North Hempstead, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

047
FXUS61 KOKX 190833
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
433 AM EDT Sat Apr 19 2025

.SYNOPSIS...
A cold front approaches the region late today, crossing tonight.
High pressure builds over the northeast Sunday into Monday. A
frontal system then moves across the region Monday night into
Tuesday. High pressure returns for Wednesday and Thursday with
potential of another frontal system for the end of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages:

* Unseasonably warm temperatures (15 to 20 degrees above
  normal) areawide today, particularly away from southern and
  eastern coast, with highs in the upper 70s to mid 80s.

* Cold water submersion dangers for recreational boaters,
  canoers or kayakers this weekend with warm air temperatures,
  but water temps remaining in the 40s.

East coast upper ridging holds strong today, giving way to an
amplifying northern stream shortwave/closed low tracking east
from eastern Ontario into Quebec tonight. At the surface, a
developing low pressure system takes a similar track today,
intensifying under the upper low tonight, while high pressure
remains anchored off the SE US coast.

In between, a deep SW flow of subtropical origin air continues to
stream into the NE US today, with strong SW surface flow (15-25g25-
35mph) developing later this morning into afternoon as area is
squeezed between SE Canadian low pressure and elongated Atlantic
high pressure to the south. High-res guidance indicating flow
backing more to the WSW away from southern and eastern coastal
areas. Potential for a few peak winds gusts to 40 mph in the
warmest areas in the late afternoon as llj strengthens ahead of
approaching cold front.

850 mb temps have trended a degree or so slightly warmer than
24 hrs ago. With WSW flow and mixing towards 850mb away from
southern and eastern coasts, and unseasonably warm temps aloft
(+1-2 STD 850mb temps), have continued to lean to NBM 50-75th
percentile and HRRR. With temps already starting near seasonable
highs this morning, widespread high temps in the upper 70s to
mid 80s are expected away from southern and eastern coastal
areas (greater maritime influence). This will result in temps
approaching records for the date for a few spots. NBM
deterministic is still generally running in the lower 25th
quartile of guidance for max temps today, which appears to be
low based on the anomalously warm airmass.

High-res guidance signaling the weakening remnants of MCS activity
over the Ohio Valley early this morning potentially bringing a
few showers to NW portions of the Tri-State late morning/early
afternoon along with approaching/developing pre-frontal trough.
Strong shear profiles and some weak elevated instability warrant
slight chance pops. More likely is this activity weakening, but
bringing an increase in convective debris to filter sunshine
this afternoon, which could limit max heating potential.
Otherwise, stronger signal for a line of broken convection
developing along approaching cold front over western/central NY
this afternoon, moving into the region this evening. With weak
and waning instability this evening, and best forcing still well
to the N&W, this convection will likely be weakening as it
approaches and enters the region. This should present a
scattered shower/iso thunderstorm threat N&W of NYC, weakening
to isolated showers for the city/coast. Severe weather is not
expected.

Cold front pushes south of the entire region by midnight, with a
windshift to the NW advecting in a much cooler and drier airmass.
Temps will remain unseasonably mild for this time of year with mixed
low-levels (mid to upper 40s interior to lower to mid 50s coast)

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Key Messages:

* Much cooler but still above normal temps on Sunday (High is
  the lower to upper 60s).

* Below seasonable temperatures on Monday.

Vigorous northern stream closed low slides east through the
Canadian Maritimes on Sunday into Sunday Night, with southern
upper ridging building back towards the region Sunday Night into
Monday. At the surface, a cold front pushes well south of the
region by Sunday AM, with weak Canadian high pressure building
in Sunday Night and sliding east on Monday.

Overall gusty NW winds 10-20G20-30mph, drier and much cooler
conds expected Sunday. Temps will still run several degrees
above normal with unseasonably mild start to the day and deep
mixing and plenty of sunshine in a gradual caa regime. Have
stayed close to NBM 50th for temps based on the above, which has
a better representation of warmer temps along the coast in NW
flow than the NBM deterministic. Temps in the lower to mid 60s
interior and mid to upper 60s for city/coast.

Canadian high pressure noses in Sunday Night with potential for
good radiational cooling conds for pine barrens of LI and
interior Tri-State with temps dropping into the lower to mid 30s
and bringing frost conditions. 40s elsewhere for the
city/coast..

Meanwhile, a vigorous closed upper low over the SW US lifts
through the central plains on Sunday and into the upper Great
Lakes on Monday, with a resultant low pressure system taking a
similar track, and associated warn front approaching Monday
Night.

A strengthening return SE flow develops Monday as high pressure
slides offshore. Maritime flow off mid 40 degree waters, and
developing/ne advecting stratus under a strong low-level
inversion, will likely result in temps running a few degrees
below seasonable across the region on Monday, from mid 50s along
southern and eastern coasts to around 60 interior.

LLJ will strengthen ahead of approaching trailing cold/occluded
front Monday Night, with warm front approaching and entering the
region just ahead of it. Modest theta-e advection and lift over this
boundary will bring potential for scattered showers Monday Night.
Limited forcing and moisture will keep QPF light.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
There has been little change to the overall forecast thinking in
the long term and have stuck close to the previous forecast/NBM.

The long term period starts off with a chance of showers on Tuesday,
mainly in the morning with as a cold front approaches and move
across the region during the afternoon/evening hours. Thereafter,
weak high pressure remains over the region Wednesday and Thursday.
The high moves east on Friday, with another shortwave/low pressure
system approaching for late Friday into the weekend. Mainly looking
at just chance POPs (30-35 percent) late Friday into the weekend
for now.

The warmest day of the week will be Tuesday with highs in the NYC/NJ
metro area reaching the upper 70s. The remainder of the region will
see highs in the 60s and lower to middle 70s. Mid 60s to mid 70s can
be expected Wednesday and Thursday, and 60s and lower 70s for Friday
and Saturday. Locations right along the immediate coast will likely
see slightly cooler temperatures.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
A warm front lifts through the area early this morning. A cold
front approaches from the west today, and moves across the area
this evening and overnight.

Mainly a VFR forecast outside of any isolated to scattered
showers, mainly after 22Z Saturday. PROB30 was used to highlight
this chance. Confidence is too low at this time to mention
thunder, but best chance would be at KSWF.

Gusts have dropped off quite a bit, however occasional gusts to
20 kt will remain possible through early this morning at the coastal
terminals. SW LLWS 40-50kt at 2kft through about 12-14z. Wind will
then ramp back up after 12Z, becoming WSW-SW and increasing to 12-
20kt G22-30kt by late morning into early afternoon. Winds shift to
the W then NW with the cold frontal passage.

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

Occasional gusts to around 20 kt at KJFK possible overnight.

Chance of an isolated thunderstorm Saturday evening.

.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...

Saturday Night: Mainly VFR. WSW G25-30kt early. Chance of
showers in the evening, possibly a thunderstorm.

Sunday: VFR. NW wind gusts around 20kt possible.

Monday: VFR, then sub VFR possible at night with a chance of showers.

Tuesday: Becoming VFR with W winds.

Wednesday: VFR.

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

&&

.MARINE...
After a brief lull in SCA winds early this morning, SCA wind gusts
expected to develop on all water this morning and continue through
this afternoon. Ocean seas build to 5 to 8 ft today.

Nearshore winds should subside below SCA this evening, with
potential for a brief burst of marginal SCA gusts in wake of cold
front between 03z and 08z tonight. Otherwise winds should subside
below SCA on the ocean late in the evening (after 03z).

Sub SCA winds then expected on all waters Sunday through Monday as
high pressure moves across the waters, but southerly SCA ocean
swells may take until Sunday afternoon to fall below 5ft.

Marginal SCA conditions possible on the ocean waters Monday Night
into Tuesday morning ahead of cold frontal passage. Otherwise,
conditions will remain below SCA levels Tuesday afternoon
through Friday with a relatively weak pressure gradient over the
waters.

&&

.FIRE WEATHER...
Marginally elevated wildfire spread threat today and Monday.

Dry conditions remain. There is potential for scattered showers
N&W of NYC this evening, and isolated showers elsewhere. A
widespread wetting rain is not expected.

Highs in the upper 70s to mid 80s, with southwest winds of 15 to
25 mph with gusts 25 to 35 mph and min RH values in the 35 to 45
percent range.

Highs in the 60s on Sunday, with northwest winds of 10 to 20 mph
with gusts 20 to 30 mph and min RH values in the mid 20 percent
range.

&&

.HYDROLOGY...
There are no hydrologic issues through next week.

&&

.CLIMATE...
Record high temps for Today April 19th. Temps will approach
records at BDR, LGA, JFK, ISP.

EWR...92
BDR...82
NYC...92
LGA...85
JFK...84
ISP...82

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 8 AM this morning to 8 PM EDT this
     evening for ANZ331-332-340.
     Small Craft Advisory until 8 PM EDT this evening for ANZ335-
     338-345.
     Small Craft Advisory until 2 PM EDT Sunday for ANZ350-353.
     Small Craft Advisory until 11 AM EDT Sunday for ANZ355.

&&

$$

SYNOPSIS...BC/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...BC
AVIATION...BC
MARINE...BC/NV
FIRE WEATHER...NV
HYDROLOGY...BC/NV
CLIMATE...NV