459
FXUS61 KPHI 131913
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
313 PM EDT Mon Oct 13 2025

.SYNOPSIS...
The coastal low that has been bringing impacts to the region
will begin to move eastward tonight and into Tuesday. A cold
front will move through the area Wednesday, with strong high
pressure building in to close out the week. A low pressure
system may approach from the west late this weekend into early
next week.

&&

.NEAR TERM /THROUGH TUESDAY/...
A complex double-barrel coastal low continues to impact the
Eastern Seaboard this afternoon. The primary surface low
centered south of Cape Fear NC is beginning to pivot east into
the western Atlantic. Meanwhile, closer to home, a secondary
surface low is meandering just east of the mouth of the
Delaware Bay which is the main culprit of the miserable weather
occuring across the area today. As the low off the coast of NC
continues to track east tonight, the low off of our coast will
gradually weaken and pivot south, while morphing into the other
low on Tuesday.

For the rest of today and into tonight, gusty winds will
continue especially along the coast. Wind gusts so far today
have generally been upwards of 45 mph along the coast, lesser
inland. These gusts should begin to subside tonight, though
gusts up to 30 mph may still linger. The region will also
continue to encounter periods of light rain, intermittent
showers, mist, and drizzle early this evening as the low-levels
of the atmosphere remain completely saturated with the surface
low continuing to throw precipitation back toward the coast.
Around or after midnight, the low will begin to weaken and morph
into the primary low. This will cause precip to cease from
northwest to southeast overnight as the low begins to pull away.
Still, shower activity and mist/drizzle will continue along the
coast. Additional rainfall totals up around a 0.1-0.5 inches
are possible, with the greatest totals mainly along the coast
where coastal convergence is maximized. Lows tonight range from
the upper 40s north and west to upper 50s south and east.

For Tuesday, an overall improvement in conditions is in store
as some drier air begins to work into the area as the low
departs. Although clouds will be stubborn to erode in the
morning, should expect to see some breaks in the clouds with
sunshine returning by mid to late afternoon from west to east.
Winds will remain gusty though at times with gusts up to 20-30
mph possible. High temperatures will range from the mid 60s to
low 70s.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
To start the period, a large upper-trough will be located to
the east over the Western Atlantic, with a closed upper-low over
Quebec. Significant ridging will be in place over the South
Central US. This will place our region under enhanced
northwesterly flow aloft. The upper-low over Quebec will
gradually open into Wednesday night, and take the form of a
digging trough to our east. At the surface, the coastal low will
continue to track away from the area Tuesday night. A cold
front will approach and push through the area during the day on
Wednesday. After the cold front has passed, strong high pressure
will shift southeastward from the Great Lakes and into our
region.

Residual clouds Tuesday night will likely be confined to near
the NJ and DE coasts, and should diminish completely overnight.
Low temperatures Tuesday night look to be in the upper 40s
across the Poconos and into far northern NJ, near 50 across the
remainder of eastern PA and NJ outside of the urban corridor and
coastal regions, and in the mid 50s for the urban corridor,
coastal regions, and the Delmarva.

The cold frontal passage on Wednesday should be dry, with only
some modest increase in cloud cover. Ahead of the front across
southeastern PA, the southern half of NJ, and the Delmarva,
temperatures will rise into the upper 60s to near 70. Behind the
front across our northern PA counties and far northern NJ,
temperatures may struggle to reach 60. Lows Wednesday night will
range from the upper 30s to near 40 across most of eastern PA
and NJ to the low 40s across the Delmarva. Despite the cold air
advection, breezy north winds will likely preclude any frost or
freeze concerns.

Thursday looks to be a chilly day under mostly clear skies and
a continued breezy north wind. Highs will range from the upper
50s to lower 60s areawide. Thursday night looks to be a better
radiational cooling night with lowering winds. Low temperatures
will likely fall into the mid 30s for eastern PA and much of NJ,
slightly cooler for the higher elevations and slightly warmer
for the urban corridor, coastal areas, and the Delmarva. A
freeze is possible for northern areas, though this will depend
on how much the northerly breeze diminishes.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A progressive pattern looks to take shape during the extended
period. The trough to the east will track away from the area
while a ridge axis over central portions of the US approaches.
The ridge axis is expected to be over our area Saturday. Beyond
this, models suggest a trough will begin shifting into our area
Sunday. At the surface, strong high pressure will initially be
in control. A surface cyclone and associated cold front may
bring unsettled weather to the area Sunday into Monday.

Friday and Saturday look to feature fair weather and a warming
trend, with below average temperatures Friday into Friday night
and near normal temperatures Saturday into Saturday night.
Overall, these look like the two best weather days of the next
week.

Cloud cover and associated rain chances will begin to increase
on Sunday. Right now, PoPs looks to be in the chance (30% or
greater) to likely (60% or greater) range, particularly Sunday
night. There is plenty of inherent uncertainty at this range,
but there could be enough instability present to support a few
thunderstorms. Based on current timing in model guidance, PoPs
decrease by Monday afternoon, but again this is subject to
change. Temperatures Sunday into Sunday night appear slightly
above average,and near normal on Monday.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of Today...A mix of MVFR and IFR conditions around the
region. Likely IFR conditions are to prevail for KMIV/KACY, with
MVFR prevailing at all other terminals. Periods of light rain,
intermittent showers, mist and drizzle expected. North-northeast
winds around 10-15 kt with gusts up to 25-30 kt possible.
Moderate- low confidence overall.

Tonight...Anticipate IFR conditions (primarily ceilings) to
prevail for much of the overnight period at all terminals.
Visibility restrictions possible as light rain transitions to
showers, mist and drizzle, especially after midnight. Northeast
winds around 10-15 kt with isolated gusts up to 20 kt possible,
especially near KACY. Low confidence overall.

Tuesday...IFR ceilings early, improving to MVFR ceilings by
mid-late morning. Gradual improvement to VFR possible after 18Z
from west to east. North-northeast winds around 10-15 kt with
occasional gusts up to 20 kt. Moderate-high confidence.

Outlook...

Tuesday night...Sub-VFR conditions will be possible in residual
low clouds southeast of I-95, especially early.

Wednesday through Saturday...VFR. No significant weather.

&&

.MARINE...
As of 3:00 PM, have downgraded the Gale Warning on the upper
Delaware Bay to a Small Craft Advisory which is in effect
through Tuesday. Elsewhere, remaining Gale Warnings remain
unchanged which remain in effect through at least tonight and
Tuesday.

North-northeast winds sustained between 20-30 kt will continue
into tonight with gusts upwards of 30-40 kt possible, especially
on the Atlantic coastal waters. North-northeast winds continue
on Tuesday, but will begin to subside by the afternoon with
winds mainly between 15-25 kt with occasional gusts up to 35 kt.
Seas of 10-14 feet will abate to around 8-12 feet tonight and
on Tuesday. Periods of light rain, showers, mist and drizzle
likely.

Outlook...

Tuesday night through Friday...SCA conditions are likely to
continue. While winds may briefly fall below 25 kt on Wednesday,
they are expected to increase again to 20-30 kt Wednesday
night. Winds will likely begin to diminish on Friday. Seas will
remain elevated through much of Friday, gradually decreasing
from 6-10 feet to 4-6 feet. Seas are expected to decrease below
5 feet by Friday evening.

Friday night through Saturday...No marine headlines expected.
Winds below 25 kt and seas below 5 feet.

&&

.TIDES/COASTAL FLOODING...
Updated the tide forecasts based on current tidal departures.
No changes made to the coastal flood warnings and advisories.
With the latest update, the only site still forecast to get to
major flooding is Barnegat Inlet and southern portions of
Barnegat Bay. Otherwise, moderate flooding is expected for the
remainder of the New Jersey and Delaware coasts, Delaware Bay,
and southern shores of the Raritan Bay. Minor tidal flooding is
expected on the tidal Delaware River with this evening`s high
tide, where a Coastal Flood Advisory remains in effect.

Additional beach erosion and dune breaching are possible along
the entire New Jersey Shore and for Delaware Beaches due to the
very high/dangerous surf conditions through today.

It looks as if the high tide later today will be the last tide
of significant concern. There may minor tidal flooding with the
high tide tonight and especially tomorrow. However, we will have
a better idea the degree and extent of minor tidal flooding
with those cycles once we see the tidal departure trends with
today`s high tide.

That being said, given the nature of this event, tidal flooding
impacts could linger longer on back bays such as Barnegat Bay
in NJ and the Indian River Bay, Rehoboth Bay, and Little
Assawoman Bay in DE.

No tidal flooding is expected for our eastern shore counties
along Chesapeake Bay.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory until 11 PM EDT this evening for PAZ070-
     071-106.
NJ...Coastal Flood Warning until 9 PM EDT this evening for NJZ016.
     Coastal Flood Warning until 8 PM EDT this evening for
     NJZ012>014-020>027.
     Coastal Flood Advisory until 11 PM EDT this evening for
     NJZ017>019.
DE...Coastal Flood Warning until 9 PM EDT this evening for DEZ001.
     Coastal Flood Warning until 8 PM EDT this evening for
     DEZ002>004.
MD...None.
MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ430.
     Gale Warning until 6 PM EDT Tuesday for ANZ431-451>455.
     Gale Warning until 6 AM EDT Tuesday for ANZ450.

&&

$$

SYNOPSIS...Cooper
NEAR TERM...DeSilva
SHORT TERM...Cooper
LONG TERM...Cooper
AVIATION...Cooper/DeSilva
MARINE...Cooper/DeSilva
TIDES/COASTAL FLOODING...