Alert archive / New Jersey / Flash Flood Warnings in 2021
Flash Flood Warning 28, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 29, 2021, 6:56 PM EDT for 5 counties in New Jersey. It was in force for 4 hr. 12 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 29, 2021, 6:56 PM EDT (22:56 UTC)
- Expired
- Jul 29, 2021, 10:51 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Somerset County, NJ
The radar
The Philadelphia radar (KDIX), 35 km from the middle of the area, began a volume at 22:55 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 29, 7:20 PM EDT | FLASH FLOOD | 1 Ssw East Windsor Twp, NJ | VEHICLES TRAPPED IN FLOOD WATERS. |
| Jul 29, 7:20 PM EDT | FLASH FLOOD | East Windsor Twp, NJ | US ROUTE 130 NORTHBOUND CLOSED NEAR PRINCETON HIGHTSTOWN ROAD. |
| Jul 29, 7:20 PM EDT | FLASH FLOOD | Hightstown, NJ | NUMEROUS WATER RESCUES IN EAST WINDSOR TOWNSHIP AND HIGHTSTOWN. |
| Jul 29, 7:20 PM EDT | FLASH FLOOD | Hightstown, NJ | MAIN STREET CLOSED DUE TO FLOODING. |
| Jul 29, 7:20 PM EDT | FLASH FLOOD | Hightstown, NJ | SOCIAL MEDIA VIDEO AND REPORT OF FLOODING ON ROUTE 33. CARS DISABLED. |
| Jul 29, 7:45 PM EDT | FLASH FLOOD | 3 N Lawrenceville, NJ | SOCIAL MEDIA VIDEO OF CARTER ROAD FLOODED. |
| Jul 29, 8:00 PM EDT | FLASH FLOOD | 1 Wnw West Freehold, NJ | NJ ROUTE 33 IN FREEHOLD TOWNSHIP WAS CLOSED DUE TO FLOODING. |
| Jul 29, 8:08 PM EDT | FLASH FLOOD | 1 Wsw Concordia, NJ | SOCIAL MEDIA IMAGE OF HOMES AND CARS UNDERWATER ON TIMBER HILL DRIVE. |
| Jul 29, 8:08 PM EDT | FLASH FLOOD | Hightstown, NJ | SOCIAL MEDIA VIDEO OF ROADS FLOODED. WATER UP TO CAR TIRES. |
| Jul 29, 8:12 PM EDT | HEAVY RAIN 1.62 | 3 Ese Freehold Twp, NJ | 1.54 INCHES IN 32 MINUTES. |
| Jul 29, 8:17 PM EDT | HEAVY RAIN 4.42 | 2 Wsw East Windsor Twp, NJ | |
| Jul 29, 9:19 PM EDT | FLASH FLOOD | Cranbury, NJ | NORTH MAIN STREET COMPLETELY FLOODED BETWEEN RT-130 AND OLD CRANBURY RD. BECOMING IMPASSABLE. |
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, 10.9 hours before the alert went out and 166 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
- 54 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 823 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 65 m²/s²
- 0-3 km storm-relative helicity
- 127 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
026
WGUS51 KPHI 292256
FFWPHI
NJC021-023-025-029-035-300300-
/O.NEW.KPHI.FF.W.0028.210729T2256Z-210730T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
656 PM EDT Thu Jul 29 2021
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Mercer County in central New Jersey...
Southwestern Monmouth County in central New Jersey...
Southwestern Middlesex County in northern New Jersey...
South Central Somerset County in northern New Jersey...
Northwestern Ocean County in southern New Jersey...
* Until 1100 PM EDT.
* At 656 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 2 inches of rain
have fallen. Additional rainfall amounts of 1 to 2 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 will experience flash flooding include...
Trenton, Jackson, Manalapan, Ewing, Princeton, Jamesburg,
Hightstown, Cranbury, Allentown, Roosevelt, Rocky Hill, and Twin
Rivers.
This includes the following highways...
New Jersey Turnpike between exits 8 and 9.
Interstate 295 in New Jersey between mile markers 61 and 71.
Interstate 195 in New Jersey between mile markers 1 and 28.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
Flooding is occurring or is imminent. Most flood related deaths
occur in automobiles. Do not attempt to cross water covered bridges,
dips, or low water crossings. Never try to cross a flowing stream,
even a small one, on foot. To escape rising water find another route
over higher ground.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4023 7481 4043 7468 4027 7416 4003 7430
4017 7468 4018 7470 4018 7471 4020 7476
4022 7477
FLASH FLOOD...RADAR INDICATED
$$
MPS3 follow-up statements
588
WGUS71 KPHI 300036
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
836 PM EDT Thu Jul 29 2021
NJC021-023-025-029-035-300300-
/O.CON.KPHI.FF.W.0028.000000T0000Z-210730T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mercer NJ-Middlesex NJ-Monmouth NJ-Ocean NJ-Somerset NJ-
836 PM EDT Thu Jul 29 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM EDT THIS
EVENING FOR MERCER, SOUTHWESTERN MONMOUTH, SOUTHWESTERN MIDDLESEX,
SOUTH CENTRAL SOMERSET, AND NORTHWESTERN OCEAN COUNTIES...
At 836 PM EDT, Doppler radar indicated thunderstorms produced heavy
rain across the warned area. Additional rainfall amounts of 0.5
inches are possible in the warned area. Flash flooding is already
occurring.
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...
Trenton, Jackson, Manalapan, Ewing, Princeton, Jamesburg,
Hightstown, Cranbury, Allentown, Roosevelt, Rocky Hill, and Twin
Rivers.
This includes the following highways...
New Jersey Turnpike between exits 8 and 9.
Interstate 295 in New Jersey between mile markers 61 and 71.
Interstate 195 in New Jersey between mile markers 1 and 27.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
Flooding is occurring or is imminent. Most flood related deaths
occur in automobiles. Do not attempt to cross water covered bridges,
dips, or low water crossings. Never try to cross a flowing stream,
even a small one, on foot. To escape rising water find another route
over higher ground.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4023 7481 4043 7468 4027 7416 4003 7430
4017 7468 4018 7470 4018 7471 4020 7476
4022 7477
FLASH FLOOD...RADAR INDICATED
$$
MPS308
WGUS71 KPHI 300046
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
846 PM EDT Thu Jul 29 2021
NJC021-023-025-029-035-300300-
/O.CON.KPHI.FF.W.0028.000000T0000Z-210730T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mercer NJ-Middlesex NJ-Monmouth NJ-Ocean NJ-Somerset NJ-
846 PM EDT Thu Jul 29 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM EDT THIS
EVENING FOR MERCER, SOUTHWESTERN MONMOUTH, SOUTHWESTERN MIDDLESEX,
SOUTH CENTRAL SOMERSET, AND NORTHWESTERN OCEAN COUNTIES...
At 846 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Radar estimates of between 2 and 4
inches of rain have fallen. Additional rainfall amounts of 0.5 to 1
inch are possible in the warned area. Flash flooding is already
occurring.
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...
Trenton, Jackson, Manalapan, Ewing, Princeton, Jamesburg,
Hightstown, Cranbury, Allentown, Roosevelt, Rocky Hill, and Twin
Rivers.
This includes the following highways...
New Jersey Turnpike between exits 8 and 9.
Interstate 295 in New Jersey between mile markers 61 and 71.
Interstate 195 in New Jersey between mile markers 1 and 27.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4023 7481 4043 7468 4027 7416 4003 7430
4017 7468 4018 7470 4018 7471 4020 7476
4022 7477
FLASH FLOOD...RADAR INDICATED
$$
MPS355
WGUS71 KPHI 300251
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
1051 PM EDT Thu Jul 29 2021
NJC021-023-025-029-035-300301-
/O.CAN.KPHI.FF.W.0028.000000T0000Z-210730T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mercer NJ-Middlesex NJ-Monmouth NJ-Ocean NJ-Somerset NJ-
1051 PM EDT Thu Jul 29 2021
...FLASH FLOOD WARNING IS CANCELLED FOR MERCER, SOUTHWESTERN
MONMOUTH, SOUTHWESTERN MIDDLESEX, SOUTH CENTRAL SOMERSET, AND
NORTHWESTERN OCEAN COUNTIES...
Flood waters have receded. The heavy rain has ended. Flooding is no
longer expected to pose a threat. Please continue to heed remaining
road closures.
LAT...LON 4023 7481 4043 7468 4027 7416 4003 7430
4017 7468 4018 7470 4018 7471 4020 7476
4022 7477
$$
MPSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 29, 3:33 AM EDT | Small Craft Advisory | PHI | 20 hr | |
| Jul 29, 1:33 PM EDT | Special Marine Warning | PHI | 42 min | |
| Jul 29, 2:53 PM EDT | Special Marine Warning | PHI | 100 min | |
| Jul 29, 4:26 PM EDT | Special Weather Statement | PHI | Morris | 34 min |
| Jul 29, 4:30 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Warren | 45 min |
| Jul 29, 4:57 PM EDT | Areal Flood Advisory | PHI | Hunterdon, Morris, Sussex, Warren | 3 hr |
| Jul 29, 5:01 PM EDT | Special Weather Statement | PHI | Morris | 29 min |
| Jul 29, 5:03 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Morris, Somerset, Sussex, Warren | 42 min |
| Jul 29, 5:08 PM EDT | Tornado Warning | PHI | Hunterdon | 37 min |
| Jul 29, 5:27 PM EDT | Areal Flood Advisory | PHI | Hunterdon, Mercer, Morris, Somerset | 3 hr |
| Jul 29, 5:32 PM EDT | Flash Flood Warning | PHI | Warren | 2 hr |
| Jul 29, 5:32 PM EDT | Tornado Warning | PHI | Hunterdon | 28 min |
| Jul 29, 5:51 PM EDT | Tornado Warning | PHI | Hunterdon, Mercer | 24 min |
| Jul 29, 5:58 PM EDT | Flash Flood Warning | PHI | Hunterdon, Mercer, Somerset | 3 hr |
| Jul 29, 6:06 PM EDT | Tornado Warning | PHI | Burlington, Hunterdon, Mercer, Middlesex, Monmouth | 39 min |
| Jul 29, 6:44 PM EDT | Tornado Warning | PHI | Mercer, Monmouth, Ocean | 46 min |
| Jul 29, 6:45 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Mercer | 45 min |
| Jul 29, 7:07 PM EDT | Tornado Warning | PHI | Burlington | 23 min |
| Jul 29, 7:12 PM EDT | Flash Flood Warning | PHI | Burlington | 4 hr |
| Jul 29, 7:18 PM EDT | Tornado Warning | PHI | Mercer, Middlesex, Monmouth, Ocean | 27 min |
| Jul 29, 7:25 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Monmouth, Ocean | 50 min |
| Jul 29, 7:28 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Mercer, Middlesex, Monmouth, Ocean | 47 min |
| Jul 29, 7:52 PM EDT | Special Marine Warning | PHI | 113 min |
Nearby
Flash Flood Warnings in New Jersey, 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.