Alert archive / New Jersey / Flash Flood Warnings in 2025

Flash Flood Warning 16, NWS Philadelphia/Mount Holly

May 31, 2025Burlington County, Mercer County, New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at May 31, 2025, 12:34 AM EDT for Burlington County, Mercer County, New Jersey; Bucks County, Pennsylvania. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 31, 2025, 12:34 AM EDT (04:34 UTC)
Expired: May 31, 2025, 3:37 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Burlington County, NJ, Mercer County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 42 km from the middle of the area, began a volume at 04:37 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 4.6 hours before the alert went out and 177 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 558 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

097 
WGUS51 KPHI 310434
FFWPHI
NJC005-021-PAC017-310845-
/O.NEW.KPHI.FF.W.0016.250531T0434Z-250531T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1234 AM EDT Sat May 31 2025

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Mercer County in central New Jersey...
  North Central Burlington County in southern New Jersey...
  Southeastern Bucks County in southeastern Pennsylvania...

* Until 445 AM EDT.

* At 1234 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. The expected rainfall rate is 0.5 to 1.5 inches in 1 
  hour. 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 may experience flash flooding include...
  Trenton, Ewing, Florence, Hightstown, Bordentown, Pennington, 
  Yardley, Newtown, Tullytown, Langhorne, Ivyland and Woodside.

This includes the following streams and drainages...
  Crafts Creek CROSSWICKS-NESHAMINY, Bacons Run 
  CROSSWICKS-NESHAMINY, Delaware River CROSSWICKS-NESHAMINY, MIDDLE 
  DELAWARE-MUSCONETCONG, Millstone River RARITAN, Newtown Creek 
  CROSSWICKS-NESHAMINY, Branch of Pond Run MIDDLE 
  DELAWARE-MUSCONETCONG, Pleasant Run CROSSWICKS-NESHAMINY, 
  Neshaminy Creek CROSSWICKS-NESHAMINY, Pennypack Creek LOWER 
  DELAWARE, Doctors Creek CROSSWICKS-NESHAMINY, Mill Creek LOWER 
  DELAWARE, Houghs Creek MIDDLE DELAWARE-MUSCONETCONG, Buck Creek 
  MIDDLE DELAWARE-MUSCONETCONG, Crosswicks Creek 
  CROSSWICKS-NESHAMINY, Delaware River MIDDLE DELAWARE-MUSCONETCONG, 
  Queen Anne Creek CROSSWICKS-NESHAMINY, Rocky Brook RARITAN, Stony 
  Brook RARITAN, Woolsey Brook MIDDLE DELAWARE-MUSCONETCONG, 
  Assiscunk Creek CROSSWICKS-NESHAMINY, West Branch Shabakunk Creek 
  MIDDLE DELAWARE-MUSCONETCONG, Duck Pond Run RARITAN, Pidcock Creek 
  MIDDLE DELAWARE-MUSCONETCONG, Bear Brook RARITAN, Mill Creek 
  CROSSWICKS-NESHAMINY, Southampton Creek LOWER DELAWARE, Shabakunk 
  Creek MIDDLE DELAWARE-MUSCONETCONG, Barkers Brook 
  CROSSWICKS-NESHAMINY, Little Neshaminy Creek CROSSWICKS-NESHAMINY, 
  Bridegroom Run MIDDLE DELAWARE-MUSCONETCONG, Rock Run 
  CROSSWICKS-NESHAMINY, Back Creek CROSSWICKS-NESHAMINY, Robin Run 
  CROSSWICKS-NESHAMINY, Edges Brook CROSSWICKS-NESHAMINY, Bear Brook 
  MIDDLE DELAWARE-MUSCONETCONG, Jacobs Creek MIDDLE 
  DELAWARE-MUSCONETCONG, RARITAN, Assunpink Creek MIDDLE 
  DELAWARE-MUSCONETCONG, Martins Creek CROSSWICKS-NESHAMINY, Pond 
  Run MIDDLE DELAWARE-MUSCONETCONG, Bustleton Creek 
  CROSSWICKS-NESHAMINY, Miry Run MIDDLE DELAWARE-MUSCONETCONG, 
  CROSSWICKS-NESHAMINY and Rancocas Creek LOWER DELAWARE.

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 4034 7476 4032 7465 4030 7460 4029 7453
      4026 7450 4020 7456 4018 7461 4012 7460
      4006 7471 4002 7479 4005 7482 4008 7480
      4012 7481 4015 7494 4016 7505 4019 7509
      4027 7503 4030 7499 4034 7485

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...0.5-1.5 INCHES IN 1 HOUR

$$

Hoeflich

2 follow-up statements

371 
WGUS71 KPHI 310724
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
324 AM EDT Sat May 31 2025

NJC005-021-PAC017-310845-
/O.CON.KPHI.FF.W.0016.000000T0000Z-250531T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Mercer NJ-Bucks PA-
324 AM EDT Sat May 31 2025

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 AM EDT EARLY THIS 
MORNING FOR MERCER, NORTH CENTRAL BURLINGTON AND SOUTHEASTERN BUCKS 
COUNTIES...

At 324 AM 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 may experience flash flooding include...
  Trenton, Ewing, Florence, Hightstown, Bordentown, Pennington, 
  Yardley, Newtown, Tullytown, Langhorne, Ivyland and Woodside.

This includes the following streams and drainages...
  Crafts Creek CROSSWICKS-NESHAMINY, Bacons Run 
  CROSSWICKS-NESHAMINY, Delaware River CROSSWICKS-NESHAMINY, MIDDLE 
  DELAWARE-MUSCONETCONG, Millstone River RARITAN, Newtown Creek 
  CROSSWICKS-NESHAMINY, Branch of Pond Run MIDDLE 
  DELAWARE-MUSCONETCONG, Pleasant Run CROSSWICKS-NESHAMINY, 
  Neshaminy Creek CROSSWICKS-NESHAMINY, Pennypack Creek LOWER 
  DELAWARE, Doctors Creek CROSSWICKS-NESHAMINY, Mill Creek LOWER 
  DELAWARE, Houghs Creek MIDDLE DELAWARE-MUSCONETCONG, Buck Creek 
  MIDDLE DELAWARE-MUSCONETCONG, Crosswicks Creek 
  CROSSWICKS-NESHAMINY, Delaware River MIDDLE DELAWARE-MUSCONETCONG, 
  Queen Anne Creek CROSSWICKS-NESHAMINY, Rocky Brook RARITAN, Stony 
  Brook RARITAN, Woolsey Brook MIDDLE DELAWARE-MUSCONETCONG, 
  Assiscunk Creek CROSSWICKS-NESHAMINY, West Branch Shabakunk Creek 
  MIDDLE DELAWARE-MUSCONETCONG, Duck Pond Run RARITAN, Pidcock Creek 
  MIDDLE DELAWARE-MUSCONETCONG, Bear Brook RARITAN, Mill Creek 
  CROSSWICKS-NESHAMINY, Southampton Creek LOWER DELAWARE, Shabakunk 
  Creek MIDDLE DELAWARE-MUSCONETCONG, Barkers Brook 
  CROSSWICKS-NESHAMINY, Little Neshaminy Creek CROSSWICKS-NESHAMINY, 
  Bridegroom Run MIDDLE DELAWARE-MUSCONETCONG, Rock Run 
  CROSSWICKS-NESHAMINY, Back Creek CROSSWICKS-NESHAMINY, Robin Run 
  CROSSWICKS-NESHAMINY, Edges Brook CROSSWICKS-NESHAMINY, Bear Brook 
  MIDDLE DELAWARE-MUSCONETCONG, Jacobs Creek MIDDLE 
  DELAWARE-MUSCONETCONG, RARITAN, Assunpink Creek MIDDLE 
  DELAWARE-MUSCONETCONG, Martins Creek CROSSWICKS-NESHAMINY, Pond 
  Run MIDDLE DELAWARE-MUSCONETCONG, Bustleton Creek 
  CROSSWICKS-NESHAMINY, Miry Run MIDDLE DELAWARE-MUSCONETCONG, 
  CROSSWICKS-NESHAMINY and Rancocas Creek LOWER DELAWARE.

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 4034 7476 4032 7465 4030 7460 4029 7453
      4026 7450 4020 7456 4018 7461 4012 7460
      4006 7471 4002 7479 4005 7482 4008 7480
      4012 7481 4015 7494 4016 7505 4019 7509
      4027 7503 4030 7499 4034 7485

FLASH FLOOD...RADAR INDICATED

$$

Hoeflich

758 
WGUS71 KPHI 310737
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
337 AM EDT Sat May 31 2025

NJC005-021-PAC017-310747-
/O.CAN.KPHI.FF.W.0016.000000T0000Z-250531T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Mercer NJ-Bucks PA-
337 AM EDT Sat May 31 2025

...FLASH FLOOD WARNING IS CANCELLED FOR MERCER, NORTH CENTRAL 
BURLINGTON AND SOUTHEASTERN BUCKS 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.

A Flood Watch remains in effect until 800 AM EDT for portions of 
northern Delaware and Pennsylvania.

A Flood Watch remains in effect until 800 AM EDT for portions of 
central, northern, northwest, and southern New Jersey.

&&

LAT...LON 4034 7476 4032 7465 4030 7460 4029 7453
      4026 7450 4020 7456 4018 7461 4012 7460
      4006 7471 4002 7479 4005 7482 4008 7480
      4012 7481 4015 7494 4016 7505 4019 7509
      4027 7503 4030 7499 4034 7485

$$

Hoeflich

The office that day

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

Issued	Product	Office	Counties	Lasted
May 30, 9:04 PM EDT	Wind Advisory	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more	10 hr
May 30, 11:12 PM EDT	Flash Flood Warning	PHI	Gloucester, Salem	3 hr
May 30, 11:36 PM EDT	Flash Flood Warning	PHI	Burlington, Camden, Gloucester	4 hr
May 31, 4:00 AM EDT	Areal Flood Warning	PHI	Morris, Sussex, Warren	9 hr
May 31, 4:19 AM EDT	Areal Flood Warning	PHI	Hunterdon	6 hr
May 31, 5:13 AM EDT	Areal Flood Warning	PHI	Somerset	97 min
May 31, 8:46 AM EDT	Areal Flood Warning	PHI	Somerset	7 hr
May 31, 2:12 PM EDT	Special Marine Warning	PHI		63 min
May 31, 3:10 PM EDT	Special Marine Warning	PHI		65 min
May 31, 3:14 PM EDT	Severe Thunderstorm Warning	PHI	Cape May	16 min
May 31, 4:51 PM EDT	Special Marine Warning	PHI		84 min
May 31, 5:04 PM EDT	Severe Thunderstorm Warning	PHI	Cumberland, Gloucester, Salem	41 min
May 31, 6:20 PM EDT	River Flood Warning	PHI	Morris	12 hr
May 31, 1:04 AM EDT	Flash Flood Warning	PHI	Berks, Bucks, Lehigh, Montgomery	4 hr
May 31, 5:06 AM EDT	Areal Flood Warning	PHI	Lehigh, Montgomery	5 hr
May 31, 8:42 AM EDT	Areal Flood Warning	PHI	Lehigh	4 hr

Nearby

Flash Flood Warnings in New Jersey, 2025 Flash Flood Warnings in Pennsylvania, 2025 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.