897
FXUS61 KPHI 170229
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1029 PM EDT Thu Apr 16 2026

.WHAT HAS CHANGED...
Increased PoPs for a time tonight from about I-78 north.

&&

.KEY MESSAGES...
1. Above normal temperatures into the first half of the
weekend. Some showers and thunder for parts of the area tonight
and again Friday.

2. A strong cold front will cross through the area on Sunday
resulting in a period of increased showers and some thunderstorms.
Much cooler temperatures will follow into early next week,
potentially frost and/or freeze concerns.

&&

.DISCUSSION...
KEY MESSAGE 1...Above normal temperatures into the first half of the
weekend. Some showers and thunder for parts of the area tonight
and again Friday.

With high pressure situated over the western Atlantic Ocean, a
return flow remains across the area. As is typical in Spring
though, temperatures along/near the coast will be significantly
cooler due to the colder sea surface temperatures and diurnal
sea breeze. While a weak surface front passes through early
Friday morning, temperatures will stay well above normal into
Saturday with highs mainly in the mid 70s to mid 80s.

With the approach of the cold front tonight, there will be some
showers and a few thunderstorms especially for the I-78 corridor
northward. Given radar trends, increased the PoPs quite a bit
for a time tonight for these areas. Another round of some showers
will be overnight with the frontal passage. On Friday, there
may be a few additional showers as the trough aloft moves across
the area and some daytime instability may lead to some weak
convection.


KEY MESSAGE 2...A strong cold front will cross through the area
on Sunday resulting in a period of increased showers and some
thunderstorms. Much cooler temperatures will follow into early
next week, potentially frost and/or freeze concerns.

A backdoor cold front arrives Friday night into Saturday across
parts of the area and guidance is now keen on having this backdoor
front pushing completely south of our region by Saturday afternoon.
This would lead to cooler temperatures expected on Saturday, where
highs are currently forecast to be mainly in the 70s, cooler along
the coast and warmest further inland. This backdoor front will then
move back north as a warm front by Saturday night as a strong upper
level trough begins to approach the area.

A strong cold front will precede this trough and slide across the
region late Saturday night into Sunday morning. A weak area of low
pressure may also develop along the front in our vicinity. As the
main trough axis hangs back farther to the west, much of the shower
activity may occur behind the actual front. Given the strength of
the incoming upper-level trough, forcing for ascent should be strong
enough to result in increasing shower coverage for a time. The
thunder risk at this time looks rather low given the timing of the
front, however some rumbles of thunder cannot be ruled out. This
will be beneficial rain, and it will also result in a significant
cool down into early next week. A gusty wind will also occur
especially in the wake of the cold front for Sunday afternoon into
Sunday night, and this should limit frost formation into early
Monday morning. Much lighter winds and a colder air mass with high
pressure settling overhead should set the stage for frost and/or
freeze conditions Monday night into early Tuesday morning.
Temperatures then rebound Tuesday through Thursday.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Tonight...Mainly VFR. Some showers and a thunderstorm may lead
to brief lower conditions however especially at KRDG and KABE
where a TEMPO is included. Southwesterly winds 5-10 knots
becoming northwest. Low confidence.

Friday...VFR. Northwest winds 5-10 knots, with gusts 15-20 knots
during the day. A few showers may develop through the day. Moderate
confidence.

Outlook...

Friday night through Saturday...VFR. No significant weather expected.

Saturday night through Sunday night...Sub-VFR conditions likely at
times. Widespread showers likely with perhaps an isolated
thunderstorm. Winds will become increasingly gusty by Sunday
afternoon with gusts up to 25 kt.

Monday through Tuesday...VFR. Wind gusts up to 25 kt possible on
Monday, otherwise no significant weather expected.

&&

.MARINE...
South to southwest winds 10-15 knots, with gusts 20-25 knots through
this evening and overnight. Winds overall should remain below
advisory levels, but occasional gusts may gust around 25 knots.
Winds shift to west to northwest overnight into Friday around 5-15
knots.

Outlook...

For Delaware Bay Waters...A period of Small Craft Advisory
conditions probable on Sunday and possibly into Monday due to wind
gusts around 25-30 kt. Otherwise, no marine headlines are expected.

For Atlantic Coastal Waters...A period of Small Craft Advisory
conditions probable on Sunday and possible again on Monday due to
wind gusts around 25-30 kt. Otherwise, no marine headlines are
expected.

For Atlantic Offshore Waters...No marine headlines expected through
Tuesday. Aside for some gusty winds possible on Sunday, winds should
remain below 34 kt during this period.

&&

.CLIMATE...
Record breaking heat occurred at several locations today, including
potential for some sites to experience monthly record warmest low
temperatures for April.

Below are record highs and record high minimum temperatures for
April 16th and monthly warmest low temperature records for
April.


Record High Temperatures
                          April 16
Site                  Record/Year
Allentown (ABE)           90/2012
AC Airport (ACY)          89/2002
AC Marina (55N)           88/2002
Georgetown (GED)          89/2002
Mount Pocono (MPO)        85/2002
Philadelphia (PHL)        90/2002
Reading (RDG)             90/2012
Trenton (TTN)             91/2012
Wilmington (ILG)          92/1896

Record Warmest Low Temperatures
                          April 16
Site                  Record/Year
Allentown (ABE)           60/1941
AC Airport (ACY)          62/2002
AC Marina (55N)           64/2002
Georgetown (GED)          65/2012
Mount Pocono (MPO)        56/2002
Philadelphia (PHL)        62/2002
Reading (RDG)             65/1941
Trenton (TTN)             62/2002
Wilmington (ILG)          63/2002

Record Warmest Low Temperatures
             Entire Month of April
Site                  Record/Date (Year)
Allentown (ABE)           64/19th (1985 and 2019) and 30th (1983)
AC Airport (ACY)          70/26th (2009)
AC Marina (55N)           67/26th (2009)
Georgetown (GED)          71/29th (2017)
Mount Pocono (MPO)        65/25th (1960)
Philadelphia (PHL)        70/8th (1929) and 19th (1896)
Reading (RDG)             68/25th (1960)
Trenton (TTN)             70/19th (1896) and 20th (1896)
Wilmington (ILG)          74/19th (1896)

&&

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

&&

$$

DISCUSSION...DeSilva/Gorse/Robertson/Staarmann
AVIATION...DeSilva/Gorse/RCM/Robertson/Staarmann
MARINE...DeSilva/Gorse/Robertson/Staarmann