476
FXUS61 KOKX 061008
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
608 AM EDT Thu Jun 6 2024
.SYNOPSIS...
A warm front approaches from the south tonight and lifts north
of the area Thursday morning. A cold frontal passage will follow
Thursday night. A broad area of low pressure meanders nearby
over southeast Canada Friday and into early next week. High
pressure follow for the middle of next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Forecast is on track with only minor updates to PoPs. Swath of
heavier precipitation is moving quickly across eastern Long
Island and southeastern CT. Recent observations from automated
gages and MRMS show a swath of about 0.5 - 1.0" associated with
this activity. This precip will continue to work east and be
clear of the area in the next hour or two.
Mid and upper ridge axis heads east of the area today as a
sprawling upper low approaches the Great Lakes. Upper flow
flattens as a result through this evening. At the surface, a
warm front was located on a line from about BLM- TTN- RDG as the
attendant sfc low heads through Ontario. A cold front was also
located back to the west across eastern OH/western PA.
Precip ahead of the warm front has been pushing northeast out
of central NJ and has had embedded convective elements with
some lightning. Bulk of the activity should remain over the
waters and move over central and eastern Long Island and
southern CT over the next few hours. SPC mesoanalysis depicts a
narrow corridor of MUCAPE across these areas that the
unorganized precip is moving over.
Warm front will continue to push north today as the cold front heads
toward and passes through the local area by the afternoon into the
evening. The early morning precip should end areawide by 15Z, with
a dry period and some breaks of sun into early afternoon. CAMs
suggest convective initiation holds off until after 18Z for the
western portions of the area, to the west and north of NYC. While
thermodynamics look favorable (SBCAPE 1000-1500 J./kg) some question
on whether the flow aloft/shear (~30kts 0-6km) will be sufficient
for organized storms. The local area is also removed somewhat from
the more favorable upper environment to the north associated with
the upper low. Regardless, given the environment, any thunderstorms
that do develop have a risk of strong winds (Bulk of the CAPE below
the hail growth zone) and locally heavy precip (air mass Pwats still
near 1.5-1.75"). See hydro. section for more details. SPC maintains
the MRGL risk of severe for the whole area except eastern Long
Island.
One more warm and humid day today with highs in the low to mid 80s,
and dewpoints in the upper 60s to near 70.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
The upper low remains over New England for the period. Scattered
showers and thunderstorms are possible Friday afternoon under
west/northwest flow and the cold pool aloft. CAMs/HREF are depicting
that potential, especially across the interior by Friday afternoon.
For now have elected to keep thunder out of the forecast, with very
marginal thermo profiles. Westerly flow should keep temperatures in
the 80s for most, but with dewpoints in the mid and upper 50s, it
will feel less humid than Thursday. Well-mixed boundary afternoon
boundary layer may also allow for some westerly wind gusts near
20mph.
With the upper low still meandering over the northeast, Saturday
looks similar to Friday, with another day of diurnally-driven
showers with the cold pool aloft.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
No changes made to the long term this update.
A relatively unsettled period this weekend into early next week
with an upper low cutting off and meandering over the Great
Lakes region and southeast Canada much of the time, with
multiple vorticies rotating around it that may periodically
enhance rain chances locally.
The broad low nearby likely instigates diurnal shower activity with
varying coverage each day, especially inland. As the cold pool moves
aloft, also can`t rule out the possibility of thunderstorms with
added instability. Global guidance continues to offer differing
solutions with any potential vorticies however and this will need to
be resolved for further clarity on when rain chances will be
highest.
Temperatures, while hampered by cloud cover and rain at times,
should still manage to get into the 70s and lower 80s most
afternoons, or about typical for this time of year. For now,
continued to cap PoPs at 50%, otherwise, national blend was followed
with subtle adjustments.
After Tuesday, global guidance varies. They agree on the meandering
low finally pushing out into the open Atlantic. They disagree on
what happens afterwards with some of the guidance hinting at a
ridging pattern taking hold, while others bring in another trough
from the west.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A warm front liftS north of the region this morning, followed
by a cold front this evening.
Most of the terminals are either MVFR or IFR, with some isolated LIFR
condition, mainly right along the coastlines. This is mainly due
to lower cigs. Any restrictions to visibility look to occur
with heavier showers early this morning.
Embedded thunder will be possible early this morning but will
remain too isolated to include in the TAF at this time.
Steadiest of the showers exits around 10-12z this morning. We
get a break in the precipitation, then another round of
showers and thunderstorms is then possible this afternoon.
Higher confidence in thunder for this period and will convert
the PROB30s to TEMPOs. Any storms will be capable of gusty
winds and heavy downpours.
Southerly flow persists today, speeds around or slightly above 10
kt. Winds tonight become more westerly behind the cold front.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely due to changing flight categories. A
thunderstorm cannot be ruled out, especially with the steadier
rainfall through 12Z.
Timing of flight category declines and SHRA late this evening
may be off by a few hours.
OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
Thursday Night: Mainly VFR. MVFR or lower possible in showers
and thunderstorms early Thursday evening.
Friday: Mainly VFR. Chance of showers and thunderstorms for KSWF.
Saturday-Monday: Chance of MVFR in showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
SCA continues for the ocean waters through tonight. Marginal
seas 4-5ft and southerly gusts 20-25kt look to continue until
early Friday with the frontal system in the vicinity.
Conditions are expected to remain below SCA levels through the
weekend into Monday.
&&
.HYDROLOGY...
Rainfall amounts of 0.50 to 1.00" with localized higher amounts are
expected through tonight. Minor nuisance poor drainage flooding will
be the primary threat especially in urban and low lying areas. The
flooding potential will be limited due to the expected speed of the
showers and thunderstorms.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
Have continued the ongoing Coastal Flood Advisory for coastal
Fairfield, Westchester, and S Nassau counties for this evening`s
high tide cycle. Elevated astronomical high tides associated
with the new moon combined with onshore flow will continue to
support water levels touching or just surpassing minor flood
benchmarks in these areas.
It is uncertain whether the Fri evening high tide cycle will also be
impacted, as multiple high tide cycle surge events such as this can
sometimes last longer than model forecasts.
There is a high rip current risk at the Suffolk County ocean
beaches today. There is a moderate risk elsewhere. This is due
to building seas, southerly swell, and a strengthening southerly
flow. A moderate chance of rip currents is in place for Friday,
as well.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
Friday for CTZ009.
NY...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
Friday for NYZ071.
High Risk for Rip Currents through this evening for NYZ080-081.
Coastal Flood Advisory from 8 PM to 11 PM EDT this evening for
NYZ179.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ350-353-355.
&&
$$
SYNOPSIS...BC/DBR
NEAR TERM...DBR
SHORT TERM...DBR
LONG TERM...BC/BR
AVIATION...BC
MARINE...BC/DBR
HYDROLOGY...BC/DBR
TIDES/COASTAL FLOODING...