Alert archive / Pennsylvania / Flash Flood Warnings in 2021
Flash Flood Warning 69, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 1, 2021, 4:42 PM EDT for Chester County, Delaware County, Montgomery County, Pennsylvania. It was in force for 6 hr. 35 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
- Sep 1, 2021, 4:42 PM EDT (20:42 UTC)
- Expired
- Sep 1, 2021, 10:15 PM EDT
- In force
- 6 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Emergency
- Flash flood emergency
- Damage threat
- Considerable
- Flood severity
- None
Counties Chester County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 99 km from the middle of the area, began a volume at 20:43 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 |
|---|---|---|---|
| Sep 1, 5:15 PM EDT | FLASH FLOOD | 1 Nne Marshallton, PA | THE GAUGE ON EAST BRANCH BRANDYWINE CREEK BELOW DOWNINGTOWN (DWNP1) REACHED FLOOD STAGE AT 515 PM 9/1, CRESTING AT AT 19.11 FEET (RECORD FLOODING) AT 1115 PM 9/1. |
| Sep 1, 5:15 PM EDT | FLASH FLOOD | 1 Ssw Schwenksville, PA | TOWNSHIP LINE ROAD AND MAIN STREET CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 5:15 PM EDT | FLASH FLOOD | Chesterbrook, PA | THE GAUGE ON VALLEY CREEK AT VALLEY FORGE REACHED FLOOD STAGE AT 515 PM 9/1, CRESTING AT 16.44 FEET (MAJOR FLOOD) AT 630 PM 9/1. |
| Sep 1, 5:16 PM EDT | FLASH FLOOD | Valley Forge, PA | VALLEY FORGE GAUGE AT VALLEY CREEK EXCEEDED FLOOD STAGE. |
| Sep 1, 5:30 PM EDT | FLASH FLOOD | 1 S Devault, PA | MULTIPLE CARS STUCK IN OVER ONE FOOT OF WATER AT THE INTERSECTION OF PA 29 AND GREAT VALLEY PARKWAY. TIME ESTIMATED. |
| Sep 1, 5:30 PM EDT | FLASH FLOOD | 2 Sw Pennsburg, PA | THE GAUGE ON WEST BRANCH PERKIOMEN CREEK AT HILLEGASS (HLGP1) REACHED FLOOD STAGE AT 530 PM 9/1, CRESTING AT 6.42 FEET (MODERATE FLOODING) AT 1015 PM 9/1. |
| Sep 1, 5:30 PM EDT | FLASH FLOOD | 3 Ese Lower Pottsgrove, PA | NEIFFER ROAD AND GAME FARM ROAD CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 5:34 PM EDT | FLASH FLOOD | 2 Sw Upper Hanover Twp, PA | KUTZTOWN ROAD CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 5:34 PM EDT | FLASH FLOOD | 2 W King Of Prussia, PA | GULPH ROAD CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 5:34 PM EDT | FLASH FLOOD | 3 Wnw Uwchlan Twp, PA | ROUTE 100 CLOSED NEAR I-76 FROM FLASH FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 5:40 PM EDT | FLASH FLOOD | East Whiteland Twp, PA | U.S. HIGHWAY 202 CLOSED NEAR ROUTE 401 FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 5:45 PM EDT | FLASH FLOOD | 1 S Upper Hanover Twp, PA | THE GAUGE ON PERKIOMEN CREEK AT EAST GREENVILLE (EGRP1) REACHED FLOOD STAGE AT 545 PM 9/1. CRESTING AT 9.24 FEET (MAJOR FLOODING) AT 915 PM 9/1. |
| Sep 1, 5:45 PM EDT | FLASH FLOOD | Lower Providence Townsh, PA | MANY WATER RESCUES ONGOING AROUND MONTGOMERY COUNTY. |
| Sep 1, 5:49 PM EDT | FLASH FLOOD | 1 Nw Malvern, PA | ROUTE 29 CLOSED BETWEEN U.S. HIGHWAY 30 AND INTERSTATE 76. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 5:57 PM EDT | FLASH FLOOD | Skippack Twp, PA | STATE HIGHWAY 73 CLOSED NEAR ROUTE 113 FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 5:59 PM EDT | FLASH FLOOD | 2 Sse Montgomeryville, PA | ROUTE 309 CLOSED IN VICINITY OF STUMP ROAD FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 6:00 PM EDT | FLASH FLOOD | 2 Ene Schwenksville, PA | THE GAUGE ON EAST BRANCH PERKIOMEN CREEK AT SCHWENKSVILLE (SWVP1) REACHED FLOOD STAGE AT 600 PM 9/1, CRESTING AT 16.07 FEET (RECORD FLOODING) AT 1215 AM 9/2. |
| Sep 1, 6:07 PM EDT | FLASH FLOOD | 1 Ssw King Of Prussia, PA | CLOSURES ON INTERSTATE 76 FROM FLOODING. TIME BASED ON DISPATCH REPORTS. |
| Sep 1, 6:15 PM EDT | FLASH FLOOD | Graterford, PA | THE GAUGE AT PERKIOMEN CREEK AT GRATERFORD (GRAP1) REACHED FLOOD STAGE AT 615 PM. |
| Sep 1, 6:25 PM EDT | FLASH FLOOD | 1 Nne Graterford, PA | FLOODING CLOSED SKIPPACK PIKE NEAR CROSS ROAD. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 6:32 PM EDT | FLASH FLOOD | Collegeville, PA | FLOODING CLOSED STATE ROUTE 29 NEAR THE MAIN STREET INTERSECTION. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 6:32 PM EDT | FLASH FLOOD | South Pottstown, PA | FLASH FLOODING CLOSED PORTIONS OF U.S. HIGHWAY 422 NEAR STATE ROUTE 100 IN SOUTH POTTSTOWN. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 6:38 PM EDT | FLASH FLOOD | Bridgeport, PA | FLOODING ON STATE ROUTE 23 IN THE BRIDGEPORT AND SWEDESBURG AREAS. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 6:45 PM EDT | FLASH FLOOD | Bridgeport, PA | THE GAUGE ON THE SCHUYLKILL RIVER AT NORRISTOWN (NRSP1) REACHED FLOOD STAGE AT 645 PM 9/1, CRESTING AT 26.85 FEET (RECORD FLOODING) AT 615 AM 9/2. |
| Sep 1, 7:09 PM EDT | FLASH FLOOD | 2 Nne West Vincent Twp, PA | FLOODING CLOSED PUGHTOWN ROAD, COLD STREAM ROAD, AND DAISY POINT ROAD. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 7:14 PM EDT | HEAVY RAIN 5.13 | 1 Ese East Vincent Twp, PA | |
| Sep 1, 7:43 PM EDT | FLASH FLOOD | 1 S Perkiomenville, PA | STATE HIGHWAY 29 CLOSED SOUTH OF PERKIOMENVILLE. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 7:50 PM EDT | FLASH FLOOD | Green Lane, PA | STATE HIGHWAY 63 EAST OF PERKIOMENVILLE CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 7:59 PM EDT | FLASH FLOOD | 2 Wnw Upper Hanover Twp, PA | ADAMS ROAD AND PALM HILL ROAD CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 8:02 PM EDT | FLASH FLOOD | 1 E Spring Mount, PA | FLOODING CLOSED SPRING MOUNT ROAD AND LEDERACH ROAD NEAR SCHWENKSVILLE ROAD. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 8:03 PM EDT | FLASH FLOOD | 1 Nw Cedarville, PA | FLOODING CLOSED ROUTE 724 WEST OF POTTSTOWN LANDING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 8:30 PM EDT | FLASH FLOOD | South Pottstown, PA | THE GAUGE ON THE SCHUYLKILL RIVER AT POTTSTOWN (PTNP1) REACHED FLOOD STAGE AT 830 PM 9/1, CRESTING AT 16.79 FEET (MODERATE FLOODING) AT 445 PM 9/2. |
| Sep 1, 9:00 PM EDT | FLASH FLOOD | Skippack Twp, PA | *** 1 FATAL *** FLASH FLOODING SWEPT AWAY A CAR AND KILLED AN OCCUPANT IN SKIPPACK TWP. |
| Sep 1, 10:00 PM EDT | FLASH FLOOD | Bridgeport, PA | *** 1 FATAL *** A MAN WAS FOUND DEAD IN HIS RESIDENCE IN BRIDGEPORT FROM FLASH FLOODING. |
| Sep 1, 10:01 PM EDT | FLASH FLOOD | 1 Ne Skippack, PA | FLASH FLOODING OF WEST BRANCH SKIPPACK CREEK FORCED THE CLOSURE OF OLD FORTY FOOT ROAD. TIME BASED ON DISPATCH REPORT. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 8.7 hours before the alert went out and 207 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
- 558 J/kg
- Mixed-layer CIN
- -21 J/kg
- Mixed-layer LCL
- 575 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 122 m²/s²
- 0-3 km storm-relative helicity
- 223 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 2.6
The text
As transmitted.
921
WGUS51 KPHI 012042
FFWPHI
PAC029-045-091-020045-
/O.NEW.KPHI.FF.W.0069.210901T2042Z-210902T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
442 PM EDT Wed Sep 1 2021
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Northeastern Chester County in southeastern Pennsylvania...
Northwestern Delaware County in southeastern Pennsylvania...
Montgomery County in southeastern Pennsylvania...
* Until 845 PM EDT.
* At 442 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1.5 and 2.5 inches of
rain have fallen. Additional rainfall amounts of 1.5 to 3 inches
are possible in the warned area. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Life threatening flash flooding caused by
thunderstorms.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets, and underpasses.
* Some locations that may experience flash flooding include...
West Chester, Norristown, Pottstown, Phoenixville, Lansdale, West
Norriton, East Norriton, Westtown, Downingtown, Souderton, Ambler,
and Collegeville.
This includes the following highways...
Pennsylvania Turnpike between mile markers 307 and 333.
Interstate 76 in Pennsylvania between mile markers 327 and 330.
Interstate 476 in Pennsylvania near mile marker 18.
Northeast Extension between mile markers 21 and 38.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4030 7565 4040 7557 4044 7554 4044 7553
4022 7516 4003 7537 3994 7550 3993 7553
3992 7554 3992 7555 3994 7567 4001 7581
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
NC3 follow-up statements
556
WGUS71 KPHI 012203
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
603 PM EDT Wed Sep 1 2021
PAC029-045-091-020045-
/O.CON.KPHI.FF.W.0069.000000T0000Z-210902T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-Montgomery PA-
603 PM EDT Wed Sep 1 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM EDT THIS
EVENING FOR NORTHEASTERN CHESTER, NORTHWESTERN DELAWARE, AND
MONTGOMERY COUNTIES...
At 603 PM EDT, emergency management reported thunderstorms producing
heavy rain and flooding across the warned area. Between 2.5 and 4
inches of rain have fallen. Additional rainfall amounts of 1 to 3
inches are possible in the warned area. Flash flooding is already
occurring with numerous streams and creeks in flood stage including
Valley Forge, French Creek, and the East Bank of the Brandywine
Creek.
HAZARD...Life threatening flash flooding caused by thunderstorms.
SOURCE...Emergency management reported.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets, and underpasses.
Some locations that may experience flash flooding include...
West Chester, Norristown, Pottstown, Phoenixville, Lansdale, West
Norriton, East Norriton, Westtown, Downingtown, Souderton, Ambler,
and Collegeville.
This includes the following highways...
Pennsylvania Turnpike between mile markers 307 and 333.
Interstate 76 in Pennsylvania between mile markers 327 and 330.
Interstate 476 in Pennsylvania between mile markers 17 and 19.
Northeast Extension between mile markers 21 and 38.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4030 7565 4040 7557 4044 7554 4044 7553
4022 7516 4003 7537 3994 7550 3993 7553
3992 7554 3992 7555 3994 7567 4001 7581
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
NC144
WGUS71 KPHI 012221
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
621 PM EDT Wed Sep 1 2021
PAC029-045-091-020045-
/O.CON.KPHI.FF.W.0069.000000T0000Z-210902T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-Montgomery PA-
621 PM EDT Wed Sep 1 2021
...FLASH FLOOD EMERGENCY FOR MONTGOMERY COUNTY...
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM EDT THIS
EVENING FOR NORTHEASTERN CHESTER, NORTHWESTERN DELAWARE, AND
MONTGOMERY COUNTIES...
At 621 PM EDT, Thunderstorms are producing heavy rain in Northern
Chester County and Southern Montgomery County. Between 3 and 4.5
inches of rain have fallen. Additional rainfall amounts of 1.5 to 3
inches are possible in the warned area. Flash flooding is already
occurring. Over 30 water rescues are ongoing in portions of
Montgomery County.
This is a FLASH FLOOD EMERGENCY for Montgomery County. This is a
PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW!
HAZARD...Life threatening flash flooding caused by thunderstorms.
SOURCE...Emergency management reported.
IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER
GROUND NOW! Life threatening flash flooding of low water
crossings, small creeks and streams, urban areas,
highways, streets, and underpasses.
Some locations that may experience flash flooding include...
West Chester, Norristown, Pottstown, Phoenixville, Lansdale, West
Norriton, East Norriton, Westtown, Downingtown, Souderton, Ambler,
and Collegeville.
This includes the following highways...
Pennsylvania Turnpike between mile markers 307 and 333.
Interstate 76 in Pennsylvania between mile markers 327 and 330.
Interstate 476 in Pennsylvania between mile markers 17 and 19.
Northeast Extension between mile markers 21 and 38.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to higher ground now! This is an extremely dangerous and
life-threatening situation. Do not attempt to travel unless you are
fleeing an area subject to flooding or under an evacuation order.
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Motorists should not attempt to drive around barricades or drive
cars through flooded areas.
&&
LAT...LON 4030 7565 4040 7557 4044 7554 4044 7553
4022 7516 4003 7537 3994 7550 3993 7553
3992 7554 3992 7555 3994 7567 4001 7581
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC
$$
NC899
WGUS51 KPHI 020020
FFWPHI
PAC029-045-091-020215-
/O.EXT.KPHI.FF.W.0069.000000T0000Z-210902T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
820 PM EDT Wed Sep 1 2021
...FLASH FLOOD EMERGENCY FOR NORTHERN CHESTER AND MONTGOMERY
COUNTY...
The National Weather Service in Mount Holly has extended the
* Flash Flood Warning for...
Northeastern Chester County in southeastern Pennsylvania...
Northwestern Delaware County in southeastern Pennsylvania...
Montgomery County in southeastern Pennsylvania...
* Until 1015 PM EDT.
* At 820 PM EDT, emergency management reported thunderstorms
producing heavy rain in Northern Chester County and Southern
Montgomery County. Between 4.5 and 7 inches of rain have fallen.
Additional rainfall amounts of 1.5 to 3 inches are possible in the
warned area. Flash flooding is already occurring and dozens of
water rescues have been observed over the last several hours..
This is a FLASH FLOOD EMERGENCY for Northern Chester and
Montgomery County. This is a PARTICULARLY DANGEROUS SITUATION.
SEEK HIGHER GROUND NOW!
HAZARD...Life threatening flash flooding caused by
thunderstorms.
SOURCE...Emergency management reported.
IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK
HIGHER GROUND NOW! Life threatening flash flooding of
low water crossings, small creeks and streams, urban
areas, highways, streets, and underpasses.
* Some locations that may experience flash flooding include...
West Chester, Norristown, Pottstown, Phoenixville, Lansdale, West
Norriton, East Norriton, Westtown, Downingtown, Souderton, Ambler,
and Collegeville.
This includes the following highways...
Pennsylvania Turnpike between mile markers 307 and 333.
Interstate 76 in Pennsylvania between mile markers 327 and 330.
Interstate 476 in Pennsylvania between mile markers 17 and 19.
Northeast Extension between mile markers 21 and 38.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to higher ground now! This is an extremely dangerous and
life-threatening situation. Do not attempt to travel unless you are
fleeing an area subject to flooding or under an evacuation order.
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Motorists should not attempt to drive around barricades or drive
cars through flooded areas.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4030 7565 4040 7557 4044 7554 4044 7553
4022 7516 4003 7537 3994 7550 3993 7553
3992 7554 3992 7555 3994 7567 4001 7581
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC
$$
NCThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 6:19 AM EDT | Areal Flood Advisory | PHI | Chester, Delaware | 116 min |
| Sep 1, 6:49 AM EDT | Flash Flood Warning | PHI | Chester, Delaware, Philadelphia | 86 min |
| Sep 1, 11:24 AM EDT | Areal Flood Advisory | PHI | Berks, Carbon, Lehigh, Monroe, Northampton | 3 hr |
| Sep 1, 12:07 PM EDT | Flash Flood Warning | PHI | Carbon, Monroe | 4 hr |
| Sep 1, 1:29 PM EDT | Flash Flood Warning | PHI | Berks, Lehigh | 6 hr |
| Sep 1, 2:53 PM EDT | Flash Flood Warning | PHI | Berks, Chester, Delaware, Montgomery | 9 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Montgomery | 36 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Chester, Montgomery, Philadelphia | 43 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Montgomery, Philadelphia | 41 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Philadelphia | 39 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Berks | 24 hr |
| Sep 1, 4:02 PM EDT | River Flood Warning | PHI | Monroe | 24 hr |
| Sep 1, 4:04 PM EDT | Areal Flood Warning | PHI | Carbon, Monroe, Northampton | 24 hr |
| Sep 1, 4:10 PM EDT | River Flood Warning | PHI | Monroe | 19 hr |
| Sep 1, 4:12 PM EDT | Flash Flood Warning | PHI | Berks, Bucks, Lehigh, Montgomery, Northampton | 7 hr |
| Sep 1, 4:12 PM EDT | River Flood Warning | PHI | Lehigh, Northampton | 25 hr |
| Sep 1, 4:12 PM EDT | River Flood Warning | PHI | Lehigh, Northampton | 24 hr |
| Sep 1, 4:12 PM EDT | River Flood Warning | PHI | Carbon | 15 hr |
| Sep 1, 4:13 PM EDT | Tornado Warning | PHI | Chester | 32 min |
| Sep 1, 4:20 PM EDT | River Flood Warning | PHI | Montgomery | 22 hr |
| Sep 1, 4:21 PM EDT | River Flood Warning | PHI | Bucks | 29 hr |
| Sep 1, 5:07 PM EDT | River Flood Warning | PHI | Chester | 17 hr |
| Sep 1, 5:13 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 47 min |
| Sep 1, 5:15 PM EDT | Tornado Warning | PHI | Delaware, Montgomery, Philadelphia | 30 min |
| Sep 1, 5:26 PM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 9 hr |
| Sep 1, 5:34 PM EDT | Tornado Warning | PHI | Bucks, Montgomery, Philadelphia | 26 min |
| Sep 1, 5:42 PM EDT | Flash Flood Warning | PHI | Bucks | 10 hr |
| Sep 1, 5:57 PM EDT | Tornado Warning | PHI | Bucks | 33 min |
| Sep 1, 6:08 PM EDT | Flash Flood Warning | PHI | Monroe, Northampton | 6 hr |
| Sep 1, 6:20 PM EDT | Tornado Warning | PHI | Bucks | 40 min |
| Sep 1, 6:22 PM EDT | Tornado Warning | PHI | Philadelphia | 23 min |
| Sep 1, 6:38 PM EDT | River Flood Warning | PHI | Chester, Delaware | 26 hr |
| Sep 1, 6:42 PM EDT | Tornado Warning | PHI | Bucks, Philadelphia | 33 min |
| Sep 1, 6:59 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 61 min |
| Sep 1, 7:04 PM EDT | Tornado Warning | PHI | Bucks | 26 min |
| Sep 1, 7:05 PM EDT | Flash Flood Warning | PHI | Bucks | 8 hr |
| Sep 1, 7:22 PM EDT | Tornado Warning | PHI | Bucks | 11 min |
| Sep 1, 7:23 PM EDT | Areal Flood Warning | PHI | Berks, Lehigh | 14 hr |
| Sep 1, 7:31 PM EDT | Flash Flood Warning | PHI | Bucks | 4 hr |
| Sep 1, 7:53 PM EDT | River Flood Warning | PHI | Delaware | 13 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.