Greenburgh, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

881
FXUS61 KOKX 302331
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
731 PM EDT Sun Mar 30 2025

.SYNOPSIS...
A stationary boundary nearby and over the region tonight will lift
north as a warm front early on Monday. Low pressure consolidates
just north of the Canadian border during Monday and drags a pair of
cold fronts through Monday night and Tuesday morning. High pressure
builds in through Wednesday, then a frontal system quickly works
into the region on Thursday, potentially stalling near the area
through the weekend.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
The fcst is on track. With a low level boundary (stationary
front) locked down to the south of the Del Marva and Southern
New Jersey, our sfc winds should continue to provide mainly an E
to ESE flow this evening. Later tonight more of a true SE wind
sets up as the sfc winds begin to veer. A complex frontal system
with elongated low pressure over the Northern Great Lakes
begins to consolidate some with an upper level jet streak
working into the Ohio Valley. This should cause some height
amplification downstream into our region and into the Western
Atlantic tonight into Monday morning. In response to this a LLJ
begins to ramp up, especially across eastern portions of the
area. The 925 mb warm front lifts north tonight while BUFKIT fx
soundings continue to show a strong low level inversion just
ahead and along the sfc warm front. Getting closer to daybreak
guidance eventually begins to lift the warm front into southern
portions of the CWA. With the lower level inversion in place
really not expected stronger winds aloft to mix down to the sfc.
Since the region will be just ahead of the returning boundary /
warm front tonight the region will remain socked in with low
clouds and areas of fog will be a concern. Questions remain with
low level wind speeds, especially closer to the coast. Thus
there remains some uncertainty with how dense the fog will
become. The overall expectation is for mainly 1 mi vsby, or
perhaps less across a good portion of the area.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
The warm front lifts north during the morning. The cloud deck
overall should gradually lift some, with cloudy skies remaining with
a strong warm advection pattern ensuing. Some guidance is suggesting
that fog may attempt to stick around a little longer than
anticipated for Monday morning. A difficult call since this time of
year regarding the warm sector as it can get rather complicated with
advection off the colder ocean. A strong synoptic gradient will be
in place with a S to SSW flow regime, thus overall expecting the
lowest clouds to break and dissipate. A few showers from time to
time are on the table through the early afternoon, but it may
actually not be raining much of the time. Most of the forcing will
reside west of the area through a good portion of the day. It really
shouldn`t be until later in the afternoon that showers should become
more widespread with scattered shower activity beginning to fill in
with higher moisture values and higher PWATs advecting in. By late
in the day and evening PWAT values begin to climb into the 1.25 to
1.50 inch range. SPC has placed far western portions of the area in
a Slight Risk of severe weather, with a marginal risk into the NYC
metro. With the forcing ramping up CAM guidance indicates a
potential squall line by early evening for the western part of the
area which would likely weaken as it encounters maritime dominated
air as it gets further east. Despite overall CAPE being limited,
some stronger wind gusts cannot be ruled out (especially west of the
NYC metro) with any convection that can get going for the evening.
Overall, the convection should allow some embedded heavier shower
activity to pivot through the region. With the southerly flow off
the ocean for the eastern 2/3rds of the CWA, it may be difficult to
get stronger gusts down to the surface with what is left of any low
level inversion and the maritime influence. Rainfall totals should
be in the 0.7 to 1.4 inch range across the area with WPC maintaining
a Marginal Risk of excessive rainfall. See the hydrology section for
further details.

The shower activity and any convection will get further east by the
late evening and overnight as the cold front begins to pivot into
and through the area. The winds immediately behind the boundary will
switch to the NW. This should take place for the NYC metro towards
or shortly after midnight. The NW flow picks up into the Tuesday AM
commute as a secondary cold front pivots through early.

Low pressure exits further off the NE coast as high pressure builds
on Tuesday. A N to NNW flow regime ushers in drier air. A seasonable
day temperature wise with mainly middle 50s as full sunshine
develops. Chose to stick close to NBM guidance temp wise as the flow
will be more northerly as opposed to westerly, thus temperatures
should not get too much above guidance with less overall adiabatic
compression / warming.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Dry wx Tue ngt thru the day on Wed with high pres building in. Temps
Tue ngt still on track for 20s and 30s, although the NBM has trended
up slightly for cstl areas, likely due to nly flow thru the ngt
minimizing the radiational cooling potential.

Increasing clouds Wed with a warm front approaching. Chances for
shwrs Wed ngt as the theta-e ridge builds in. There could be some
fog and dz as well, but kept out for now in case the front stalls S
of the area before jumping nwd Thu mrng.

Warm sectored on Thu, with areas W of the Hudson the warmest,
possibly 20 degrees or so warmer than Montauk. Went with the blended
approach for rain chances per the NBM, but these numbers may end up
a bit high if the cdfnt remains too far W as the 12Z GFS suggests.

As the main upr lvl energy with the sys ejects into Canada, the
residual boundary looks to meander over the area right thru the
weekend, at times S of the area, at times over the area. The fcst is
NBM pops meaning chances for shwrs thru the period. The 12Z ECMWF
and GFS suggest this pattern wipes out around next Mon with a strong
upr low dropping down out of Canada.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A warm front slowly approaches from the south this
evening, lifting across the terminals overnight into early
Monday morning. A cold front approaches on Monday, passing
through the terminals Monday night.

Conditions will continue to lower this evening to IFR with most
terminals falling to LIFR overnight. Fog will also become
likely overnight with visibilities lowering to IFR/LIFR and
potentially as low as VLIFR. Visibilities should begin improving
as the warm front lifts north through Monday morning. Ceilings
should remain LIFR to IFR through middle morning with the
likelihood of improvement thereafter to MVFR for most terminals
except across Long Island and Southern Connecticut. There is
also a chance for VFR at KEWR, KTEB, and KSWF, especially Monday
afternoon.

E winds 5-10 kt this evening will gradually become SE-S overnight
into early Monday morning, then SSW toward daybreak Monday with
wind speeds beginning to increase. The warm front will likely
pass earlier across Long Island terminals allowing winds to
shift faster to the S. SSW gusts 20-25kt develop late Monday
morning into early afternoon. LLWS is expected at coastal
terminals early Monday with SW winds 40-50 kt at 2kft. Gusts
likely become occasional late afternoon with winds shifting to
the NW behind the cold front passage late Monday evening.

A few showers are possible tonight. Higher probabilities of
showers exists late Monday afternoon into Monday evening mainly
for NYC terminals on NW. Thunderstorms are also possible and
have included PROB30s to account for this potential at KEWR,
KTEB, and KSWF. These thunderstorms could briefly produce gusty
winds. Confidence is much lower for thunder further east.

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

Timing of lowering to IFR and LIFR this evening may be off
by 1-3 hours.

Amendments are likely for timing of category changes tonight
into Monday.

VLIFR visibilities are possible tonight, especially at KJFK.

Timing of SHRA and potential TSRA (at KEWR and KTEB) may be off
by 1- 3 hours Monday evening.

.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...

Monday night: Showers with possible thunderstorms in the evening.
The best chance for thunder exists for NYC terminals on NW.
MVFR-IFR, with local LIFR possible, mainly Long Island and Southern
CT terminals in the evening. Improvements to VFR likely late. SW
winds shift to the NW overnight and become gusty 20-25 kt.

Tuesday: VFR. NW wind gusts 20-25 kt during the day.

Wednesday: VFR during the day. MVFR or lower possible at night with
a chance of showers. SE wind gusts 15-20 kt.

Thursday: MVFR or lower possible with a chance of showers with the
highest chance NW of the NYC metro terminals. SW wind gusts 15-25
kt, highest along the cost.

Friday: VFR.

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

&&

.MARINE...
A marine dense fog advisory is in effect for tonight into Monday
morning for reduces visibilities in areas of fog.

Sub advisory conditions through this evening with ocean seas around
4 ft.  A southerly flow picks up during the overnight out on the
ocean as seas begin to climb resulting in small craft conditions
developing, with far eastern LI Sound approaching small craft
conditions towards day break.  The non-ocean waters then go to small
craft by mid to late morning on Monday. Other than a brief lull in
conditions with a wind switch from S-SW to NW Monday night, small
craft conditions resume by Tuesday morning on a NW wind. Small craft
gusts to around 25 kt will take shape on all waters on Tuesday,
along with elevated seas out on the ocean.

Small craft conditions may linger for the majority of the time on
the ocean Tue ngt thru Fri. Elsewhere, SCA winds possible Wed ngt
and Thu behind a warm frontal passage.

&&

.HYDROLOGY...
WPC has placed the region in a marginal risk of excessive rainfall
on Monday (mainly for rain that would fall in association with
embedded convective elements late Monday and Monday night). At this
time only some localized minor nuisance / poor drainage urban type
flooding is anticipated in association with a potential line of
heavier shower activity mainly during the first half of Monday
night. The overall thinking at this time points to a shorter
duration of heavier rain in association with moderate rainfall
rates, which should preclude any consequential flooding.

No hydrologic impacts are expected for the remainder of the period,
Tue-Sun.

&&

.TIDES/COASTAL FLOODING...
Astronomical levels are high with recent new moon. This combined
with continuous easterly flow has built up water levels. Minor
coastal flooding will be easy to achieve in some areas tonight
around times of high tide.

More sites are forecast to reach minor coastal flood benchmarks
for tonight around times of high tide. This expands beyond the
shorelines of Fairfield CT to also include some other adjacent
shoreline areas along the western Sound as well as the Long
Island South Shore Bays and the Lower NY Harbor. This is where
widespread minor coastal flooding is expected. Most other
shorelines are expected to have isolated minor coastal flooding.

Additional minor coastal flooding is possible around the times
of high tide Monday night.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
     Monday for CTZ009.
NY...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
     Monday for NYZ071.
     Coastal Flood Advisory until 1 AM EDT Monday for NYZ074-075-
     178-179.
NJ...None.
MARINE...Dense Fog Advisory until 11 AM EDT Monday for ANZ331-332-335-
     338-340-345-350-353-355.
     Small Craft Advisory from 9 AM Monday to 6 AM EDT Tuesday for
     ANZ331-335-338-340-345.
     Small Craft Advisory from 6 AM Monday to 6 AM EDT Tuesday for
     ANZ332.
     Small Craft Advisory from midnight tonight to 6 AM EDT Tuesday
     for ANZ350-353-355.

&&

$$

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