Alert archive / Delaware / Flash Flood Warnings in 2023

Flash Flood Warning 59, NWS Philadelphia/Mount Holly

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

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 16, 2023, 3:54 AM EDT for Caroline County, Maryland; Kent County, Sussex County, Delaware. It was in force for 4 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 16, 2023, 3:54 AM EDT (07:54 UTC)
Expired
Jul 16, 2023, 8:00 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 7.9 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 00:00Z on 2023-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1610 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 00:00Z on 2023-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.1939Sfc1 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
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.

749 
WGUS51 KPHI 160754
FFWPHI
DEC001-005-MDC011-161200-
/O.NEW.KPHI.FF.W.0059.230716T0754Z-230716T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly has issued a

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

* Until 800 AM EDT.

* At 354 AM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 2 inches of rain have fallen. The expected rainfall rate is 
  1 to 1.5 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...
  Dover, Milford, Harrington, Federalsburg, Bridgeville, Bowers, 
  Viola, Andrewsville, Rising Sun-Lebanon, Rising Sun, Dover Base 
  Housing, and Big Stone Beach.

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 3870 7586 3922 7542 3899 7521 3863 7571
      3869 7576 3868 7580 3870 7580

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

$$

SFJ
2 follow-up statements
449 
WGUS71 KPHI 160915
FFSPHI

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

DEC001-005-MDC011-161200-
/O.CON.KPHI.FF.W.0059.000000T0000Z-230716T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-Caroline MD-
515 AM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING 
FOR SOUTHEASTERN KENT, NORTHWESTERN SUSSEX, AND SOUTHEASTERN 
CAROLINE COUNTIES...

At 515 AM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 2 
and 4 inches of rain have fallen. The expected rainfall rate is 1 to 
1.5 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...
  Dover, Milford, Harrington, Federalsburg, Bridgeville, Bowers, 
  Viola, Andrewsville, Rising Sun-Lebanon, Rising Sun, Dover Base 
  Housing, and Big Stone Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3870 7586 3922 7542 3899 7521 3863 7571
      3869 7576 3868 7580 3870 7580

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

$$

SFJ
671 
WGUS71 KPHI 161155
FFSPHI

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

DEC001-005-MDC011-161205-
/O.EXP.KPHI.FF.W.0059.000000T0000Z-230716T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-Caroline MD-
755 AM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 8 AM EDT THIS MORNING FOR 
SOUTHEASTERN KENT, NORTHWESTERN SUSSEX, AND SOUTHEASTERN CAROLINE 
COUNTIES...

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 3870 7586 3922 7542 3899 7521 3863 7571
      3869 7576 3868 7580 3870 7580

$$

MJL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 1:21 AM EDTSpecial Weather StatementPHICaroline, Queen Anne's24 min
Jul 16, 2:17 AM EDTSpecial Weather StatementPHIKent, Queen Anne's28 min
Jul 16, 12:19 PM EDTAreal Flood AdvisoryPHICaroline60 min
Jul 16, 1:19 PM EDTFlash Flood Warning Considerable damage threatPHICaroline4 hr
Jul 16, 2:47 AM EDTSpecial Weather StatementPHINew Castle28 min
Jul 16, 3:09 AM EDTSpecial Weather StatementPHIKent36 min
Jul 16, 7:02 AM EDTFlash Flood WarningPHISussex108 min
Jul 16, 11:08 AM EDTFlash Flood WarningPHINew Castle3 hr
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

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; the sounding from the Mesonet's radiosonde archive.