Alert archive / New Jersey / Flash Flood Warnings in 2025

Flash Flood Warning 93, NWS Philadelphia/Mount Holly

August 17, 2025Burlington County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 17, 2025, 8:12 PM EDT for Burlington County, 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
Aug 17, 2025, 8:12 PM EDT (00:12 UTC)
Expired
Aug 17, 2025, 11:55 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Burlington County, NJ

The radar

The Philadelphia radar (KDIX), 30 km from the middle of the area, began a volume at 00:14 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

TimeReportWhereRemark
Aug 17, 8:50 PM EDTRAIN 2.521 Sse Rancocas, NJ2.52 inches of rain in one hour.
Aug 17, 9:00 PM EDTFLASH FLOODLumberton, NJSeveral roads flooded and impassable.
Aug 17, 9:18 PM EDTRAIN 2.991 Ese Lumberton Twp, NJMesonet station GW2630 Lumberton.
Aug 17, 9:20 PM EDTRAIN 1.831 Nne Rancocas, NJMesonet station FW5135 Willingboro.
Aug 17, 9:30 PM EDTRAIN 3.74Lumberton Twp, NJPrivate weather station.
Aug 17, 9:50 PM EDTRAIN 3.321 Sse Rancocas, NJUpdated report from 1 SSE Rancocas. 2.52 inches of rain occurred from about 7:50 PM to 8:50 PM.
Aug 17, 10:00 PM EDTRAIN 1.971 Nne Rancocas, NJMesonet station FW5135 Willingboro.
Aug 17, 10:00 PM EDTRAIN 2.19Mount Holly Wfo, NJMesonet station EW3827 Westampton.
Aug 17, 10:00 PM EDTRAIN 3.88Lumberton Twp, NJPersonal weather station.
Aug 17, 10:30 PM EDTRAIN 3.061 Nne Rancocas, NJMesonet station FW5135 Willingboro.
Aug 17, 10:56 PM EDTFLASH FLOODWillingboro, NJEast River Drive flooded with approximately 2 feet of water.
Aug 17, 11:27 PM EDTFLASH FLOOD1 Ese Mount Holly Wfo, NJRT541 is flooded in all lanes - 2 vehicles stuck in water.

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 00:00Z, 0.2 hours before the alert went out and 190 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.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2025-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 677 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2025-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
677 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
920 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

314 
WGUS51 KPHI 180012
FFWPHI
NJC005-180215-
/O.NEW.KPHI.FF.W.0093.250818T0012Z-250818T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
812 PM EDT Sun Aug 17 2025

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Central Burlington County in southern New Jersey...

* Until 1015 PM EDT.

* At 812 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 
  30 minutes. Additional rainfall amounts of 0.5 to 1.5 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 may experience flash flooding include...
  Willingboro, Medford, Lumberton, Mount Holly, Pemberton, 
  Leisuretowne, Cinnaminson, Nws Office, Pemberton Heights and 
  Moorestown-Lenola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 3995 7460 3988 7459 3987 7468 3989 7480
      3994 7490 4000 7500 4004 7492 4002 7482
      3999 7470

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 30 MINUTES

$$

Gorse
3 follow-up statements
614 
WGUS71 KPHI 180049
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
849 PM EDT Sun Aug 17 2025

NJC005-180215-
/O.CON.KPHI.FF.W.0093.000000T0000Z-250818T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-
849 PM EDT Sun Aug 17 2025

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM EDT THIS 
EVENING FOR CENTRAL BURLINGTON COUNTY...

At 849 PM EDT, trained weather spotters reported thunderstorms 
producing heavy rain across the warned area. Between 1 and 2.5 
inches of rain have fallen. The expected rainfall rate is 1 to 2 
inches in 30 minutes. Additional rainfall amounts of 0.5 to 1.5 
inches are possible in the warned area. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters 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 may experience flash flooding include...
  Willingboro, Medford, Lumberton, Mount Holly, Pemberton, 
  Leisuretowne, Cinnaminson, Nws Office, Pemberton Heights and 
  Moorestown-Lenola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3995 7460 3988 7459 3987 7468 3989 7480
      3994 7490 4000 7500 4004 7492 4002 7482
      3999 7470

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL RATE...1-2 INCHES IN 30 MINUTES

$$

Gorse
796 
WGUS51 KPHI 180150
FFWPHI
NJC005-180415-
/O.EXT.KPHI.FF.W.0093.000000T0000Z-250818T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
950 PM EDT Sun Aug 17 2025

The National Weather Service in Mount Holly has extended the

* Flash Flood Warning for...
  Central Burlington County in southern New Jersey...

* Until 1215 AM EDT.

* At 950 PM EDT, Doppler radar and automated rain gauges indicate 
  another area of showers and thunderstorms producing heavy rain 
  will arrive across the warned area from the west. Between 1.5 and 
  4 inches of rain has fallen from the first round. The expected 
  rainfall rate is 1.5 to 2.5 inches in 1 hour. 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 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 may experience flash flooding include...
  Willingboro, Medford, Lumberton, Mount Holly, Pemberton, 
  Leisuretowne, Cinnaminson, Nws Office, Pemberton Heights and 
  Moorestown-Lenola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3995 7460 3988 7459 3987 7468 3989 7480
      3994 7490 4000 7500 4004 7492 4002 7482
      3999 7470

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...1.5-2.5 INCHES IN 1 HOUR

$$

Gorse
568 
WGUS71 KPHI 180355
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1155 PM EDT Sun Aug 17 2025

NJC005-007-PAC017-091-101-180405-
/O.CAN.KPHI.FF.W.0093.000000T0000Z-250818T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Camden NJ-Bucks PA-Montgomery PA-Philadelphia PA-
1155 PM EDT Sun Aug 17 2025

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN BURLINGTON, 
NORTHWESTERN CAMDEN, SOUTHEASTERN BUCKS, SOUTHEASTERN MONTGOMERY AND 
PHILADELPHIA COUNTIES...

Flash Flood Warnings have been converted to an areal Flood Warning 
as the flood waters will take several hours for all the water from 
these storms to work through local drainage systems in urban areas.

Please continue to heed remaining road closures.

&&

LAT...LON 4019 7514 4024 7505 4019 7487 4012 7473
      4002 7484 4004 7492 4000 7499 3996 7493
      3987 7507 3996 7521 4007 7529

$$

Deal

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 17, 9:09 PM EDTSpecial Marine WarningPHI66 min
Aug 17, 10:01 PM EDTFlash Flood WarningPHIBurlington, Camden119 min
Aug 17, 11:55 PM EDTAreal Flood WarningPHIBurlington, Camden4 hr
Aug 18, 4:45 AM EDTCoastal Flood AdvisoryPHIAtlantic, Burlington, Cape May17 hr

Nearby

Flash Flood Warnings in New Jersey, 2025Every flash flood warning in 2025

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.