Alert archive / Pennsylvania / Flash Flood Warnings in 2026
Flash Flood Warning 42, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 11, 2026, 2:46 PM EDT for 4 counties in Pennsylvania. It was in force for 4 hr. 8 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 11, 2026, 2:46 PM EDT (18:46 UTC)
- Expired
- Jul 11, 2026, 6:45 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 18:48 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 11, 2:54 PM EDT | FLASH FLOOD | 1 Sw Ardmore, PA | Report of a water rescue near East County Line Road and Biddle Street. Flood water coming into the vehicle. |
| Jul 11, 3:00 PM EDT | FLASH FLOOD | 1 E Bryn Mawr, PA | Water rescue reported at Old Gulph Road and Morris Avenue. |
| Jul 11, 3:00 PM EDT | FLASH FLOOD | Wynnefield, PA | Photo shows at least 10 vehicles floating in or sitting in a foot or more of flood waters at 57th/58th and Lebanon Avenue. Time estimated. |
| Jul 11, 3:02 PM EDT | FLASH FLOOD | 1 Nne Ardmore, PA | Water rescue reported on Grays Lane near Mille Creek Road. |
| Jul 11, 3:03 PM EDT | FLASH FLOOD | 1 Sse Bala Cynwyd, PA | Water rescue reported at City Avenue and Old Lancaster Road. |
| Jul 11, 3:15 PM EDT | FLASH FLOOD | 1 S Penn Wynne, PA | The Cobbs Creek river gauge at Route 1 near the Norristown SEPTA line reach minor flood stage in less than 30 minutes. |
| Jul 11, 3:17 PM EDT | FLASH FLOOD | 1 N Mantua, PA | Report of flash flooding near Girard and Sedgley in Lemon Hill Park. Time estimated. |
| Jul 11, 3:19 PM EDT | FLASH FLOOD | 1 W Haverford, PA | Public report of flooding along the Norristown SEPTA line west of the Haverford station. Train service has stopped due to flooding on the tracks. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Brookhaven, NY (KOKX), launched 12:00Z, 6.8 hours before the alert went out and 220 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.
- Mixed-layer CAPE
- 98 J/kg
- Mixed-layer CIN
- -95 J/kg
- Mixed-layer LCL
- 1078 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 7 m²/s²
- 0-3 km storm-relative helicity
- 78 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.3
The text
As transmitted.
680
WGUS51 KPHI 111846
FFWPHI
PAC029-045-091-101-112245-
/O.NEW.KPHI.FF.W.0042.260711T1846Z-260711T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
246 PM EDT Sat Jul 11 2026
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
East Central Chester County in southeastern Pennsylvania...
Northeastern Delaware County in southeastern Pennsylvania...
Southeastern Montgomery County in southeastern Pennsylvania...
Philadelphia County in southeastern Pennsylvania...
* Until 645 PM EDT.
* At 246 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1 inch of rain
has fallen. The expected rainfall rate is 1.5 to 3 inches in 1
hour. Additional rainfall amounts of 0.5 to 1.5 inches are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
* Some locations that may experience flash flooding include...
Philadelphia, Camden, Norristown, Phoenixville, West Norriton,
East Norriton, Yeadon, Conshohocken, Folcroft, Narberth, National
Park and East Lansdowne.
People attending Lemon Hill should seek shelter immediately.
This includes the following highways...
Interstate 476 in Pennsylvania between mile markers 5 and 19.
Interstate 76 in Pennsylvania between mile markers 327 and 351.
Interstate 95 in Pennsylvania between mile markers 11 and 29.
Interstate 676 in Pennsylvania between mile markers 0 and 1.
Northeast Extension between mile markers 21 and 24.
Pennsylvania Turnpike between mile markers 321 and 337.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4018 7532 4002 7502 4001 7505 3998 7507
3997 7511 3996 7513 3993 7514 3991 7513
3988 7515 3988 7519 3986 7523 3989 7531
4011 7556
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR
$$
Kruzdlo3 follow-up statements
785
WGUS71 KPHI 111931
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
331 PM EDT Sat Jul 11 2026
PAC029-045-091-101-112245-
/O.CON.KPHI.FF.W.0042.000000T0000Z-260711T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-Montgomery PA-Philadelphia PA-
331 PM EDT Sat Jul 11 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM EDT THIS
EVENING FOR EAST CENTRAL CHESTER, NORTHEASTERN DELAWARE,
SOUTHEASTERN MONTGOMERY AND PHILADELPHIA COUNTIES...
At 331 PM EDT, emergency management reported flash flooding
occurring in Lower Merion. Between 1.0 and 2.0 inches of rain have
fallen, and it fell in about 30 minutes. Although the heaviest
rainfall has moved east, flooding continues. There are reports of
water assists and rescues. Do not drive through flooded roadways.
Additional thunderstorms are possible this afternoon.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that may experience flash flooding include...
Philadelphia, Camden, Norristown, Phoenixville, West Norriton,
East Norriton, Yeadon, Conshohocken, Folcroft, Narberth, National
Park and East Lansdowne.
People attending Lemon Hill should seek shelter immediately.
This includes the following highways...
Interstate 476 in Pennsylvania between mile markers 5 and 19.
Interstate 76 in Pennsylvania between mile markers 327 and 351.
Interstate 95 in Pennsylvania between mile markers 11 and 29.
Interstate 676 in Pennsylvania between mile markers 0 and 1.
Northeast Extension between mile markers 21 and 24.
Pennsylvania Turnpike between mile markers 321 and 337.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4018 7532 4002 7502 4001 7505 3998 7507
3997 7511 3996 7513 3993 7514 3991 7513
3988 7515 3988 7519 3986 7523 3989 7531
4011 7556
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR
$$
Kruzdlo835
WGUS71 KPHI 112115
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
515 PM EDT Sat Jul 11 2026
PAC029-045-112125-
/O.CAN.KPHI.FF.W.0042.000000T0000Z-260711T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-
515 PM EDT Sat Jul 11 2026
...FLASH FLOOD WARNING IS CANCELLED FOR EAST CENTRAL CHESTER AND
NORTHEASTERN DELAWARE COUNTIES...
Thunderstorms have moved out of the area. Flooding is no longer
expected to pose a threat. The flash flood warning has been
cancelled.
&&
LAT...LON 4002 7502 4001 7505 3998 7507 3996 7513
3993 7514 3991 7513 3988 7515 3987 7521
3988 7526 3994 7524 3996 7525 3997 7528
4007 7537 4006 7539 4010 7542 4009 7546
4011 7547 4012 7546 4013 7550 4018 7532
$$
PAC091-101-112245-
/O.CON.KPHI.FF.W.0042.000000T0000Z-260711T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-Philadelphia PA-
515 PM EDT Sat Jul 11 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM EDT THIS
EVENING FOR SOUTHEASTERN MONTGOMERY AND PHILADELPHIA COUNTIES...
At 515 PM EDT, Doppler radar indicated that the heavy rainfall has
moved east. Although the heavy rain has ended, it will take some
additional time for all the water to drain. Earlier this afternoon,
there were reports of water assists and rescues in Lower Merion. If
you are on the road the next hour or two and encounter flooding, do
not drive through the high water.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4002 7502 4001 7505 3998 7507 3996 7513
3993 7514 3991 7513 3988 7515 3987 7521
3988 7526 3994 7524 3996 7525 3997 7528
4007 7537 4006 7539 4010 7542 4009 7546
4011 7547 4012 7546 4013 7550 4018 7532
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR
$$
Kruzdlo238
WGUS71 KPHI 112235
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
635 PM EDT Sat Jul 11 2026
PAC091-101-112245-
/O.EXP.KPHI.FF.W.0042.000000T0000Z-260711T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-Philadelphia PA-
635 PM EDT Sat Jul 11 2026
...FLASH FLOOD WARNING WILL EXPIRE AT 645 PM EDT THIS EVENING FOR
SOUTHEASTERN MONTGOMERY AND PHILADELPHIA COUNTIES...
Flood waters have receded. The heavy rain has ended. Flooding is no
longer expected to pose a threat.
&&
LAT...LON 4002 7502 4001 7505 3998 7507 3996 7513
3993 7514 3991 7513 3988 7515 3987 7521
3988 7526 3994 7524 3996 7525 3997 7528
4007 7537 4006 7539 4010 7542 4009 7546
4011 7547 4012 7546 4013 7550 4018 7532
$$
KruzdloThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 2:44 PM EDT | Severe Thunderstorm Warning | PHI | Delaware, Montgomery, Philadelphia | 46 min |
| Jul 11, 4:02 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 43 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2026Every flash 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.