000
FXUS61 KOKX 201945
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
345 PM EDT Tue Aug 20 2019
.SYNOPSIS...
High pressure across the region will shift east tonight. A warm
front will then move north of the area on Wednesday followed by
an approaching front late Wednesday night. A cold front will slowly
move through the area Thursday into Friday, followed by high
pressure into the weekend. Unsettled weather may return early
next week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
High pressure across the area will shift east tonight as a warm
front approaches from the south. This will allow for moisture to
increase across the area late tonight and into Wednesday. PoPs will
increase across the area late tonight and into Wednesday morning.
Temperatures tonight will be in the upper 60s to lower 70s.
There is a low risk of rip current development at ocean beaches
today.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
As a warm front pushes north across the area on Wednesday, a very
humid airmass will usher in across the area with dewpoints rising
into the lower 70s in southerly flow. A weak shortwave will interact
with the warm front as it lifts north, which could spark a few
morning showers and thunderstorms. Given the moist airmass, any
thunderstorms will have the potential for gusty winds and local
downpours, especially north across of our CWA.
Thunderstorms will continue through Wednesday afternoon as an upper
trough over the Great Lakes sends a cold front towards the area.
Upper level jet support combined with mid level shortwave energy
will initiate convective development during the afternoon. Forecast
soundings showing >2000 J/kg of CAPE into the afternoon along with
increasing shear with the incoming trough. With a favorable storm
environment, the Storm Prediction Center has placed the area under
a slight risk. Southwesterly flow will advect in precipitable water
of near 2 inches, therefore heavy downpours are likely in any storm.
Showers will continue through Wednesday night as the cold front
approaches the area from the west.
Temperatures on Wednesday will be in the mid to upper 80s to near
90. The combination of heat and increasing dewpoints will result in
heat indices in the low to mid 90s with the exception of eastern
Long Island and southeastern coastal Connecticut.
Wednesday night lows will be in the upper 60s to lower 70s.
There is a moderate risk of rip current development at ocean
beaches for Wednesday.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Cold front slowly pushes through the area Thu into Thu night.
Both GFS and NAM soundings are indicating a capping inversion
around H8 which would limit shower/tstm activity. This inversion
may weaken late in the afternoon and into the evening so have
highest pops during this time, although only chc appear
warranted at this time. The low chc showers continues Thu night
as the front moves through. It should clear the area by Fri
morning and appears to be far enough south to keep any pcpn
associated with weak waves of low pres riding along it to the
south as well. The heat and humidity will vanish as well as a
Cp airmass is ushered in behind the front.
Upper trough will remain over the Northeast into the weekend,
although increasing subsidence from strong sfc high pres
traversing eastern Canada will result in dry and pleasant
conditions. Have maintained a dry forecast into early next week
although an increasing easterly flow Sun/Mon could lead to low
clouds and perhaps some drizzle or light rain at the coast. The
12z EC is also less progressive with the upper flow and is now
cutting off the flow at H5 over the northeast. GFS does this as
well but over the Northern Atlantic. If the former pans out,
then there could be more shower activity around between Sun and
Tue as it is slow to depart. Temperatures are expected to be
below normal levels Fri through Mon, then near normal on Tue.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
VFR conditions are expected through much of the TAF period.
Only exceptions would be brief reductions to MVFR or possibly
lower in any showers/thunderstorms or within any fog/low
stratus. There is a slight chance of showers and thunderstorms
early Wednesday and a better chance again Wednesday afternoon.
With the uncertainty in timing and location for showers and
thunderstorms, these were mentioned mostly as vicinity.
Winds remain light under 10 kts through the TAF period but
switch to more S-SE flow Wednesday.
NY Metro Enhanced Aviation Weather Support...
Detailed information, including hourly TAF wind component fcsts,
can be found at:
http:/www.weather.gov/zny/n90
KJFK TAF Comments: Amendments possible for any shower or
thunderstorm that impacts the terminal on Wednesday.
KLGA TAF Comments: Amendments possible for any shower or
thunderstorm that impacts the terminal on Wednesday.
KEWR TAF Comments: Amendments possible for any shower or
thunderstorm that impacts the terminal on Wednesday.
KTEB TAF Comments: Amendments possible for any shower or
thunderstorm that impacts the terminal on Wednesday.
KHPN TAF Comments: Amendments possible for any shower or
thunderstorm that impacts the terminal on Wednesday. Amendments
possible for early morning stratus or fog.
KISP TAF Comments: Amendments possible for any shower or
thunderstorm that impacts the airports on Wednesday.
.OUTLOOK FOR 20Z WEDNESDAY THROUGH SUNDAY...
.20Z Wednesday-Thursday night...Mainly VFR, but MVFR or lower
possible in showers or thunderstorms. Patchy fog with MVFR or lower
possible late tonight.
.Friday-Sunday...VFR. Late day stratus possible on Sunday.
&&
.MARINE...
Winds and seas will remain below SCA criteria through Wednesday with
seas increasing to SCA criteria by Wednesday night ahead of a cold
front.
Winds and seas on the ocean waters may reach marginal SCA levels Sun
into Mon due to an increasing easterly flow. Otherwise, sub-advsy
conds are expected through the remainder of the period.
&&
.HYDROLOGY...
Locally heavy rainfall is possible with thunderstorms that
develop Wednesday, which may result in localized flooding for
urban and poor drainage areas. No hydrologic impacts are
expected Thu through Tue.
&&
.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off
the air.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
NWS OKX Office Area Forecast Discussion
