Alert archive / Delaware / Flash Flood Warnings in 2023

Flash Flood Warning 68, NWS Philadelphia/Mount Holly

July 16, 2023Kent County, Sussex County, Delaware; Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 16, 2023, 1:19 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Maryland. It was in force for 4 hr. 4 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
Jul 16, 2023, 1:19 PM EDT (17:19 UTC)
Expired
Jul 16, 2023, 5:15 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Kent County, DE, Sussex County, DE, Caroline County, MD

What was reported inside it

TimeReportWhereRemark
Jul 16, 2:28 PM EDTFLOOD1 Sw Greenwood, DEPicture of yard and street flooding in Greenwood, DE.
Jul 16, 2:30 PM EDTFLOODFederalsburg, MDMinor street flooding in Federalsburg.
Jul 16, 2:30 PM EDTFLOODGreenwood, DEReport of some houses in Greenwood with basement flooding.
Jul 16, 3:01 PM EDTFLASH FLOODGreenwood, DESussex County EM reports 4 homes with water intrusion, 4 vehicles with water damage, with DelDOT assisting with water on the roadways.

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, 5.3 hours before the alert went out and 99 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-pSkew-T log-p diagram, Wallops Is Stn, VA at 12:00Z on 2023-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1072 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 12:00Z on 2023-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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.

357 
WGUS51 KPHI 161719
FFWPHI
DEC001-005-MDC011-162115-
/O.NEW.KPHI.FF.W.0068.230716T1719Z-230716T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southern Kent County in central Delaware...
  Western Sussex County in southern Delaware...
  Southeastern Caroline County in eastern Maryland...

* Until 515 PM EDT.

* At 119 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 5 inches of rain have fallen through earlier this morning. 
  The expected rainfall rate is 1.5 to 3 inches in 1 hour. 
  Additional rainfall amounts of 1 to 4 inches are possible in the 
  warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Life threatening flash flooding caused by
           thunderstorms.

  SOURCE...Radar and automated gauges.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets, and underpasses.

* Some locations that may experience flash flooding include...
  Dover, Georgetown, Milford, Seaford, Laurel, Harrington, 
  Federalsburg, Milton, Bridgeville, Ellendale, Bowers, and Viola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles. Motorists should not attempt to 
drive around barricades or drive cars through flooded areas.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3870 7585 3895 7566 3916 7547 3924 7538
      3910 7538 3901 7530 3892 7527 3877 7530
      3846 7561 3846 7569 3864 7571 3869 7576
      3868 7580 3870 7580

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL RATE...1.5-3 INCHES IN 1 HOUR

$$

Staarmann
2 follow-up statements
777 
WGUS71 KPHI 161846
FFSPHI

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

DEC001-005-MDC011-162115-
/O.CON.KPHI.FF.W.0068.000000T0000Z-230716T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-Caroline MD-
246 PM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM EDT THIS 
AFTERNOON FOR SOUTHERN KENT, WESTERN SUSSEX, AND SOUTHEASTERN 
CAROLINE COUNTIES...

At 246 PM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 3 
and 7 inches of rain have fallen. The expected rainfall rate is 0.5 
to 1 inch in 1 hour. Additional rainfall amounts of 0.5 to 1.5 
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...
  Dover, Georgetown, Milford, Seaford, Laurel, Harrington, 
  Federalsburg, Milton, Bridgeville, Ellendale, Bowers, and Viola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles. Motorists should not attempt to 
drive around barricades or drive cars through flooded areas.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3870 7585 3895 7566 3916 7547 3924 7538
      3910 7538 3901 7530 3892 7527 3877 7530
      3846 7561 3846 7569 3864 7571 3869 7576
      3868 7580 3870 7580

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

$$

Staarmann
970 
WGUS71 KPHI 162107
FFSPHI

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

DEC001-005-MDC011-162117-
/O.EXP.KPHI.FF.W.0068.000000T0000Z-230716T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-Caroline MD-
507 PM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 515 PM EDT THIS AFTERNOON FOR 
SOUTHERN KENT, WESTERN 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 any 
remaining road closures.

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

LAT...LON 3870 7585 3895 7566 3916 7547 3924 7538
      3910 7538 3901 7530 3892 7527 3877 7530
      3846 7561 3846 7569 3864 7571 3869 7576
      3868 7580 3870 7580

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 1:21 AM EDTSpecial Weather StatementPHIKent24 min
Jul 16, 2:47 AM EDTSpecial Weather StatementPHINew Castle28 min
Jul 16, 3:09 AM EDTSpecial Weather StatementPHIKent36 min
Jul 16, 3:54 AM EDTFlash Flood WarningPHIKent, Sussex4 hr
Jul 16, 7:02 AM EDTFlash Flood WarningPHISussex108 min
Jul 16, 11:08 AM EDTFlash Flood WarningPHINew Castle3 hr
Jul 16, 12:19 PM EDTAreal Flood AdvisoryPHIKent, Sussex60 min
Jul 16, 1:08 PM EDTAreal Flood AdvisoryPHIKent, New Castle3 hr
Jul 16, 1:42 PM EDTSpecial Weather StatementPHIKent33 min
Jul 16, 1:47 PM EDTAreal Flood AdvisoryPHINew Castle80 min
Jul 16, 2:23 PM EDTAreal Flood AdvisoryPHISussex71 min
Jul 16, 3:34 PM EDTFlash Flood WarningPHISussex116 min
Jul 16, 2:17 AM EDTSpecial Weather StatementPHIKent, Queen Anne's28 min

Nearby

Flash Flood Warnings in Delaware, 2023Flash Flood Warnings in Maryland, 2023Every 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.