042
FXUS61 KPHI 141731
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
131 PM EDT Sat Jun 14 2025

.SYNOPSIS...
A front will remain across southern Delmarva through the
weekend. Several waves of weak low pressure with some showers
and thunderstorms will impact the region along with below
average temperatures through early next week. Bermuda high
pressure will then begin to take hold toward the middle of next
week with increasing temperatures and daily chances of showers
and thunderstorms remaining. A cold front may impact the region
later next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
There is a forest fire in Shamong Township, NJ, and east to
northeast winds are pushing areas of smoke inland to the west.
The inversion over the area should gradually lift through this
afternoon, allowing air quality to somewhat improve, but smoke
will be noticed across portions of southern New Jersey, the
Philadelphia area, northern Delaware, and northern portions of
the eastern shores of Maryland.

Cloudy, showery, drizzly, and humid conditions expected through
the entire weekend along with below normal temperatures.
Overall, nothing of particular interest to note as far as
impacts go with the convective activity in our region, however
the lousy conditions won`t be good news for any outdoor
activities.

Quasi zonal and relatively weak flow will continue to prevail
aloft, though we will remain in the vicinity of the right
entrance region of a zonal jet toward our northeast. This will
provide a prolonged period of modest ascent through tonight,
which will lead to prevailing cloudy skies and periods of
showery weather. At the surface, a stalled to slowly moving
frontal boundary will remain in place across Delmarva into
Virginia. Weak low pressure will slide offshore today, then
surface ridging will strengthen some into tonight, which should
push the frontal boundary a little farther south (south of our
area completely).

As far as precipitation chances go, not great confidence
through tonight regarding any details of timing and coverage.
There will be a lot of mesoscale factors at play. Showers and
any storms will be directly influenced by the remnants of
whatever happens upstream to our west and southwest. With that
said, the daytime today, perhaps focused in the first half of
the day, looks to have the highest probability of measurable
rain for the entire weekend, though there will be chances of
showers through the period. PWats will be high (1.5-2.0"), so
any robust and persistent convection that can develop will be
capable of locally heavy rainfall.

The forcing from the aforementioned jet streak to our northeast
appears to maximize around mid to late morning, then wanes into
the afternoon. So anticipate the maximum coverage of showers
and any storms in our area to be focused around that time. Later
into the afternoon, more diurnally driven convection should
develop within the vicinity of the frontal boundary to our west
and southwest. Some additional shower activity could impact our
area from that activity, especially in our western and
southwestern zones (SE PA into Delmarva). The latest CAMs tend
to support this general evolution as well. We should get a lull
in shower activity overnight due to lack of forcing and
strengthening surface ridging, though cannot rule out some stray
showers. Drizzle may develop across the coastal plain overnight
as well.

Our southern and western most areas remain highlighted in a
Marginal Risk for excessive rainfall by WPC for at least a 5%
risk of heavy rainfall leading to flooding. The severe risk is
low overall, and we are not currently outlooked by SPC.
Lightning is certainly possible with any stronger cells though.

For temperatures, highs will be mainly in the mid 60s to 70s.
The 70 degree line looks to extend from around Reading southeast
into the Philly metro, then southeast toward Ocean County.
Northeast of there will be stuck in the 60s all day with 70s to
the southwest. Southern Delaware and portions of the eastern
shore of Maryland near the front could get into the low 80s
briefly. Lows tonight in the mid 50s to low 60s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Gradual improvement thru the period with periods of
showers/tstms Sunday/Sunday which will end from North to South
Monday. Fair weather expected Monday night. Temperatures largely
below normal with abundant clouds Sunday. Highs upper 60s/low
70s and lows in the 50s across the north and 60s further S/E.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A upper ridge will remain across the Southeast U.S. while a
trough across the Upper Great Lakes and Midwest remains in place
into midweek before getting pushed to the east. This means that
unsettled conditions will be across the Middle Atlantic Tuesday
thru Thursday with a chance for showers or tstms each day.
Lower pops for Friday and into the start of next weekend as the
disturbance gets pushed offshore and high pressure starts to
build in from the north.

Temperatures will be near normal Tuesday, but then milder
conditions with above normal temps Wed thru Sat. Readings on
Thursday will be well above normal with low 90s common across
much of southern NJ, metro Philadelphia and Delmarva. Across N/W
counties, mid/upper 80s are the expected highs.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of Today...Generally MVFR/IFR CIGs, though there may be
some brief VFR CIGs from time to time. -SHRA and BR will reduce
VSBYs to MVFR/IFR. 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 are more likely to be due to BR. A few TSRA
possible, but any lightning will be brief and isolated. NE
winds 5 to 10 kt. High confidence overall, low confidence on
timing.

Tonight...IFR/LIFR CIGs. MVFR/IFR VSBY in BR. Some -SHRA
possible late. A few TSRA possible this evening, but any
lightning will be brief and isolated. E winds 5 to 10 kt.
Moderate confidence.

Sunday...IFR CIGs, possibly lifting to MVFR late in the day.
MVFR VSBYs in the morning, giving way to VFR VSBYs in the
afternoon. E winds 5 to 10 kt. Moderate confidence.

Outlook...

Sunday night thru Monday night... Lower CIGs/VSBYs at times
with scattered showers/tstms at times.

Tuesday/Wednesday... VFR mostly but scattered showers/tstms
during the afternoon hours may bring restrictions.

&&

.MARINE...
Visibilities are improving on the waters, so will go ahead and
cancel the Marine Dense Fog Advisory.

Conditions will remain below advisory criteria through today,
although winds and seas will build, especially into the
afternoon. By this evening and overnight, seas will build to
near 3-5 feet across the Atlantic waters, and northeast winds
will increase to 15- 20 kts with gusts near 25 kts possible
north of Atlantic City. The stronger winds and seas will be near
and especially north of Atlantic City, where a Small Craft
Advisory is in effect from 6 PM this evening through noon
Sunday. Periods of showers possible through the daytime, with a
lull expected tonight.

Outlook...

Sub-SCA most of the time. Scattered showers/tstms
Sunday/Monday. More showers Tue/Wed, but mostly during the
afternoon/early evening.

Rip Currents...

For today, northeast winds will increase through the day to
around 15-20 mph by late afternoon, but will be lighter through
midday. Breaking wave heights remain around 1-2 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 given light winds and low breaking wave heights.

For Sunday, stronger onshore flow will remain with a 15-20 mph
northeast wind. Wave heights increase to around 2 to 3 feet or
higher and with multiple swell groups in the surf zone, there
will be a MODERATE risk for dangerous rip currents at all
beaches.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Air Quality Alert until midnight EDT tonight for PAZ070-071-
     101>106.
NJ...Air Quality Alert until midnight EDT tonight for NJZ016>019-
     021>025.
DE...Air Quality Alert until midnight EDT tonight for DEZ001.
MD...Air Quality Alert until midnight EDT tonight for MDZ012-015.
MARINE...Small Craft Advisory from 6 PM this evening to noon EDT Sunday
     for ANZ450>452.

&&

$$

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