945
FXUS61 KOKX 031124
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
724 AM EDT Thu Jul 3 2025
.SYNOPSIS...
A Canadian cold front approaches and passes this afternoon into
evening. High pressure builds in behind the front tonight through
Friday night, then offshore for Saturday into Saturday night. A
cold front approaches from the Great Lakes Sunday into Monday,
passing slowly across the area Tuesday or even stalling in close
proximity.
&&
.NEAR TERM /THROUGH TONIGHT/...
Some fog has advected in over eastern coastal areas. This will
lead to areas of 1 mi visibility with pockets of patchy dense
fog through daybreak into mid-morning before clearing.
An upper-level polar low dives southeast through western Quebec
today into tonight with its associated 1 std deep shortwave trough
passing the area this afternoon & evening with a Canadian cold
front.
Model soundings show a well-mixed environment today. Mainly sunny
skies are expected other than some lingering partly sunny skies for
far eastern locales from a stalled front that washes out east of the
area over the ocean early today. Light offshore flow in a sunny,
well-mixed environment should allow temperatures to warm into
the upper-80s for most with some spots at or just above 90 this
afternoon in NE NJ and the NYC metro area.
A warm, sunny, well-mixed environment in the early afternoon today
will leave us well set for an active afternoon and evening of
showers and thunderstorms. A Canadian cold front will pass the area
mid-afternoon into early evening, providing lift for shower and
thunderstorm development along with shortwave energy passing aloft.
PWATs along and ahead of the front will be suitable rain to develop.
00Z CAMs are showing an unstable environment with good SBCAPE values
and acceptable MLCAPE values for surface based convection along the
passing cold front. With 35-50 kts of mainly unidirectional shear,
any thunderstorms that do develop, could see scattered instances of
strong to damaging wind gusts in the form of squall lines or bowing
segments along the cold front. Low level lapse rates look potent.
Despite the cap breaking just before midday, the mid-level lapse
rates look too low for most of the morning and early afternoon for
thunderstorm development. They do eventually climb to marginal
values (6.5-6.9 C/km) with the approaching front helping with storm
initiation in the mid/late afternoon to early evening. Given this,
most storms will likely develop along the cold front rather than
well ahead of it.
00Z CAMs have showers and thunderstorms timed to start around midday
to our west, entering our area with the cold front 2-4 pm for NW
interior locales then follow the cold front through the area west-to-
east, exiting east by 7-9 pm. SPC has the entire area under a Slight
Risk for severe thunderstorms. The primary risk will be for damaging
winds, but isolated occurrences of hail can not be ruled out.
N&W of NYC there may be scattered instances of strong to
damaging winds, but as the line of storms track east with the
cold front in the early evening strong to damaging winds may
become more isolated.
Following FROPA this evening, clouds clear by early in the night as
cooler/drier Canadian air gets advected in, aided by the upper-level
trough axis centering over the area. Lows will be in the mid-60s for
coastal locations, upper-60s to low-70s in urbanized areas of
NE NJ, NYC, and Nassau counties, and drop into the low-60s to
upper-50s in interior locations.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
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 Friday through Saturday night. At
the surface, high pressure builds in from the west Friday into
Friday night, passing east offshore, but remaining in control,
Saturday into Saturday night.
Friday through Saturday will be dry and mainly sunny given
widespread subsidence. Temperatures will be close to just above
climatological norms with highs in the 80s and lows in the upper-50s
to near 70.
Ideal conditions are expected for Independence Day celebrations.
Sunny, dry, warm weather for afternoon activities with temperatures
falling into the 70s under clear skies in the evening.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
No significant changes were made to the extended forecast and
stuck close to the NBM/previous Forecast.
Key Points:
* Warm and humid conditions expected Sunday and Monday .
* A weak cold front moves into the area on Tuesday with a chance of
showers and thunderstorms
High pressure both aloft and at the surface will slide offshore
Sunday and Monday. With an approaching upper trough trough over the
Great Lakes Sunday into early next week, vertical temperatures
profiles will be on the rise with 85h temps near 18C by Monday. In
addition, a prolonged period of southerly flow will result in
gradually increase humidity during this time.
A weak cold front associated with the aforementioned upper trough
approaches late Monday into Tuesday with increasing chances of
showers and thunderstorms. Environment is weakly sheared, but
moderately unstable ahead of the front. There is some uncertainty as
to when the front pushes through, or if it simply washes out in
close proximity Tuesday into Wednesday. This is reflected in some
increasing spread for temperatures between the 25th and 75th
percentiles. Once again, the NBM deterministic temperatures are
generally at or below the 25th percentile during the forecast
period.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
A cold front will approach this afternoon and move across the area
this evening and overnight.
Mainly VFR. Any lower LIFR or lower condition across the
eastern terminals is quickly dissipating and should be gone by
12z or shortly after.
NW winds to start the day. Winds then back to the SW from mid to
late morning. Speeds increase to 10 kt, with gusts toward 20 kt
possible after 18Z, though may be more occasional at some
sites. Risk for TSRA late afternoon and early eve, mainly 20Z to
00Z Fri. Any TSRA could produce brief IFR conditions. Drier and
VFR conditions expected tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Can not rule out low cigs reaching KJFK early this morning.
Gusts 20 kt possible this afternoon, may be more occasional.
Timing of TSRA may be off by an hour or two.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday: VFR. NW winds G15-18kt.
Saturday through Monday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.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 Thu
aft/eve.
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 early 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...BR
NEAR TERM...BR
SHORT TERM...BR
LONG TERM...
AVIATION...BC
MARINE...BR
HYDROLOGY...BR
TIDES/COASTAL FLOODING...