Alert archive / Maryland / Flash Flood Warnings in 2024

Flash Flood Warning 47, NWS Philadelphia/Mount Holly

August 7, 2024Caroline County, Maryland; Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 7, 2024, 4:08 PM EDT for Caroline County, Maryland; Sussex County, Delaware. It was in force for 3 hr. 2 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 7, 2024, 4:08 PM EDT (20:08 UTC)
Expired: Aug 7, 2024, 6:48 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Sussex County, DE, Caroline County, MD

The radar

The Dover AFB radar (KDOX), 24 km from the middle of the area, began a volume at 20:11 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

Time	Report	Where	Remark
Aug 7, 4:32 PM EDT	FLOOD	1 S Seaford, DE	Flooded roads a few inches deep on High Street and Market Street near Seaford, relayed by broadcast media.
Aug 7, 4:43 PM EDT	FLOOD	Seaford, DE	A picture relayed of street flooding at intersection of High Street and N Cannon Street. Water starting to come up on sidewalks relayed by broadcast media.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 8.1 hours before the alert went out and 86 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: 178 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 851 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -23 m²/s²
0-3 km storm-relative helicity: 24 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

874 
WGUS51 KPHI 072008
FFWPHI
DEC005-MDC011-080015-
/O.NEW.KPHI.FF.W.0047.240807T2008Z-240808T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
408 PM EDT Wed Aug 7 2024

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southwestern Sussex County in southern Delaware...
  Southeastern Caroline County in eastern Maryland...

* Until 815 PM EDT.

* At 408 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. Additional rainfall amounts up 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, Laurel, Federalsburg, Bridgeville, Sycamore, Blades, 
  Greenwood and Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3883 7558 3871 7557 3874 7540 3846 7555
      3846 7569 3864 7571 3869 7576 3868 7578
      3868 7579 3876 7574

FLASH FLOOD...RADAR INDICATED

$$

DeSilva

2 follow-up statements

871 
WGUS71 KPHI 072100
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
500 PM EDT Wed Aug 7 2024

DEC005-MDC011-080015-
/O.CON.KPHI.FF.W.0047.000000T0000Z-240808T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-Caroline MD-
500 PM EDT Wed Aug 7 2024

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM EDT THIS 
EVENING FOR SOUTHWESTERN SUSSEX AND SOUTHEASTERN CAROLINE COUNTIES...

At 500 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Reports of flash flooding on roadways 
has been reported in Seaford. Between 2 and 5 inches of rain have 
fallen. Additional rainfall amounts up to 1 inch are possible in the 
warned area. Flash flooding is already occurring.

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, Laurel, Federalsburg, Bridgeville, Sycamore, Blades, 
  Greenwood and Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3883 7558 3871 7557 3874 7540 3846 7555
      3846 7569 3864 7571 3869 7576 3868 7578
      3868 7579 3876 7574

FLASH FLOOD...RADAR INDICATED

$$

DeSilva

205 
WGUS71 KPHI 072248
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
648 PM EDT Wed Aug 7 2024

DEC005-MDC011-072258-
/O.CAN.KPHI.FF.W.0047.000000T0000Z-240808T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-Caroline MD-
648 PM EDT Wed Aug 7 2024

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN SUSSEX AND 
SOUTHEASTERN CAROLINE COUNTIES...

The heavy rain has ended, and flood waters are receding. Flooding is 
no longer expected to pose a threat. Please continue to heed 
remaining road closures.

&&

LAT...LON 3883 7558 3871 7557 3874 7540 3846 7555
      3846 7569 3864 7571 3869 7576 3868 7578
      3868 7579 3876 7574

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 7, 5:59 PM EDT	Flash Flood Warning	PHI	Caroline, Queen Anne's, Talbot	115 min
Aug 7, 3:02 PM EDT	Flash Flood Warning	PHI	Kent, Sussex	3 hr

Nearby

Flash Flood Warnings in Maryland, 2024 Flash Flood Warnings in Delaware, 2024 Every flash flood warning in 2024

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.