Alert archive / Maryland / Flash Flood Warnings in 2017

Flash Flood Warning 44, NWS Philadelphia/Mount Holly

August 7, 2017Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 7, 2017, 10:44 AM EDT for Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Delaware. It was in force for 4 hr. 9 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, 2017, 10:44 AM EDT (14:44 UTC)
Expired
Aug 7, 2017, 2:45 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

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

The radar

The Dover AFB radar (KDOX), 57 km from the middle of the area, began a volume at 14:43 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 7, 12:00 PM EDTFLOODGrasonville, MDREPORTS OF FLOODING IN THE PROSPECT BAY AREA. WATER ENTERING GARAGES AS MUCH AS 6 INCHES DEEP. TIME ESTIMATED.
Aug 7, 12:11 PM EDTHEAVY RAIN 3.39Belle Point Farm, MD
Aug 7, 12:18 PM EDTHEAVY RAIN 2.49Garrison Lake Green, DE
Aug 7, 12:30 PM EDTFLOODEdge Hill, DEWATER REPORTED OVER THE ROAD ON HIGHWAY 13 JUST NORTH OF WHITE OAK ROAD. TIME ESTIMATED.
Aug 7, 12:54 PM EDTHEAVY RAIN 2.04Voshell Cove, DE
Aug 7, 1:01 PM EDTHEAVY RAIN 4.13Belle Point Farm, MD
Aug 7, 2:00 PM EDTFLOODDover, DEMINOR STREET FLOODING REPORTED IN DOWNTOWN DOVER. TIME ESTIMATED.
Aug 7, 2:04 PM EDTFLOODEdge Hill, DERIGHT LANE CLOSED ON HIGHWAY 13 JUST NORTH OF WHITE OAK ROAD.
Aug 7, 2:32 PM EDTHEAVY RAIN 3.71Laurel Bend, DE

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, 2.7 hours before the alert went out and 115 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 12:00Z on 2017-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 220 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 12:00Z on 2017-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 square meters per square second.1939587897Sfc1 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
220 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
780 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
128 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

015 
WGUS51 KPHI 071444
FFWPHI
DEC001-MDC011-035-041-071845-
/O.NEW.KPHI.FF.W.0044.170807T1444Z-170807T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1044 AM EDT MON AUG 7 2017

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Northern Kent County in central Delaware...
  Northeastern Talbot County in eastern Maryland...
  Central Queen Anne's County in northeastern Maryland...
  Northern Caroline County in eastern Maryland...

* Until 245 PM EDT

* At 1042 AM EDT...Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three inches of rain have
  already fallen. Flash flooding is expected to begin shortly in the
  areas of heaviest rain.

* Some locations that could experience flooding include...
  Dover, Centerville, Smyrna, Centreville, Camden, Greensboro,
  Oakland, Ridgely, Cheswold, Goldsboro, Queen Anne, Hartly,
  Grasonville, Starr, Woodland Beach, Copperville, Jumptown,
  Hazlettville, Dover Base Housing and Dover Speedway.

Additional rainfall amounts of two to three inches are possible in 
the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3895 7624 3896 7624 3936 7546 3927 7537
      3917 7537 3877 7621 3881 7623 3880 7621
      3883 7619 3889 7620 3891 7625 3891 7621
      3893 7620 3892 7626 3894 7627

$$

SFJ
2 follow-up statements
027 
WGUS71 KPHI 071713
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
113 PM EDT MON AUG 7 2017

DEC001-MDC011-035-041-071845-
/O.CON.KPHI.FF.W.0044.000000T0000Z-170807T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Talbot MD-Queen Anne's MD-Caroline MD-
113 PM EDT MON AUG 7 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 PM EDT FOR
NORTHERN KENT...NORTHEASTERN TALBOT...CENTRAL QUEEN ANNE'S AND
NORTHERN CAROLINE COUNTIES...

At 112 PM EDT...Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Up to five inches of rain have 
fallen. Flash flooding is expected to begin shortly. Flooding of 
several garages has been reported in Grasonville. 

Some locations that could experience flooding include...
Dover, Centerville, Smyrna, Centreville, Camden, Greensboro, Oakland,
Ridgely, Cheswold, Goldsboro, Queen Anne, Hartly, Grasonville, Starr,
Woodland Beach, Copperville, Jumptown, Hazlettville, Dover Base
Housing and Dover Speedway.

Additional rainfall amounts of One to three inches are possible in 
the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life. Turn 
around don't drown. 

&&

LAT...LON 3895 7624 3896 7624 3936 7546 3927 7537
      3917 7537 3877 7621 3881 7623 3880 7621
      3883 7619 3889 7620 3891 7625 3891 7621
      3893 7620 3892 7626 3894 7627

$$

MWG
090 
WGUS71 KPHI 071845
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
245 PM EDT MON AUG 7 2017

DEC001-MDC011-035-041-071854-
/O.EXP.KPHI.FF.W.0044.000000T0000Z-170807T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Talbot MD-Queen Anne's MD-Caroline MD-
245 PM EDT MON AUG 7 2017

...THE FLASH FLOOD WARNING FOR NORTHERN KENT...NORTHEASTERN TALBOT...
CENTRAL QUEEN ANNE'S AND NORTHERN CAROLINE COUNTIES WILL EXPIRE AT
245 PM EDT...

The heavy rain has ended. Flash Flooding is no longer expected to 
pose a threat. Please continue to heed any remaining road closures. 
An areal flood warning is in effect into the evening. 

LAT...LON 3895 7624 3896 7624 3936 7546 3927 7537
      3917 7537 3877 7621 3881 7623 3880 7621
      3883 7619 3889 7620 3891 7625 3891 7621
      3893 7620 3892 7626 3894 7627

$$

MWG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 8:54 AM EDTAreal Flood AdvisoryPHICecil, Kent, Queen Anne's3 hr
Aug 7, 11:41 AM EDTAreal Flood AdvisoryPHICaroline, Talbot3 hr
Aug 7, 1:35 PM EDTFlash Flood WarningPHICaroline, Queen Anne's, Talbot4 hr
Aug 7, 2:40 PM EDTAreal Flood WarningPHICaroline, Queen Anne's, Talbot6 hr
Aug 7, 4:32 PM EDTSpecial Weather StatementPHITalbot58 min
Aug 7, 5:25 PM EDTAreal Flood WarningPHICaroline, Queen Anne's, Talbot4 hr
Aug 7, 9:59 AM EDTAreal Flood AdvisoryPHIKent, New Castle3 hr
Aug 7, 12:36 PM EDTAreal Flood AdvisoryPHIKent4 hr
Aug 7, 1:47 PM EDTSpecial Weather StatementPHISussex43 min
Aug 7, 1:58 PM EDTSevere Thunderstorm WarningPHISussex47 min
Aug 7, 2:06 PM EDTFlash Flood WarningPHIKent, Sussex4 hr
Aug 7, 2:08 PM EDTTornado WarningPHISussex37 min
Aug 7, 2:22 PM EDTAreal Flood AdvisoryPHISussex4 hr
Aug 7, 2:41 PM EDTSevere Thunderstorm WarningPHISussex34 min
Aug 7, 4:57 PM EDTAreal Flood WarningPHISussex4 hr

Nearby

Flash Flood Warnings in Maryland, 2017Flash Flood Warnings in Delaware, 2017Every flash flood warning in 2017

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.