Alert archive / New Jersey / Flash Flood Warnings in 2021
Flash Flood Warning 27, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 29, 2021, 5:58 PM EDT for Hunterdon County, Mercer County, Somerset County, New Jersey; Bucks County, Pennsylvania. It was in force for 3 hr. 1 report 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, 5:58 PM EDT (21:58 UTC)
- Expired
- Jul 29, 2021, 9:25 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Hunterdon County, NJ, Mercer County, NJ, Somerset County, NJ, Bucks County, PA
The radar
The Philadelphia radar (KDIX), 66 km from the middle of the area, began a volume at 22:02 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, 6:48 PM EDT | FLASH FLOOD | 2 Nw Lumberville, PA | SOCIAL MEDIA VIDEO OF WATER RUSHING ACROSS RIVER ROAD. MULTIPLE ROADS FLOODED. |
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, 10.0 hours before the alert went out and 180 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.
950
WGUS51 KPHI 292158
FFWPHI
NJC019-021-035-PAC017-300200-
/O.NEW.KPHI.FF.W.0027.210729T2158Z-210730T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
558 PM EDT Thu Jul 29 2021
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Northwestern Mercer County in central New Jersey...
Southwestern Somerset County in northern New Jersey...
Southeastern Hunterdon County in northwestern New Jersey...
Central Bucks County in southeastern Pennsylvania...
* Until 1000 PM EDT.
* At 558 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 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...
Trenton, Ewing, Byram, Pennington, New Hope, Yardley, Hopewell,
Stockton, Washington Crossing, Sergeantsville, and Sand Brook.
This includes the following highways...
Interstate 295 in New Jersey between mile markers 72 and 76.
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 4047 7502 4049 7500 4043 7468 4038 7472
4023 7481 4034 7514
FLASH FLOOD...RADAR INDICATED
$$
MPS2 follow-up statements
330
WGUS71 KPHI 300006
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
806 PM EDT Thu Jul 29 2021
NJC019-021-035-PAC017-300200-
/O.CON.KPHI.FF.W.0027.000000T0000Z-210730T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Somerset NJ-Bucks PA-
806 PM EDT Thu Jul 29 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 10 PM EDT THIS
EVENING FOR NORTHWESTERN MERCER, SOUTHWESTERN SOMERSET, SOUTHEASTERN
HUNTERDON, AND CENTRAL BUCKS COUNTIES...
At 806 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 up to 0.5 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 will experience flash flooding include...
Trenton, Ewing, Byram, Pennington, New Hope, Yardley, Hopewell,
Stockton, Washington Crossing, Sergeantsville, and Sand Brook.
This includes the following highways...
Interstate 295 in New Jersey between mile markers 72 and 76.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
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 4047 7502 4049 7500 4043 7468 4038 7472
4023 7481 4034 7514
FLASH FLOOD...RADAR INDICATED
$$
MPS548
WGUS71 KPHI 300125
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
925 PM EDT Thu Jul 29 2021
NJC019-021-035-PAC017-300135-
/O.CAN.KPHI.FF.W.0027.000000T0000Z-210730T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Somerset NJ-Bucks PA-
925 PM EDT Thu Jul 29 2021
...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN MERCER,
SOUTHWESTERN SOMERSET, SOUTHEASTERN HUNTERDON, AND CENTRAL BUCKS
COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 4047 7502 4049 7500 4043 7468 4038 7472
4023 7481 4034 7514
$$
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, 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, 6:56 PM EDT | Flash Flood Warning | PHI | Mercer, Middlesex, Monmouth, Ocean, Somerset | 4 hr |
| 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 | |
| Jul 29, 3:48 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Lehigh, Northampton | 42 min |
| Jul 29, 4:03 PM EDT | Tornado Warning | PHI | Berks, Lehigh, Northampton | 27 min |
| Jul 29, 4:27 PM EDT | Tornado Warning | PHI | Lehigh, Northampton | 16 min |
| Jul 29, 4:46 PM EDT | Areal Flood Advisory | PHI | Berks, Lehigh, Northampton | 3 hr |
| Jul 29, 4:56 PM EDT | Tornado Warning | PHI | Bucks, Lehigh, Northampton | 34 min |
| Jul 29, 6:21 PM EDT | Special Weather Statement | PHI | Bucks | 24 min |
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.