisory until 6 PM EDT this evening for NJZ002-004-006-
103>108.
MARINE...None.
&&
$$
SYNOPSIS...JC
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...
AVIATION...BC
MARINE...JC
HYDROLOGY...JC
TIDES/COASTAL FLOODING...
CLIMATE...