Alert archive / Pennsylvania / Areal Flood Warnings in 2026

Areal Flood Warning 4, NWS Philadelphia/Mount Holly

June 15, 2026Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at Jun 15, 2026, 1:37 AM EDT for Delaware County, Pennsylvania. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 15, 2026, 1:37 AM EDT (05:37 UTC)
Expired
Jun 15, 2026, 5:45 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Delaware County, PA

The radar

The Philadelphia radar (KDIX), 85 km from the middle of the area, began a volume at 05:38 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 5.6 hours before the alert went out and 201 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2026-06-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 916 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2026-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
916 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
1620 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
225 m²/s²
Significant tornado parameter
0.2
Supercell composite
6.4

Open this sounding in Storm Lab

The text

As transmitted.

350 
WGUS41 KPHI 150537
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
137 AM EDT Mon Jun 15 2026

PAC045-150945-
/O.NEW.KPHI.FA.W.0004.260615T0537Z-260615T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Delaware PA-
137 AM EDT Mon Jun 15 2026

...FLOOD WARNING IN EFFECT UNTIL 545 AM EDT EARLY THIS MORNING...

* WHAT...Small stream flooding caused by excessive rainfall is 
  expected.

* WHERE...A portion of southeast Pennsylvania, including the 
  following county, Delaware.

* WHEN...Until 545 AM EDT.

* IMPACTS...Flooding of rivers, creeks, streams, and other low-lying 
  and flood-prone locations is imminent or occurring. Streams 
  continue to rise due to excess runoff from earlier rainfall. 
  Expect many areas of slow moving or standing water.

* ADDITIONAL DETAILS...
  - At 137 AM EDT, emergency management reported flooding in the
    warned area due to thunderstorms. Spring Run has flooded with
    Ridley Creek, Chester Creek, and Darby Creek all rising or in
    flood. Flooding is already occurring. Between 1.5 and 3
    inches of rain have fallen.
  - Flooding impacts will continue, but no additional rainfall is
    expected.
  - Some locations that may experience flooding include...
    Chester, Yeadon, Folcroft, Swarthmore, Nether Providence
    Township, Lima, Broomall, Chester Township, Newtown Square,
    Gradyville, Drexel Hill and Chelsea.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3992 7553 3995 7551 3999 7543 4000 7533
      3992 7525 3988 7527 3985 7530 3986 7536
      3984 7541 3984 7545 3991 7552


$$

Hoeflich
1 follow-up statement
420 
WGUS81 KPHI 150938
FLSPHI

Flood Statement
National Weather Service Mount Holly NJ
538 AM EDT Mon Jun 15 2026

PAC045-150948-
/O.EXP.KPHI.FA.W.0004.000000T0000Z-260615T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Delaware PA-
538 AM EDT Mon Jun 15 2026

...FLOOD WARNING WILL EXPIRE AT 545 AM EDT EARLY THIS MORNING...

The Flood Warning will expire at 545 AM EDT early this morning for 
Central Delaware County.

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

&&

LAT...LON 3992 7553 3995 7551 3999 7543 4000 7533
      3992 7525 3988 7527 3985 7530 3986 7536
      3984 7541 3984 7545 3991 7552


$$

Fitzsimmons

What forecasters said that day

The local office's own words before this areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this areal flood warning went out at Jun 14, 11:23 PM EDT, 2 hours 14 minutes earlier. Its key messages:

  • 1. Strong to severe thunderstorms with heavy rainfall and areas of flash flooding are ongoing late this evening across parts of the area but will move out overnight. 2. Widespread minor coastal flooding continues with the evening high tide cycles tonight along the Atlantic coast and Delaware Bay. A Coastal Flood Advisory remains in effect for tonight's high tide. 3. Some severe thunderstorms possible Thursday afternoon and evening.
Area forecast discussion, Jun 14, 11:23 PM EDT, 2 hours 14 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
1123 PM EDT Sun Jun 14 2026

.WHAT HAS CHANGED...
Removed our northwest zones from the Severe Thunderstorm Watch
(Berks, Lehigh, Northampton, Carbon, and Monroe Counties) as the
threat has ended for these areas.

The Small Craft Advisory has been extended until 3 AM.

&&

.KEY MESSAGES...
1. Strong to severe thunderstorms with heavy rainfall and areas
of flash flooding are ongoing late this evening across parts of
the area but will move out overnight.

2. Widespread minor coastal flooding continues with the evening
high tide cycles tonight along the Atlantic coast and Delaware
Bay. A Coastal Flood Advisory remains in effect for tonight's
high tide.

3. Some severe thunderstorms possible Thursday afternoon and evening.

&&

.DISCUSSION...
KEY MESSAGE 1...1. Strong to severe thunderstorms with heavy rainfall and areas
of flash flooding are ongoing late this evening across parts of
the area but will move out overnight.

Severe thunderstorm Watch Continues for portions of the area
until 1 AM.

11 PM Update...Very heavy thunderstorms bringing excessive
rainfall and flash flooding are ongoing late this evening across
the urban corridor. Locally damaging winds are still possible
but at this time this is evolving into more or a hydro/flash
flood situation. We've removed our NW zones from the Severe Thunderstorm Watch
(Berks, Lehigh, Northampton, Carbon, and Monroe Counties) as the
threat has ended for these areas. Main threat area will be the
urban corridor and points S/E.

The cold front and associated convection should be largely out
of the area by 2-4 AM Monday though the severe threat should be
largely over by 1 AM.

KEY MESSAGE 2...Widespread minor coastal flooding continues with
the evening high tide cycles tonight along the Atlantic coast and
Delaware Bay. A Coastal Flood Advisory remains in effect for tonight's
high tide.

A New Moon is occurring this weekend and resulting in higher than
normal astronomical tides. Further rounds of tidal flooding are
expected with the evening/nighttime high tide cycles tonight and
potentially Monday for the Atlantic Coast and Delaware Bay.

The tidal Delaware River and its tributaries could experience some
spotty minor tidal flooding (non-advisory) with tonight's high tide
but generally these astronomical tide driven flooding events produce
more noteworthy impacts for the Atlantic coasts and Delaware Bay.
The highest of the New Moon tides will be tonight and Monday night.
A Coastal Flood Advisory remains in effect for this evening (Jersey
Shore/Delaware Beaches/Delaware Bay Communities/Middlesex County for
the Raritan Bay).

Tidal flooding is not currently expected along the eastern shore of
Chesapeake Bay.

KEY MESSAGE 3...Some severe thunderstorms possible Thursday afternoon
and evening.

An upper-level trough centered over south-central Canada is forecast
to strengthen eastward and also southward across the Great Lakes to
end the week. A strong shortwave rounding the base of this trough
may result in a portion of it taking on a negative tilt across the
eastern Great Lakes and toward New England late Wednesday and Thursday.
This feature is a bit stronger in the ECMWF solution, while the
GFS ensembles are mostly a little weaker. A deepening surface low
will accompany it and track across the eastern Great Lakes and into
adjacent Canada during Thursday. A strong cold front will then arrive
into our area Thursday afternoon or Thursday evening.

As the synoptic pattern evolves, the flow will increase out of the
south and southwest. This will advect deeper moisture northward, and
in tandem with strengthening warm air advection will lead to
increased instability during the day Thursday. In addition, a strong
mid to upper level jet is forecast to extend eastward from the
eastern Great Lakes. While the core of the 500 mb jet (80-100 knots)
is forecast to remain mainly northwest of our area, 40-70 knots of
flow at 500 mb is still forecast across our area Thursday afternoon
into the evening. This increased flow will result in greater shear
magnitudes. While there remains some timing differences among the
guidance regarding the main features, the consensus is that enough
instability should overlap with the stronger shear along with
incoming stronger forcing. As a result, there continues to be some
severe thunderstorm potential Thursday afternoon and evening. As of
now, locally damaging winds are the primary threat especially if
convection develops into a squall line. However if shear and
instability ends up being even greater, than all severe thunderstorm
hazards may come into play especially if the mode is discrete for a
time. The details remain much less certain at this time range given
the typical uncertainty with instability and the thermodynamic
profiles. The forecast synoptic setup however with a deepening
surface low tracking to our northwest with strong flow within a
warmer and more moist environment suggests some risk for severe
thunderstorms. In addition, the main trough may end up arriving on
Friday with some additional chances for showers and some
thunderstorms.

The I-95 corridor and the coastal plain (away from the immediate
coast) looks to be the hottest during Thursday ahead of the
convection, with the heat indices potentially getting very close to
100 degrees.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...Prevailing VFR to start the night. Showers and thunderstorms
are likely to move into the area around 01-04Z for western areas,
and 03-06Z for eastern areas. Expect brief periods of MVR/IFR conditions
with storms with a lingering period of some showers and MVFR conditions
in wake of the storms. Improvement expected by 06-09Z. Southerly
winds around 5-10 kt tonight, becoming northwesterly around 10-15
kt in wake of the front. Winds associated with evening convection
could briefly gust to 40+ knots. Moderate confidence as a whole.

Monday...VFR with a few/scattered clouds in the afternoon. Northwest
winds around 10-15 kt, occasionally gusting up to 20 kt. High confidence.

Outlook...

Monday night...VFR. Northwest winds quickly diminish and becoming
light and variable.

Tuesday...Mainly VFR.

Wednesday...Some sub-VFR conditions with a few showers or a
thunderstorm possible.

Thursday...A period of sub-VFR conditions probable in the afternoon
and evening as showers and some thunderstorms increase.

Friday...Some showers and thunderstorms may linger with areas of sub-
VFR conditions possible at times.

&&

.MARINE...
The Small Craft Advisory for portion of our Atlantic coastal
waters and the Delaware Bay has been extended until 3 AM.

Winds will diminish overnight as winds turn northwesterly
behind a cold front. Northwest winds will generally remain
around 15-20 kt through Monday morning, however a few rogue
gusts up to 22-23 kt are possible before further diminishing
throughout the day. Seas generally around 2-4 feet, locally 5
feet tonight, and around 2-3 feet on Monday.

Showers and thunderstorms are likely through tonight, which may
cause localized higher winds/seas. Some marine fog possible tonight
as well. On Monday, fair weather expected.

Outlook...

Monday night through Wednesday...The conditions are anticipated to
be below Small Craft Advisory criteria.

Thursday...A period of Small Craft Advisory conditions probable.
Southerly wind gusts could near gale force for a time later Thursday.
Some gusty thunderstorms late in the afternoon and evening possible.

Friday...The conditions are anticipated to be below Small Craft
Advisory criteria.

Rip Currents...

For Monday, winds become northwest 10-20 mph with a continued
medium southerly swell of 6-7 seconds. With breaking waves 2
feet or less, have gone with a LOW risk for the development of
dangerous rip currents at all beaches.

For Tuesday, winds start northerly before shifting southeasterly,
but only at around 5 mph with a continued medium southerly
swell of 6-7 seconds. With breaking waves 2 feet or less, have
gone with a LOW risk for the development of dangerous rip
currents at all beaches.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory until 1 AM EDT Monday for NJZ012>014-
     020>027.
DE...Coastal Flood Advisory until 1 AM EDT Monday for DEZ002>004.
MD...None.
MARINE...Small Craft Advisory until 3 AM EDT Monday for ANZ430-431-
     450>454.

&&

DISCUSSION...DeSilva/Fitzsimmons/Gorse/Hoeflich
AVIATION...DeSilva/Gorse
MARINE...Fitzsimmons/Gorse
Hazardous weather outlook, Jun 14, 3:47 AM EDT, 21 hours 50 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
347 AM EDT Sun Jun 14 2026

MDZ012-015-019-020-150915-
Kent MD-Queen Annes-Talbot-Caroline-
347 AM EDT Sun Jun 14 2026

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Today and tonight.

There is a SLIGHT Risk (level 2 out of 5) of severe thunderstorms
late this afternoon into this evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

There is a low probability for widespread hazardous weather.

.SPOTTER INFORMATION STATEMENT...

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

In the hours before

Local storm report, Jun 15, 12:34 AM EDT, 1 hour 3 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
1234 AM EDT Mon Jun 15 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1027 PM     Tstm Wnd Dmg     1 ENE Wayne             40.05N 75.36W
06/14/2026                   Delaware           PA   911 Call Center

            Trees down around Radnor Township. Time
            estimated from radar.

&&

Hoeflich
Local storm report, Jun 15, 12:41 AM EDT, 56 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
1241 AM EDT Mon Jun 15 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1236 AM     Flash Flood      1 SSW Summerdale        40.02N 75.10W
06/15/2026                   Philadelphia       PA   Other Federal

            Frankford Creek went into flood stage.

&&

Hoeflich
Local storm report, Jun 15, 12:50 AM EDT, 47 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
1250 AM EDT Mon Jun 15 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1117 PM     Tstm Wnd Dmg     2 S Mercerville         40.21N 74.68W
06/14/2026                   Mercer             NJ   Public

            Trees and wires down around Hamilton
            Township. Time estimated from radar.

&&

Hoeflich
Local storm report, Jun 15, 12:59 AM EDT, 38 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
1259 AM EDT Mon Jun 15 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1113 PM     Tstm Wnd Dmg     Gloucester City         39.89N 75.12W
06/14/2026                   Camden             NJ   911 Call Center

            Wires down in Gloucester City. Time
            estimated from radar.

&&

Hoeflich
Local storm report, Jun 15, 1:04 AM EDT, 33 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
104 AM EDT Mon Jun 15 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1125 PM     Tstm Wnd Dmg     1 NE Princeton          40.35N 74.65W
06/14/2026                   Mercer             NJ   Dept of Highways

            Downed Trees on NJ 27 Northbound North of US
            206 (Princeton Twp), All lanes closed. Time
            estimated from radar.

&&

Hoeflich
Local storm report, Jun 15, 1:26 AM EDT, 11 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
126 AM EDT Mon Jun 15 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0100 AM     Flash Flood      1 NNE Middletown Twp.   39.92N 75.42W
06/15/2026                   Delaware           PA   Emergency Mngr

            Spring Run has flooded near Rose Tree Road
            with Ridley Creek rising. Time given in
            report.

&&

Hoeflich

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 14, 8:16 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe44 min
Jun 14, 9:06 PM EDTSevere Thunderstorm WarningPHIChester54 min
Jun 14, 9:50 PM EDTFlash Flood WarningPHIChester3 hr
Jun 14, 9:54 PM EDTSevere Thunderstorm WarningPHIChester, Delaware51 min
Jun 14, 10:15 PM EDTFlash Flood WarningPHIChester, Delaware3 hr
Jun 14, 10:21 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Montgomery, Philadelphia39 min
Jun 14, 10:26 PM EDTFlash Flood WarningPHIChester, Delaware, Montgomery, Philadelphia3 hr
Jun 14, 10:38 PM EDTFlash Flood WarningPHIDelaware3 hr
Jun 14, 10:44 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia46 min
Jun 14, 10:51 PM EDTFlash Flood WarningPHIBucks, Philadelphia3 hr
Jun 14, 10:58 PM EDTSevere Thunderstorm WarningPHIBucks47 min
Jun 14, 11:16 PM EDTSevere Thunderstorm WarningPHIPhiladelphia29 min
Jun 15, 2:12 AM EDTRiver Flood WarningPHIDelaware2 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2026Every areal flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.