Alert archive / Pennsylvania / Flash Flood Warnings in 2021
Flash Flood Warning 12, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 2, 2021, 4:54 PM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 5 hr. 4 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 2, 2021, 4:54 PM EDT (20:54 UTC)
- Expired
- Jul 2, 2021, 10:00 PM EDT
- In force
- 5 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 57 km from the middle of the area, began a volume at 20:57 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 2, 6:00 PM EDT | FLASH FLOOD | 1 Ese Tioga, PA | FLOODING REPORTED ON BROAD ST NEAR RISING SUN AVE. DISPATCHERS REPORTED SEVERAL FLOODING RELATED CALLS IN THIS SECTION OF PHILADELPHIA. |
| Jul 2, 6:00 PM EDT | FLASH FLOOD | 1 Sw Philadelphia, PA | FLOODING REPORTED ON ALLEGHENY AVE. |
| Jul 2, 6:00 PM EDT | FLASH FLOOD | Philadelphia, PA | FLOODING ON 9TH ST AT ERIE AVE. |
| Jul 2, 8:24 PM EDT | FLOOD | Tacony, PA | AN MPING REPORT OF ROADWAY FLOODING. |
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, 8.9 hours before the alert went out and 208 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
- 51 J/kg
- Mixed-layer CIN
- -35 J/kg
- Mixed-layer LCL
- 836 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 11 m²/s²
- 0-3 km storm-relative helicity
- 28 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.1
The text
As transmitted.
686
WGUS51 KPHI 022054
FFWPHI
PAC091-101-030100-
/O.NEW.KPHI.FF.W.0012.210702T2054Z-210703T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
454 PM EDT Fri Jul 2 2021
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Southeastern Montgomery County in southeastern Pennsylvania...
Central Philadelphia County in southeastern Pennsylvania...
* Until 900 PM EDT.
* At 454 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1 inch of rain
has fallen. Additional rainfall amounts of 0.5 to 1 inch 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 will experience flash flooding include...
Philadelphia, Rockledge, Bryn Athyn, Wissinoming, Tacony,
Holmesburg, Kensington, Center City, Northeast Philadelphia and
Roxborough.
This includes the following highways...
Interstate 95 in Pennsylvania between mile markers 22 and 33.
Interstate 76 in Pennsylvania between mile markers 340 and 344.
Interstate 676 in Pennsylvania near mile marker 0.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Motorists should not attempt to drive around barricades or drive
cars through flooded areas.
&&
LAT...LON 4015 7506 4008 7496 4008 7497 4006 7498
4005 7497 4002 7501 4001 7505 3998 7507
3997 7511 3996 7513 3997 7527 4001 7520
FLASH FLOOD...RADAR INDICATED
$$
Iovino4 follow-up statements
296
WGUS71 KPHI 022246
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
646 PM EDT Fri Jul 2 2021
PAC091-101-030100-
/O.CON.KPHI.FF.W.0012.000000T0000Z-210703T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-Philadelphia PA-
646 PM EDT Fri Jul 2 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 PM EDT THIS EVENING
FOR SOUTHEASTERN MONTGOMERY AND CENTRAL PHILADELPHIA COUNTIES...
At 646 PM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
1.5 and 2 inches of rain have fallen. Additional rainfall amounts up
to 0.5 inches are possible in the warned area. Rainfall rates have
decreased over the warning area, but runoff from earlier rainfall
will continue. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that will experience flash flooding include...
Philadelphia, Palmyra, Rockledge, Bryn Athyn, Wissinoming, Tacony,
Holmesburg, Kensington, Center City, Northeast Philadelphia,
Roxborough, and Pennsauken.
This includes the following highways...
Interstate 95 in Pennsylvania between mile markers 23 and 33.
Interstate 76 in Pennsylvania between mile markers 340 and 343.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4015 7506 4008 7496 4008 7497 4006 7498
4005 7497 4002 7501 4001 7505 3998 7507
3997 7511 3996 7513 3997 7527 4001 7520
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$
JEO830
WGUS71 KPHI 030044
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
844 PM EDT Fri Jul 2 2021
PAC091-030054-
/O.CAN.KPHI.FF.W.0012.000000T0000Z-210703T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-
844 PM EDT Fri Jul 2 2021
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN MONTGOMERY
COUNTY...
Flooding is no longer expected to pose a threat. Please continue to
heed remaining road closures.
LAT...LON 4007 7502 4008 7498 4007 7498 4006 7498
4005 7497 4002 7501 4001 7505 3999 7507
3998 7507 3998 7509 3998 7511 3999 7514
$$
PAC101-030100-
/O.CON.KPHI.FF.W.0012.000000T0000Z-210703T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Philadelphia PA-
844 PM EDT Fri Jul 2 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 PM EDT THIS EVENING
FOR EAST CENTRAL PHILADELPHIA COUNTY...
At 844 PM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between 2
and 2.5 inches of rain have fallen. Flash flooding is ongoing.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that will experience flash flooding include...
Philadelphia, Palmyra, Tacony, Wissinoming, Holmesburg,
Pennsauken, and Riverton.
This includes the following highways...
Interstate 95 in Pennsylvania between mile markers 25 and 33.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4007 7502 4008 7498 4007 7498 4006 7498
4005 7497 4002 7501 4001 7505 3999 7507
3998 7507 3998 7509 3998 7511 3999 7514
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$
JEO550
WGUS51 KPHI 030046
FFWPHI
PAC101-030200-
/O.EXT.KPHI.FF.W.0012.000000T0000Z-210703T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
846 PM EDT Fri Jul 2 2021
The National Weather Service in Mount Holly has extended the
* Flash Flood Warning for...
East Central Philadelphia County in southeastern Pennsylvania...
* Until 1000 PM EDT.
* At 846 PM EDT, local law enforcement reported thunderstorms
producing heavy rain across the warned area. Between 2 and 2.5
inches of rain have fallen. Little to no additional rainfall is
expected, but thunderstorms are just now exiting the warned area
so continued flooding is likely. Flash flooding is already
occurring.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Law enforcement reported.
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 will experience flash flooding include...
Philadelphia, Palmyra, Tacony, Wissinoming, Holmesburg,
Pennsauken, and Riverton.
This includes the following highways...
Interstate 95 in Pennsylvania between mile markers 25 and 33.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4007 7502 4008 7498 4007 7498 4006 7498
4005 7497 4002 7501 4001 7505 3999 7507
3998 7507 3998 7509 3998 7511 3999 7514
FLASH FLOOD...OBSERVED
$$
JEO068
WGUS71 KPHI 030151
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
951 PM EDT Fri Jul 2 2021
PAC101-030201-
/O.EXP.KPHI.FF.W.0012.000000T0000Z-210703T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Philadelphia PA-
951 PM EDT Fri Jul 2 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 10 PM EDT THIS EVENING FOR
EAST CENTRAL PHILADELPHIA COUNTY...
Flood waters have receded. The heavy rain has ended. Flooding is no
longer expected to pose a threat. Please continue to heed remaining
road closures.
LAT...LON 4007 7502 4008 7498 4007 7498 4006 7498
4005 7497 4002 7501 4001 7505 3999 7507
3998 7507 3998 7509 3998 7511 3999 7514
$$
JEOThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 2, 11:16 AM EDT | Areal Flood Advisory | PHI | Delaware, Philadelphia | 119 min |
| Jul 2, 5:29 PM EDT | Special Weather Statement | PHI | Carbon | 46 min |
| Jul 2, 5:44 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 46 min |
| Jul 2, 6:42 PM EDT | Special Weather Statement | PHI | Northampton | 48 min |
| Jul 2, 6:53 PM EDT | Severe Thunderstorm Warning | PHI | Monroe, Northampton | 52 min |
| Jul 2, 7:41 PM EDT | Flash Flood Warning | PHI | Philadelphia | 3 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2021Every flash flood warning in 2021
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.