Alert archive / Maryland / Flash Flood Warnings in 2020

Flash Flood Warning 63, NWS Philadelphia/Mount Holly

August 13, 2020Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 13, 2020, 12:02 PM EDT for Kent County, Queen Anne's County, Maryland. It was in force for 2 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: Aug 13, 2020, 12:02 PM EDT (16:02 UTC)
Expired: Aug 13, 2020, 2:19 PM EDT
In force: 2 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

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

The radar

The Dover AFB radar (KDOX), 75 km from the middle of the area, began a volume at 16:07 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 4.0 hours before the alert went out and 111 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: 646 J/kg
Mixed-layer CIN: -243 J/kg
Mixed-layer LCL: 481 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -37 m²/s²
0-3 km storm-relative helicity: -5 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

130 
WGUS51 KPHI 131602
FFWPHI
MDC029-035-132000-
/O.NEW.KPHI.FF.W.0063.200813T1602Z-200813T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1202 PM EDT Thu Aug 13 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 400 PM EDT.

* At 1202 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. 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.

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.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 3920 7625 3928 7620 3929 7617 3930 7618
      3932 7618 3936 7586 3902 7590 3906 7623
      3909 7623 3914 7626

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

JJM

2 follow-up statements

544 
WGUS71 KPHI 131647
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1247 PM EDT Thu Aug 13 2020

MDC029-035-132000-
/O.CON.KPHI.FF.W.0063.000000T0000Z-200813T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Queen Anne's MD-Kent MD-
1247 PM EDT Thu Aug 13 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM EDT FOR
NORTHEASTERN QUEEN ANNE'S AND NORTHEASTERN KENT COUNTIES...

At 1246 PM EDT, Doppler radar indicated thunderstorms producing 
heavy rain across a portion of the warned area.  Flash flooding is 
still possible in this area. 

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.

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.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 3934 7606 3935 7598 3934 7597 3935 7597
      3935 7592 3934 7592 3935 7591 3936 7586
      3902 7590 3905 7611 3912 7611

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

JJM

607 
WGUS71 KPHI 131819
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
219 PM EDT Thu Aug 13 2020

MDC029-035-131827-
/O.CAN.KPHI.FF.W.0063.000000T0000Z-200813T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Queen Anne's MD-Kent MD-
219 PM EDT Thu Aug 13 2020

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

The heavy rain has moved out of the area. While minor flooding is 
still possible from lighter rain around the area, flooding is no 
longer expected to pose a major threat.  Please continue to heed any 
remaining road closures.

LAT...LON 3934 7606 3935 7598 3934 7597 3935 7597
      3935 7592 3934 7592 3935 7591 3936 7586
      3902 7590 3905 7611 3912 7611

$$

JJM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 13, 3:02 AM EDT	Flash Flood Watch	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	17 hr
Aug 13, 10:14 AM EDT	Flash Flood Warning	PHI	Kent, Queen Anne's	4 hr
Aug 13, 11:28 AM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	4 hr
Aug 13, 11:46 AM EDT	Areal Flood Advisory	PHI	Cecil, Kent	3 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.