Alert archive / Maryland / Flash Flood Warnings in 2020

Flash Flood Warning 43, NWS Philadelphia/Mount Holly

August 6, 2020Cecil County, Kent County, Queen Anne's County, Maryland; Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 6, 2020, 7:13 AM EDT for Cecil County, Kent County, Queen Anne's County, Maryland; Kent County, New Castle County, Delaware. It was in force for 3 hr. 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
Aug 6, 2020, 7:13 AM EDT (11:13 UTC)
Expired
Aug 6, 2020, 10:09 AM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Kent County, DE, New Castle County, DE, Cecil County, MD, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 60 km from the middle of the area, began a volume at 11:14 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

TimeReportWhereRemark
Aug 6, 8:30 AM EDTFLASH FLOODGalena, MDFLOODING REPORTED AROUND THE GALENA, MD AREA. ROAD CLOSURES REPORTED. TIME ESTIMATED FROM RADAR.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 11.2 hours before the alert went out and 147 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, Washington/Dulle, VA at 00:00Z on 2020-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 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, Washington/Dulle, VA at 00:00Z on 2020-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 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
16 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
1600 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

085 
WGUS51 KPHI 061113
FFWPHI
DEC001-003-MDC015-029-035-061515-
/O.NEW.KPHI.FF.W.0043.200806T1113Z-200806T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
713 AM EDT Thu Aug 6 2020

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Southwestern New Castle County in northern Delaware...
  Northern Kent County in central Delaware...
  Northeastern Queen Anne's County in northeastern Maryland...
  Northeastern Kent County in northeastern Maryland...
  Southeastern Cecil County in northeastern Maryland...

* Until 1115 AM EDT.

* At 712 AM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  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 could experience flooding include...
  Dover, Smyrna, Clayton, Cheswold, Church Hill, Cecilton,
  Millington, Sudlersville, Hartly, Sassafras, Woodland Beach, Green
  Spring, Morgnec, Delaney Corner, Massey, Crumpton, Dover Speedway,
  Kennedyville, Townsend and Galena.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 3940 7599 3942 7551 3934 7542 3916 7537
      3915 7599 3929 7604

FLASH FLOOD...RADAR INDICATED

$$

BAH
2 follow-up statements
170 
WGUS71 KPHI 061142
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
742 AM EDT Thu Aug 6 2020

DEC001-003-MDC015-029-035-061515-
/O.CON.KPHI.FF.W.0043.000000T0000Z-200806T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Kent DE-Queen Anne's MD-Kent MD-Cecil MD-
742 AM EDT Thu Aug 6 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 AM EDT FOR
SOUTHWESTERN NEW CASTLE...NORTHERN KENT...NORTHEASTERN QUEEN
ANNE'S...NORTHEASTERN KENT AND SOUTHEASTERN CECIL COUNTIES...

At 740 AM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to two inches of rain have already
fallen. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas. Over two inches of rain has already 
         fallen this morning with highest totals around the Kent and 
         New Castle county line. There have also been a few road 
         closures around Galena, MD.

Some locations that could experience flooding include...
Dover, Smyrna, Clayton, Cheswold, Church Hill, Cecilton, Millington,
Sudlersville, Hartly, Sassafras, Woodland Beach, Green Spring,
Morgnec, Delaney Corner, Massey, Crumpton, Dover Speedway,
Kennedyville, Townsend and Galena.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 3940 7599 3942 7551 3934 7542 3916 7537
      3915 7599 3929 7604

FLASH FLOOD...RADAR INDICATED

$$

BAH
379 
WGUS71 KPHI 061409
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1009 AM EDT Thu Aug 6 2020

DEC001-003-MDC015-029-035-061419-
/O.CAN.KPHI.FF.W.0043.000000T0000Z-200806T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Kent DE-Queen Anne's MD-Kent MD-Cecil MD-
1009 AM EDT Thu Aug 6 2020

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN NEW CASTLE...NORTHERN
KENT...NORTHEASTERN QUEEN ANNE'S...NORTHEASTERN KENT AND SOUTHEASTERN
CECIL COUNTIES IS CANCELLED...

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

LAT...LON 3940 7599 3942 7551 3934 7542 3916 7537
      3915 7599 3929 7604

$$

BAH

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 3:37 AM EDTFlash Flood WatchPHICaroline, Cecil, Kent, Queen Anne's, Talbot44 hr
Aug 6, 5:36 AM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot39 min
Aug 6, 6:13 AM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot62 min
Aug 6, 6:19 AM EDTAreal Flood AdvisoryPHIKent, Queen Anne's116 min
Aug 6, 6:43 AM EDTAreal Flood AdvisoryPHICaroline, Cecil, Kent, Queen Anne's, Talbot3 hr
Aug 6, 8:43 AM EDTAreal Flood AdvisoryPHICecil, Kent, Queen Anne's87 min
Aug 6, 6:49 AM EDTSevere Thunderstorm WarningPHIKent, New Castle41 min
Aug 6, 7:13 AM EDTSevere Thunderstorm WarningPHIKent, Sussex47 min
Aug 6, 7:18 AM EDTSevere Thunderstorm WarningPHIKent, New Castle42 min
Aug 6, 7:46 AM EDTSpecial Weather StatementPHISussex29 min
Aug 6, 8:16 AM EDTSevere Thunderstorm WarningPHISussex44 min

Nearby

Flash Flood Warnings in Maryland, 2020Flash Flood Warnings in Delaware, 2020Every flash flood warning in 2020

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.