900
FXUS61 KOKX 271449
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1049 AM EDT Sun Jul 27 2025
.SYNOPSIS...
-- Changed Discussion --
High pressure moves offshore as a weak frontal system moves into
the area today. The front heads east of the region tonight into
early Monday. High pressure then returns Monday into Tuesday. A
cold front approaches Wednesday and moves across the area
Wednesday night into Thursday. High pressure builds in from the
Great Lakes Friday into next Saturday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
GOES-16 6.95um WV channel depicts a mid/upper shortwave racing
through the eastern Great Lakes and into western upstate New
York region late this morning. A weak N-S oriented surface warm
front/trough was located in eastern PA and was moving slowly
eastward. A moderately unstable airmass east of the frontal
feature (MUCAPE 500- 1000J/kg) was maintaining a convective
complex with showers and embedded thunderstorms moving through
northeastern PA.
Much of the day remains cloudy with the warm front moving slowly
to the east, and will limit overall airmass destabilization.
Another round of showers/thunderstorms associated with the
approaching shortwave and warm front are likely this afternoon.
Model soundings do show an appreciable increase in PWAT, with
over 2" by this afternoon along with at least some increase in
instability (MUCAPE 1000-1700J/kg) and shear (0-6km shear
values 25- 30kts) with the approaching shortwave. SPC maintains
a marginal risk of severe thunderstorms for a small portion of
the CWA, with the risk over much of central and southern New
Jersey and into the southern portion of NYC. In addition, there
is at least a localized flash flood threat this afternoon with
any thunderstorms given the high PWAT environment. HREF
probabilities of 3" in 3/hr are around 10%, however, further
supporting the localized nature of any flash flooding.
Any convective activity should weaken as it heads east, given the
more stable environment and loss of upper support this evening.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
* Heat and humidity builds on Monday and continues into Tuesday.
Heat Advisory in effect for the entire area for both days.
Weak upper ridging aloft takes over for Monday and Tuesday as the
area continues to reside on the eastern edge of a large upper ridge.
An increase in heat and humidity on Monday as weak ridging builds
back in behind the departing shortwave. Dry weather is expected.
However, h850 temperatures approach 20-21C Monday afternoon with
dewpoint in the mid 70s (per NBM). Thus, heat indices of 100-105 for
northeast NJ and 95-100 elsewhere look possible once again Monday
afternoon.
More heat and humidity on Tuesday, under mainly dry conditions, as
the upper ridging begins to break down.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
The NBM was followed with no changes.
Key Points:
* Heat and humidity will continue on Wednesday. Widespread heat
index values between 95 and 99 with some locations reaching
the 100-104 mark. Heat headlines will be expanded into
Wednesday.
* Chances for showers and thunderstorms increases Wednesday into
Wednesday night as a cold front approaches and moves across the
region. Showers could persist into Thursday.
* High pressure returns to end the week and should dominate the
pattern this weekend bringing cooler temperatures and low humidity
levels.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
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A weak front lift slides through the region this afternoon into
evening. High pressure builds towards the region tonight into
Monday.
MVFR cigs will continue to overspreads the area from w to e
ahead of stalled warm front, with MVFR vsby from combination of
haze and smoke from western wildfires smoke rotating through
southern Canada into the NE US. MVFR cigs should gradually
improve to VFR late this aft/eve for western terminals as warm
front moves trough, but likely remain for eastern terminals and
potentially falling to IFR.
In terms of shra/tsra, showers across NE PA likely affect
NYC/NJ metro terminals btwn 15z and 17z with locally IFR in
heavy showers possible. Prob of TSRA is very low with this
activity.
Low and sparse thunderstorm (30 percent prob at an airport) and
heavy downpour activity expected this aft/eve with slow moving
frontal boundary, producing brief IFR conds. There is a less
than 5% probability of a severe thunderstorm within 10 miles of
NYC/NJ terminals.
S/SW winds today 5 to 10 kt with occasional gusts to 15 kt today.
Light W/NW winds tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Low and sparse thunderstorm (30 percent prob at an airport) and
heavy downpour activity expected for this aft/eve push (18-02z)
with slow moving frontal boundary, producing brief IFR conds.
Improvement to VFR cigs/vsby likely through the late aft/eve
push, outside of shra/tsra. Timing may be off by 1 to 2 hrs.
.OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
Monday - Tuesday: VFR.
Wednesday: Mainly VFR. A chance of showers and thunderstorms
late in the day and at night.
Thursday: VFR. A chance of showers with MVFR possible.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
A weak pressure gradient thru Wednesday will lead to the
continuation of conditions below Small Craft Advisory levels.
Conditions should remain below Advisory levels next Thursday,
but there may be a slight increase in winds and seas due to the
passage of a cold front.
&&
.HYDROLOGY...
-- Changed Discussion --
Isolated instances of flash flooding are possible late this
afternoon and evening, mainly for NYC and points N&W. Rainfall
rates of 2"/hr are possible. There are currently no hydrologic
concerns next week.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
A low rip current risk overall is expected today and Monday
with any onshore swell component a bit weaker and a light
southerly wind wave Monday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from 11 AM Monday to 8 PM EDT Tuesday for
CTZ005>012.
NY...Heat Advisory from 11 AM Monday to 8 PM EDT Tuesday for
NYZ067>075-078>081-176>179.
Air Quality Alert until midnight EDT tonight for NYZ067>075-
078>081-176>179.
NJ...Heat Advisory from 11 AM Monday to 8 PM EDT Tuesday for NJZ002-
004-006-103>108.
MARINE...None.
&&
$$
SYNOPSIS...BC/DBR
NEAR TERM...DBR/MET
SHORT TERM...DBR
LONG TERM...
AVIATION...NV
MARINE...BC/DBR/MET
HYDROLOGY...BC/DBR
TIDES/COASTAL FLOODING...