479
FXUS61 KOKX 030055
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
855 PM EDT Fri Aug 2 2024
.SYNOPSIS...
Weak low pressure and a stalled frontal boundary will be in the
vicinity through this weekend. Weak high pressure across the area
Monday will then give way to a cold front that slowly sags south
and east and through the midweek. At the same time, a potential
tropical cyclone works northeast along the southeast coast.
This could impact the position of the front and whether or not
it stalls across the area. Refer to the latest NHC forecast
information on this potential storm.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
Convection has weakened across the area considerably the last
hours and what is left will work across CT and LI, mainly as
dissipating showers. Most of the lift with the shortwave that`s
helping drive this convection will shift north and east of the
area overnight with shower/thunderstorm chances dropping off.
Low stratus and patchy fog possible mainly over eastern LI and
SE CT. Muggy overnight with lows in the 70s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
Weak low pressure and a surface boundary remain in the vicinity
through this weekend. Both days expected to feature diurnally-
driven convection with the help of shortwave lift aloft. Shear
both days will be fairly weak, so the overall severe
thunderstorm threat is low so far with perhaps isolated pulse
severe possible. A somewhat bigger threat would be flooding, but
the flash flooding threat looks to be only on the isolated side
as well with minor/poor drainage flooding the main mode.
Perhaps the flooding threat could increase on Sunday with the
frontal boundary and focused moisture convergence more likely
right over us, but this will also depend on how much antecedent
rainfall occurs.
Max temps at the top of the mixed layer will be slightly cooler
on Saturday versus today, and even cooler on Sunday. Some
uncertainty with cloud cover and subsequent impacts on high
temperatures for Saturday, but dewpoints should once again
average in the mid 70s. No changes to the heat advisory at this
time. Not enough confidence in 2-day criteria being met in
Orange and Putnam Counties due to today`s cloud cover/convection
and only marginally widespread forecast heat indices of 95 or
higher on Saturday. Therefore, no extension of the advisory
here. A better argument exists to add eastern Suffolk County and
maybe Southern Middlesex Counties to the advisory based on what
could end up occurring for the rest of today and what is
forecast for tomorrow, but not enough confidence here either to
expand the advisory into these zones. For Sunday, the cooler
temperatures preclude the extension of any heat advisory, but
not out of the question that parts of the NE NJ urban corridor
eventually end up with an advisory on Sunday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Quite a bit of uncertainty heading into next week with a potential
tropical cyclone working northeast along the southeast coast.
Please refer to the latest NHC forecast on this potential storm.
A weak upper trough departs from the Northeast Sunday with any
lingering showers/thunderstorms coming to end by the early
morning hours Monday. Thereafter, a nearly zonal flow along the
U.S./Canadian border begins to take a dip across the Great Lakes
and Northeast in the Tuesday into Wednesday timeframe. This
will allow a cold front to sag slowly southeast during the time.
Due to quite a bit of uncertainty in the forecast, stayed in
line with the NBM which takes the boundary through the area
Tuesday night. This part of the forecast will partly hinge on
the future track of the aforementioned potential tropical cyclone.
The 12Z GFS has trended slower with the frontal passage which
is likely due to the fact it is the fastest and most northern
solution with respect to the tropical system. Thus, expect
there to be some fluctuation with the position in subsequent
forecasts. Furthermore, this boundary may interact with tropical
moisture during the midweek time frame.
The best chance at this time for showers and thunderstorms will
be Tuesday afternoon and night as the front is forecast to
settle south and east through the forecast area. After that,
plan on just having low chances for the rest of the week with
the boundary lingering close to the forecast area. This is too
far out in time to provide any more details than that, but it is
advisable to monitor subsequent forecast, especially as we head
into next week.
Warm, humid conditions will continue Monday into Tuesday, with
a cool down for the second half of the week with the front
forecast to be south of the area. Highs Monday with be well into
the mid 80s to lower 90s (except immediate Atlantic coast), but
perhaps slightly cooler on Tuesday with the approach of the
front.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
One wave of low pressure passes through the region this evening,
followed by weak high pressure. Another wave approaches Saturday
and moves into the area late Saturday into Saturday evening,
then stalls.
A line of showers and isolated thunderstorms was moving through
the region, generally east of the NYC terminals, and was
gradually weakening at 23Z. MVFR to locally IFR conditions are
possible with this line. Thereafter, Generally VFR conditions
are expected, except at the outlying terminals and along the
coast where stratus and fog are likely with IFR to LIFR
conditions until early Saturday morning. However, there is low
confidence in the forecast of the stratus and fog.
VFR Saturday until late in the day, after 20Z, when another
round of showers and thunderstorms will be likely. These may be
more scattered than Friday`s line.
Southerly winds this evening become SW, and light and variable
at the outlying terminals. A SW flow is expected Saturday with
seas breezes developing and winds becoming southerly.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Thunderstorms were moving east of KLGA and KJFK and did not
mention in the 00Z terminals as theses storms should be to the
east shortly after 00Z.
There is uncertainty with the development of stratus and fog
especially at KJFK, and may not occur as winds become more SW.
Low confidence forecast.
OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
Saturday-Sunday: Chance of MVFR or lower in afternoon/evening
SHRA/TSRA.
Monday: VFR.
Tuesday-Wednesday: Mainly VFR. Low chance of SHRA/TSRA, with
MVFR or lower.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Sub-SCA conditions expected on all waters through Saturday morning,
then a southern fetch and building swell push seas on the ocean to 5-
6 feet Saturday afternoon and night. Have issued a SCA for the ocean
Sat aftn and night. Might eventually need to extend the advisory
through at least Sunday.
Marginal SCA conditions may linger on the ocean waters Sunday
night into Monday due to a prolonged southerly fetch and swell.
In addition, the middle of next week could feature building
long period southerly swells from a potential tropical cyclone.
Refer to latest forecast information from the NHC.
&&
.HYDROLOGY...
Multiple rounds of showers and thunderstorms could lead to some
locally heavy downpours going through this weekend. WPC has a
marginal risk for excessive rainfall for much of the region each day
through this weekend with a slight risk west of the Hudson for
today. Mainly minor urban and poor drainage flood impacts
potential, but localized flash flooding cannot be ruled out each
day.
There is the potential for heavy rainfall Tuesday into Tuesday
as a frontal boundary interacts with tropical moisture. However,
it much too early for any specific details.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
An onshore southerly flow the next two days at 10-15 kt and a
building southerly swell (5-6ft) will produce a moderate rip
current risk on the ocean beaches Saturday and a high risk on
Sunday. There is a chance that the risk increases to high late
in the day Saturday.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Heat Advisory until 7 PM EDT Saturday for CTZ005>010.
Air Quality Alert until 11 PM EDT this evening for CTZ009.
NY...Heat Advisory until 7 PM EDT Saturday for NYZ069>075-078-080-
176>179.
Air Quality Alert until 11 PM EDT this evening for NYZ069>075-
078>081-176>179.
NJ...Heat Advisory until 7 PM EDT Saturday for NJZ002-004-006-
103>108.
Air Quality Alert until 11 PM EDT this evening for NJZ002-004-
006-103>108.
MARINE...Small Craft Advisory from 2 PM Saturday to 6 AM EDT Sunday for
ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...JC/DW
SHORT TERM...JC
LONG TERM...DW
AVIATION...MET
MARINE...JC/DW
HYDROLOGY...JC/DW
TIDES/COASTAL FLOODING...