Alert archive / Delaware / Flash Flood Warnings in 2023

Flash Flood Warning 69, NWS Philadelphia/Mount Holly

July 16, 2023Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 16, 2023, 3:34 PM EDT for Sussex County, Delaware. It was in force for 116 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, 3:34 PM EDT (19:34 UTC)
Expired: Jul 16, 2023, 5:30 PM EDT
In force: 116 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, 4:15 PM EDT	FLOOD	1 W Bethany Beach, DE	Report from Sunday afternoon. Vehicle stranded in high water at Half Moon Dr and Collins St. Several pictures of street 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 12:00Z, 7.6 hours before the alert went out and 71 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: 1072 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 644 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.5

Open this sounding in Storm Lab

The text

As transmitted.

663 
WGUS51 KPHI 161934
FFWPHI
DEC005-162130-
/O.NEW.KPHI.FF.W.0069.230716T1934Z-230716T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly has issued a

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

* Until 530 PM EDT.

* At 334 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  0.5 and 2 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 and automated gauges.

  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...
  Lewes, Selbyville, Dagsboro, Millville, Henlopen Acres, Cape 
  Henlopen State Park, Long Neck, Ocean View, Frankford, South 
  Bethany, and Dewey Beach.

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 3845 7531 3880 7515 3881 7507 3845 7503
      3846 7505 3845 7505 3845 7508 3845 7509

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...1.5-2.5 INCHES IN 1 HOUR

$$

Staarmann

2 follow-up statements

542 
WGUS71 KPHI 162034
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
434 PM EDT Sun Jul 16 2023

DEC005-162130-
/O.CON.KPHI.FF.W.0069.000000T0000Z-230716T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
434 PM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM EDT THIS 
AFTERNOON FOR SOUTHEASTERN SUSSEX COUNTY...

At 434 PM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 1 
and 4 inches of rain have fallen. The expected rainfall rate is 0.5 
to 1 inch in 1 hour. Additional rainfall amounts up to 0.5 inches 
are possible in the warned area. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

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...
  Lewes, Selbyville, Dagsboro, Millville, Henlopen Acres, Cape 
  Henlopen State Park, Long Neck, Ocean View, Frankford, South 
  Bethany, and Dewey Beach.

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 3845 7531 3880 7515 3881 7507 3845 7503
      3846 7505 3845 7505 3845 7508 3845 7509

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...0.5-1 INCH IN 1 HOUR

$$

Staarmann

160 
WGUS71 KPHI 162126
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
526 PM EDT Sun Jul 16 2023

DEC005-162136-
/O.EXP.KPHI.FF.W.0069.000000T0000Z-230716T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
526 PM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 530 PM EDT THIS AFTERNOON FOR 
SOUTHEASTERN SUSSEX COUNTY...

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

A Flood Watch remains in effect until 800 PM EDT for portions of 
Delaware...and northeast Maryland.

LAT...LON 3845 7531 3880 7515 3881 7507 3845 7503
      3846 7505 3845 7505 3845 7508 3845 7509

$$

Staarmann

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, 7:02 AM EDT	Flash Flood Warning	PHI	Sussex	108 min
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

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.