081
FXUS61 KPHI 310602
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
202 AM EDT Sun Aug 31 2025

.SYNOPSIS...
The dominant feature in our weather pattern through Wednesday
will be a large area of surface high pressure over much of the
northeastern U.S. An area of low pressure is expected to develop
well off the coast and lift northeast through mid week. A cold
front is then expected to arrive into our region Thursday night
into Friday. High pressure then returns for next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Early this morning, weak troughing remains across the eastern
US, with a stronger shortwave axis extending from portions of
New Brunswick and Nova Scotia into far northern New England.
This feature will track northeastward away from our area through
the period. Meanwhile, weaker troughing will remain in place.
At the surface, high pressure will over the Great Lakes will
spread eastward into the Mid-Atlantic and New England. A surface
cyclone over the Atlantic waters off the Mid-Atlantic coast
should track east-northeastward, remaining well offshore.

With light winds and clear skies, strong radiational cooling
will lead to another chilly morning across the area, with
temperatures generally in the upper 40s to near 50. Low-mid 40s
are expected in the Poconos. For much of this morning into early
this afternoon, skies will be mostly clear. However, cloud
cover will begin to increase by mid-late afternoon. Even with
some increase in cloud cover, it is still expected to warm into
the mid 70s for most locations, with some areas nearing or
reaching 80.

Skies tonight will remain partly to mostly cloudy, with warmer
temperatures. Overnight lows in the low-mid 50s can be expected
for most locations, with upper 50s to lower 60s in coastal
locations and for the urban corridor.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
By Monday and Tuesday, the surface high will be shifting closer
to the area. In the upper levels, a cutoff low from the
departing trough will meander towards northern New England by
Tuesday. Many of the latest deterministic model runs now show
the coastal low staying well east of the coast and starting to
progress northeastward during this time - likely not resulting
in any impacts to our weather.

The net result is continued tranquil and dry conditions. High
temps on Monday and Tuesday will mainly be in the 70s to around
80 degrees with low temps at night mainly in the 50s (with 40s
in sheltered locations and 60s along immediate coastal areas).

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Focus in the long term remains on the cold front expected to
cross through the region Thursday night into Friday.

For Wednesday and Thursday, the main change from the previous
forecast is that with the coastal low now expected to be well
east of our region, there will be a longer window of opportunity
for deep southwest flow to develop. This could spark a brief
warming trend. Current blend of guidance has highs both days
ranging from the mid 70s to lower 80s, but if this trend
continues, there is a potential for the forecast to trend
warmer, especially if the timing of the cold front continues to
be Thursday night.

Best chance for widespread rain will be just ahead of and with
the cold frontal passage. Thus, have a 20 to 40% chance of rain
Thursday afternoon, but then the chance increases to 40 to 70%
Thursday night. Depending on the forward progression of the
front, some showers may linger into Friday as well. However,
once the front clears the region, precipitation chances should
dwindle with the return of cooler and dry weather returning by
the start of next weekend.

&&

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

Through 12Z...VFR/SKC. Wind light and variable, with periods of
calm likely. High confidence.

Today...VFR. SCT/BKN high clouds increase from southwest to
northeast this afternoon. Northeasterly wind 5-10 kt. A sea
breeze may develop and make it as far inland as MIV and ACY
during the 19- 21Z time frame, causing wind to be east to east-
southeasterly. High confidence overall.

Tonight...VFR. SCT/BKN high clouds. Wind quickly diminishing to
light and variable. High confidence.

Outlook...

Monday through Wednesday night...VFR. No significant weather
expected.

Thursday...Sub-VFR conditions possible with a chance of
showers, especially Thursday night.

&&

.MARINE...
Through tonight...No marine headlines. Winds and seas will
begin to increase tonight. However, it currently appears that
conditions will remain below SCA criteria, with east-
northeasterly wind increasing to around 15 kt and seas to 3-4
feet.

Outlook...

Monday and Tuesday...Winds and seas should generally remain
below SCA criteria. However, seas could get close to 5 feet,
especially further off shore, and wind gusts may exceed 20 kt at
times.

Wednesday and Thursday...Winds and seas should stay below SCA
criteria.

Rip Currents...

For Sunday, northerly wind 5-10 mph will become easterly during
the afternoon. Breaking wave heights 1-2 feet. Easterly swell
around 2 feet at 5 to 7 seconds in length. Will maintain the LOW
risk for the development of dangerous rip currents for all
beaches.

East/northeasterly winds increase a little bit on Monday to
around 10 to 15 mph but period remains 5 to 7 seconds with only
2 foot breaking waves in the surf zone. Will keep the LOW risk
going through Monday but some of the NWPS rip probability
guidance does indicate a moderate may be needed if wave heights
increasing in the surf zone or onshore winds increase.

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

&&

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

&&

$$

SYNOPSIS...DeSilva/Johnson
NEAR TERM...Cooper
SHORT TERM...DeSilva/Johnson
LONG TERM...DeSilva/Johnson
AVIATION...Cooper/Johnson
MARINE...Cooper/Johnson