304
FXUS61 KPHI 091050
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
650 AM EDT Tue Jun 9 2026

.WHAT HAS CHANGED...
No significant changes to the forecast.

&&

.KEY MESSAGES...
1. Dry conditions expected through much of tonight, however a
few isolated showers or storms may arrive by around dawn
Wednesday. Warmer today, but with humidity remaining low.

2. Dangerous heat is likely during the latter portion of the
week.

3. There are multiple chances for thunderstorms Wednesday
through Monday.

&&

.DISCUSSION...
KEY MESSAGE 1...Dry conditions expected through much of
tonight, however a few isolated showers or storms may arrive by
around dawn Wednesday. Warmer today, but with humidity remaining
low.

Broad upper ridging will build through tonight. At the surface,
high pressure will slide offshore, beginning a transition to a
warm advection regime which will ramp up late tonight as a warm
front lifts north. A mid level shortwave trough associated with
upstream convection will approach the area by dawn Wednesday.

Following a cool morning, high temperatures this afternoon will
be mainly in the low to mid 80s (mid to upper 70s for the
immediate coast and higher elevations). The high pressure
departing offshore will be just slow enough to prevent moisture
return and keep our dewpoints low today, mixing out into the
40s to low 50s by early afternoon. This will keep conditions
very comfortable despite the increasing temperatures. Enjoy it
while it lasts though, as we do not have dewpoints this low in
the forecast again for at least the next 7 days. Scattered
cumulus developing with scattered to broken cirrus today,
thickening up later in the day.

Lows tonight will be upward of 10-15 degrees warmer than this
morning, mainly in the mid 50s to mid 60s under increasing cloud
cover. We`ll have to keep an eye on the remnant convection
approaching from upstream overnight. Current indications are
that instability will weaken considerably toward the east as the
remnant activity moves in overnight into our area. This will
likely result in some isolated decaying showers and embedded
rumbles of thunder moving in around dawn or so across the
western half of the forecast area.


KEY MESSAGE 2...Dangerous heat is likely during the latter
portion of the week.

In general, mid-level ridging is expected to build into the
region during the middle and latter part of the week. However,
guidance has been trending southward with placement of an upper-
low over Canada and associated troughing over the CONUS, and
therefore featuring a slightly weaker ridge axis through our
region. In addition, it appears increasingly likely that at
least a few shortwave impulses will traverse the region. At the
surface, the region will be under the influence of high pressure
centered over portions of the Southeast, with a few subtle
fronts potentially passing through the area.

Despite these subtle changes, dangerous heat is still expected
across the area, with Thursday and Friday currently looking like
the hottest days. Temperatures on both days look to climb into
the low to mid 90s across most of the area. With dewpoints
generally in the low 70s, heat indices are expected to climb
into the upper 90s, with low 100s looking increasingly likely
across portions of southeastern PA, southern NJ, and the
Delmarva. This level of heat and humidity can become dangerous
quickly for sensitive individuals and those outdoors for
extended periods of time. It still appears likely that heat
headlines will eventually be necessary during this time period
to cover this threat.

A cold front looks to move through the region late Friday into
Saturday, which will likely knock temperatures and dewpoints
down. Though it will still be hot, at least some relief appears
probable for the weekend and into early next week.


KEY MESSAGE 3...There are multiple chances for thunderstorms
Wednesday through Friday.

It still appears that the pattern in place will become
increasingly conducive for precipitation chances across the
region beginning on Wednesday. Much of this activity looks to be
in the form of diurnally driven convection, though some
guidance is beginning to indicate a few better opportunities for
more widespread shower and storm development.

The first opportunity appears to come on Wednesday, with a weak
shortwave and surface trough moving through the region. Given
somewhat limited instability and little shear, severe weather
potential currently appears low. As of right now, PoPs are
around 40- 60% across the Delmarva and southern NJ, and 60-80%
for eastern PA and northern NJ. It should be noted that even
with the high PoPs, not everywhere will see rain given the
scattered nature of the expected convection. Thursday features a
less obvious trigger for convection, but isolated to scattered
showers and storms are still possible. PoPs are generally
30-60%.

On Friday, the region is expected to begin feeling the
influence of the upper trough to the west of the region. In
addition, a cold front at the surface will approach the area
late Friday into Saturday. Scattered showers and storms may
focus near and ahead of this boundary, and with strong
destabilization and slightly better wind fields aloft, there is
concern that some severe threat could materialize. This will
need to be monitored in the coming days.

Guidance continues to trend drier for the first part of the
weekend in the wake of the cold front. However, another front
may approach towards the end of the weekend and into early next
week, so the pattern is expected to remain fairly unsettled.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...VFR. SSW winds increasing to near 10 kts by 16Z. Some
occasional gusts up to 20 kt are possible, but have left out of
the TAFs for now. SCT clouds around 4-6 kft AGL likely during
the afternoon, otherwise, increasing high clouds late. High
confidence.

Tonight...VFR to start, and for much of the night. By 09Z or so,
a few isolated showers and SCT to BKN MVFR ceilings will
develop. Southerly winds near 5-10 kts. High confidence in VFR
through 09Z, then low confidence on timing/coverage of any
restrictions from stratus or showers.

Outlook...

Wednesday through Wednesday night...Periods of sub-VFR
conditions likely in scattered showers and storms.

Thursday through Thursday night...Primarily VFR. Brief periods
of sub-VFR conditions can`t be ruled out in isolated to
scattered afternoon showers and storms.

Friday through Friday night...Periods of sub-VFR conditions are
possible in scattered showers and storms.

Saturday...Primarily VFR. An isolated shower or storm is
possible.

&&

.MARINE...
No marine hazards expected through tonight. Southerly winds
increasing to 10-15 kts with gusts up to 20 kts and seas 2-3
feet.

Outlook...

Wednesday through Wednesday night...SCA conditions are possible
with south winds 15-20 kt and gusts near 25 kt, becoming
southwest Wednesday night and diminishing late. Seas 3-5 feet,
also diminishing late Wednesday night.

Thursday through Saturday...No marine headlines currently
anticipated. Winds under 25 kt and seas under 5 feet.

Rip Currents...

For today, light south winds in the morning will increase to 10
to 15 mph with gusts up to 20 mph in the afternoon. Breaking
waves will average 1 to 2 feet with a light easterly swell with
a period around 7 seconds. As a result, there is a LOW risk for
the development of dangerous and life threatening rip currents
at the Jersey Shore and at Delaware Beaches.

On Wednesday, south winds increase to 15 to 20 mph with gusts
up to 30 mph. Breaking waves will be 1 to 3 feet with a light
easterly swell around 8 seconds. This will result in a LOW risk
for the development of dangerous and life threatening rip
currents at the Jersey Shore in Monmouth county and Delaware
Beaches, and a MODERATE risk at the Jersey Shore in Ocean,
Atlantic, and Cape May counties.

Ocean water temperatures are gradually increasing, but remain
mostly in the 60s.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

DISCUSSION...Cooper/Staarmann
AVIATION...Cooper/Staarmann
MARINE...Cooper/MPS/Staarmann