886
FXUS61 KPHI 081109
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
709 AM EDT Mon Jun 8 2026

.WHAT HAS CHANGED...
Updated discussion for 12Z TAFs

&&

.KEY MESSAGES...
1. Mainly dry conditions expected through the middle of the
week with temperatures gradually warming.

2. Dangerous heat is likely during the second half of the week.

3. There are multiple chances for thunderstorms Wednesday
through Sunday

&&

.DISCUSSION...
KEY MESSAGE 1...Mainly dry conditions expected through the
middle of the week with temperatures gradually warming.

The region will remain embedded within a belt of somewhat
enhanced mid-level flow today as a sharp trough located over
New England dives south into the Western Atlantic. Thereafter,
mid- level ridging will likely begin to take shape across the
region through mid-week. At the surface, high pressure will be
in place until it gradually builds off the coast on Tuesday. In
large part thanks to the broad area of high pressure, there
aren`t any significant rain chances through Tuesday.

Easterly, on-shore flow will result in a notable east-west
gradient in temperatures today thanks to the presence of the
marine layer closer to the coast. Temperatures Tonight will fall
into the low to mid 50s, maybe some 40s in the typical cool
spots.

The cool down will be short lived, as by Tuesday, low level flow
will shift to southerly, kick starting a warming trend.

KEY MESSAGE 2..Dangerous heat is likely during the second half
of the week.

There is increasing concern for the potential for dangerously
hot conditions during the second half of the week. A warm front
is expected to cross through the region on Wednesday, adding to
the warning trend that will begin on Tuesday. Thursday at this
point, Thursday looks like the highest chance for dangerously
hot conditions, with maximum hot air advection in the wake of
the warm front. There is more uncertainty on Friday - some
deterministic models have shortwave ridging over the region on
Friday, which would mean warmer conditions than Thursday. The
the majority of model solutions however, depict mid level short
wave trough over the eastern seaboard which would result in
cooler conditions as compared to Thursday both due to lower
thicknesses and increased cloud cover.

When discussing heat impacts, it is not only a factor of the
temperature but also humidity. Regardless of the pattern that
the models are split between, this pattern favors higher
dewpoints, thanks in large part to the persistent southerly
return flow.

The net result is widespread temperatures in the 90s and maximum
heat index values near or above 100 degrees on Thursday, and in
the 90s on Friday.

Beyond Friday, the risk for extreme heat is expected to decrease
depending on the timing of a pair of cold fronts over the
weekend.


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

The pattern in place will begin to support daily chances for
showers and thunderstorms Wednesday through Sunday. While there
are a few features to focus on for the highest potential of
storms, there will be chances every day just from diurnally
driven convection developing off the sea breeze or orographic
lift.

The higher chances for widespread precipitation come first with
the potential mid level trough on Friday. As noted by the
previous shift, that some of the machine learning guidance from
CSU is beginning to highlight Friday as potentially a severe
weather day. Still a lot of details to tune out between now and
then, but just something to monitor at this time.

Additionally, several models are depicting a pair of cold fronts
crossing through the region this weekend into early next week.
There are still wide differences in the timing of these cold
fronts, so hard to say at this stage at what point the focus
will be for precipitation Saturday and Sunday.

&&

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

Today...Periods of MVFR possible this morning as marine layer
stratus spreads over the region. Ceilings associated with this
stratus range anywhere from 1500 ft AGL to 4000 ft AGL. This
stratus should gradually dissipate through 15Z. Winds will be
gradually shifting from the Northeast to the East through the
day. Wind speeds ranging from 5 to 15 kt gusting to 25 kt, with
the highest speeds expected at KACY. Low confidence.

Tonight...Prevailing VFR. Winds should gradually shift to
southeasterly and may eventually shift to southerly. Moderate
confidence.

Outlook...

Tuesday...VFR. No significant weather expected.

Wednesday though Friday...Prevailing VFR. A few brief periods
of sub- VFR conditions possible with isolated to scattered
afternoon thunderstorms each day.

&&

.MARINE...
Winds and seas should stay below Small Craft Advisory criteria
through tonight, though gusts near 20 kt are possible through
this morning.

Outlook...

Tuesday through Tuesday night...No marine headlines expected.
Winds generally between 10-20 kt with seas around 2-3 feet.

Wednesday through Wednesday night...SCA conditions possible
mainly due to wind gusts around 25 kt. Seas around 2-4 feet,
possibly up to 5 feet.

Thursday through Friday...No marine headlines expected. Winds
generally between 10-20 kt with seas around 2-3 feet.

Rip Currents...

For today, there is increasing concern for rip currents thanks
in part to the robust onshore flow developing. Northeast winds
in the morning around 15-20 mph with a few gusts to 25 mph,
becoming easterly in the afternoon around 10-15 mph. Breaking
waves 2 to 3 feet. The dominant swell is expected to have a
period of 6 to 7 seconds. However, there is an underlying longer
period swell of 8 to 10 seconds. Given these factors, forecasted
a MODERATE risk for the development of dangerous and life
threatening rip currents along the Jersey and Delaware coasts.

Tuesday, light winds in the morning will increase out of the
south- southeast to 10-15 mph in the afternoon. Breaking wave
heights generally 1 to 2 feet. Light east-northeasterly swell
6-7 seconds in length. These factors lead to a LOW risk for the
development of dangerous and life threatening rip currents at
all Jersey Shore and Delaware beaches.

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...DeSilva/Johnson/MJL/RCM
AVIATION...DeSilva/Johnson/MJL/RCM
MARINE...Cooper/DeSilva/Johnson/RCM