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017
FXUS61 KPHI 260748
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
348 AM EDT Thu Jun 26 2025

.SYNOPSIS...
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The strong upper level ridge to our southwest will weaken and allow
a back door cold front to track though much of the forecast area
today through Friday. The front will then push back to the north
as a warm front on Saturday and Sunday with high pressure remaining
in control into Monday. Another cold front looks to cross through
the area on Tuesday.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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Much of the region will see modest relief from the extreme heat of
the past few days today thanks to a backdoor cold front moving in
from the northeast throughout the day today. The frontal boundary
looks to reach somewhere near or just southwest of Philadelphia by
the afternoon, possibly stalling for a little bit, before moving
further southwest and enveloping the while CWA tonight. As a result,
we can expect a rather notable temperature and heat index gradient
across the region this afternoon. Northeast of the front, afternoon
highs will be closer to climatology with mid to upper 80s; expect
upper 70s and low 80s across the higher elevations of the Poconos
and northwest NJ. South and west of the boundary, afternoon
temperature will remain rather hot with low to mid 90s, mainly
across extreme southern NJ and the Delmarva Peninsula. Heat indicies
will still be around 95-105 degrees south and west of the front,
thus areas across the Delmarva Peninsula have a Heat Advisory in
effect.

As the backdoor front moves through the region, scattered showers
and thunderstorms are expected to form around and along the front.
In terms of severe weather potential, the risk is overall marginal
across areas along and southwest of the front, mainly including the
southeast PA, the Philly Metro, southern NJ, and the Delmarva,
mainly thanks to CAPE values building to 1500-2500 J/kg. That said,
overall shear will be weak, limiting severe potential. The greatest
risk would be an isolated strong downdraft in the strongest of
storms. In terms of flooding potential, weak storm motion and PWAT
values around 1.75-2.00 inches would support the potential for slow-
moving thunderstorms with heavy downpours. While more of an isolated
threat, flash flooding from a training thunderstorm is certainly
possible.

Tonight, isolated showers and thunderstorms may linger into the
evening but diminish into the overnight hours. The backdoor front is
expected to push through the rest of the region, allowing much
cooler temperatures to arrive for everyone with lows in the 60s to
around 70.
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&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
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The wavy front nearby and low pressure moving along it will keep
clouds and showers across the area Thursday night and Friday. Friday
will be noteworthy with high temps probably only topping out in the
upper 60s/low 70s across the north and mid/upper 70s for Delmarva
and south NJ. These highs are some 20 degrees less than recent days.
We`ll have mostly chance pops for showers/tstms from Thursday night
thru Friday night with the greater chances for the N/W counties and
lesser POPS for S/E areas. On Saturday, the fronts draw nearer and
Likely POPs are in the grids for N/W areas with high chance pops for
E/SE areas. Highs Sat will snap back to slightly above normal levels
with 85 to 90 degree temps again most spots with low 80s N/W.
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&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

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The storm track will remain nearby late this weekend and into the
beginning/middle parts of next week. The strong ridge that has been
across the area lately will have diminished and moved offshore. This
will keep the extreme heat away from the area. Still, temperatures
will be near normal Sunday followed by slightly above normal
readings for Monday thru Wednesday. Readings are not expected to be
record setting like this past week has been. Highs will mostly be
upper 80s with some low 90s across the S/E areas and low/mid 80s for
north NJ and the southern Poconos. Lows will mostly be in the upper
60s to low 70s with some mid 70s in urban areas.

Another result of the storm track being nearby will ensure more
showers and clouds for the long term. There are chances for
showers/tstms each day with Tue having the highest POPs (low likely
range mostly) and low numbers for Wednesday when POPs are only
slight chance attm. Upper troughing develops later next week, so
more showers and normal temps (if not below) may arrive later next
week. The different models offer with the degree of troughing, so
there is uncertainty with how mild it will actually be.
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&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
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Rest of tonight...VFR with a few high clouds. W-NW winds around 5 kt
or less, becoming light and variable at times. High confidence.

Early this morning (through 12Z)...Mainly VFR. Brief period of sub-
VFR conditions possible with an isolated shower or thunderstorm,
mainly in the evening. A small chance also exists for some
reductions to vsby in mist later at night. Winds becoming light and
variable. Moderate confidence.

Thursday...Mainly VFR. Spotty showers/t-storms possible during the
day especially western terminals. Winds turning northeasterly 5-10
kts. Low confidence.

Thursday night...Sub-VFR conditions possible. For RDG/ABE, low
stratus possible thanks to increased chance for low level moisture
from showers and storms earlier in the day.  For the I-95 and
MIV/ACY, onshore flow will help bring about low stratus in addition
to some fog for areas that see a shower or storm. Northeasterly
winds 5-10 kts. Low confidence.

Outlook...

Friday/Friday night...Plenty of low clouds and showers expected with
onshore flow across the area. Mostly areas with have low-end
MVFR with IFR strongly possible too. Further inland, (KABE,KRDG)
the CIGS may not be as low and will trend closer to VFR at
times.

Saturday thru Monday... Largely VFR but a few showers/tstms at times
with lower CIGs/VSBYs expected.
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.MARINE...
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No marine headlines expected through Thursday night. NW winds 5-10
kts tonight turning NE on Thursday into Thursday night behind a
backdoor cold front, increasing to 10-15 kts with some gusts up to
20 kts. A spotty gusty thunderstorm possible Thursday afternoon/evening.
Seas around 2 feet this morning build to 3 to 4 feet late afternoon
and into tonight.

Outlook...

Winds and seas will remain below SCA levels for Friday and into the
weekend. The biggest hazard will be scattered tstms for the periods.
The mostly likely times will be afternoons into the early evening
period.
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&&

.TIDES/COASTAL FLOODING...
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The recent New Moon and increasing onshore flow will lead to higher
confidence in advisories potentially being needed starting this evening.
While we get away from the New Moon, onshore flow will result in
water piling up and more widespread minor tidal flooding for the
coastal and Delaware Bay communities.

No tidal flooding is expected within the tidal Delaware River or
Chesapeake Bay.
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&&

.PHI WATCHES/WARNINGS/ADVISORIES...
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PA...None.
NJ...None.
DE...Heat Advisory until 8 PM EDT this evening for DEZ001>003.
MD...Heat Advisory until 8 PM EDT this evening for MDZ012-015-019-
     020.
MARINE...None.
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&&

$$

SYNOPSIS...RCM/Robertson/PO
NEAR TERM...MJL
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...MJL/OHara
MARINE...MJL/OHara
TIDES/COASTAL FLOODING...