-- Discussion containing changed information from previous version are highlighted. --
973
FXUS61 KPHI 122325
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
725 PM EDT Thu Jun 12 2025

.SYNOPSIS...
A weak cold front approaches from the northwest tonight and
becomes nearly stationary over the Mid- Atlantic into the
weekend. Several waves of low pressure will affect the area
starting late Friday and continuing into the new week, with
multiple rounds of showers and storms, and below normal
temperatures likely.

&&

.NEAR TERM /THROUGH FRIDAY/...
Weak high pressure continues over the region as temps warm well
into the upper 80`s to the lower 90s across the region. PHL has
reached 90F for the first time since August 28, 2024. Surface
moisture has been increasing with the light westerly winds as
dew points have pushed into the low to mid 60s. Day Cloud Phase
Satellite imagery is showing some a narrow range of CU
developing along and south of a slow moving frontal boundary
draped across portions of northern PA into NY. Thus far as of
2pm, the updrafts haven`t been strong enough to see any
glaciation in the clouds so there`s been no threat of thunder as
of yet. Surface convergence has been minimal so while
instability has been increasing and there`s decent bulk shear,
the threat of any lightning thus far as been almost non
existent. Will continue to mention a slight chance of
thunderstorms for portions of northern NJ and PA and if any
showers can develop they could bring some locally moderate
rainfall along with gusty winds.

By the overnight hours, diurnal instability will wane rapidly
and any showers/thunderstorms will quickly come to an end. Temps
should moderate a bit overnight however most areas will stay in
the low 70s until just before daybreak as a weak cold front
slowly moves through across the region.

Weak high pressure moves over the area tomorrow as the front
becomes stationary over the Mid Atlantic. We`ll see an area of
low pressure approach on Friday increasing the chances for
rainfall and some isolated thunderstorms however the more
expansive chances will be coming Friday evening into Saturday.
Temps will be warming into the upper 70s to low 80s for the
areas along the shore and for the higher terrain of the Poconos.
For the urban corridor, temps will warm again into the mid to
possibly upper 80s.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
Low pressure will be advancing along the aforementioned
stationary boundary Friday night rapidly increasing the
potential for showers through Saturday morning with the passage
of the low. After the low departs late Saturday morning, the
stationary front over the Mid- Atlantic lifts north as a warm
front as low pressure moves into the Great Lakes. Some shortwave
energy ahead of that low moves into the northern half of the
forecast area. With surface dew points rising through the 60s
and approaching 70, another round of showers and thunderstorms
is possible late in the day. PoPs will mostly be chance, but
PoPs will be likely for portions of the southern Poconos and
western Lehigh Valley. The threat for severe weather is minimal,
but with increasing dew points and PWATs over 1.5 inches for
most of the area, and over 2 inches for Delmarva, locally heavy
rain is a threat. This is an overall weakly forced event so
while there is moderate confidence in the pattern, the specific
details of where it will shower and how much rain will fall will
be subject to change.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Low pressure approaches from the west and slowly works its way
through the Mid-Atlantic and Delmarva Sunday through Monday. A
prolonged period of unsettled weather is on tap during this time
with showers and isolated to scattered thunderstorms. Given
abundant low level moisture with surface dew points well in the
60s, locally heavy rain will develop from time to time. WPC has
a Marginal Risk (1 out of 4) for excessive rain Saturday night
through Sunday and again Sunday through Sunday night. Rain
tapers off on Monday as low pressure departs. With a prolonged
period of onshore flow, temperatures will be on the cool side
through the weekend and into Monday with highs on Sunday in the
low to mid 70s and highs on Monday in the upper 60s to low 70s.

Several additional shortwaves approach from the west as the
week progresses, and weak waves of low pressure will develop as
a result. This will keep low chance PoPs in the forecast through
Wednesday. Temperatures will rebound somewhat on Tuesday before
warming back into the 80s on Wednesday. After multiple cloudy
days, a return of sunshine should be anticipated on Wednesday as
well.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...VFR with spotty SHRA/TSRA dwindling early. Winds
west-southwest 5-10 kts this evening becoming north or
northeasterly overnight. High confid overall.

Friday...VFR mainly, but scattered SHRA with brief sub- VFR
conds possible. Winds northeasterly becoming easterly 5-10 kts.
Moderate confid.

Outlook...

Friday night through Saturday...Prevailing MVFR to IFR likely,
mainly from low ceilings. SHRA and scattered TSRA. A break in
SHRA possible around midday Saturday before ramping up again
Saturday afternoon.

Saturday night through Monday...Prevailing MVFR to IFR likely,
mainly from low ceilings. SHRA and scattered TSRA.
-- End Changed Discussion --

&&

.MARINE...
High pressure offshore and a cold front approaching from the
North/Northwest later today and tonight. Winds will remain below
SCA levels as winds come in from the West/Southwest today and
early tonight. After that, winds across the northern waters will
turn North/Northeast into the evening and this wins shift will
trend southward thru the night. Fair weather overall, but a
stray shower across the far northern waters possible this
evening. Low confid regarding shower activity.

Outlook...

Friday through Monday...Overall, sub-SCA conditions expected,
though there is the potential for SCA conditions Sunday night
through Monday. VSBY restrictions in showers, drizzle, and
isolated to scattered thunderstorms throughout this period.
Areas of fog also possible.

Rip Currents...

For Friday, east- northeast winds around 5-10 mph turn more
easterly in the afternoon. Breaking wave heights remain around
1-3 feet with a weak southeasterly swell of 1 foot around 9
seconds. There will be a LOW risk for dangerous rip currents at
all beaches.

For Saturday, weak southerly winds in the morning will
transition to northeasterly in the afternoon and increase to
around 10 mph. Breaking wave heights remain around 1-3 feet with
a continued weak southeasterly swell around 1 foot at 9-10
seconds in length. Will maintain a LOW risk for dangerous rip
currents at all beaches.


For Saturday,

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

&&

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

&&

$$

SYNOPSIS...Deal/MPS/Staarmann
NEAR TERM...Deal/Staarmann
SHORT TERM...Deal/MPS/Staarmann
LONG TERM...MPS/Staarmann
AVIATION...Deal/MPS/OHara/RCM/Staarmann
MARINE...Deal/MPS/OHara/Staarmann