000
FXUS61 KOKX 290047
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
847 PM EDT Fri Jul 28 2023

.SYNOPSIS...
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High pressure over the area weakens tonight and gives way to
an approaching frontal system for Saturday. A cold front moves
through the area Saturday evening. High pressure will then
slowly build in from the northwest through the middle of next
week. Another frontal system could impact the area late next
week.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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A convective complex over the Lower Susquehanna Valley of
southeast PA is likely to remain south of the area overnight.
Latest CAMs dissipate the area as it approaches the coast.
However, spotty showers can`t be ruled out as what is left of
a convectively induced vort move through the region. As such,
kept a slight chance of showers and thunderstorms for the area
overnight.

Temperatures are looking to remain elevated tonight with lows
only dropping into the middle 70s for much of the area. Portions
of the NYC metro may not drop below 80 tonight.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
The extent of coverage of thunderstorms around the area in the
morning depends nearly entirely on if upstream convection from over
the Ohio Valley sustains itself overnight. This will also impact
both the convection potential for the remainder of the day and how
high the temperatures rise during the afternoon. If there are more
showers and thunderstorms in the morning, increased cloud cover may
limit the rising temperatures a bit into the afternoon if skies
don`t clear out for a time. This may also result in decreased
instability for the cold front in the afternoon to spark new
convection.

As of now, the thinking is that the approaching shortwave is strong
enough to spark convection into the afternoon with a fair
amount of instability and shear in place. SPC has but much of
the area in a slight risk for severe thunderstorms, mainly
tomorrow afternoon and into the evening. The primary threat for
any storms would be damaging wind gusts, but hail and a brief
tornado can not be ruled out.

As for the heat, temperatures are expected to rise into the low to
middle 90s for much of the area again. A southerly flow ahead of the
approaching front may drive dewpoints slightly higher than they were
on Friday so heat index values of 95-100 will be once again
widespread. As such, heat advisories remain in effect for the entire
area.

The cold front moves through in the evening ushering in drier and
a more seasonable airmass Saturday night. Lows are expected to drop
into the upper 60s to low 70s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
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Through much of the long term forecast the Northeast will be under
the influence of a longwave upper trough. This will prevent
temperatures from warming too significantly. Highs will be in
the low-80s to upper-70s early next week. Winds will also remain
from the north through Wednesday which will help keep the
humid, warmer air away. In fact, dewpoints appear to drop into
the mid, even low- 50s some days early next week, which means we
will have a very dry airmass in place. This is also helped by
building surface high pressure to the west and north. This
should allow for some radiational cooling in some interior spots
and in the LI Pine Barrens. The 12Z GFS indicates PWATs
remaining under 1" Tuesday and Wednesday, and at times nearing
0.6 or 0.55", indicating very dry air for a few days next week.
Other models concur with drier air possible. According to SPC`s
Sounding Climatology Page the Min Moving Average for PWAT is
0.5" in early August. Mostly sunny conditions are likely at this
time with less moisture available.

Winds return from the south ahead of a frontal system associated
with an upper and surface low in Canada after Wednesday. This will
increase dewpoints and cloud cover late Wednesday into Thursday. I
have forecasted increasing shower and thunderstorm chances into the
day on Thursday, but given its at the end of the forecast period
timing and strength of the approaching frontal system may still
change until models come into better agreement on these points.
-- End Changed Discussion --

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
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A cold front will approach from the northwest and pass through
the area Saturday evening.

Mainly a VFR forecast outside of any showers a thunderstorms
associated with the cold front Saturday afternoon/evening. A few
of these storms may be accompanied by heavy rain and strong
gusty winds. Timing will continue to be better refined as we
get closer to event. Prior to this, there could be some spotty
activity during the overnight into Saturday morning, but
confidence of this happening remains low.

S-SW winds this evening diminish to around 5 kt or less, then
become SW-W and increase to around 10 kt by early Saturday
afternoon. A few gusts of 15-20kt possible. There is some
uncertainty as to how much the flow backs at the coastal
terminals due to the seabreeze influence. Expect more of a
hybrid seabreeze with more of a westerly component. Behind the
cold front Saturday evening, winds will become NW-N around 10
kt.

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

Low chance for MVFR cigs overnight as well as spotty showers.

Winds Saturday afternoon likely vary +/- 20 degrees at coastal
terminals due to some seabreeze influence.

Chance of strong to severe thunderstorms Sat afternoon/early
evening.

OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...

Saturday Night: Chance of thunderstorms early. Winds shift to
the NW-N. Behind the cold front, there could be a brief period
of MVFR ceilings overnight.

Sunday-Monday: Mainly VFR. Slight chance of shwrs, primarily in the
aftn.

Tuesday-Wednesday: VFR.

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

&&

.MARINE...
A Marine Weather Statement continues for Long Island Sound. The
US Coast Guard still indicates a large debris field caused by
recent flooding across New England.

Sub-SCA conditions are expected on all waters through Saturday
morning. Wind and seas may approach SCA thresholds for the
central and eastern ocean zones Saturday afternoon into the
early evening ahead of a cold frontal passage. Was not confident
enough at this time to issue a SCA but one may be needed.

Sub-SCA conditions are once again expected by Sunday and lasting
through at least the middle of next week.

&&

.HYDROLOGY...
Locally heavy rain which could lead to localized flash flooding
is possible with the cold frontal passage on Saturday afternoon
and evening. The area remains in a marginal risk for excessive
rainfall with the northern portions of the area, mainly southern
Connecticut and Putnam and Orange counties, in a slight risk
for excessive rainfall.

No hydrologic concerns are expected Sunday through next week.

&&

.TIDES/COASTAL FLOODING...
On Saturday, with an increasing SW flow and building waves,
there is a high rip current risk for Suffolk beaches, with a
moderate risk west towards Nassau and NYC beaches. The rip
current risk remains high on Sunday for Suffolk beaches and
increases to high for Nassau beaches, remaining moderate for NYC
beaches.

&&

.CLIMATE...
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No records for today will be broken.

Today`s (July 28) Record High Temperatures

Central Park...97 (1892, 1931, 1949, 1999)
LaGuardia......98 (1949)
JFK............98 (1949)
Newark........101 (1949)
Islip..........96 (1999)
Bridgeport.....95 (1949)

Today`s (July 28) Record High Minimum Temperatures

Central Park...80 (2020)
LaGuardia......83 (2020)
JFK............79 (2020)
Newark.........80 (2020)
Islip..........77 (2020)
Bridgeport.....77 (2020)
-- End Changed Discussion --

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Heat Advisory until 8 PM EDT Saturday for CTZ005>012.
NY...Heat Advisory until 8 PM EDT Saturday for NYZ067>075-078>081-
     176>179.
     High Rip Current Risk from 6 AM EDT Saturday through Saturday
     evening for NYZ080-081.
NJ...Heat Advisory until 8 PM EDT Saturday for NJZ002-004-006-
     103>108.
MARINE...None.
-- End Changed Discussion --

&&

$$

SYNOPSIS...BR/MW
NEAR TERM...BR/DW/MW
SHORT TERM...MW
LONG TERM...BR
AVIATION...DW
MARINE...BR/MW
HYDROLOGY...BR/MW
TIDES/COASTAL FLOODING...
CLIMATE...