Alert archive / New Jersey / Flash Flood Warnings in 2026

Flash Flood Warning 122, NWS Philadelphia/Mount Holly

August 20, 2026Atlantic County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 20, 2026, 5:24 PM EDT for Atlantic County, New Jersey. It was in force for 4 hr. 5 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 20, 2026, 5:24 PM EDT (21:24 UTC)
Expired
Aug 20, 2026, 9:30 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Atlantic County, NJ

The radar

The Philadelphia radar (KDIX), 63 km from the middle of the area, began a volume at 21:26 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 20, 5:30 PM EDTFLASH FLOOD1 Nne Cardiff, NJSeveral inches of water on AC Expressway near mile marker 8.9. One lane impassable.
Aug 20, 5:50 PM EDTRAIN 1.981 Se Atlantic City Inte, NJCoCoRaHS station reported 1.98 inches of rain over 2 hours.
Aug 20, 8:30 PM EDTRAIN 4.952 Se Mays Landing, NJ
Aug 20, 9:05 PM EDTRAIN 2.151 Ese Egg Harbor Twp, NJMesonet station 2078D 1 ESE Egg Harbor Twp.
Aug 20, 9:10 PM EDTRAIN 2.63 Ese Hamilton Twp, NJMesonet station MYSWD 2 ESE Hamilton Twp.

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, 9.4 hours before the alert went out and 219 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 12:00Z on 2026-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2026-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1229 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
21 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

039 
WGUS51 KPHI 202124
FFWPHI
NJC001-210130-
/O.NEW.KPHI.FF.W.0122.260820T2124Z-260821T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
524 PM EDT Thu Aug 20 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southeastern Atlantic County in southern New Jersey...

* Until 930 PM EDT.

* At 524 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 1 and 2 inches of rain
  have fallen. The expected rainfall rate is 1.5 to 3 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. Flooding may be exacerbated with it being close to high
  tide.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flash flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other poor
           drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Atlantic City, Pleasantville, Somers Point, Ventnor City,
  Brigantine, Northfield, Absecon, Margate City, Estell Manor and
  Longport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3941 7480 3950 7463 3951 7457 3950 7447
      3945 7436 3942 7434 3935 7441 3929 7454
      3930 7456 3929 7457 3931 7468 3934 7477

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR

$$
2 follow-up statements
108 
WGUS71 KPHI 202231
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
631 PM EDT Thu Aug 20 2026

NJC001-210130-
/O.CON.KPHI.FF.W.0122.000000T0000Z-260821T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-
631 PM EDT Thu Aug 20 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM EDT THIS
EVENING FOR SOUTHEASTERN ATLANTIC COUNTY...

At 631 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain in flooding on the Atlantic City Expressway near exit 9 and the
Garden State Parkway. . Between 2 and 4 inches of rain have fallen.
The expected rainfall rate is 1.5 to 3 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. Thunderstorms producing
         flash flooding.

SOURCE...Radar indicated.

IMPACT...Life threatening flash flooding of creeks and streams, urban
         areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Atlantic City, Ocean City, Pleasantville, Somers Point, Ventnor
  City, Brigantine, Northfield, Absecon, Margate City, Estell Manor
  and Longport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3941 7480 3950 7463 3951 7457 3950 7447
      3945 7436 3942 7434 3935 7441 3929 7454
      3930 7456 3929 7457 3931 7468 3934 7477

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR

$$
889 
WGUS71 KPHI 210121
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
921 PM EDT Thu Aug 20 2026

NJC001-210131-
/O.EXP.KPHI.FF.W.0122.000000T0000Z-260821T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-
921 PM EDT Thu Aug 20 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 930 PM EDT THIS EVENING FOR
SOUTHEASTERN ATLANTIC COUNTY...

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 3941 7480 3950 7463 3951 7457 3950 7447
      3945 7436 3942 7434 3935 7441 3929 7454
      3930 7456 3929 7457 3931 7468 3934 7477

$$

Hoeflich

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 2:04 PM EDTSpecial Marine WarningPHI86 min
Aug 20, 3:26 PM EDTSpecial Marine WarningPHI94 min
Aug 20, 4:38 PM EDTTornado WarningPHIAtlantic37 min
Aug 20, 4:41 PM EDTFlash Flood WarningPHIAtlantic, Cape May, Cumberland4 hr
Aug 20, 5:13 PM EDTSpecial Marine WarningPHI92 min
Aug 20, 5:14 PM EDTSpecial Marine WarningPHI91 min
Aug 20, 5:27 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIGloucester, Salem48 min
Aug 20, 5:36 PM EDTSpecial Marine WarningPHI84 min
Aug 20, 5:39 PM EDTFlash Flood WarningPHICamden, Gloucester, Salem4 hr
Aug 20, 6:09 PM EDTSevere Thunderstorm WarningPHICumberland, Gloucester, Salem51 min
Aug 20, 6:13 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Mercer, Salem47 min
Aug 20, 6:15 PM EDTSpecial Marine WarningPHI60 min
Aug 20, 6:26 PM EDTFlash Flood WarningPHIMercer4 hr
Aug 20, 6:30 PM EDTSpecial Marine WarningPHI90 min
Aug 20, 6:38 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland37 min
Aug 20, 6:44 PM EDTSpecial Marine WarningPHI61 min
Aug 20, 7:01 PM EDTTornado WarningPHIAtlantic, Cape May, Cumberland29 min
Aug 20, 7:08 PM EDTTornado Warning Tornado observedPHICape May22 min
Aug 20, 7:10 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland50 min
Aug 20, 7:37 PM EDTSpecial Marine WarningPHI2 hr
Aug 20, 7:43 PM EDTSpecial Marine WarningPHI2 hr

Nearby

Flash Flood Warnings in New Jersey, 2026Every flash flood warning in 2026

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.