087
FXUS61 KPHI 291713
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
113 PM EDT Sun Jun 29 2025

.SYNOPSIS...
A weak cold front will inch south into Delmarva and southern
New Jersey this morning and then stall out there tonight. The
front will then return northward as a warm front Monday followed
by a cold front later Tuesday. High pressure builds closer later
Wednesday into Thursday before settling over our area on Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
The weakening front crossing the area early today will dissipate
across south NJ and Delmarva this afternoon. While drier air will
likely remain across the northern counties, the southern areas
will remain very warm and humid thru the day. High temperatures will
reach the upper 80s to low 90s across the area with some low 80s
across the far NW areas. Dew points will vary from the low/mid 60s
across the NW counties and low/mid 70s for S/E counties.

These warm and humid conditions will result in scattered showers and
tstms developing this afternoon. The SPC has placed these southern
areas in a Marginal risk for severe weather today. We`ll have pops
in the chance (30%-40%) range for the southern counties today. These
pops and expected weather are supported by the most recent CAMs and
the trends are similar to the previous fcsts as well. Damaging winds
and slow moving cells perhaps causing localized flooding are the
main hazards with tstms today.

Tonight... Scattered showers and tstms will diminish during the
evening with the loss of daytime heating. Skies will become partly
cloudy overnight. Lows will drop into the low/mid 60s across north
NJ and NE PA. Across southern NJ, Delmarva and metro Philadelphia,
lows will remain in the low/mid 70s. The lingering humidity across
the southern areas could result in fog formation overnight too.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
As we go through Monday, an upper-level trough across the
Midwest and adjacent Canada is forecast to shift eastward and
amplify some as it approaches the Northeast. A front warm lifts
north across our area on Monday. A few showers or thunderstorms
are possible with the northward movement of the warm front, with
the greatest chance (40-60 percent) mainly across south and
western parts of our forecast area. Temperatures will make a run
at 90 degrees for many areas and with dew points on the rise,
heat indices will also be on the increase. As of now, the
forecast heat indices are just below Heat Advisory criteria
(even for the the I-95 urban corridor, Wilmington to
Philadelphia to Trenton, where the criteria is lower through
June 30th). Showers and scattered thunderstorms continue into
Monday Night with the warm front lifting north. Again, looking
muggy and mild with lows in the mid to even upper 70s over
Delmarva.

For Tuesday...An upper-level trough is forecast to shift
eastward and amplify some as it overspreads the Northeast and
Mid-Atlantic. This will drive a cold front across our region
later Tuesday. An uptick in the shear is forecast, especially
across Pennsylvania and New Jersey where the stronger mid level
flow is forecast to be. Moderate instability may develop and if
this overlaps with the greater shear, a favorable area for
severe thunderstorms (damaging winds) may develop Tuesday
afternoon and/or early evening. The details will depend on the
magnitude of the shear and instability as well as the timing of
the cold front and upper-level trough axis. 12z suite of
guidance continues to look favorable for some severe weather
though and through the extended, this will be the day to watch.
Temperatures are forecast to top out between 85-90F for much of
the region, although if cloud cover and convection hold off
long enough the highs could be a little higher than forecast.
While it will be rather humid, extreme heat is currently not
forecast.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Summary...Some showers and thunderstorms to start, otherwise no
extreme heat forecast.

Synoptic Overview...An upper-level trough is forecast to move
into much of the East by Tuesday Night. This trough looks to
become reinforced as it remains across much of the East through
the end of next week. At the surface, a cold front moves
offshore by Tuesday Night, then high pressure builds closer
later Wednesday into Thursday before settling over our area on
Friday.

For Tuesday Night, the cold front pushes offshore, with the last
of the showers and thunderstorms moving off the coast by
midnight or so. Lows should be a few degrees cooler than the
previous nights, with upper 60s/low 70s expected.

For Wednesday and Thursday...The upper- level trough across the
Northeast and Mid- Atlantic may tend to sharpen again as
additional energy rounds its base. The cold front should be
south and east of our area to start Wednesday, and while
temperatures do not look to drop much, the dew points are
forecast to lower some in the wake of the cold front. Despite
the presence of the upper-level trough, less in the way of
deeper moisture should keep the instability lower as well. Given
surface high pressure building closer to our area with time,
the chance for any showers and thunderstorms at this time is
little to none.

For Friday...The upper-level trough is forecast to still be in
place with weak surface high pressure becoming more established
over our area. The return flow up the Ohio Valley will increase
the low-level warm air advection with a northeastward moving
warm front. The forcing for this, as of now, looks to remain
well to our west and therefore little in the way of shower
chances. Daytime temperatures in the 80s for most, and the dew
points are forecast to be in the low to mid 60s. Overall, looks
like a nice forecast for the 4th of July. Nice weather should
continue into the holiday weekend.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of Today (through 00z)...Primarily VFR. 20-40% chance of
showers and thunderstorms at KMIV/KACY which could result in
brief restrictions. Winds out of the west around 5-10 kt.
Moderate confidence.

Tonight...Primarily VFR through 06z. Patchy fog developing
around the area. Kept some terminals VFR but added in a TEMPO
group at KRDG/KILG/KMIV/KACY where probabilities of MVFR VSBYs
are around 30-40%. Probabilities are less around KPHL and points
north, only around 15-20%, so kept out for now. Cannot rule out
some visibility restrictions though. Winds light and variable.
Moderate confidence.

Monday...Primarily VFR. Any fog mixes out by 12z. Winds pick up
out of the south around 5-10 kt by the late morning. Chance for
scattered showers and thunderstorms (30-50%) which could bring
brief restrictions to all terminals.

Outlook...


Monday Night...Primarily VFR. Restrictions possible though with
scattered showers and thunderstorms (30-50%).

Tuesday through Tuesday Night...Restrictions likely (60-80%)
with showers and thunderstorms moving through, mainly in the
afternoon.

Wednesday through Thursday...VFR. No significant weather.

&&

.MARINE...
A weak front will linger across the waters today with winds favoring
a South or SouthWest direction but perhaps more West or NorthWest for
Delaware Bay. The exact position of the front is uncertain since its
washing out as it arrives today. No mater where it ends up, wind
speeds and seas will remain below SCA criteria for today and
tonight. The main hazard will be scattered tstms which will form
this afternoon and linger into the evening. Higher winds and seas
locally near tstms. SMW products are possible today.

Outlook...

Sunday Night through Wednesday...No marine headlines expected.
Some showers and thunderstorms possible (50-70%) later in the
day on Tuesday and into Tuesday Night.

Rip Currents...

For Sunday, seas lessen some and winds become more variable,
however the period will increase to around 9 seconds with
breaking waves around 2 to 3 feet. Thus, we`ll keep a MODERATE
risk for the development of dangerous rip currents for the NJ
Shore and Delaware Beaches.

For Monday, winds become more southerly and the period will
remain around 9 seconds with breaking waves around 2 to 3 feet.
Thus, we`ll keep a MODERATE risk for the development of
dangerous rip currents for the NJ Shore and went LOW risk for
Delaware Beaches.

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

&&

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

&&

$$

SYNOPSIS...Hoeflich/RCM
NEAR TERM...OHara
SHORT TERM...Hoeflich
LONG TERM...Hoeflich
AVIATION...Hoeflich
MARINE...Hoeflich