Area Forecast Discussion
Issued by NWS Upton, NY

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592
FXUS61 KOKX 121502
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1102 AM EDT Wed Jun 12 2024

.SYNOPSIS...
High pressure remains in control through Thursday. A cold front
will pass late Friday afternoon-evening. High pressure takes over
this weekend into the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Cumulus building with growing coverage with daytime heating.
Made some increases to cloud coverage in the forecast with a
slight increase to temperatures. The scattered to broken cloud
cover is expected across the region going into the afternoon.

Remnants of the NE upper level low and troughing continues to
fill in and push northeast into SE Canada later today. A weak
shortwave attempts to slide in from the west later this
afternoon. It is not out of the realm of possibility that this
shortwave could help initiate a few isolated pop-up showers for
the afternoon and for the very early evening as indicated by
some CAMs. There are isolated showers in the forecast for
interior SE Connecticut this afternoon into early evening.

Otherwise, the dry airmass that has been in place does begin to
undergo some slight modification later today and tonight. We
should get one more fairly comfortable day in terms of fairly
low humidity for this time of year before things to start to
feel a bit more summerlike. Seasonable temperatures once gain
with highs mainly in the upper 70s and lower 80s. Sea breeze
enhancement takes place quickly in the afternoon with a weak
pressure gradient in place and high pressure in control. Some
higher res guidance does indicate a slight chance of shower or
isolated t-shower activity across northeast sections with an sfc
trough acting as a focus for some cumulus attempting to build.
Overall another predominantly dry and seasonable day.

For tonight it will be slightly warmer as the area undergoes the
start of a return flow regime. Look for mainly clear skies, with
perhaps a little bit of radiational patchy fog just before daybreak
in the some of the interior valleys. Lows will be in the 60s for the
city and the coast, with middle to upper 50s across much of the
interior.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
On Thursday a semi-zonal upper level pattern takes place. A
southwest flow will become more southerly with localized hybrid sea
breeze interaction further east across the area towards afternoon.
Look for a good deal of sunshine with just some scattered cumulus
likely at 4 to 5 kft as indicated by BUFKIT forecast soundings. A SW
flow at 850 mb gets 5kft temperatures climb to about 14 to 16 C.
This will yield warmer temperatures region wide, with the warmer
temperatures muted slightly further east across the CWA due to sea
breeze development during the afternoon. Daytime max temperatures
will be in the 80s for the most part CWA wide, with just some upper
70s across SE coastal communities. The winds may get gusty in the 20
to 25 mph range later in the afternoon for portions of southern
Nassau, Queens, and Brooklyn as an Ambrose jet feature is suggestive
on some guidance.

For Thursday night with high pressure still in control look for
mainly clear skies. A SW synoptic flow regime should keep
temperatures above normal at night for the first time in awhile.
Lows should range primarily from the middle 60s to lower 70s.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
A shortwave trough embedded in a longwave trough will lead to
lowering heights on Friday before it becomes centered over the area
Friday night. A frontal passage will occur with this shortwave,
currently progged to pass through late Friday afternoon into Friday
evening. Showers and thunderstorms are likely to occur in the
afternoon and evening with the FROPA.

The risk for moderate to heavy downpours in some of these
thunderstorms is supported by models showing a surge of 1.5-2" PWATs
being advected in ahead of the cold front from southerly flow with
forcing coming from the frontal boundary. Currently projecting
rainfall amounts anywhere from 0.5" to 1.5", with isolated higher
totals possible in stronger thunderstorms. Long, skinny CAPE
profiles with a deep warm cloud layer of 10,000 to 14,000 feet
indicate some thunderstorms may have efficient rainfall processes.
The good news is the progression of these storms is supposed to be
on the fast side, which should limit significant flood concerns,
with the most likely outcome being limited to minor urbanized/poor
drainage flooding. Isolated instances of flash flooding in a strong
thunderstorm can not be ruled out, but can not be stated with
confidence, at this time. When Friday comes into view with
convective-allowing models this afternoon and tomorrow morning, a
better understanding of the flood risk will become apparent.

The same goes for the risk of severe weather, with guidance from
CAMs not yet within view. However, severe weather is still being
considered a possibility. The frontal boundary along with warm
surface temperatures forecasted to reach the low-80s to near 90 and
dewpoints in the mid/upper-60s will aid in storm development. WHile
the shortwave won;t center itself over the area until Friday night
(after the frontal passage), there are some spokes of mid-level
energy depicted by models that arrive ahead of the shortwave which
should help increase lapse rates and provide somewhat of a cold pool
aloft. The latest global and regional guidance have SBCAPE ranging
between 1000-2000 J/kg, primarily in SW CT, NE NJ, and the Lower
Hudson Valley, with the most significant CAPE in the Lower Hudson
Valley. THis is the case for many other parameters such as the lapse
rates, 45-55kt 0-6km Bulk, Shear and the Lifted Index. Thunderstorms
will likely have less chance of becoming severe as they advance
south and east, but again, confidence will increase as better
resolution models come into view for this event.

High pressure builds in from the NW during the weekend with dry
conditions and more comfortable dewpoints. High temperatures will be
pretty close or just above normal on Saturday and Sunday. A strong
ridge will continue to build with warm aid advection aloft at 850mb,
allowing for increasing temperatures which may reach the mid-90s
next week and keep us dry for the rest of the long-term period. The
only exception to this will be Monday night where the is a small
chance for showers and thunderstorms stemming from a minor shortwave
passing embedded within the larger longwave ridge.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
High pressure in control through Thursday with a weak surface
trough lingering this evening.

VFR. BKN cigs during this time, generally 5-7 kft AGL. Some
cigs near KSWF may become MVFR at 3 kft through this afternoon.

Light and variable winds into early this afternoon. Coastal sea
breezes should develop by early afternoon, with speeds 10 kt or
less. Light WSW flow tonight. Winds increase to above 10 kts
late Thursday morning into Thursday afternoon.

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

Timing of sea breeze may vary by a few hours.

OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...

MVFR possible in showers/tstms Friday afternoon and night,
otherwise VFR.

Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
Fairly tranquil conditions continue on the coastal waters with
light winds and ocean seas generally 2 ft or less through
tonight. A return flow gets established with a south to
southwest flow regime later tonight and into Thursday. S winds
start to increase, especially on the ocean late in the day
Thursday and into Thursday night with gusts approaching small
craft criteria Thursday night, especially out on the ocean.
Wind gusts and seas on the ocean may come close to reaching
advisory criteria on Friday, with sub-advisory conditions
likely continuing through the remainder of the forecast period.

&&

.HYDROLOGY...
Showers and thunderstorms Friday afternoon/evening may produce 0.5-
1.5 inches of rain, with locally higher amts possible in stronger
thunderstorms. Impacts will most likely be limited to minor
urbanized/poor drainage flooding due to the progressive nature of
storm cells, but an isolated flash flood instance can not yet be
ruled out.

&&

.TIDES/COASTAL FLOODING...
There remains a low risk of rip currents at the ocean beaches today,
with a moderate risk by Thursday afternoon for all ocean beaches.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...JE/BR
NEAR TERM...JE/JM
SHORT TERM...JE
LONG TERM...BR
AVIATION...BR/MW
MARINE...JE/BR
HYDROLOGY...JE/BR
TIDES/COASTAL FLOODING...