Area Forecast Discussion
Issued by NWS Upton, NY

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637
FXUS61 KOKX 081011
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
611 AM EDT Wed May 8 2024

.SYNOPSIS...
A warm front pushes to the northeast while a cold front moves
through late today into this evening. The cold front then stalls
just to the south tonight with developing low pressure approaching
Thursday and Thursday night and stalling over the area on
Friday. The low pressure then moves east of the region Friday
night. Weak high pressure briefly builds in Saturday before
another low moves across late Saturday into Sunday. Weak
offshore high pressure establishes for early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
MCC which emerged out of PA is weakening as it pushes into NW
portions of the CWA. Some lightning strikes early this morning
just to the north of Orange County and up into the Mid Hudson
Valley and Catskills this morning. This complex is stratifying,
thus expect showers but with a few rumbles of thunder in all
likelihood well N and NW this morning. Otherwise shower
activity moves across this morning, especially further north,
with another area of stratifying convection emerging out of
East-Central PA which looks to scrape southern and southwestern
portions of the CWA for the morning commute. All this as the
warm front is now beginning its push through the area. Previous
discussion follows.

Clouds around this morning as a warm front pushes through that will
have some showers and possibly a few rumbles of thunder with some
instability in the mid levels. At this time the chances for any sfc
based convection this morning is low. This however looks to change
to some degree getting towards the early afternoon. By early
afternoon as the warm front by and large gets northeast of the CWA
fx soundings indicate a fair amount of instability in the mid and
upper levels. SPC has placed the region in a marginal risk of
sever weather. The amount of convective coverage is very much in
doubt as convective initiation may be difficult to achieve as
some guidance indicates significant drying of the column which
would not be conducive for updrafts to survive due to dry air
entrainment. Also fx soundings indicate a weak mid-level CAP.
Thus it may be difficult to get parcels to the LFC. With this
said, there may be enough to get a few isolated storms to pop
based on potential CAPE of 800 to 1500 J. Mid levels appear
rather dry relatively speaking, so the main concern with any
pop-up storms would be strong, gusty winds with DCAPE values of
800 to 1000 J with an inverted V type sounding. Chose to go
with iso to slight chance of thunder with gusty winds wording
with regard to any pop-up storms. Winds will be out of the south
and should result in a large temperature spread across the
region with developing mid to late afternoon sun from west to
east. Temperatures by the afternoon are likely to range anywhere
from the lower to middle 80s across western sections, to the 70s,
with mainly 60s across coastal and eastern most sections.
Overall temperatures average above normal for today into
tonight, but there will a wide spread in temperatures this
afternoon with a southerly trajectory to the wind. Some 50s are
possible or even likely by the start of the evening across the
twin forks of Long Island.

For tonight the region should be in-between weather disturbances.
Another low pressure system takes shape across the Midwest with a
frontal boundary extending east into the Ohio Valley. This
boundary likely approaches towards midday Thursday as a warm /
stationary front as low pressure moves into the Ohio Valley.
After some clearing late Wed and much of Wed night clouds should
increase again towards Thursday AM. It should remain rain free
through tonight with temperatures averaging somewhat above
normal with lows in the 50s, and around 60 in the NYC and NE NJ
metro.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
The column is expected to gradually moisten during the day Thursday
with more clouds arriving in advance of a frontal boundary to the
immediate south and southwest with developing low pressure over the
Ohio Valley. The system will move east and with the area being just
north of the boundary and low pressure look for the column in the
lower and mid levels to remain stable with an onshore flow out of
the ENE. This should lead to a stratiform rain / shower activity.
This activity will become more widespread Thursday evening. On and
off rain is anticipated for Thursday night. WPC has maintained a
marginal risk of excessive rainfall for much of the region, but
rainfall rates appear quite underwhelming, thus flooding related to
heavy rainfall is not a concern at this time. Temperatures should
average closer to normal for the most part during this time, perhaps
a few degrees below average in some spots during the day Thursday.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Upper-levels will have us in a troughing pattern through the weekend
with two mid-level shortwaves, one Friday night and a larger, slower-
moving one late Saturday into Sunday with high pressure only
briefing present between the two. These shortwaves, each with an
associated surface low, will bring chances for showers. More rain
will be likely across the area with the first shortwave with higher
PWATs in place. After Friday, the column dries out more, but in
addition to showers, thunderstorms look to occur on Sunday aided by
cold air advection aloft from the deepening trough. Temperatures
will be below seasonal with highs in the mid-50s to near 60.
Saturday and Sunday will be a little warmer in the low/mid-60s.

A fairly zonal pattern settles in aloft for the first half of next
week with weak high pressure at the surface. This will keep us in a
mostly dry pattern with only slight chance POPs Monday night through
Wednesday. Its highs will be warmer by Tuesday near or above
seasonal averages in the upper-60s to mid-70s.

&&

.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
A warm front lifts through the region through this morning. A
cold front moves through the region late Wednesday and Wednesday
night.

Conditions are expected to lower early this morning, but timing
could still be off by a few hours with showers developing with
the approach of a warm front, and shortwave energy moving
through the upper midwest. IFR is expected with some moments of
LIFR possible. Isolated thunderstorms are possible this morning,
however, the chances are low and not included in the TAFs.
Conditions improve back to VFR with the warm front passage.
Isolated showers and maybe a thunderstorm will be possible this
afternoon into the early evening with the passage of the cold
front. However, chances and confidence too low to include at
this time. VFR expected otherwise into Wednesday night.

Winds remain light south to southeast this morning, and light and
variable in a few locations. Winds increase from the southwest ahead
of a cold front, and then become westerly and gusty, up to 20kt,
behind the front. Gusts may be briefly higher with the initial cold
frontal passage. NW winds relax below 10 kts and variable in a few
spots Wednesday night.


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

Timing uncertainties with the lowering and subsequent improving
conditions this morning, may be a few hours off in the TAFs. There
is a low chance of isolated thunderstorms early this morning.

Low chance of SHRA or TS Wed afternoon, too low to include in TAF at
this time.

OUTLOOK FOR 09Z THURSDAY THROUGH SUNDAY...

Thursday: MVFR/IFR. Showers likely, especially in the afternoon and
at night.

Friday: MVFR/VFR with chance of showers.

Saturday: Chance of showers with MVFR cond at KSWF, otherwise VFR.
Chance of showers at night with MVFR.

Sunday: MVFR/IFR with a chance of showers and possibly a
thunderstorm.

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

&&

.MARINE...
Winds and seas are expected to remain below SCA conditions through
Thursday night as seas will essentially average around 3 ft,
perhaps approaching 4 ft towards early Friday morning for the
southern portions of the ocean waters.

Sub-SCA conditions are expected through the long-term forecast
period with the exception of seas occasionally reaching 5 feet in
the eastern ocean Friday through Sunday.

&&

.HYDROLOGY...
WPC has placed mainly western interior portions of the areas in a
marginal risk of excessive rainfall on Thursday. The risk of
flooding from heavy rainfall appears to be limited at this time for
later this week, and no hydrologic impacts are expected during
the long-term forecast period.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides run high the next few days with the new moon from
last night.

Minor flood benchmarks are likely to be exceeded during the evening
high tide cycles tonight through Friday night for southern
Nassau, southern Queens, and Fairfield and Westchester counties
with inundation up to a foot. Coastal flood statements will be
in place for tonight`s high tide for Newark Bay in Hudson county
and southern Queens with water levels perhaps just touching
minor benchmarks. Localized moderate flooding is possible during
Fri evening`s high tides in the most vulnerable spots of
southern Nassau, with advisories and statements likely in
similar locations tonight, and perhaps including SW Suffolk and
portions of the north shore of Long Island in subsequent
evening high tide cycles through Friday. Statements may also be
needed for Thursday and Friday evening for portions of coastal
NE NJ and Staten Island.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 11 PM this evening to 2 AM EDT
     Thursday for CTZ009.
NY...Coastal Flood Advisory from 11 PM this evening to 2 AM EDT
     Thursday for NYZ071.
     Coastal Flood Advisory from 8 PM to 11 PM EDT this evening for
     NYZ179.
NJ...None.
MARINE...None.

&&

$$

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