472
FXUS61 KPHI 110916
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
516 AM EDT Thu Jun 11 2026

.WHAT HAS CHANGED...
Added key message regarding minor tidal flooding that is
forecast to occur this weekend. Otherwise, no significant
changes to the forecast.

&&

.KEY MESSAGES...
1. There is a risk of severe thunderstorms both this afternoon
and Friday afternoon.

2. Dangerous heat (potentially record heat) and humidity for
much of the region today through Friday, then much less humid
over the weekend.

3. Chances for showers and storms will return as a cold front
passes through Sunday night, then turning more seasonable
through the middle of next week.

4. Minor tidal flooding is forecast to occur with the
evening/night high tides on Saturday and Sunday along the
Atlantic coast and Delaware Bay.

&&

.DISCUSSION...
KEY MESSAGE 1...There is a risk of severe thunderstorms both
this afternoon and Friday afternoon.

The pattern in place will continue to support some additional
showers and thunderstorms across the region today and Friday,
mainly during each late afternoon to evening period. Better
synoptic forcing will arrive on Friday however with a cold
front.

Large scale forcing and shear are expected to remain relatively
weak today, however we will have a convectively enhanced
shortwave from remnant convection upstream in the Midwest to
contend with. This will enhance the forcing and potentially
shear at the mesoscale. Guidance has come into a consensus on
timing of convection developing locally associated with this
feature, mainly between about 5 PM to 11 PM from west to east.
Hotter temperatures and high dewpoints will yield steeper low-
level lapse rates compared to Wednesday. This is a pretty
typical severe thunderstorm setup for our region, but the
details in exactly how the storms will evolved still remains
less certain. Current indications from the CAMs suggest
scattered convection redeveloping along the mid level wave
across western and central PA this afternoon, then gradually
congealing into a broken line and moving east toward our area by
late afternoon and evening.

A SLIGHT risk (level 2 out of 5) for a severe thunderstorm
potential remains in place for today. Damaging winds will be
the main threat as storms may cluster or evolve into one or more
broken lines with some bowing, however large hail cannot be
ruled out given the magnitude of the instability that is
forecast.

On Friday, the region is expected to begin feeling the
influence of the upper-level trough to the west of the region,
in addition to a cold front that will be arriving from the west.
Some showers and thunderstorms should focus near and ahead of
this front, and with strong destabilization and slightly better
wind fields aloft, a severe threat will once again be present.
The convective coverage could be once again enhanced by a
convectively induced shortwave from the Great Lakes or upper
Ohio Valley. This evolution is less certain, however our entire
area is highlighted in a SLIGHT risk (level 2 out of 5) for
severe thunderstorms. Damaging winds will once again be the main
threat as storms may tend to cluster or evolve into one or more
short lines with some bowing.


KEY MESSAGE 2...Dangerous heat (potentially record heat) and
humidity for much of the region today through Friday, then much
less humid over the weekend.

A mid-level ridge slides across the Mid-Atlantic and Northeast
today and Friday, however a shortwave trough crosses New
England for a time. At the surface, high pressure remains
centered off the Southeast U.S. coast which will continue to
direct a hot and humid airmass across our area.

Dangerous heat is expected across much of our region today and
Friday, with even some record high temperatures potentially
getting challenged. High temperatures both today and Friday are
forecast to peak into the low to mid 90s across most of the
area, though highs may be a little warmer on Friday compared to
Thursday. Dewpoints will start out in the low to mid 70s, but
with afternoon heating and mixing, these should mix down to the
upper 60s and low 70s. This still results in peak heat index
values of 95 to 105 degrees across the majority of the area,
outside of the southern Poconos. This level of heat and humidity
can become dangerous quickly for sensitive individuals and
those outdoors for extended periods of time. A Heat Advisory
remains in effect today through Friday for areas where the heat
index criteria starts at 96F and 100F. The advisory for coastal
Monmouth County was extended through Friday. Latest hi-res
guidance indicates the westerly flow should be just strong
enough to keep the sea breeze boundary just offshore there,
though it could certainly start to push onshore later in the
day and result in some more immediate cooling off the ocean.

A cold front is forecast to move through the region late
Friday, which will knock the temperatures and especially the
dewpoints down several degrees. Though it will still be hot with
high temperatures in the upper 80s to mid 90s over the weekend,
dewpoints will return to much more comfortable levels (into the
50s in some areas Saturday) and this minimizes the risk for
additional heat related advisories.


KEY MESSAGE 3...Chances for showers and storms will return as a
cold front passes through Sunday night, then turning more
seasonable through the middle of next week.

A shortwave trough will push another cold front through the
region late Sunday night. This will give us another round of
scattered showers and thunderstorms, however this one will be
different than the activity we`re experiencing this week. The
unfavorable timing of the front overnight will significantly
limit instability, which will probably translate to a lower
severe threat. There looks to be plenty of synoptic forcing
though. PWats look to recover enough to give us some much
needed rainfall. Exact details on this setup remain unclear, but
the setup is promising for some decent rain.

The frontal passage will usher in a much more seasonable airmass
that will stick around through at least the middle of next
week. Highs will be in the upper 70s to mid 80s Monday through
Wednesday, with lows in the mid 50s to low 60s. Dewpoints in the
50s and low 60s will make for much more pleasant conditions.
Can`t completely rule out a few stray showers, but overall the
chances for rain look low during this period.


KEY MESSAGE 4...Minor tidal flooding is forecast to occur with
the evening/night high tides on Saturday and Sunday along the
Atlantic coast and Delaware Bay.

Higher than normal astronomical tides are expected to occur this
weekend, associated with the New Moon on Sunday. While tide
departure/surge values are not particularly high, mainly less
than 1 foot, astronomical tides will only be about a half a foot
below minor flood stage. Thus, we should see widespread minor
tidal flooding occurring with the Saturday and Sunday
evening/night high tides along the Atlantic coasts of New Jersey
and Delaware, and Delaware Bay. Tidal flooding is not currently
expected along the tidal Delaware River or eastern shore of
Chesapeake Bay.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through 12Z...Some areas of fog and low stratus, mainly until
11z, with MVFR to IFR conditions. Latest observations show this
activity may be slow to impact ACY/MIV, and may not occur there
at all. Any restrictions should lift by 12z. Winds generally
light around 5 kt, favoring a southwesterly direction. Low
confidence on timing details and degree of restrictions.

Today...Primarily VFR but another round of showers and
thunderstorms is expected late in the afternoon, mainly after
22z. Have included a thunder mention for all terminals, as
likelihood of thunder is increasing. Storms could produce brief
strong wind gusts. Winds out of the west increasing to around
10 kt. High confidence in prevailing VFR through the day,
moderate confidence in thunder timing.

Tonight...Scattered showers and thunderstorms should end by 03Z
everywhere, likely resulting in some restrictions, then VFR.
Cannot rule out some patchy fog late. West to southwest winds 5
kts or less. Moderate confidence.

Outlook...

Friday...Prevailing VFR expected through the period. Brief
restrictions are possible, with scattered showers and
thunderstorms during the afternoon and evening hours.

Saturday through Sunday...VFR. No significant weather expected.

Sunday night through Monday...Restrictions possible with the
chance for showers and storms.

&&

.MARINE...
No prevailing marine hazards expected through tonight. A
southwest wind at 10 kt with gusts 15-20 kt and seas of 3-4
feet. A line of showers and thunderstorms may impact the
nearshore waters and Delaware Bay during the evening, with brief
strong wind gusts possible.

Outlook...

Friday through Saturday...No marine hazards anticipated. Winds
will generally remain between 5-15 kt through Saturday. Seas
generally around 2-3 feet. Isolated to scattered showers and
thunderstorms possible on Friday. Fair weather expected for
Saturday.

Sunday...A brief period of marginal Small Craft Advisory
conditions are possible Sunday afternoon and evening with wind
gusts near 25 kt.

Monday...No marine hazards anticipated with winds 5-10 kt and
seas 2-3 feet.

Rip Currents...

For today, south to southwest winds will be around 10 mph with
breaking waves of 1 to 2 feet and a southerly swell with a
period around 6 seconds. As a result, there is a LOW risk for
the development of dangerous and life threatening rip currents
for the Jersey Shore and Delaware Beaches.

Conditions will be fairly similar on Friday, so the LOW risk
for the development of dangerous and life threatening rip
currents continues for the Jersey Shore and Delaware Beaches.

Ocean water temperatures are mostly in the mid to upper 60s.

For specific beach forecasts, visit weather.gov/beach/phi

&&

.CLIMATE...
A very hot and humid airmass will overspread our area through
Friday. Some record high and warmest low temperatures could be
challenged Thursday and/or Friday.

Location                   6/11 Record Highs/Year

Mount Pocono                  91/1911
Allentown                     94/1984
Reading                       98/1911
Philadelphia                  95/1986
Trenton                       96/1911
Atlantic City Airport         97/1984
Atlantic City Marina          91/1959
Wilmington                    95/1973
Georgetown                    95/1947 & 1959


Location                   6/12 Record Warmest Low/Year

Mount Pocono                  69/2005
Allentown                     70/1942
Reading                       75/1958
Philadelphia                  75/2015
Trenton                       72/2015 & 2017
Atlantic City Airport         73/1973 & 2015
Atlantic City Marina          79/2016
Wilmington                    73/2015
Georgetown                    73/1947, 1973, 1986, & 2017


Location                   6/12 Record Highs/Year

Mount Pocono                  87/1967
Allentown                     92/1949, 1961, 2015, & 2017
Reading                       95/1984
Philadelphia                  95/1947 & 2015
Trenton                       94/1933
Atlantic City Airport         94/2017
Atlantic City Marina          93/1880 & 1914
Wilmington                    96/1933
Georgetown                    95/2017

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory from 11 AM this morning to 8 PM EDT Friday for
     PAZ060>062-070-071-101>106.
NJ...Heat Advisory from 11 AM this morning to 8 PM EDT Friday for
     NJZ001-007>010-012>015-017>020-027.
DE...Heat Advisory from 11 AM this morning to 8 PM EDT Friday for
     DEZ001.
MD...None.
MARINE...None.

&&

$$

DISCUSSION...Gorse/Staarmann
AVIATION...Hoeflich/Staarmann
MARINE...Guzzo/MPS/Staarmann