North Hempstead, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

894
FXUS61 KOKX 201746
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
146 PM EDT Sun Jul 20 2025

.SYNOPSIS...
A warm front pushes through the area this morning, followed by
a cold frontal passage this evening. High pressure builds in
Monday into Tuesday, and centers over the area Tuesday night
into Wednesday. The high shifts offshore Wednesday night into
Thursday. A low passing into east Quebec Friday will bring
through a cold front late Friday into Friday night.

&&

.NEAR TERM /THROUGH TONIGHT/...
A warm front pushes northeast of the region this afternoon,
allowing temps to warm to the upper 80s and lower 90s. Max
Apparent Ts expected to rise into the upper 90s with isolated
100 as Tds hold in the lower to mid 70s. This is below the one
day Heat Advisory criteria.

Falling heights ahead of deep shortwave pivoting towards
northern New England this aft/eve with 1500 J/kg of MLCAPE
already indicated for the western half of the area via SPC
mesoanalysis, accompanied by left front quad of 70 kt ulj
should be suitable forcing for isolated to scattered severe
thunderstorms along a cold front approaching late in the day in
a marginal to moderately unstable, moderately sheared (0-6km
bulk shear of 30 to 40 kt), with mid- level dry air. Environment
is conditionally favorable for strong to damaging wind gusts,
with the limiting factors for coverage being a lack of a
distinct shortwave, a skinny CAPE profile with weak lapse rates.
A slight risk has been maintained across the same areas as
previous forecasts for NYC north and west, with the primary
threat being damaging wind gusts.

Showers and thunderstorms are likely done by midnight with a
much cooler and drier airmass filtered in behind the cold
front on gusty NW flow.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Some of the more comfortable weather days of the summer are expected
in the short term period with dry conditions, sunny skies, 80 degree
highs and cool nights.

As high pressure builds in on Monday the pressure gradient will
briefly be tight and a breezy northwest flow is expected at least on
Monday morning. Some decent mixing is seen in forecast soundings,
but with winds not too strong aloft only expecting about 20 mph
gusts at the surface.

The high will bring with it a cooler and drier airmass. NBM was
followed for highs. Monday highs will be about normal and for
Tuesday they will be a few degrees below normal. Dewpoints and lows
were adjusted slightly to account for NBM biases. Monday night could
be the coolest night in a while with low to mid 50s possible across
the interior and upper 50s to mid 60s elsewhere. Dewpoints look
to bottom out in the 40s and low 50s Monday night. At this time
it looks like Tuesday night will be a bit warmer due to a
return flow kicking in.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Key Messages:

 * Temps climb Wed into Thu. Heat index may exceed 100 by Fri.

 * Dry through Thu night.

 * Showers & thunderstorms possible with cold front Fri/Fri
   night.

In the upper-levels, a ridge builds in from the west and
amplifies through Wednesday night. This ridge then flattens
Thursday into Thursday night. Shortwave energy passes late
Friday into Friday night.

At the surface, high pressure centers over the area into
Wednesday, then shifts offshore Wednesday night into Thursday. A
low passing into east Quebec Friday moves into the North
Atlantic Friday night into Saturday. This low brings through a
cold front late Friday into Friday night.

Wednesday through Friday, temperatures will warm each day in
response to the high moving east and higher heights aloft. Heat
index values may exceed 95 on Thursday for parts of the area, then
exceed 100 for large portions of the area on Friday.

With ample heating, shortwave energy passing aloft, high dewpoints &
atmospheric moisture, and lift from an approaching/passing cold
front, scattered showers and thunderstorms are expected late Friday
into early Friday night.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A cold front approaches this afternoon and moves through this
evening.

Mainly VFR to start the afternoon. A isolated-scattered line of
convection is then expected between 19Z and 02Z along and ahead of
the approaching cold front, with a severe wind gust threat possible
but confidence remains too low to include in TAFs at this time. This
thunderstorm chance is being handled with PROB30 for most terminals,
this includes the city terminals. A tempo group for TSRA was used in
TAFs for KSWF, KHPN, and KGON as the risk of thunderstorm occurrence
is slightly higher for these terminals. The cold front will clear
KSWF around 23Z, NYC terminals 00-01Z, and LI and CT terminals 01-
02Z with any brief MVFR conditions quickly returning to VFR.

S to SW winds for this afternoon mainly around 10kt. A few
occasional gusts for the coastal terminals remains a possibility but
was not included in TAFs for this afternoon. Winds become NW tonight
behind the cold front 10-13kt with G20kt for city terminals
overnight, with gusts less likely or more occasional for outlying
terminals. NW gusts prevail at all terminals towards 13-14z on
Monday morning.

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

Amendments may be needed for TSRA activity this afternoon and the
first half of the evening (until 01-02z).

.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...

Monday: Mainly VFR. NW winds 10-15g20kt.

Monday night through Thursday: VFR.

Friday: VFR likely through morning, possibly followed by periods of
sub VFR in showers and thunderstorms for the afternoon and evening.

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

&&

.MARINE...
Winds and waves look to stay below Small Craft Advisory criteria
through the week with a weak pressure gradient in place.
Occasional nearshore gusts to 25 kt possible late tonight thru
Monday afternoon in NW flow.

However, there is potential for strong to possibly a few severe
thunderstorms late this afternoon and evening. Locally stronger
wind gusts and higher waves are possible in any thunderstorms.

&&

.HYDROLOGY...
At this time, there are no hydrologic concerns through the week.

&&

.TIDES/COASTAL FLOODING...
Mainly a low rip current risk this afternoon, with the
exception being for the eastern Suffolk ocean beaches where a
moderate risk is more likely by afternoon with lingering E to SE
8 second period swells. A low rip current risk is expected for
all ocean beaches on Monday with more of a land breeze out of
the northwest.

&&

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

&&

$$

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