Alert archive / New Jersey / Flash Flood Warnings in 2021
Flash Flood Warning 71, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 1, 2021, 5:42 PM EDT for 5 counties in New Jersey; Bucks County, Pennsylvania. It was in force for 10 hr. 37 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, 5:42 PM EDT (21:42 UTC)
- Expired
- Sep 2, 2021, 3:52 AM EDT
- In force
- 10 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Hunterdon County, NJ, Mercer County, NJ, Morris County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA
The radar
The Philadelphia radar (KDIX), 53 km from the middle of the area, began a volume at 21:41 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, 6:48 PM EDT | FLASH FLOOD | 1 E Bloomsbury, NJ | FLOODING FORCED THE CLOSURE OF STATE HIGHWAY 173 EAST OF U.S. HIGHWAY 22. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 6:55 PM EDT | FLASH FLOOD | 1 S Lambertville, NJ | FLOODING CLOSED STATE HIGHWAY 29 NEAR WEEDEN STREET. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 7:00 PM EDT | FLASH FLOOD | 3 Ne Ringoes, NJ | THE GAUGE ON THE NESHANIC RIVER AT REAVILLE (REAN4) REACHED FLOOD STAGE AT 700 PM ON 9/1. |
| Sep 1, 7:05 PM EDT | FLASH FLOOD | 3 Ese Bethlehem Twp, NJ | THE GAUGE ON MULHOCKAWAY CREEK AT CLINTON (CLNN4) REACHED FLOOD STAGE AT 705 PM 9/1, CRESTING AT 7.25 FEET AT 815 PM 9/1. |
| Sep 1, 7:10 PM EDT | FLASH FLOOD | 2 Ssw Richboro, PA | FLOODING CLOSED BRSTOL ROAD, OLD BRISTOL ROAD, CHINQUAPIN ROAD, AND GIBSON ROAD. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 7:15 PM EDT | FLASH FLOOD | 1 Sw Wrightstown Twp, PA | THE GAUGE ON NESHAMINY CREEK AT PENNS PARK (PEPP1) REACHED FLOOD STAGE AT 715 PM 9/1. |
| Sep 1, 7:15 PM EDT | FLASH FLOOD | 2 Ne Bloomsbury, NJ | THE GAUGE ON THE MUSCONETCONG RIVER AT BLOOMSBURY (BLBN4) REACHED FLOOD STAGE AT 715 PM 9/1, CRESTING AT 9.2 FEET (RECORD FLOODING) AT 945 PM 9/1. |
| Sep 1, 7:25 PM EDT | FLASH FLOOD | 1 Sse Glen Gardner, NJ | THE GAUGE ON SPRUCE RUN AT GLEN GARDNER (SRGN4) REACHED FLOOD STAGE AT 725 PM 9/1, CRESTING AT 7.99 FEET (MINOR FLOODING) AT 815 PM 9/1. |
| Sep 1, 7:30 PM EDT | FLASH FLOOD | 1 Sse Prospect Park, NJ | MULTIPLE WATER RESCUES ONGOING ACROSS MERCER COUNTY. |
| Sep 1, 7:42 PM EDT | FLASH FLOOD | 1 Nw Bensalem, PA | FLOODING CLOSED GALLOWAY ROAD NEAR I-276. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 7:56 PM EDT | FLASH FLOOD | 2 Nne Ewing, NJ | INTERSTATE 295 CLOSED FROM FLOODING BETWEEN EXITS 72 AND 73. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 8:00 PM EDT | FLASH FLOOD | 2 W Stanton, NJ | THE GAUGE ON THE SOUTH BRANCH RARITAN RIVER AT STANTON (STTN4) REACHED FLOOD STAGE AT 800 PM 9/1, CRESTING AT 15.16 FEET (MAJOR FLOODING) AT 1130 PM 9/1. |
| Sep 1, 8:23 PM EDT | HEAVY RAIN 6.78 | Readington Twp, NJ | |
| Sep 1, 8:30 PM EDT | FLASH FLOOD | 2 Sse Village Shires, PA | THE GAUGE ON NESHAMINY CREEK NEAR LANGHORNE (LNGP1) REACHED FLOOD STAGE AT 830 PM 9/1, CRESTING AT 20.84 FEET (MAJOR FLOODING) AT 630 AM 9/2. |
| Sep 1, 8:37 PM EDT | FLASH FLOOD | 1 Nw Trenton, NJ | FLOODING ON STATE ROUTE 29 NEAR CALHOUN STREET. ALL LANES CLOSED. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 8:40 PM EDT | HEAVY RAIN 7.05 | Ringoes, NJ | |
| Sep 1, 9:00 PM EDT | FLASH FLOOD | Flemington, NJ | PICTURE OF MULTIPLE VEHICLES SUBMERGED IN OVER A FOOT OF WATER. |
| Sep 1, 9:06 PM EDT | FLASH FLOOD | 3 E Tullytown, PA | THE TIDAL GAUGE ON THE DELAWARE RIVER AT NEWBOLD ISLAND (NBLP1) REACHED A RECORD LEVEL OF 13.22 FEET AT 1112 PM 9/2 FROM A COMBINATION OF TIDAL AND FRESHWATER FLOODING. TIME USED HEREIN IS BASED ON THE TIME THE GAUGE REACHED FLOOD STAGE DURING THE HIGH TIDE. |
| Sep 1, 9:15 PM EDT | FLASH FLOOD | 1 Ne High Bridge, NJ | THE GAUGE ON THE SOUTH BRANCH RARITAN RIVER AT HIGH BRIDGE (HBRN4) REACHED FLOOD STAGE AT 915 PM 9/1, CRESTING AT 10.97 FEET (MINOR FLOODING) AT 600 AM 9/2. |
| Sep 1, 9:45 PM EDT | FLASH FLOOD | 1 Ne Trenton, NJ | THE GAUGE ON ASSUNPINK CREEK AT TRENTON (TACN4) REACHED FLOOD STAGE AT 945 PM 9/1, CRESTING AT 12.59 FEET (MAJOR FLOODING) AT 300 AM 9/2. |
| Sep 1, 9:45 PM EDT | FLASH FLOOD | 1 Nnw Hamilton Twp, NJ | THE GAUGE ON ASSUNPINK CREEK NEAR MERCERVILLE (MERN4) REACHED FLOOD STAGE AT 945 PM 9/1, CRESTING AT 15.82 FEET (MAJOR FLOODING) AT 245 PM 9/2. |
| Sep 1, 9:45 PM EDT | FLASH FLOOD | Clinton, NJ | THE GAUGE ON SPRUCE RUN AT CLINTON (SRCN4) REACHED FLOOD STAGE AT 945 PM 9/1, CRESTING AT 5.35 FEET (RECORD FLOODING) AT 1215 AM 9/2. |
| Sep 1, 10:00 PM EDT | FLASH FLOOD | Washington Crossing, PA | THE GAUGE ON THE DELAWARE RIVER AT WASHINGTON CROSSING (WASN4) REACHED FLOOD STAGE AT 1000 PM 9/1, CRESTING AT 16.91 FEET (MINOR FLOODING) AT 1115 PM 9/1. |
| Sep 1, 10:26 PM EDT | HEAVY RAIN 6.42 | Whitehouse Station, NJ | |
| Sep 1, 10:30 PM EDT | FLASH FLOOD | 1 Nw Trenton, NJ | THE GAUGE ON THE DELAWARE RIVER AT TRENTON (TREN4) REACHED FLOOD STAGE AT 1030 PM 9/1, CRESTING AT 20.7 FEET (MINOR FLOODING) AT 1115 PM 9/1. |
| Sep 1, 11:00 PM EDT | FLASH FLOOD | 2 Sw Pennington, NJ | *** 2 FATAL *** DOZENS OF WATER RESCUES IN MERCER COUNTY DURING THE FLASH FLOODING SEPTEMBER 1-2, WITH TWO FATALITIES IN HOPEWELL TOWNSHIP. THREE POLICE OFFICERS WERE RESCUED AFTER BEING SWEPT AWAY BY FLOOD WATERS NEAR THE INTERSECTION OF ROUTES 518 AND 31. |
| Sep 1, 11:04 PM EDT | FLASH FLOOD | 2 Sse Trenton, NJ | FLASH FLOODING CLOSED STATE HIGHWAY 29 BETWEEN STATE HIGHWAY 129 AND SULLIVAN WAY. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 11:06 PM EDT | FLASH FLOOD | 1 Sse Raritan Twp, NJ | FLASH FLOODING OF THE NESHANIC RIVER FORCED THE CLOSURE OF U.S. HIGHWAY 202. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 11:24 PM EDT | FLASH FLOOD | 1 Ene Prospect Park, NJ | U.S. HIGHWAY 206 SOUTH OF PRINCETON PIKE CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 11:41 PM EDT | FLASH FLOOD | 1 Nne Richboro, PA | WORTHINGTON MILL ROAD CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 2, 12:00 AM EDT | FLASH FLOOD | Flemington, NJ | *** 6 FATAL *** OVER 300 WATER RESCUES WERE CONDUCTED IN HUNTERDON COUNTY DURING THE FLASH FLOODING SEPTEMBER 1-2 WITH SIX CONFIRMED FATALITIES AS OF SEPTEMBER 4. |
| Sep 2, 12:13 AM EDT | FLASH FLOOD | 1 Ne Bristol, PA | GREEN LANE CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 2, 12:45 AM EDT | FLASH FLOOD | 2 Ssw Wrightstown Twp, PA | STATE HIGHWAY 232 CLOSED OVER NESHAMINY CREEK FROM FLASH FLOODING. TIME BASED ON DISPATCH REPORT. |
| Sep 2, 1:19 AM EDT | FLASH FLOOD | 3 Ne Lambertville, NJ | FLOODING ON U.S. HIGHWAY 202 SOUTH OF QUEEN ROAD. TIME BASED ON DISPATCH REPORT. |
| Sep 2, 1:37 AM EDT | FLASH FLOOD | 1 N Village Shires, PA | FLASH FLOODING OF NESHAMINY CREEK FORCED THE CLOSURE OF STATE HIGHWAY 332. TIME BASED ON DISPATCH REPORT. |
| Sep 2, 2:39 AM EDT | FLASH FLOOD | 2 N Ringoes, NJ | FLASH FLOODING CLOSED U.S. HIGHWAY 202 SOUTH OF HAMPTON CORNER ROAD. TIME BASED ON DISPATCH REPORT. |
| Sep 2, 3:27 AM EDT | FLASH FLOOD | 2 Ese Lawrence Twp, NJ | FLOODING ON U.S. HIGHWAY 1 BETWEEN FRANKLIN CORNER ROAD AND QUAKER BRIDGE ROAD. ALL LANES CLOSED. 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
Brookhaven, NY (KOKX), launched 12:00Z, 9.7 hours before the alert went out and 179 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
- -80 J/kg
- Mixed-layer LCL
- 1274 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 31 m²/s²
- 0-3 km storm-relative helicity
- 201 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
123
WGUS51 KPHI 012142
FFWPHI
NJC019-021-027-035-041-PAC017-020345-
/O.NEW.KPHI.FF.W.0071.210901T2142Z-210902T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
542 PM EDT Wed Sep 1 2021
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Western Mercer County in central New Jersey...
Southwestern Morris County in northern New Jersey...
Western Somerset County in northern New Jersey...
Hunterdon County in northwestern New Jersey...
Southwestern Warren County in northwestern New Jersey...
Eastern Bucks County in southeastern Pennsylvania...
* Until 1145 PM EDT Wednesday.
* At 542 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1.5 inches of
rain have fallen. The expected rainfall rate is 1 to 2 inches in 1
hour. Additional rainfall amounts of 1 to 3 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...
Trenton, Ewing, Burlington, Bristol, Byram, Washington,
Flemington, High Bridge, Clinton, Pennington, New Hope, and
Yardley.
This includes the following highways...
Pennsylvania Turnpike between mile markers 352 and 359.
Interstate 95 in Pennsylvania between mile markers 38 and 40.
Interstate 78 in New Jersey between mile markers 6 and 27.
Interstate 295 in New Jersey between mile markers 59 and 62...and
between mile markers 68 and 76.
Interstate 195 in New Jersey between mile markers 0 and 1.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4078 7512 4078 7489 4073 7472 4018 7470
4018 7471 4017 7471 4017 7470 4016 7471
4012 7478 4013 7482 4010 7484 4009 7486
4008 7486 4008 7488 4019 7506
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR
$$
CMS3 follow-up statements
774
WGUS71 KPHI 012215
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
615 PM EDT Wed Sep 1 2021
NJC019-021-027-035-041-PAC017-020345-
/O.CON.KPHI.FF.W.0071.000000T0000Z-210902T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Morris NJ-Somerset NJ-Warren NJ-Bucks PA-
615 PM EDT Wed Sep 1 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1145 PM EDT THIS
EVENING FOR WESTERN MERCER, SOUTHWESTERN MORRIS, WESTERN SOMERSET,
HUNTERDON, SOUTHWESTERN WARREN, AND EASTERN BUCKS COUNTIES...
At 615 PM EDT, local law enforcement reported thunderstorms
producing heavy rain across the warned area. Between 1 and 3 inches
of rain have fallen. The expected rainfall rate is 1 to 2 inches in
1 hour. Additional rainfall amounts of 1 to 3 inches are possible in
the warned area. Flash flooding is already occurring.
HAZARD...Life threatening flash flooding caused by thunderstorms.
SOURCE...Law enforcement reported.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets, and underpasses.
Some locations that may experience flash flooding include...
Trenton, Ewing, Burlington, Bristol, Byram, Washington,
Flemington, High Bridge, Clinton, Pennington, New Hope, and
Yardley.
This includes the following highways...
Pennsylvania Turnpike between mile markers 352 and 359.
Interstate 95 in Pennsylvania between mile markers 38 and 40.
Interstate 78 in New Jersey between mile markers 6 and 27.
Interstate 295 in New Jersey between mile markers 59 and 62...and
between mile markers 68 and 76.
Interstate 195 in New Jersey between mile markers 0 and 1.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4078 7512 4078 7489 4073 7472 4018 7470
4018 7471 4017 7471 4017 7470 4016 7471
4012 7478 4013 7482 4010 7484 4009 7486
4008 7486 4008 7488 4019 7506
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR
$$
CMS764
WGUS51 KPHI 020323
FFWPHI
NJC019-021-027-035-041-PAC017-020800-
/O.EXT.KPHI.FF.W.0071.000000T0000Z-210902T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1123 PM EDT Wed Sep 1 2021
The National Weather Service in Mount Holly has extended the
* Flash Flood Warning for...
Western Mercer County in central New Jersey...
Southwestern Morris County in northern New Jersey...
Western Somerset County in northern New Jersey...
Hunterdon County in northwestern New Jersey...
Southwestern Warren County in northwestern New Jersey...
Eastern Bucks County in southeastern Pennsylvania...
* Until 400 AM EDT.
* At 1123 PM EDT, local law enforcement reported widespread flash
flooding across the warned area. Numerous roads are closed, water
rescues are still ongoing, and many river and stream gauges are in
flood. Flash flooding will likely continue for the next few hours.
Between 4 and 8 inches of rain have fallen.
HAZARD...Life threatening flash flooding caused by heavy rain.
SOURCE...Law enforcement reported.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets, and underpasses.
* Some locations that may experience flash flooding include...
Trenton, Ewing, Burlington, Bristol, Byram, Washington,
Flemington, High Bridge, Clinton, Pennington, New Hope, and
Yardley.
This includes the following highways...
Pennsylvania Turnpike between mile markers 352 and 359.
Interstate 95 in Pennsylvania between mile markers 38 and 40.
Interstate 78 in New Jersey between mile markers 6 and 27.
Interstate 295 in New Jersey between mile markers 59 and 62...and
between mile markers 68 and 76.
Interstate 195 in New Jersey between mile markers 0 and 1.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4078 7512 4078 7489 4073 7472 4018 7470
4018 7471 4017 7471 4017 7470 4016 7471
4012 7478 4013 7482 4010 7484 4009 7486
4008 7486 4008 7488 4019 7506
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
CMS127
WGUS71 KPHI 020752
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
352 AM EDT Thu Sep 2 2021
NJC019-021-027-035-041-PAC017-020802-
/O.CAN.KPHI.FF.W.0071.000000T0000Z-210902T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Morris NJ-Somerset NJ-Warren NJ-Bucks PA-
352 AM EDT Thu Sep 2 2021
...FLASH FLOOD WARNING FOR WESTERN MERCER, SOUTHWESTERN MORRIS,
WESTERN SOMERSET, HUNTERDON, SOUTHWESTERN WARREN, AND EASTERN BUCKS
COUNTIES HAS BEEN REPLACED WITH A FLOOD WARNING...
Please heed road closures.
LAT...LON 4078 7512 4078 7489 4073 7472 4018 7470
4018 7471 4017 7471 4017 7470 4016 7471
4012 7478 4013 7482 4010 7484 4009 7486
4008 7486 4008 7488 4019 7506
$$
CMSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 3:23 AM EDT | Gale Warning | PHI | 32 hr | |
| Sep 1, 3:23 AM EDT | Small Craft Advisory | PHI | 41 hr | |
| Sep 1, 4:34 AM EDT | Rip Current Statement | PHI | Atlantic, Cape May, Monmouth, Ocean | 39 hr |
| Sep 1, 7:58 AM EDT | Severe Thunderstorm Warning | PHI | Burlington, Ocean | 47 min |
| Sep 1, 8:39 AM EDT | Severe Thunderstorm Warning | PHI | Monmouth, Ocean | 39 min |
| Sep 1, 9:11 AM EDT | Special Marine Warning | PHI | 64 min | |
| Sep 1, 11:24 AM EDT | Areal Flood Advisory | PHI | Sussex, Warren | 3 hr |
| Sep 1, 4:04 PM EDT | Areal Flood Warning | PHI | Warren | 24 hr |
| Sep 1, 4:12 PM EDT | Flash Flood Warning | PHI | Hunterdon, Warren | 7 hr |
| Sep 1, 4:27 PM EDT | River Flood Warning | PHI | Morris, Somerset | 6 days |
| Sep 1, 4:27 PM EDT | River Flood Warning | PHI | Essex, Morris, Passaic | 8 days |
| Sep 1, 4:27 PM EDT | River Flood Warning | PHI | Essex, Morris, Passaic | 6 days |
| Sep 1, 4:27 PM EDT | River Flood Warning | PHI | Essex, Passaic | 21 days |
| Sep 1, 4:33 PM EDT | River Flood Warning | PHI | Morris, Passaic | 46 hr |
| Sep 1, 4:40 PM EDT | River Flood Warning | PHI | Hunterdon, Somerset | 36 hr |
| Sep 1, 4:40 PM EDT | River Flood Warning | PHI | Somerset | 22 hr |
| Sep 1, 4:40 PM EDT | River Flood Warning | PHI | Middlesex, Somerset | 42 hr |
| Sep 1, 4:40 PM EDT | River Flood Warning | PHI | Middlesex, Somerset | 48 hr |
| Sep 1, 4:41 PM EDT | River Flood Warning | PHI | Somerset | 61 hr |
| Sep 1, 5:13 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer | 47 min |
| Sep 1, 5:26 PM EDT | Flash Flood Warning | PHI | Burlington, Camden, Gloucester, Salem | 9 hr |
| Sep 1, 5:33 PM EDT | Special Marine Warning | PHI | 27 min | |
| Sep 1, 5:34 PM EDT | Tornado Warning | PHI | Mercer | 26 min |
| Sep 1, 5:35 PM EDT | Tornado Warning | PHI | Cumberland, Salem | 25 min |
| Sep 1, 5:57 PM EDT | Tornado Warning | PHI | Gloucester, Salem | 33 min |
| Sep 1, 5:57 PM EDT | Tornado Warning | PHI | Hunterdon, Mercer, Somerset | 33 min |
| Sep 1, 6:05 PM EDT | Flash Flood Warning | PHI | Hunterdon, Mercer, Middlesex, Morris, Somerset | 10 hr |
| Sep 1, 6:08 PM EDT | Flash Flood Warning | PHI | Hunterdon, Morris, Somerset, Sussex, Warren | 6 hr |
| Sep 1, 6:14 PM EDT | Special Marine Warning | PHI | 61 min | |
| Sep 1, 6:20 PM EDT | Tornado Warning | PHI | Hunterdon, Mercer, Somerset | 40 min |
| Sep 1, 6:22 PM EDT | Tornado Warning | PHI | Burlington, Camden, Gloucester | 23 min |
| Sep 1, 6:42 PM EDT | Tornado Warning | PHI | Burlington, Camden | 33 min |
| Sep 1, 6:59 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset | 61 min |
| Sep 1, 7:04 PM EDT | Tornado Warning | PHI | Burlington, Mercer | 26 min |
| Sep 1, 7:22 PM EDT | Tornado Warning | PHI | Hunterdon, Mercer | 11 min |
| Sep 1, 7:28 PM EDT | Tornado Warning | PHI | Mercer, Middlesex, Morris, Somerset | 47 min |
| Sep 1, 7:31 PM EDT | Flash Flood Warning | PHI | Hunterdon, Mercer, Somerset | 4 hr |
| Sep 1, 7:44 PM EDT | Special Marine Warning | PHI | 61 min | |
| 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, 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, 4:10 PM EDT | River Flood Warning | PHI | Monroe | 19 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, 4:42 PM EDT | Flash Flood Warning | PHI | Chester, Delaware, Montgomery | 6 hr |
| Sep 1, 5:07 PM EDT | River Flood Warning | PHI | Chester | 17 hr |
| Sep 1, 5:15 PM EDT | Tornado Warning | PHI | Delaware, Montgomery, Philadelphia | 30 min |
| Sep 1, 6:38 PM EDT | River Flood Warning | PHI | Chester, Delaware | 26 hr |
| Sep 1, 7:05 PM EDT | Flash Flood Warning | PHI | Bucks | 8 hr |
| Sep 1, 7:23 PM EDT | Areal Flood Warning | PHI | Berks, Lehigh | 14 hr |
| Sep 1, 7:53 PM EDT | River Flood Warning | PHI | Delaware | 13 hr |
Nearby
Flash Flood Warnings in New Jersey, 2021Flash 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.