Severe Thunderstorm Warning 109, NWS Philadelphia/Mount Holly

642 
WWUS51 KPHI 012243
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
643 PM EDT Wed Jul 1 2026

PAC017-077-095-012252-
/O.EXP.KPHI.SV.W.0109.000000T0000Z-260701T2245Z/
Lehigh PA-Bucks PA-Northampton PA-
643 PM EDT Wed Jul 1 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LEHIGH...
NORTHWESTERN BUCKS AND SOUTH CENTRAL NORTHAMPTON COUNTIES WILL EXPIRE
AT 645 PM EDT...

The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

LAT...LON 4036 7506 4033 7534 4034 7535 4034 7536
      4056 7538 4057 7519 4057 7516 4058 7515
      4058 7512
TIME...MOT...LOC 2242Z 350DEG 13KT 4034 7521 

$$

Guzzo

Area Forecast Discussion
National Weather Service Mount Holly NJ
337 PM EDT Wed Jul 1 2026

.WHAT HAS CHANGED...
Aviation section updated for 18Z TAFs.

Slight risk of severe weather expanded southward this
afternoon/evening.

&&

.KEY MESSAGES...
1. Dangerous heat and humidity will build over the Northeast
and Mid Atlantic through Saturday. All time record high
temperatures could be challenged Thursday and Friday.

2. There is a chance for thunderstorms across portions of the
area into this evening, a few of which may be severe with
damaging winds.

3. There is the potential for additional and more widespread
afternoon and evening thunderstorms starting on Friday and
lasting into the holiday weekend.

&&

.DISCUSSION...
KEY MESSAGE 1...Dangerous heat and humidity will build over the
Northeast and Mid Atlantic through Saturday. All time record
high temperatures could be challenged Thursday and Friday.

Strong mid-level ridging across the Mississippi Valley, Great
Lakes, and Ohio Valleys is building eastward into the Northeast
and Mid Atlantic and will persist into the holiday weekend. A
west to southwest flow today will shift more west to northwest
by Friday. The ridge will finally start to break and retreat
some starting Saturday into Sunday.

High temperatures will climb into the mid and upper 90s today,
and then from 100 to 105 degrees on Thursday and Friday. With a
south to southwest flow, dewpoints are less likely to mix out
significantly this afternoon. Resulting heat indices are
forecast to range mainly from around 100-105 degrees. By
Thursday and especially Friday, the shift to a more west or
northwest flow will allow for better mixing out of dewpoints
during the afternoon, and also a component of downsloping
(adiabatic warming) from the Appalachians. This will support
temperatures climbing above 100 degrees as dewpoints mix out
into the mid 60s during the afternoon hours. Resulting forecast
heat indices are mostly in the 105-110 degree range. This is
indeed the type of synoptic pattern that could challenge all
time record high temperatures in our region. Areas north of
I-78 are forecast to experience the hottest air temperatures
(upper 90s to near 100 degrees, even as high as 95 degrees at
Mount Pocono) on Thursday. Further south, the hottest air
temperatures (mainly in the 100-105 degree range, and in the
upper 90s to near 100 degrees for the New Jersey Shore and
Delaware Beaches) are forecast to occur on Friday. See the
Climate section below for more information on record
temperatures.

Temperatures may begin to abate somewhat on Saturday as the
ridge begins to break and retreat to the southwest. However,
high temperatures will still be in the mid 90s to around 100
degrees. The prevailing flow direction will dictate how much
mixing out of dewpoints occur on Saturday. Currently, we have
upper 60s to near 70 degree dewpoints, which results in 100-108
degree heat indices. Highs will remain in the low to mid 90s
Sunday, though may drop into the mid and upper 80s on Monday.
Heat index values on Sunday may still be in the mid 90s to
around 100, so heat related impacts will continue beyond
Saturday despite a slight improvement in temperatures. Once the
details regarding the heat on Sunday becomes more clear, the
current Extreme Heat Warning or a new Heat Advisory may be
issued.

Confidence remains high for significant impacts from the 3 to 4
day (and potentially 5 day) excessive heat and humidity, with
heat indices reaching into the 100-110 degree range each day.
The Extreme Heat Warning for Delmarva and far southern New
Jersey remains in effect starting at noon on Thursday and
continuing through at least 8 PM Saturday. The hottest
conditions are forecast to occur on Friday in this area.

A Heat Advisory remains in effect for the New Jersey Shore
(barrier islands), including coastal Ocean, coastal Atlantic,
and coastal Cape May Counties. The strong southerly coastal jet
should prevent the islands from getting too hot during the
afternoon, though the wind direction will be more southwesterly
on Friday. This should allow for temperatures to rise into the
mid 90s to potentially near 100 degrees, resulting in daily
maximum heat indices Thursday through Saturday from 95 to 105
degrees. The advisory is also in effect beginning at noon on
Thursday through 8 PM Saturday. The hottest conditions are
forecast to occur on Friday in this area. The Extreme Heat
Warning remains in effect for coastal Monmouth County.

For the remainder of the area, the Extreme Heat Warning remains
in effect starting at noon today through 8 PM Saturday for all
of southeastern Pennsylvania, northern Delaware, and much of New
Jersey. While heat indices may fall shy of warning criteria by
Saturday, impacts will likely be worsened by the multiple days
of heat and busy outdoor holiday festivities.

The mid-level ridge will break and retrograde back towards the
south and west beginning Saturday, and a mid-level trough will
try to slide down into the Northeast. This pattern change will
begin to favor slightly cooler temperatures and a break in the
extreme heat by Sunday and Monday, as well as the potential for
showers and thunderstorms for the holiday weekend (see Key
Message 3 below).

KEY MESSAGE 2...There is a chance for thunderstorms across
portions of the area into this evening, a few of which may be
severe with damaging winds.

Instability is forecast to be high (potentially 3000 J/kg or
greater) across the area, especially along and northwest of
I-95. Due to the strong subsidence and ridging building in from
the west, there will also be a lot of mid level dry air
contributing to high DCAPE (1000-1500 J/kg). Latest CAMs
continue showing some convective initiation within this
environment, despite the strong subsidence, and as of 2 PM radar
is bearing this out. While coverage of any thunderstorms would
be isolated to scattered, any storms that do form could be
capable of producing strong microbursts with damaging winds. SPC
has expanded the MARGINAL (level 1 out of 5) risk for severe
thunderstorms and the SLIGHT (level 2 out of 5) significantly
further south with the midday update, encompassing nearly all of
the northern half of the CWA in slight. Its not impossible a
severe thunderstorm watch is necessary, and have added enhanced
wording to forecast, but for the moment will be watching
progression of convection upstream.

KEY MESSAGE 3...There is the potential for additional and more
widespread afternoon and evening thunderstorms starting on
Friday and lasting into the holiday weekend.

The mid-level ridge looks to break down and retrograde back to
the south and west starting on Friday, and this will allow mid-
level troughiness to develop over the Northeast. With several
shortwaves riding over the top of the ridge and into the local
area, this may support more widespread afternoon and evening
showers and thunderstorms starting on Friday, but especially on
Saturday and Sunday. Currently, PoPs are around 10-30% on Friday
afternoon and evening and generally 30-50% on Saturday.
Activity becomes more active on Sunday and Monday, with PoPs
around 60% for most of the area.

While details of this activity will not become clear until
later this week, it is important to point out that any holiday
weekend festivities could be impacted by thunderstorms (in
addition to the extreme heat). The environmental setup would be
favorable for strong to severe thunderstorms, if any storms do
develop. This potential will continue to be monitored.

&&

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

Rest of Today into this evening...VFR. 10-20% chance of a
shower or thunderstorm. South to southwest winds around 5-10 kts
with gusts upwards of 20. High confidence overall, low
confidence in convective impacts.

Overnight tonight...VFR. Winds settling out of the southwest
around 5-10 kts. High confidence.

Thursday...VFR. Winds west-southwest 5-10 kts. High confidence.

Outlook...

Thursday night through Saturday...Generally VFR, though
isolated to scattered SHRA and TSRA may result in localized sub-
VFR conds.

Sunday through Monday...Sub-VFR conds in afternoon and evening
SHRA and TSRA. VFR otherwise.

&&

.MARINE...
A Small Craft Advisory remains in effect for all of the
nearshore Atlantic coastal waters through midnight tonight.

Southerly winds 15-25 kts this afternoon across the Atlantic
waters. Seas are 3-4 feet will build closer to 5 feet as well.
Winds and seas will then diminish later tonight. A gusty
thunderstorm also can't be ruled out, especially across the
northern ocean zones.

Small Craft Conditions look likely to redevelop in a similar
manner as today on the ocean zones for Thursday.

Outlook...

Thursday night...Lingering SCA conditions possible with
elevated seas around 5 feet.

Friday through Monday...Generally sub-SCA conditions. Isolated
to scattered showers and thunderstorms Friday and Saturday
afternoons and evenings, then showers and thunderstorms become
likely SUnday and Monday.

Rip Currents...

There is a HIGH risk for the development of
dangerous rip currents for the shore areas in Cape May and
Atlantic Counties in NJ today with a Rip Current Risk Statement
remaining in effect until 8 PM this evening.

For Thursday, winds will be out of the south-southwest at 15-20
mph with gusts upwards of 25-30 mph. Seas also build to 4-5
feet. There is a southeast swell with a period of around 8
seconds. For these reasons we're forecasting a MODERATE risk for
the development of dangerous rip currents for our NJ shore
zones and a LOW risk for the Delaware beaches.

For Friday, winds will be out of the southwest at 10-15 mph.
Seas are around 2-3 feet. There is a southeast swell with a
period of around 8 seconds. For these reasons we're forecasting
a LOW risk for the development of dangerous rip currents for
our NJ shore zones and the Delaware beaches.

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

&&

.CLIMATE...
Record breaking heat is forecast from Wednesday through
Saturday. Temperature records for our climate sites are listed
below:

All Time Record High Temperatures

Site                  Record / Date
Allentown (ABE)          105 / July 3, 1966
AC Airport (ACY)         106 / June 28, 1969
AC Marina (55N)          104 / August 7, 1918
Georgetown (GED)         104 / July 22 & 23, 2011
Mount Pocono (MPO)       103 / July 3, 1911
Philadelphia (PHL)       106 / August 7, 1918
Reading (RDG)            106 / July 22, 2011
Trenton (TTN)            106 / July 9, 1936 & July 22, 2011
Wilmington (ILG)         107 / August 7, 1918

All Time Record Warmest Low Temperatures

Site                  Record / Date
Allentown (ABE)           79 / July 15, 1995
AC Airport (ACY)          84 / July 23, 2011
AC Marina (55N)           82 / July 21, 2019
Georgetown (GED)          84 / July 23, 2011
Mount Pocono (MPO)        76 / July 12, 1952
Philadelphia (PHL)        83 / July 24, 2010 & July 23, 2011
Reading (RDG)             81 / August 7, 1918
Trenton (TTN)             84 / August 11, 1895
Wilmington (ILG)          84 / August 7, 1918

Record Number of Consecutive 100+ Degree Days

Site                  Record / Date
Allentown (ABE)       3 days / July 9-11, 1936 & July 2-4, 1966
AC Airport (ACY)      3 days / July 2-4, 1966 & July 22-24, 2011
AC Marina (55N)        1 day / Occurred multiple times
Georgetown (GED)      2 days / Most recent June 24-25, 2025
Mount Pocono (MPO)     1 day / July 3, 1911
Philadelphia (PHL)    3 days / July 2-4, 1966 & July 8-10, 1993
Reading (RDG)         3 days / Most recent July 21-23, 2011
Trenton (TTN)         3 days / Most recent July 21-23, 2011
Wilmington (ILG)      3 days / Most recent July 9-11, 1936

Record High Temperatures
                          July 1
Site                  Record / Year
Allentown (ABE)           98 / 2018
AC Airport (ACY)          99 / 1968
AC Marina (55N)           98 / 1968
Georgetown (GED)          99 / 2012
Mount Pocono (MPO)        88 / 1963, 1964, 1968, & 2018
Philadelphia (PHL)       102 / 1901
Reading (RDG)            101 / 1901
Trenton (TTN)             98 / 1898, 1901, & 1945
Wilmington (ILG)          97 / 1931 & 1963

Record Warmest Low Temperatures
                          July 1
Site                  Record / Year
Allentown (ABE)           74 / 1930
AC Airport (ACY)          77 / 1945
AC Marina (55N)           79 / 1945
Georgetown (GED)          76 / 1945
Mount Pocono (MPO)        67 / 1946, 1971, 2013, 2017, 2025
Philadelphia (PHL)        82 / 1901
Reading (RDG)             76 / 1968
Trenton (TTN)             77 / 1945
Wilmington (ILG)          75 / 2013

Record High Temperatures
                          July 2
Site                  Record / Year
Allentown (ABE)          102 / 1966
AC Airport (ACY)         100 / 1966
AC Marina (55N)           97 / 1968
Georgetown (GED)          99 / 1953
Mount Pocono (MPO)        93 / 1911
Philadelphia (PHL)       103 / 1901
Reading (RDG)            102 / 1966
Trenton (TTN)            100 / 1901
Wilmington (ILG)          98 / 1941 & 1966

Record Warmest Low Temperatures
                          July 2
Site                  Record / Year
Allentown (ABE)           75 / 2013
AC Airport (ACY)          79 / 2002
AC Marina (55N)           76 / 2012
Georgetown (GED)          77 / 1959
Mount Pocono (MPO)        70 / 1903
Philadelphia (PHL)        82 / 1901
Reading (RDG)             79 / 1901
Trenton (TTN)             79 / 1901
Wilmington (ILG)          75 / 1941 & 2014

Record High Temperatures
                          July 3
Site                  Record / Year
Allentown (ABE)          105 / 1966
AC Airport (ACY)         104 / 1966
AC Marina (55N)           99 / 1919
Georgetown (GED)         101 / 1954
Mount Pocono (MPO)       103 / 1911
Philadelphia (PHL)       104 / 1966
Reading (RDG)            103 / 1898 & 1966
Trenton (TTN)            102 / 1966
Wilmington (ILG)         102 / 1966

Record Warmest Low Temperatures
                          July 3
Site                  Record / Year
Allentown (ABE)           75 / 2018
AC Airport (ACY)          78 / 2018
AC Marina (55N)           76 / 1983, 2002, & 2018
Georgetown (GED)          79 / 1953
Mount Pocono (MPO)        69 / 2013
Philadelphia (PHL)        77 / 1876, 1901, &2002
Reading (RDG)             76 / 2018
Trenton (TTN)             76 / 1901 & 1966
Wilmington (ILG)          76 / 2002

Record High Temperatures
                          July 4
Site                  Record / Year
Allentown (ABE)          102 / 1949
AC Airport (ACY)         102 / 1966
AC Marina (55N)           99 / 1966
Georgetown (GED)         100 / 1966
Mount Pocono (MPO)        99 / 1911
Philadelphia (PHL)       103 / 1966
Reading (RDG)            100 / 1911 & 1966
Trenton (TTN)             99 / 1919, 1999, & 2010
Wilmington (ILG)         102 / 1966

Record Warmest Low Temperatures
                          July 4
Site                  Record / Year
Allentown (ABE)           75 / 1999
AC Airport (ACY)          75 / 1974, 1983, 1999, & 2002
AC Marina (55N)           79 / 2002
Georgetown (GED)          75 / 1999 & 2012
Mount Pocono (MPO)        70 / 2002 & 2013
Philadelphia (PHL)        79 / 1919
Reading (RDG)             78 / 1966
Trenton (TTN)             78 / 1966
Wilmington (ILG)          76 / 1999

Annual temperature extremes
For Trenton (TTN), this may be the first year with temperatures
both below zero and 100+ since 1988. The low so far this year
was -1 on 1/21.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Extreme Heat Warning until 8 PM EDT Saturday for PAZ054-055-
     060>062-070-071-101>106.
NJ...Extreme Heat Warning until 8 PM EDT Saturday for NJZ001-
     007>010-012>020-027.
     Extreme Heat Warning from noon Thursday to 8 PM EDT Saturday
     for NJZ021>023.
     High Risk for Rip Currents until 8 PM EDT this evening for NJZ024-
     025.
     Heat Advisory from noon Thursday to 8 PM EDT Saturday for
     NJZ024>026.
DE...Extreme Heat Warning until 8 PM EDT Saturday for DEZ001.
     Extreme Heat Warning from noon Thursday to 8 PM EDT Saturday
     for DEZ002>004.
MD...Extreme Heat Warning from noon Thursday to 8 PM EDT Saturday
     for MDZ012-015-019-020.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ450>455.

&&

DISCUSSION...MPS/RCM/Staarmann
AVIATION...MPS/RCM/Staarmann
MARINE...Guzzo/MPS/RCM/Staarmann

Hazardous Weather Outlook
National Weather Service Mount Holly NJ
506 AM EDT Wed Jul 1 2026

MDZ012-015-019-020-020915-
Kent MD-Queen Annes-Talbot-Caroline-
506 AM EDT Wed Jul 1 2026

...EXTREME HEAT WARNING IN EFFECT FROM NOON THURSDAY TO 8 PM EDT
SATURDAY...

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Today and tonight.

Heat indices of 100 to 104 degrees are forecast for today.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Extreme Heat Warning.

In addition to the extreme heat, severe thunderstorms are possible
Friday through Sunday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

Staarmann