Alert archive / Maryland / Flash Flood Warnings in 2021

Flash Flood Warning 83, NWS Philadelphia/Mount Holly

September 23, 2021Kent County, Queen Anne's County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 23, 2021, 9:49 AM EDT for Kent County, Queen Anne's County, Talbot 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: Sep 23, 2021, 9:49 AM EDT (13:49 UTC)
Expired: Sep 23, 2021, 1:34 PM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

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

The radar

The Dover AFB radar (KDOX), 71 km from the middle of the area, began a volume at 13:50 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
Sep 23, 9:50 AM EDT	COASTAL FLOOD	Saint Michaels, MD	A SECTION OF MARYLAND ROUTE 33 WAS CLOSED.
Sep 23, 10:10 AM EDT	FLASH FLOOD	Queenstown, MD	WATER RESCUE WITH A VEHICLE STRANDED AT THE INTERSECTION OF MELVIN AVE AND MAIN ST.
Sep 23, 10:10 AM EDT	FLASH FLOOD	Queenstown, MD	WATER RESCUE WITH A VEHICLE STRANDED AT THE INTERSECTION OF MELVIN AVE AND MAIN ST.
Sep 23, 11:01 AM EDT	FLASH FLOOD	3 Nnw Langford, MD	STATE HIGHWAY 298 CLOSED FROM FLASH FLOODING. 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, 1.8 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-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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 517 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: -71 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted.

943 
WGUS51 KPHI 231349
FFWPHI
MDC029-035-041-231800-
/O.NEW.KPHI.FF.W.0083.210923T1349Z-210923T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
949 AM EDT Thu Sep 23 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Central Talbot County in eastern Maryland...
  Kent County in northeastern Maryland...
  Southwestern Queen Anne's County in northeastern Maryland...

* Until 200 PM EDT.

* At 949 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  have fallen for some areas. 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.

  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...
  Easton, Talbot, Chestertown, Rock Hall, St. Michaels, Overton, 
  Grasonville, Chester, Stevensville, Old Town, Langford, and 
  Copperville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3877 7637 3875 7636 3884 7626 3879 7619
      3880 7620 3879 7618 3897 7625 3890 7631
      3895 7631 3885 7636 3917 7627 3932 7619
      3937 7606 3864 7611 3876 7622 3876 7632
      3871 7633 3867 7634

FLASH FLOOD...RADAR INDICATED

$$

Robertson

2 follow-up statements

908 
WGUS71 KPHI 231507
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1107 AM EDT Thu Sep 23 2021

MDC029-035-041-231800-
/O.CON.KPHI.FF.W.0083.000000T0000Z-210923T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent MD-Queen Anne's MD-Talbot MD-
1107 AM EDT Thu Sep 23 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 2 PM EDT THIS 
AFTERNOON FOR CENTRAL TALBOT, KENT, AND SOUTHWESTERN QUEEN ANNE'S 
COUNTIES...

At 1107 AM EDT, Doppler radar indicated thunderstorms producing 
heavy rain in Queestown. Between 2 and 4 inches of rain have fallen. 
Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area. Flash flooding is already occurring, in particular 
Queenstown.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

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...
  Easton, Talbot, Chestertown, Rock Hall, St. Michaels, Overton, 
  Grasonville, Chester, Stevensville, Old Town, Langford, and 
  Copperville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3877 7637 3875 7636 3884 7626 3879 7619
      3880 7620 3879 7618 3897 7625 3890 7631
      3895 7631 3885 7636 3917 7627 3932 7619
      3937 7606 3864 7611 3876 7622 3876 7632
      3871 7633 3867 7634

FLASH FLOOD...RADAR INDICATED

$$

Robertson

744 
WGUS71 KPHI 231734
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
134 PM EDT Thu Sep 23 2021

MDC029-035-041-231744-
/O.CAN.KPHI.FF.W.0083.000000T0000Z-210923T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent MD-Queen Anne's MD-Talbot MD-
134 PM EDT Thu Sep 23 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL TALBOT, KENT, AND 
SOUTHWESTERN QUEEN ANNE'S COUNTIES...

While there will continue to be showers this afternoon, the heavy 
rain has ended, and flash flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3884 7626 3878 7622 3879 7618 3895 7621
      3897 7625 3891 7630 3895 7631 3892 7634
      3885 7636 3917 7627 3929 7617 3932 7619
      3937 7606 3864 7611 3876 7622 3876 7632
      3867 7634 3875 7637

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 23, 8:08 AM EDT	Special Weather Statement	PHI	Kent, Queen Anne's, Talbot	52 min
Sep 23, 9:03 AM EDT	Areal Flood Advisory	PHI	Kent, Queen Anne's, Talbot	3 hr
Sep 23, 9:31 AM EDT	Special Weather Statement	PHI	Kent, Queen Anne's, Talbot	59 min
Sep 23, 9:46 AM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	44 min
Sep 23, 10:35 AM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's	40 min
Sep 23, 10:55 AM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	3 hr

Nearby

Flash Flood Warnings in Maryland, 2021 Every flash flood warning in 2021

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.