254
FXUS61 KOKX 112007
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
407 PM EDT Thu Jul 11 2024

.SYNOPSIS...
A stationary front along the east coast, from Maine into the
southeastern states, remains into Saturday as a wave of low
pressure tracks slowly northward from the Carolina coast.
Stationary front to the south washes out on Sunday, otherwise a
thermal trough will set up across the area each afternoon for
the start of the week. A frontal system will then move into the
area for the middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
A cold front that moved through the region today has become
stationary just to the east, and extends southward toward the
Carolina coast. As a weak wave of low pressure begins to
develop on the boundary south of the area showers will approach
from the south and southeast tonight.

The low, and supporting upper level energy will track slowly
northward through Friday with probabilities of precipitation
increasing. Some instability does develop, especially inland, by
the afternoon, and scattered to isolated thunderstorms will be
possible. Precipitable water values increase to around 2 inches
Friday, and by late day there may be a few heavier
showers/thunderstorms. However, this becomes more likely Friday
night.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
Precipitable water values increase to near 2.25 inches Friday
night, and with an increasing low level jet and increasing warm
cloud processes, the probability of periods of moderate to
heavy rainfall will be increasing Friday night into Saturday
morning. Also, the southerly flow will increase inland
convergence, with heavier rain potential across northeastern New
Jersey into the lower Hudson Valley, and into southwestern
Connecticut. If the heavier rainfall occurs there is a chance of
local nuisance and minor urban and poor drainage flooding, and
present at least a low threat of flash flooding.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Main points:

* Potential heat wave Sunday into next week with hot and humid
  conditions. Max heat indices forecast from mid 90s to low 100s.
  Highest across urban and interior locations.

* 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.

* Precipitable water values potentially in the 1.5 to 2" range for
  early to mid next week, making heavy rain a possibility with any
  thunderstorms that form.

While heights will not be necessarily anomalously high, the forecast
area will reside at the southern edge of the westerlies. This will
result in a deep-layered westerly flow, transporting anomalously
warm air into the region. 85h temps increase to around 20C by
Monday, and event a bit higher Tuesday into Wednesday. In addition,
the low-level flow will be more from the S-SW, which will lessen the
marine influence, especially just inland from the coast. High temps
for much of the area Monday into Wednesday will be in the low to mid
90s with the exception of immediate coastal locations, especially
across eastern LI and SE CT. Forecast stayed very close to the NBM,
even with the box and whisker temperature plots showing the
deterministic values below the median (50th percentile). In other
words, there may be the potential for even higher values. However,
did blend the NBM dew points with CONSALL to get the dew points down
some. With more of westerly flow than the past heat event, expect
some drier air to mix down each afternoon. NBM often can be on the
high side. This still results in widespread heat indices of 95 to
100 Monday through Wednesday with some locations even getting this
high on Sunday. Some of the interior and urban locations even flirt
close to 105 (Excessive Heat Criteria) for Monday and Tuesday.

Also, being at the southern edge of the westerlies will result in
less capping with the potential for diurnally driven convection
Monday and Tuesday afternoon, mainly north and west of the NYC
metro. A more widespread convective event is possible mid week as a
cold front approaches from the west and PWAT values increase to
around 2 inches.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
A cold front will stall within the region and eventually move
back west tonight into early Friday.

VFR conditions are expected through much of tonight. Conditions
deteriorate early Friday morning to potentially MVFR in showers.
There is also a chance of some thunderstorms across the NYC
terminals, therefore have added VCTS starting 18Z Friday.

Gusts forecast to subside tonight with winds generally SW near 5-10
kt, becoming south in the afternoon around 10 kt.

 ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Timing of categorical changes in TAF could be off by 1-2 hours
tonight into Friday morning.

Uncertainty on end time of wind gusts, which also could be off by 1-
3 hours.

OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...

Friday through Saturday: MVFR or lower possible at times with
periods of showers/thunderstorms. Higher chances of thunderstorms
after Friday afternoon and into Saturday. Otherwise VFR.

Sunday: VFR.

Monday and Tuesday: 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

&&

.MARINE...
Ocean seas remain elevated tonight into Friday with south to
southeast swells, and the SCA was extended through Friday. Seas
may be marginally near 5 feet into Friday night, and the SCA may
need to be extended. Southerly winds Saturday with a stationary
front nearby may keep ocean seas elevated even into Saturday.
Otherwise, for the non ocean waters winds and seas remain below
advisory levels tonight through Saturday.

Winds and seas will generally be below SCA criteria Sunday through
Tuesday in a S-SW flow that increases to 10 to 15 kt by Monday. A
few gusts to 20 kt will be possible on the ocean waters Tuesday.

&&

.HYDROLOGY...
Showers and thunderstorms Friday and Saturday, associated with a
wave of low pressure along a stationary front, could produce
periods of locally heavy rainfall, especially Friday night into
Saturday, that may 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 Friday into Saturday.

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 2.0
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 until 9 PM EDT this evening for NYZ075-
     080-081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT Friday for ANZ350-353-355.

&&

$$

SYNOPSIS...MET
NEAR TERM...MET
SHORT TERM...MET
LONG TERM...DW
AVIATION...20
MARINE...MET/DW
HYDROLOGY...MET/DW
TIDES/COASTAL FLOODING...