Greenburgh, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

680
FXUS61 KOKX 121626
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1226 PM EDT Thu Jun 12 2025

.SYNOPSIS...
A cold front later this afternoon and moves across the region
tonight. The front slows down and eventually stalls south of the
region Friday into the start of the weekend. Low pressure
eventually develops and approaches the region along this front.
The cold front slowly works south into the Mid Atlantic into
early next week. Waves of low pressure will track along the
boundary during this time. The front will then return northward
as a warm front toward the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
For this update just a few cosmetic changes, mainly out east to
reflect slightly cooler temperatures than previously forecast.
Otherwise forecast remains on track. Convection late today into
tonight has quite a variance between different CAMs. Only a
couple indicate MCS potential; while others keep more isolated
convection with timing differences, along with even no
convection with some CAMs.

A very warm to hot afternoon in on tap with plenty of sun, and
increased SW flow to boost low level warm air advection. Used a
blend of MAV/MET/NBM guidance for high temperatures. Within and
around the NYC Metro area, high temperatures are forecast to get
around 90 degrees. Dewpoints are forecast to lower to the upper
50s to near 60 with vertical daytime mixing, which is going to
limit the apparent temperatures (i.e. heat indices) to not
deviate much from the actual temperature.

Clouds increase late in the day ahead of an approaching cold front.
There will be a slight chance of a shower or thunderstorm. Dry air
will be present within the atmosphere in the low to mid levels.
Convective coverage at most is expected to be isolated or a just a
slight chance probability. Temporally the convection will be limited
also, which will limit the flood threat.

The caveat though is that the main upper level jet will be
north and not too far away from the region. BUFKIT shows winds
between 10kft AGL and 30kft AGL increasing late today. The
higher winds aloft will present a chance for both increased
divergence aloft and enhanced downbursts of wind. CAPE will be
higher with the higher temperatures especially across western
portions of the region with models indicating values up to near
1000 to 1200 J/kg of CAPE. There will be a marginal risk for
severe thunderstorms with primary threat being damaging winds.

With these details about the convection being stated, not all
locations will get rain. Most locations may very well stay dry.
Once the cold front moves across, more northerly flow develops
tonight, which will help usher in a cooler but still moist
airmass. Later tonight, there still could be a few showers but
no thunderstorms are mentioned as stability in the low levels
increases with the cooler surface temperatures.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
The cold front slows down south of the region where it will
eventually stall Friday into the start of the weekend. The front is
still forecast to be within close enough proximity for low pressure
development along it to give chances for more showers during
this time period.

Friday looks to be the relatively drier day with less showers.
Much of the day and much of the area just has a slight chance of
showers. Friday night, chances for showers increase late with higher
chances Saturday. This will be as low pressure develops in the Mid-
Atlantic and eventually passes south of the area Saturday along that
stalled front.

Temperatures will be on a cooling trend as surface winds gain a more
easterly component. This will allow for a cooler maritime airmass to
encompass the area. Clouds will remain abundant. High temperatures
forecast Friday are in the 70s to near 80 and then for Saturday are
just in the mid 60s to near 70. This cooler air will make for less
instability and thunderstorms were not mentioned in the forecast.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A frontal boundary south of the area on Sunday will settle slowly
south into the Mid Atlantic states into early next week before
returning northward mid week. The challenging part of the forecast
is timing/location of frontal waves along the boundary and the
associated rainfall. Airmass is unstable Sunday in the lower to mid
levels of the atmosphere, especially for the interior. However,
shortwave energy passes to the north on Sunday and is followed by
high pressure building across eastern Canada and into the Northeast.
Therefore, chance PoPs (30-50%) for Sunday into early next week with
a chance of showers and embedded thunderstorms (best chances for any
thunderstorms would be western portions of the forecast area as they
will be less influenced by a stable regime from an easterly flow
that develops). The front pushes farther south into Monday with even
some drying of the airmass. Airmass should be stable enough to limit
convection to mainly showers at this time. Global models are in good
agreement taking weak low pressure off the Mid Atlantic coast early
Tuesday, passing to the south and east. Forecast area will be on the
northern periphery of the system and may be far enough removed from
the stratiform rain shield. Rain chances will be lower during this
time.

Temperatures Sunday through Monday will trend down through the 70s
and in some cases may struggle to get above 70 with an easterly flow
and cloud cover. Temperatures will then begin to climb back up to
normal by Tuesday and even above by Wednesday as heights begin to
rise and the front starts returning northward as a warm front. Lows
will be close to normal, but night will be humid with dew points
around 60.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
A weak cold front slowly passes through late this afternoon into
early evening.

Mainly VFR, however there`s a chance of MVFR/IFR with TSTMs late
day/early evening. Have opted to address this with PROB30. Still
can`t rule out showers and iso TSTM later tonight into the
Friday morning push, however confidence is not high enough to
include in TAFs at this time.

W to SW winds around 10kt with gusts 16-20kt. Winds then shift
NW-N this evening.

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

Showers/tstms may be only isolated at most or not occur at all.

Chance that KJFK does not shift to around 210 true late this
afternoon. Additionally, if convection does not occur, winds
could shift back to westerly near 23-00z.

Shift to NNW-N may be off by 1-2 hours.


.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...

Friday: Mainly VFR.

Friday Night-Saturday: MVFR or lower possible with a chance of
showers and a few thunderstorms possible.

Sunday: MVFR or lower possible. Chance of showers with isolated
thunderstorms possible.

Monday: MVFR or lower possible. Chance of showers.

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

&&

.MARINE...
The pressure gradient is not expected to increase much, and
therefore winds will not increase much also. Conditions in the
marine forecast for all waters stay below SCA thresholds through
the first half of the weekend. Winds and seas could very well
be higher in and near any thunderstorms but otherwise below SCA
conditions remain.

With a weak pressure gradient force expected across the forecast
waters, as a frontal boundary remains in the vicinity of the ocean
waters, winds and seas are expected to remain below SCA levels from
Sunday through Monday.

&&

.HYDROLOGY...
Some minor flooding will be possible in low-lying, urban, and poor
drainage areas especially with any locations receiving multiple
rounds of heavy rain. Layer precipitable waters are forecast to
potentially increase to near 1.75 to 2 inches early Saturday.
These higher PWAT values could be achieved late this afternoon
into early this evening but early Saturday is when these higher
PWAT values are more probable. Otherwise, no hydrologic impacts
are expected.

&&

.TIDES/COASTAL FLOODING...
A gradually diminishing southerly swell will result in another
day of a moderate rip current risk today along the ocean, but
lowering to a low rip current risk on Friday. Friday will
feature more northerly to easterly flow along the coast, less
conducive to building waves.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Air Quality Alert until midnight EDT tonight for NYZ067>075-
     078>081-176>179.
NJ...Air Quality Alert until 11 PM EDT this evening for NJZ004-006-
     103>108.
MARINE...None.

&&

$$

SYNOPSIS...JM/JP
NEAR TERM...JE/JM
SHORT TERM...JM
LONG TERM...JP
AVIATION...JC/JP
MARINE...JM/JP
HYDROLOGY...JM/JP
TIDES/COASTAL FLOODING...