505
FXUS61 KPHI 150532
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
132 AM EDT Sun Jun 15 2025

.SYNOPSIS...
A stationary front will remain situated across near the
Chesapeake region through Tuesday yielding unsettled weather
conditions. The front will then begin to lift northward as a
warm front on Tuesday night into Wednesday across our area as an
area of high pressure settles near Bermuda mid-week. A low
pressure system begins to approach the area on Thursday with a
cold frontal passage Thursday night. High pressure returns for
Friday into next weekend.

&&

.NEAR TERM /THROUGH TODAY/...
A frontal boundary remains draped from low pressure over the
Great Lakes, through the Ohio Valley, and into the Delmarva
Peninsula. That low slowly tracks east tonight and will be over
the Ohio and Tennessee Valleys by Sunday morning, then will
approach the Mid- Atlantic late Sunday. Several waves of showers
associated with mid- level shortwave energy will spin off ahead
of that low.

Unsettled conditions on tap through the period, though it will
not be a washout. The first wave of rainfall has departed the
area with the next wave of showers beginning to approach
Delmarva from the west this evening. Since Delmarva is south of
the frontal boundary, there is some instability with SB CAPE
values of 1000 to 1500 J/kg, and SPC has a Marginal Risk (1 out
of 5) for severe weather. PWATs are over 2 inches, and WPC has a
Marginal Risk (1 out of 4) for Excessive Rainfall. Some
stronger storms will be capable of stronger winds gusts and
locally heavy rain that could lead to localized flooding. This
threat should end by midnight or so.

Overnight, cloudy and foggy conditions continue. Lows tonight
will be in the 60s.

Another wave of showers approaches late tonight and may pass
through the region late tonight through Sunday morning.

Cloudy, damp, and cool conditions continue on Sunday. Highs
will be in the 60s to low 70s. Another wave of showers will
approach late Sunday.

The Mines Sprung Wildfire in Wharton State Forest in Shamong
Township, NJ, continues, though progress has been made in
containing it. As of 9:00 pm, the fire is 5,500 acres and 70%
contained. With east to northeast winds, smoke from this fire
will spread inland towards Philadelphia and Wilmington. With an
inversion developing overnight once again, smoke will get
trapped across portions of southern New Jersey, and possibly as
far back as the I-95 corridor in the Philadelphia metro area and
northern Delaware.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
Little change in the forecast has been made for the Sunday
night and Monday period as the stalled frontal boundary be
displaced well south of the region. A weak wave of low pressure
will ride along the boundary Sunday night into Monday causing a
period of light rain showers and perhaps an isolated
thunderstorm to occur (20-40%), especially to the south of
Philadelphia. For areas north of Philadelphia, perhaps a spotty
shower shall occur, but largely should remain dry (PoPs less
than 20%). The boundary will gradually start to work its way
back north Monday night and more so on Tuesday and Tuesday night
as it will then be located within the vicinity of the southern
Delmarva. Another weak disturbance will ride along the boundary
yielding another period for some rain showers and isolated
thunder to occur (PoPs 20-40%) across the entire region as the
front is in closer proximity to the area.

All in all, unsettled weather conditions are to continue
through the beginning of the week, but will not be a washout by
any means as there will be breaks in between rounds of
precipitation. However, it will remain mostly cloudy with
limited sunshine throughout the period. Highs will mainly be in
the upper 60s to mid 70s on Monday with mid to upper 70s on
Tuesday. Lows will remain uniform mainly in the 50s and 60s.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
An upper level ridge will be located over the Southeast US on
Wednesday as a trough develops over the Great Lakes region on
Thursday. This pattern will shift east on Friday with the base
of the upper trough located over the East Coast. At the surface,
the `stalled` frontal boundary will lift north as a warm front
on Wednesday across our area. Surface high pressure will be
located near Bermuda where it will persist through the end of
the week. Low pressure will also be tracking through the Great
Lakes on Thursday tracking and into New England on Friday with a
cold front trailing to the southwest, crossing through late in
the week.

For Wednesday, we`ll begin to see the beginning of a
considerable warm-up as the warm front lifts north of the area.
Some spotty thunderstorms may occur due to the combination of
the passage of the front and diurnal heating. Otherwise,
attention then turns to the cold front that will approach the
area on Thursday into Thursday night. Forcing does appear to be
quite strong with the deepening trough, so at this point it does
seem plausible for there to be at the very least some strong
thunderstorms around Thursday afternoon and evening. This is
supported quite well by the machine learning guidance by
UCAR/NCAR which has a targeted area of severe weather potential
over the Mid-Atlantic and Northeast. Obviously, this is still
5-6 days away, so a lot can change between now and then.
Regardless, the front will likely bring some showers and
thunderstorms to the area as it crosses through. Improving
weather should return by Friday and into next weekend as high
pressure returns.

In terms of temperatures, above normal temperatures are
expected throughout the period, with the warmest day of the week
appearing to be Thursday where highs will be around/in excess
of 90 degrees across the Coastal Plain. With the area being
located well into the warm sector (and a very muggy airmass in
place), this will likely result in heat indices in excess of 95
degrees in spots. Suppose if this holds true, our first set of
heat headlines may be warranted.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

THrough 12Z...Initially MVFR CIGs but IFR/LIFR CIGs developing
at times. MVFR/IFR VSBY in BR and scattered SHRA. There is a
wildfire in the Pine Barrens of southern NJ, and smoke from that
fire will spread west towards KPHL/KILG/KMIV. VSBY restrictions
in FU are possible, though restrictions may be more likely due
to BR. E winds 5 to 10 kt. Moderate confidence.

Sunday...IFR CIGs anticipated to start the day, likely lifting
to MVFR by 15Z or so. Areas of MVFR VSBYs in the morning,
giving way to VFR VSBYs in the afternoon, however scattered
showers developing again during the day will drop visibility to
MVFR at times. E wind near 10 kt. High confidence on prevailing
restrictions, low confidence on details.

Outlook...

Sunday night through Tuesday night...Primarily sub-VFR
conditions expected with several rounds of rain showers and
isolated thunderstorms possible.

Wednesday through Thursday...Primarily VFR expected with at
times periods of sub-VFR conditions possible in thunderstorms.

&&

.MARINE...
E-NE at 10 to 15 kt may result in winds gusting to 25 kt from
time to time late tonight along with seas around 4-6 feet on
the NJ ocean waters. The Small Craft Advisory remains in effect
through Sunday morning. Otherwise, sub-SCA conditions.

VSBY restrictions in showers and fog from time to time.

Outlook...

Sunday night through Thursday...No marine headlines are
expected. Winds will generally remain below 20 kt with seas of
2-4 feet. Several rounds of rain showers and thunderstorms are
expected through Thursday.

Rip Currents...

For Sunday and Monday, winds will be out of the northeast and
nearly perpendicular to shore around 10-20 MPH, with 2 to 3 foot
waves within the surf zone. Multiple swell groups are expected
as well, with the longest period being around 8 to 9 seconds.
This will result in a MODERATE risk for the development of rip
currents for all beaches both days.

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

&&

.TIDES/COASTAL FLOODING...
With onshore flow continuing over multiple tide cycles, water
will pile up within back bays and inlets. This will result in
some spotty minor tidal flooding along the Atlantic coastline
for areas in Atlantic and Cape May County, New Jersey and Sussex
County in Delaware. Cannot rule out some spotty minor tidal
flooding within the Delaware Bay and tidal Delaware River. The
overnight high tide cycle tonight looks to bring the highest
tides, with slowing declining water levels getting into next
week.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ450>452.

&&

$$

SYNOPSIS...DeSilva
NEAR TERM...AKL/MPS/Staarmann
SHORT TERM...DeSilva
LONG TERM...DeSilva
AVIATION...AKL/DeSilva/MPS/Staarmann
MARINE...DeSilva/Hoeflich/MPS
TIDES/COASTAL FLOODING...Hoeflich