AFDOKX

Area Forecast Discussion
National Weather Service New York NY
328 PM EDT Thu Jul 3 2025

.SYNOPSIS...
A cold front approaches and passes this afternoon into evening.
High pressure builds in behind the front tonight through Friday
night. High pressure remains in control through Sunday. A cold 
front approaches from the Great Lakes on Monday, passing slowly 
across the area Tuesday or even stalling in close proximity into
midweek.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
*Severe Thunderstorm Watch in effect for the entire area 
 through 10PM.

The environment this afternoon remains primed for the potential
for severe thunderstorms. A well-mixed lower atmosphere under
mostly clear skies is allowing for ample surface heating. While
the deep mixing is allowing for a localized lowering of surface
moisture, a subtle shift in the wind from a WNW to a WSW flow 
later this afternoon should allow for dew points to increase a 
few degrees. Ample cool air aloft with the approach of an upper 
level trough and a strong mid-level shortwave is allowing for 
both moderate instability and an increasing source of synoptic 
lift. Relatively strong mid and upper level flow is allowing 
for shear on the order of 30-40kt this afternoon. The 
combination of sufficient shear, moderate instability, and 
strong synoptic forcing brings the potential for severe 
thunderstorms this afternoon. 

A relatively dry BL and mid-levels means that as storms develop
or approach from the west, strong to damaging wind gusts may 
develop as rain-cooled air descends from any storm. This 
remains the primary threat for any storms this afternoon and 
evening with a secondary threat of large hail and heavy 
rainfall. Despite heavy rainfall in thunderstorms, the speed at
which they will be moving should limit hydrologic issues and 
any flooding threat should be fairly localized outside of any 
training storms. As the sun sets and surface heating diminishes,
the intensity and ability for storms to maintain themselves 
should fairly quickly weaken.

The mid-level shortwave forcing the convection this afternoon
slides overhead tonight pushing a surface cold front through.
Skies will become generally clear with NW flow brining in drier
air. Lows tonight will be in the 60s for much of the area with
some spots in the Lower Hudson Valley may drop into the upper
50s.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
*Ideal conditions are expected for Independence Day
 celebrations.

The upper-level trough axis shifts east on Friday and completely 
exits east by Friday night. At the same time, an upper-level 
ridge builds in from the west. At the surface, high pressure 
builds in from the west Friday into Friday night, passing east 
offshore.

As high pressure builds in, skies should remain mostly clear
with ample surface heating. The upper level trough still
generally over the area will limit the rising of surface 
temperatures, though highs will still be seasonable, generally
in the low to middle 80s. Long Island and the NYC Metro may
actually rise into the upper 80s under a light NW flow. Lows
Friday night will be in the 60s, with interior areas possibly
dropping into the upper 50s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Key Points:

* A predominately dry weekend with increasing warmth and humidity 
  through Monday.

* Unsettled conditions return Monday through Wednesday, with 
 shower/thunderstorm chances each day.

The NBM was largely followed with this update with no major changes. 

Good model agreement on the synoptic pattern to start the period, 
with upper ridging/rising heights Saturday and Sunday. Attendant 
southerly flow with sfc high pressure to the southwest will continue 
to advect a more warm and humid airmass into the region, peaking on 
Monday (h85 temperatures 16-18C), which would yield sfc temperatures 
in the low 90s, especially away from coastal areas. There is some 
question as to the amount of cloud cover that will be present, which 
may inhibit heating a bit and thus the high temperatures. 

Those clouds appear to be in association with a stream of moisture 
advecting north into the area from an upper low off the mid-atlantic 
coast. Guidance is more varied on the evolution of this system, and 
its possible interaction with an upper shortwave and cold front 
moving in from the Great Lakes region on Tuesday. A period of 
showers and thunderstorms is thus likely Tuesday afternoon, with the 
frontal boundary stalling south of the area into Wednesday.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
A cold front approaches this afternoon and moves across the area 
this evening.

Mainly VFR. TSRA possible late afternoon and early evening, mainly 
20Z to 00Z Fri. Any TSRA could produce brief IFR conditions and 
could contain strong, gusty winds along with a wind shift to the NW-
N. A few storms could contain wind gusts around 50 kt. A few showers 
may linger an hour or two behind the cold front passage. 

W-WSW winds this afternoon away from the immediate coastal terminals 
with wind speeds around 10 kt and gusts up to 20 kt.  SSW winds 10-
13 kt expected at KJFK, KISP, KBDR, and KGON this afternoon. Winds 
may start to shift towards the W where the sea breeze has occurred 
late in the afternoon before becoming NW this evening with the cold 
front passage. Wind speeds weaken overnight and become light and 
variable at most sites. NW winds increase Friday morning, becoming 
around 10 kt in the afternoon.

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

Wind direction may vary from 230 to 270 at KEWR and KTEB through
23z. 

Sea breeze could briefly pass across KLGA 21-22z with winds
varying between 210-230.  

Timing of TSRA may be off by an hour or two. A few storms may 
contain gusts around 50 kt along with a wind shift to the NW-N 
possible with any TSRA. 

A few showers may linger after 00z, but should have limited impact 
on ceilings and visibilities. 

.OUTLOOK FOR 18Z FRIDAY THROUGH MONDAY... 

Friday Afternoon: VFR. Occasional NW wind gusts G15-18 kt possible.

Friday night through Saturday night: VFR.

Sunday: VFR. SSW gusts up to 20 kt possible Sunday afternoon.

Monday-Tuesday: Mainly VFR. Chance of afternoon and evening showers 
and thunderstorms. 

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

&&

.MARINE...
Sub-SCA conditions are expected on all waters under a weak pressure 
gradient through Friday night. Tstms may pose a hazard of strong
winds, lightning, heavy rain, and locally rough seas this
afternoon and this evening.

Sub-SCA conditions are expected this weekend into early next week. 
Southerly flow on the ocean waters Sunday into Monday will feature 
G15-20kt with seas generally around 3 ft, possibly as 4 ft late 
Monday.

&&

.HYDROLOGY...
No widespread hydrologic impacts anticipated through the middle
of next week.

&&

.TIDES/COASTAL FLOODING...
A lingering southerly swell of 2-3 ft 6-7s will produce a moderate 
rip current risk on Thursday, and low on Friday. Surf looks to be 
around 2-3 ft Thursday and around 2 ft on Friday.

&&

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

&&

$$

SYNOPSIS...DBR/MW
NEAR TERM...MW
SHORT TERM...MW
LONG TERM...DBR
AVIATION...DS
MARINE...DBR/MW
HYDROLOGY...DBR/MW
TIDES/COASTAL FLOODING...