000
FXUS61 KOKX 061148
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
748 AM EDT Wed Sep 6 2023
.SYNOPSIS...
High pressure remains in control today and begins to weaken on
Thursday. A slow moving frontal system will impact the area Thursday
night through the weekend. The associated cold front passes through
late Sunday night into Monday. A second frontal system will follow
on its heels Tuesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
Forecast update to reflect current observations. Otherwise, an
upper level ridge will remain over the area today, resulting in
temperatures around 10 degrees above average.
Only change to the heat headlines was to expand the heat advisory to
the CT coastline. Otherwise, a heat advisory remain in place for
much of the CWA today. The combination of temperatures in the upper
80s and lower to middle 90s with high dew points will result in heat
index values in the middle and upper 90s. Only eastern Suffolk
county will have a heat advisory. Expect heat index values falling
just short of the 95 criteria. Can not rule out a few locations
touching 95. Some record high temperatures may be broken today at
our climate sites.
Otherwise, expect a mostly sunny day with dry conditions.
Tonight, it will remain mostly clear and remain warm and muggy.
Overnight lows for much of the CWA will remain in the 70s. Record
maximum lows are also possible for some climate sites tonight.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
The upper level ridge starts to weaken and slide east Thursday.
Despite this, the hot and humid conditions will remain in place
Thursday afternoon. Heat advisories remain in effect for NYC, The
Lower Hudson Valley and portions of NE NJ and Connecticut.
Record high temperatures are possible on once again for some climate
sites. Also, the warm conditions continue overnight so record
maximum lows will once again be possible Thursday night. You can
reference the climate section of this AFD for a listing of prior
records.
Isolated showers and/or thunderstorms are possible for western
interior portions of our area Thursday night from a weak frontal
system, but confidence is low on if they will occur.
For Friday, the high continues to weaken as an upper level trough
and cold front slowly approach from the west. Temperatures are
forecast to be about 5 to 8 degrees cooler on Friday, however a
stronger onshore flow should allow dew points to rise a few degrees.
As a result, expected humidity levels to remain high. Right now, it
appears most locations wont need heat headlines, however we will
need to keep an eye on parts of NE NJ, where heat index values will
come close to 95.
Otherwise, with the approaching front and trough, POPS slowly
increase through the day Friday. Will keep most of the area at
Chance or lower. The main threat with any storms will be the locally
heavy rainfall. Temperatures on Friday are expected to be in the
80s.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
A slow moving upper trough over the east with multiple pieces
of energy cutoff from the flow will get kicked slowly eastward
over the weekend as a northern branch trough amplifies as it
tracks across central Canada and the Great Lakes. This will also
send a surface cold front eastward. Ahead of it will be a deep-
layered southerly flow advecting high PWAT values into the
area. There is also some retrogression of the western Atlantic
ridge at the start of the period. This will keep the highest
rain chances initially across the western half of the forecast
area (NW of a line from NYC into SW CT) due to ridging across
eastern sections. Rounds of showers and thunderstorms are forecast
through the weekend as warm advection and convective vorts work
south to north ahead of the approaching cold front. It will not
be raining all the time. There will be diurnal component to
this activity as the airmass destabilizes during the daytime
hours with the best chances from late afternoon through the
first half of the night. For eastern areas of LI and CT, it
could be drier the first half of the weekend until the ridge
over the western Atlantic weakens.
As for rainfall, the 00Z GFS and ECMWF are in very good agreement
with their mass fields through early next week, yielding 1-2
inches of rainfall from NYC and points north and west. To the
east, rainfall amounts will decrease due to the aforementioned
ridging. Localized flash flooding is a possibility at this time.
The cold front passes through Monday morning, but looks diffuse and
may just wash out. The airmass behind it looks a bit drier, but this
will be dependent on if the cold front can fully move to our east.
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 on Tuesday
While it will cool off some during this time due to rain chances and
cloud cover, it will also be quite humid with dew points around 70
and afternoon highs around 80 (near normal). Lows over the
weekend will be in the upper 60s to lower 70s, before dropping a
bit behind the cold front early next week. Lows will be about 5
to 8 degrees above normal.-- End Changed Discussion --
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
High pressure will remain in control today with a thermal trough
setting up once again in the afternoon. High pressure then builds
offshore Thursday as a slow moving frontal system approaches from
the west.
VFR. Light and variable winds early this morning become light NW
flow to start the day (right of 300 true) likely backing to the
W/WNW (left of 300 true) in the afternoon at KTEB and KEWR. KLGA may
very well stay out of the N-NE throughout the day. Late day S sea
breezes likely for KISP/KJFK with late morning SSW sound breeze at
KBDR/KGON. Winds become light and variable once again Wed evening.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shifts could vary by 1-3 hours, but remaining under
10 kt. There is a low chance for a sea breeze making it to KEWR
during the afternoon and it may stay south of KLGA in the evening.
OUTLOOK FOR 09Z THURSDAY THROUGH SUNDAY...
Thursday: Mainly VFR. S/SW winds. Chance of late afternoon/evening
showers and thunderstorms for the NYC and Lower Hudson Valley
terminals. A slight chance elsewhere.
Friday through Sunday: MVFR possible at times in rounds of aft/eve
showers and thunderstorms. S wind gusts 15-20 kt Friday.
Potential for nocturnal coastal stratus will increase through this
period as well.
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 Thursday under high
pressure. A slow-moving frontal system approaches Thursday
night into the weekend. Winds and seas are expected to remain
below SCA levels during this time period.
&&
.HYDROLOGY...
No hydrologic impacts are expected through Thursday.
Locally heavy rainfall is possible Friday into the weekend, but
there is still too much uncertainty with the timing and extent
of the activity.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
A moderate risk of rip currents continues today as long period ESE
swells of 3 ft to 10-11s look to continue. The swells may diminish
Thursday, but given a stronger southerly flow in the afternoon and
lingering 9 second periods, it`s possible for moderate in some
locations.-- End Changed Discussion --
&&
.CLIMATE...
Some daily record highs and lows could be tied or broken over the
next couple of days. The record highs for these dates are below.
Daily Record High Temperatures...
Sep 6 Sep 7
Central Park..97 (1881)..101(1881)
LaGuardia.....96 (2018)..90 (2015)
JFK...........92 (1985)..93 (1983)
Islip.........90 (1985)..92 (1998)
Newark........98 (2018)..95 (2015)
Bridgeport....92 (2018)..91 (1983)
Daily Record High Minimum Temperatures...
Sep 6 Sep 7 Sep 8
Central Park..78 (1985)..79 (1881)..76(2015)
LaGuardia.....79 (1985)..74 (2012)..76(2015)
JFK...........77 (1985)..76 (1985)..73(1983)
Islip.........79 (1985)..74 (2012)..76(2015)
Newark........77 (1985)..74 (1999)..73(1999)
Bridgeport....75 (1985)..72 (2016)..74(2015)
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from 11 AM this morning to 8 PM EDT Thursday for
CTZ005>009.
Heat Advisory from 11 AM this morning to 8 PM EDT this evening
for CTZ010>012.
NY...Heat Advisory from 11 AM this morning to 8 PM EDT Thursday for
NYZ068-070.
Heat Advisory from 11 AM this morning to 8 PM EDT this evening
for NYZ078-080-177-179.
Heat Advisory until 8 PM EDT Thursday for NYZ067-069-071>075-
176-178.
NJ...Heat Advisory until 8 PM EDT Thursday for NJZ004-006-103>108.
MARINE...None.
&&
$$
SYNOPSIS...BC/DW
NEAR TERM...BC
SHORT TERM...BC
LONG TERM...DW
AVIATION...DW
MARINE...BC/DW
HYDROLOGY...BC/DW
TIDES/COASTAL FLOODING...
CLIMATE...