Alert archive / Maryland / Flash Flood Warnings in 2020

Flash Flood Warning 51, NWS Philadelphia/Mount Holly

August 7, 2020Caroline County, Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 7, 2020, 7:44 PM EDT for Caroline County, Kent County, Queen Anne's County, Maryland. It was in force for 4 hr. 6 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: Aug 7, 2020, 7:44 PM EDT (23:44 UTC)
Expired: Aug 8, 2020, 12:02 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Caroline County, MD, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 69 km from the middle of the area, began a volume at 23:44 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

Time	Report	Where	Remark
Aug 7, 7:45 PM EDT	FLASH FLOOD	Sudlersville, MD	MD 313 CLOSED AT CHARLES STREET DUE TO HIGH WATER.
Aug 7, 7:45 PM EDT	FLASH FLOOD	Sudlersville, MD	MD 313 CLOSED AT CHARLES STREET DUE TO HIGH WATER.
Aug 7, 8:46 PM EDT	FLASH FLOOD	2 Sw Millington, MD	DELAYED REPORT. FLASH FLOODING CLOSED STATE HIGHWAY 313 NEAR STATE HIGHWAY 544. TIME BASED ON DISPATCH REPORT.
Aug 7, 8:46 PM EDT	FLASH FLOOD	2 Sw Millington, MD	DELAYED REPORT. FLASH FLOODING CLOSED STATE HIGHWAY 313 NEAR STATE HIGHWAY 544. TIME BASED ON DISPATCH REPORT.
Aug 7, 9:07 PM EDT	FLASH FLOOD	Sudlersville, MD	DELAYED REPORT. FLASH FLOODING CLOSED STATE HIGHWAY 300 AT STATE HIGHWAY 837. TIME BASED ON DISPATCH REPORT.
Aug 7, 9:07 PM EDT	FLASH FLOOD	Sudlersville, MD	DELAYED REPORT. FLASH FLOODING CLOSED STATE HIGHWAY 300 AT STATE HIGHWAY 837. TIME BASED ON DISPATCH REPORT.

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 12:00Z, 11.7 hours before the alert went out and 105 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: 301 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 665 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: -37 m²/s²
0-3 km storm-relative helicity: 18 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

430 
WGUS51 KPHI 072344
FFWPHI
MDC011-029-035-080545-
/O.NEW.KPHI.FF.W.0051.200807T2344Z-200808T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
744 PM EDT Fri Aug 7 2020

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Queen Anne's County in northeastern Maryland...
  Northeastern Caroline County in eastern Maryland...
  Kent County in northeastern Maryland...

* Until 145 AM EDT Saturday.

* At 743 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is 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 
           poor drainage and low lying areas.

* Some locations that could experience flooding include...
  Centerville, Chestertown, Centreville, Greensboro, Oakland,
  Ridgely, Rock Hall, Church Hill, Millington, Sudlersville,
  Betterton, Goldsboro, Old Town, Grasonville, Starr, Jumptown,
  Newtown, Morgnec, Crumpton and Sassafras.

Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area.

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.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets, and underpasses
as well as other poor drainage areas and low lying spots.

&&

LAT...LON 3904 7631 3898 7628 3897 7622 3900 7617
      3901 7621 3917 7628 3932 7618 3938 7606
      3938 7577 3893 7574 3894 7610 3885 7620
      3896 7625 3891 7624 3890 7625 3894 7627
      3891 7630 3896 7631 3885 7636

FLASH FLOOD...RADAR INDICATED

$$

Iovino

1 follow-up statement

224 
WGUS71 KPHI 080402
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1202 AM EDT Sat Aug 8 2020

MDC011-029-035-080412-
/O.CAN.KPHI.FF.W.0051.000000T0000Z-200808T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Queen Anne's MD-Caroline MD-Kent MD-
1202 AM EDT Sat Aug 8 2020

...THE FLASH FLOOD WARNING FOR QUEEN ANNE'S...NORTHEASTERN CAROLINE
AND KENT COUNTIES IS CANCELLED...

Flood waters are receding. Flooding is no longer expected to pose a 
threat. Please continue to heed any remaining road closures.

LAT...LON 3904 7631 3898 7628 3897 7622 3900 7617
      3901 7621 3917 7628 3932 7618 3938 7606
      3938 7577 3893 7574 3894 7610 3885 7620
      3896 7625 3891 7624 3890 7625 3894 7627
      3891 7630 3896 7631 3885 7636

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 7, 4:41 PM EDT	Areal Flood Advisory	PHI	Cecil	3 hr
Aug 7, 5:03 PM EDT	Flash Flood Warning	PHI	Cecil	5 hr
Aug 7, 6:12 PM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent, Queen Anne's	63 min
Aug 7, 6:43 PM EDT	Areal Flood Advisory	PHI	Caroline, Cecil, Kent, Queen Anne's	4 hr
Aug 7, 7:04 PM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent, Queen Anne's	41 min

Nearby

Flash Flood Warnings in Maryland, 2020 Every 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.