Alert archive / Delaware / Flash Flood Warnings in 2025

Flash Flood Warning 74, NWS Philadelphia/Mount Holly

July 19, 2025Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 19, 2025, 10:25 PM EDT for Sussex County, Delaware. 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: Jul 19, 2025, 10:25 PM EDT (02:25 UTC)
Expired: Jul 20, 2025, 12:57 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 29 km from the middle of the area, began a volume at 02:27 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 2.4 hours before the alert went out and 81 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: 1259 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 806 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted.

156 
WGUS51 KPHI 200225
FFWPHI
DEC005-200615-
/O.NEW.KPHI.FF.W.0074.250720T0225Z-250720T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1025 PM EDT Sat Jul 19 2025

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  West Central Sussex County in southern Delaware...

* Until 215 AM EDT.

* At 1025 PM EDT, Doppler radar indicated thunderstorms, producing 
  heavy rain, were moving into the warned area. Up to 3.5 inches of 
  rain have already fallen across this same area the last couple of 
  hours. The expected rainfall rate is 1 to 2 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...
  Seaford, Blades and Bethel.

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 3856 7570 3857 7570 3859 7570 3861 7570
      3863 7571 3864 7571 3865 7571 3869 7571
      3870 7571 3872 7552 3864 7547 3858 7557

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

$$

Kruzdlo

1 follow-up statement

759 
WGUS71 KPHI 200457
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1257 AM EDT Sun Jul 20 2025

DEC005-200507-
/O.CAN.KPHI.FF.W.0074.000000T0000Z-250720T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
1257 AM EDT Sun Jul 20 2025

...FLASH FLOOD WARNING IS CANCELLED FOR WEST CENTRAL SUSSEX COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

&&

LAT...LON 3856 7570 3857 7570 3859 7570 3861 7570
      3863 7571 3864 7571 3865 7571 3869 7571
      3870 7571 3872 7552 3864 7547 3858 7557

$$

MPS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 9:58 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	47 min

Nearby

Flash Flood Warnings in Delaware, 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.