Alert archive / New Jersey / Flash Flood Warnings in 2026
Flash Flood Warning 121, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 20, 2026, 4:41 PM EDT for Atlantic County, Cape May County, Cumberland County, New Jersey. It was in force for 4 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
- Aug 20, 2026, 4:41 PM EDT (20:41 UTC)
- Expired
- Aug 20, 2026, 8:45 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ
The radar
The Dover AFB radar (KDOX), 59 km from the middle of the area, began a volume at 20:41 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 8.7 hours before the alert went out and 203 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
- 97 J/kg
- Mixed-layer CIN
- -72 J/kg
- Mixed-layer LCL
- 1192 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 115 m²/s²
- 0-3 km storm-relative helicity
- 230 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.0
The text
As transmitted.
877
WGUS51 KPHI 202041
FFWPHI
NJC001-009-011-210045-
/O.NEW.KPHI.FF.W.0121.260820T2041Z-260821T0045Z/
/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
441 PM EDT Thu Aug 20 2026
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Southwestern Atlantic County in southern New Jersey...
Northwestern Cape May County in southern New Jersey...
Southeastern Cumberland County in southern New Jersey...
* Until 845 PM EDT.
* At 441 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 3 inches of rain
have fallen. The expected rainfall rate is 1.5 to 2.5 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.
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...
Millville, Cumberland, Laurel Lake, Woodbine, Estell Manor, Corbin
City, Bricksboro, Port Elizabeth, Mauricetown, Leesburg and Port
Norris.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3931 7527 3935 7518 3938 7502 3939 7490
3939 7468 3933 7467 3924 7480 3921 7497
3920 7508 3920 7517 3921 7517 3921 7516
3923 7518 3927 7525 3927 7526 3929 7525
3929 7526
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1.5-2.5 INCHES IN 1 HOUR
$$
Hoeflich2 follow-up statements
149
WGUS71 KPHI 202324
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
724 PM EDT Thu Aug 20 2026
NJC001-009-011-210045-
/O.CON.KPHI.FF.W.0121.000000T0000Z-260821T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-Cape May NJ-Cumberland NJ-
724 PM EDT Thu Aug 20 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM EDT THIS
EVENING FOR SOUTHWESTERN ATLANTIC, NORTHWESTERN CAPE MAY AND
SOUTHEASTERN CUMBERLAND COUNTIES...
At 724 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 2 and 5 inches of rain have
fallen. The expected rainfall rate is 1.5 to 2.5 inches in 1 hour.
Additional rainfall amounts of 1 to 2 inches are possible in the
warned area. Flash flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar indicated.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Millville, Cumberland, Laurel Lake, Woodbine, Estell Manor, Corbin
City, Bricksboro, Port Elizabeth, Mauricetown, Leesburg and Port
Norris.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3931 7527 3935 7518 3938 7502 3939 7490
3939 7468 3933 7467 3924 7480 3921 7497
3920 7508 3920 7517 3921 7517 3921 7516
3923 7518 3927 7525 3927 7526 3929 7525
3929 7526
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1.5-2.5 INCHES IN 1 HOUR
$$988
WGUS71 KPHI 210036
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
836 PM EDT Thu Aug 20 2026
NJC001-009-011-210046-
/O.EXP.KPHI.FF.W.0121.000000T0000Z-260821T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-Cape May NJ-Cumberland NJ-
836 PM EDT Thu Aug 20 2026
...FLASH FLOOD WARNING WILL EXPIRE AT 845 PM EDT THIS EVENING FOR
SOUTHWESTERN ATLANTIC, NORTHWESTERN CAPE MAY AND SOUTHEASTERN
CUMBERLAND COUNTIES...
The heavy rain has ended. Flood waters have receded. Flooding is no
longer expected to pose a threat. Please continue to heed remaining
road closures.
A Flood Watch remains in effect until 200 AM EDT for portions of
northern Delaware, New Jersey, and Pennsylvania.
&&
LAT...LON 3931 7527 3935 7518 3938 7502 3939 7490
3939 7468 3933 7467 3924 7480 3921 7497
3920 7508 3920 7517 3921 7517 3921 7516
3923 7518 3927 7525 3927 7526 3929 7525
3929 7526
$$
HoeflichThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 2:04 PM EDT | Special Marine Warning | PHI | 86 min | |
| Aug 20, 3:26 PM EDT | Special Marine Warning | PHI | 94 min | |
| Aug 20, 4:38 PM EDT | Tornado Warning | PHI | Atlantic | 37 min |
| Aug 20, 5:13 PM EDT | Special Marine Warning | PHI | 92 min | |
| Aug 20, 5:14 PM EDT | Special Marine Warning | PHI | 91 min | |
| Aug 20, 5:24 PM EDT | Flash Flood Warning | PHI | Atlantic | 4 hr |
| Aug 20, 5:27 PM EDT | Severe Thunderstorm Warning | PHI | Gloucester, Salem | 48 min |
| Aug 20, 5:36 PM EDT | Special Marine Warning | PHI | 84 min | |
| Aug 20, 5:39 PM EDT | Flash Flood Warning | PHI | Camden, Gloucester, Salem | 4 hr |
| Aug 20, 6:09 PM EDT | Severe Thunderstorm Warning | PHI | Cumberland, Gloucester, Salem | 51 min |
| Aug 20, 6:13 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Camden, Gloucester, Mercer, Salem | 47 min |
| Aug 20, 6:15 PM EDT | Special Marine Warning | PHI | 60 min | |
| Aug 20, 6:26 PM EDT | Flash Flood Warning | PHI | Mercer | 4 hr |
| Aug 20, 6:30 PM EDT | Special Marine Warning | PHI | 90 min | |
| Aug 20, 6:38 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Cape May, Cumberland | 37 min |
| Aug 20, 6:44 PM EDT | Special Marine Warning | PHI | 61 min | |
| Aug 20, 7:01 PM EDT | Tornado Warning | PHI | Atlantic, Cape May, Cumberland | 29 min |
| Aug 20, 7:08 PM EDT | Tornado Warning | PHI | Cape May | 22 min |
| Aug 20, 7:10 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Cape May, Cumberland | 50 min |
| Aug 20, 7:37 PM EDT | Special Marine Warning | PHI | 2 hr | |
| Aug 20, 7:43 PM EDT | Special Marine Warning | PHI | 2 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.