North Hempstead, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

094
FXUS61 KOKX 142002
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
402 PM EDT Wed May 14 2025

.SYNOPSIS...
Weak area of low pressure and frontal boundary advances toward the
region through Thursday. Another frontal system moves across the
area Friday through Saturday. High pressure gradually returns
Sunday into early next week as low pressure lingers just east of
the New England coast. A frontal system may approach the middle of
next week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Upper level low that as been spinning off to the west over the
past several days has opened into a trough over the OH Valley
today, with a surface front and weak area of low pressure draped
to our south across the Mid Atlantic. Ridging in place has been
shifting offshore, and sandwiched in between the two is the
local region, resulting in prolonged easterly flow, with
unsettled conditions.

Stream of showers continues working north and east through the
region this afternoon, and will persist into at least early
evening as a LLJ works through. A few elevated thunderstorms
earlier have dissipated, but can`t rule out a few more isolated
rumbles of thunders into early evening. More likely, periods of
showers, with a few locally heavy downpours embedded in the
activity. While additional QPF should be relatively light, at
or under half an inch, the heavy downpours could result in
localized minor flooding, especially in the typical poor
drainage locales around the urban metro.

The bulk of the showers gradually weaken and exits the region
this evening as the best lift works north. Areas of fog likely
develop, at least patchy, with potential to become dense. Will
need to monitor overnight should a headline be needed.
Temperatures largely remain steady tonight, falling back a few
degrees into the mid to upper 50s.


&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Axis of the open trough tracks overhead on Thursday, with the
decaying surface low and warm front moving through locally.

Any morning fog should burn off by late morning, and
temperatures climb about 10 degrees above the previous day, with
afternoon highs in the lower 70s. Isolated to scattered pop up
convection is possible by late morning or early afternoon, with
the chance persisting into the early evening. A bit more mild
and moist surface conditions are expected, and 12Z HREF CAPE
values are progged up to 500-1000 J/kg. While the threat for
severe weather and significant hydrological concerns is low,
any thunderstorm could produce locally heavy rainfall.

Rain chances gradually lower by the evening, but a weak
pressure gradient and very light onshore flow Thursday night
likely allows fog to develop once again into early Friday
morning.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Key Points:

*An unsettled weather regime continues through Saturday.

*Showers and a few thunderstorms are expected Friday and Saturday
mainly in the afternoon and evening, but it will not be a complete
washout.

*An isolated shower possible inland on Sunday afternoon with
otherwise dry conditions prevailing through Tuesday.

*Temperatures will mainly run above normal through the weekend
before trending closer to normal early next week.

A blocky synoptic pattern will continue through the middle of next
week. Models continue to depict a decaying line of showers and
possible thunderstorms approaching from the west on Friday.
They are in association with a weak area of mid level shortwave
energy out of ahead of the next upper low and trough over the
Northern Plains. The potential for showers and possible
thunderstorms appears highest in the afternoon and evening, and
mainly north and west of the NYC metro. Onshore flow further east
will likely limit instability and convection potential on Friday.

The aforementioned upper low and trough will move over the Great
Lakes on Saturday helping to push the next frontal system into the
area. Conditions may become more conducive to showers and
thunderstorms and the latest NBM has increased PoPs from its
previous cycles. However, there are still factors that may limit
convective development including the main forcing remaining well to
our northwest and potential of some lingering mid level dry air. The
ECMWF appears the most aggressive with a well defined complex of
showers/storms moving across the area on Saturday. The mesoscale
setup will become better resolved over the next few days, which
should help give more confidence on the evolution of potential
convection on Saturday. Forecast precip probabilities are again
highest north and west of the NYC metro and mainly in the afternoon
and evening.

The frontal system and associated upper low/trough continue sliding
across the area Saturday night. Lingering showers cannot be ruled
out, but probabilities decrease through the night. The system will
then push east of the area on Sunday and then remain near or just
off the New England coast early next week. Lingering cyclonic flow
aloft Sunday may be enough to produce a diurnally driven isolated
shower well inland in the afternoon. Upper ridging will build just
to our west early next week with another trough amplifying over the
western states. The proximity of the ridging and upper low just
offshore should keep conditions dry Monday into Tuesday. The NBM
indicates an increase in precip probabilities on Wednesday which may
be overdone given the nearby ridging which may take some time to
break down. Will indicate a low probability for now with potential
of another frontal system attempting to approach mid next week.
&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
Low pressure remains south of the terminals through the TAF
period.

Rain along with MVFR to IFR conditions can be expected at all
the area terminals. There may be intermittent improvement to VFR
for a brief period or two.

Winds will be from the E-ESE around 15kt with some gusts to
20-25kt. Any gusts diminish this evening. Winds diminish
further, with some locations becoming light and variable.
As they do, expect LIFR conditions to develop again tonight.

There is the slight chance of a tstm mainly during the afternoon
hours today. Coverage still too vague to mention in TAF.

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

Amendments likely for changing flight categories.

.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...

Thursday: Slight improvement during the afternoon, possibly
becoming MVFR in the afternoon with chance of showers and
possibly a tstm.

Thursday night: Low stratus/fog with IFR/LIFR cond.

Friday: IFR/LIFR in the morning, then chance of MVFR in the
afternoon/evening with slight chance of tstms.

Saturday: Chance of MVFR and showers. Slight chance of tstms.

Sunday...Mainly VFR.

Monday...VFR.

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

&&

.MARINE...
Small Craft Advisory remains in effect for the ocean waters and
has NY Harbor with gusts near 25 kt, and seas at or above 5 ft
on the ocean. Winds lighten on the harbor this evening, but
ocean seas likely linger into Thursday before lowering by Thursday
night.

Conditions will remain below SCA levels Friday through next Monday
with a relatively weak pressure gradient over the waters.

&&

.HYDROLOGY...
Isolated heavy downpours could result in a quick inch of rainfall
and result in minor flooding of urban and poor drainage areas. This
threat appears limited and localized should it occur. QPF
through Thursday should average under a half inch. Additional
convection Thursday afternoon or evening could have the same result.
The overall threat for flash flooding remains low.

There are currently no hydrologic concerns Friday through early next
week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ338.
     Small Craft Advisory until 6 PM EDT Thursday for ANZ350-353-
     355.

&&

$$

SYNOPSIS...DR/DS
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...DS
AVIATION...BC
MARINE...DR/DS
HYDROLOGY...DR/DS