000
FXUS61 KOKX 250028
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
828 PM EDT Mon Jul 24 2023
.SYNOPSIS...
High pressure will remain offshore through the upcoming week. A mid-
level shortwave moves through late Tuesday. A hot airmass will build
in for the end of the week. A cold frontal passage is expected over
the weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
Models indicate increase in CAPE and slight lowering of mid to
upper level heights tonight. Shortwave activity appears to be
quite weak without much positive vorticity advection in the mid
levels. CAMs depict more convection this evening with little to
no convection overnight.
Made some minor changes to POPs compared to previous forecast.
Still could have an isolated shower or thunderstorm around the
NYC area and to the north and west this evening.
Overnight, models still agree overall on a decreasing trend with
clouds so kept the clearing part of the forecast.
Min temperatures were kept the same as previous forecast. Hourly
temperatures and dewpoints are in pretty good agreement between
forecast and observed values.
An upper level trough remains over the area through tonight.
Multiple embedded shortwaves move through this evening. At the
surface, high pressure remains in place offshore.
Skies clear late tonight and temperatures will bottom out in
the mid 60s to low 70s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
Another, stronger shortwave will move through late Tuesday. This
will bring a chance of thunderstorms and showers and bring the
threat farther east.
With high pressure offshore, a warm moist southerly flow will
allow dewpoints to reach the low 70s. Temperatures will quickly
warm up under mostly clear skies and MLCAPE values likely reach
1000-2000 J/kg by the late morning. The higher end of these
values will be across northeast NJ and the Lower Hudson Valley.
The CAMs are in decent agreement of scattered
showers/thunderstorms initiating just to our west in the early
afternoon.
The trough axis passes east early Wednesday morning and the flow
becomes more flat. A dry day is expected with temperatures in
the upper 80s to lower 90s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
20C at h85 will spill over from the plains Thu into Sat. It will
therefore be hot across the region with highs generally in the 90s
and heat indices around 100. The usual hot and cool spots can be
expected due to proximity to the water and urban corridors.
The area will be unstable as a result, with the main challenge a
trigger. The modeling indicates the potential for periodic height
falls within the generally wly flow aloft. Will fcst roughly 20-30
pops thru Fri because of this. The NAM indicates an MCS on Thu, but
confidence is very low on this several days out. Nevertheless, it
remains something to look for, especially considering the very high
EHI numbers being output.
A cfp is currently progged for Sat. Exact timing will determine
coverage and intensity, so for now pops are capped at isold-sct,
with the best coverage across the interior attm.
Generally fair and seasonable on Sun. Some aftn 20 pops with a nw
flow regime.
Dry and cooler on Mon with highs fcst blw ave attm with h85 temps in
the 10-11C range, about 10 degrees cooler than what is expected
during the end of this week.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
Offshore high pressure remains during the TAF period. Some upper
level disturbances will traverse the area with potentially showers
and thunderstorms moving across both this evening (very low
chance) and for Tuesday afternoon into Tuesday evening (higher
chance).
VFR conditions are expected to prevail for much of the TAF period.
The only exception would be brief times during showers or
thunderstorms when there could be MVFR or very briefly IFR.
Overall a higher chance and coverage of showers and thunderstorms is
forecast Tuesday afternoon into early Tuesday evening near and to
the northwest of NYC terminals.
Winds will be mainly S to SW near 5-10 kts for much of the TAF
period. Some terminals outside of NYC will have lighter winds
less than 5 kts overnight into Tuesday morning with more
variable wind directions.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
While not specifically stated in TAF, an isolated shower or
thunderstorm is possible this evening.
Timing of showers and thunderstorms Tuesday could be 1-3 hours off
from time indicated in TAF.
OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...
Tuesday night: Possible showers and thunderstorms, mainly east of
NYC terminals with brief MVFR or IFR possible. Otherwise, VFR.
Wednesday: VFR.
Thursday: Possible showers and thunderstorms at times afternoon into
evening with brief MVFR to IFR possible. Higher chances of showers
and thunderstorms near KSWF. Otherwise, VFR. SW wind gusts along
coast 15-20 kt.
Friday: Possible showers and thunderstorms at times afternoon into
evening with brief MVFR to IFR possible. Otherwise, VFR. SW wind
gusts along coast 15-20 kt.
Saturday: Chance of showers and thunderstorms afternoon into evening
with brief MVFR to IFR possible. Otherwise, VFR.
Detailed information. including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
A Marine Weather Statement remains in effect for Long Island Sound.
The National Weather Service in coordination with the United States
Coast Guard have received reports of a large debris field across
Long Island Sound, caused by recent flooding across New England.
With a weak pressure gradient in place through Wednesday, winds
and seas will remain below SCA levels.
Building seas on Thu could result in sca seas on the ocean by late
in the day, continuing thru Sat, then subsiding by Sun mrng.
Elsewhere, winds and seas are expected to remain blw sca lvls,
although tstms may pose a potential hazard at times.
&&
.HYDROLOGY...
-- Changed Discussion --
No hydrologic concerns are expected through the end of the
week. Locally heavy rain in thunderstorms on Tuesday and Thursday
may lead to minor flooding in poor drainage and low-lying areas.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
There is a low rip current risk Tuesday and Wednesday.
There may be a high risk for rip currents late Fri thru Sat,
especially for ern LI beaches.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JMC/JT
NEAR TERM...JM/JT
SHORT TERM...JT
LONG TERM...JMC
AVIATION...JM
MARINE...JMC/JT
HYDROLOGY...JMC/JT/JM
TIDES/COASTAL FLOODING...