Alert archive / Delaware / Flash Flood Warnings in 2023

Flash Flood Warning 63, NWS Philadelphia/Mount Holly

July 16, 2023Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 16, 2023, 7:02 AM EDT for Sussex County, Delaware. It was in force for 108 min. 1 report 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: Jul 16, 2023, 7:02 AM EDT (11:02 UTC)
Expired: Jul 16, 2023, 8:50 AM EDT
In force: 108 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Sussex County, DE

What was reported inside it

Time	Report	Where	Remark
Jul 16, 8:30 AM EDT	FLASH FLOOD	4 W Georgetown, DE	Report from Sunday morning, relayed through media. Farmstead flooded, had to relocate animals due to flooding.

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 00:00Z, 11.0 hours before the alert went out and 83 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: 1610 J/kg
Mixed-layer CIN: -35 J/kg
Mixed-layer LCL: 852 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

905 
WGUS51 KPHI 161102
FFWPHI
DEC005-161500-
/O.NEW.KPHI.FF.W.0063.230716T1102Z-230716T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
702 AM EDT Sun Jul 16 2023

The National Weather Service in Mount Holly has issued a

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

* Until 1100 AM EDT.

* At 702 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts of 1.5 to 2.5 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...
  Georgetown, Seaford, Laurel, Lewes, Milton, Ellendale, Blades, and 
  Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3899 7521 3880 7518 3866 7537 3851 7570
      3853 7570 3855 7570 3856 7570 3857 7570
      3859 7570 3861 7570 3863 7571

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

$$

MJL

1 follow-up statement

417 
WGUS71 KPHI 161250
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
850 AM EDT Sun Jul 16 2023

DEC005-161300-
/O.CAN.KPHI.FF.W.0063.000000T0000Z-230716T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
850 AM EDT Sun Jul 16 2023

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

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat.

A Flood Watch remains in effect until 400 PM EDT Sunday for portions 
of Delaware...and northeast Maryland.

LAT...LON 3899 7521 3880 7518 3866 7537 3851 7570
      3853 7570 3855 7570 3856 7570 3857 7570
      3859 7570 3861 7570 3863 7571

$$

MJL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 1:21 AM EDT	Special Weather Statement	PHI	Kent	24 min
Jul 16, 2:47 AM EDT	Special Weather Statement	PHI	New Castle	28 min
Jul 16, 3:09 AM EDT	Special Weather Statement	PHI	Kent	36 min
Jul 16, 3:54 AM EDT	Flash Flood Warning	PHI	Kent, Sussex	4 hr
Jul 16, 11:08 AM EDT	Flash Flood Warning	PHI	New Castle	3 hr
Jul 16, 12:19 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	60 min
Jul 16, 1:08 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	3 hr
Jul 16, 1:19 PM EDT	Flash Flood Warning Considerable damage threat	PHI	Kent, Sussex	4 hr
Jul 16, 1:42 PM EDT	Special Weather Statement	PHI	Kent	33 min
Jul 16, 1:47 PM EDT	Areal Flood Advisory	PHI	New Castle	80 min
Jul 16, 2:23 PM EDT	Areal Flood Advisory	PHI	Sussex	71 min
Jul 16, 3:34 PM EDT	Flash Flood Warning	PHI	Sussex	116 min

Nearby

Flash Flood Warnings in Delaware, 2023 Every flash flood warning in 2023

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.