Alert archive / Delaware / Flash Flood Warnings in 2017

Flash Flood Warning 47, NWS Philadelphia/Mount Holly

August 7, 2017Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 7, 2017, 2:06 PM EDT for Kent County, Sussex County, Delaware. It was in force for 4 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 7, 2017, 2:06 PM EDT (18:06 UTC)
Expired: Aug 7, 2017, 6:00 PM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Kent County, DE, Sussex County, DE

The radar

The Dover AFB radar (KDOX), 13 km from the middle of the area, began a volume at 18:10 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, 4:00 PM EDT	FLOOD	Magnolia, DE	WATER COVERING THE ROAD ON PONDEROSA DRIVE BETWEEN BARKERS LANDING ROAD AND PLAIN DEALING ROAD.

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 6.1 hours before the alert went out and 113 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: 57 J/kg
Mixed-layer CIN: -91 J/kg
Mixed-layer LCL: 996 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 176 m²/s²
0-3 km storm-relative helicity: 193 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

The text

As transmitted.

476 
WGUS51 KPHI 071806
FFWPHI
DEC001-005-072200-
/O.NEW.KPHI.FF.W.0047.170807T1806Z-170807T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Northwestern Sussex County in southern Delaware...
  Southern Kent County in central Delaware...

* Until 600 PM EDT

* At 204 PM 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, Milford, Harrington, Bowers, Woodside, Viola, Rising
  Sun-Lebanon, Rising Sun, Dover Base Housing, Big Stone Beach,
  Andrewsville, Felton, Frederica, Houston, Magnolia, Farmington,
  Riverview, Woodside East and Highland Acres.

Additional rainfall amounts of one to three inches are possible in 
the warned area. Report flooding to local law enforcement and turn 
around don't drown. 

LAT...LON 3880 7571 3900 7573 3919 7537 3905 7537
      3901 7533 3893 7529 3888 7523 3886 7522

$$

MWG

1 follow-up statement

414 
WGUS71 KPHI 071906
FFSPHI

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

DEC001-005-072200-
/O.CON.KPHI.FF.W.0047.000000T0000Z-170807T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-Kent DE-
306 PM EDT MON AUG 7 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM EDT FOR
NORTHWESTERN SUSSEX AND SOUTHERN KENT COUNTIES...

At 304 PM EDT...Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Up to five inches of rain have 
already fallen. Roadway flooding is occuring near the city of Dover. 

Some locations that could experience flooding include...
Dover, Milford, Harrington, Bowers, Woodside, Viola, Rising
Sun-Lebanon, Rising Sun, Dover Base Housing, Big Stone Beach,
Andrewsville, Felton, Frederica, Houston, Magnolia, Farmington,
Riverview, Woodside East and Highland Acres.

Additional rainfall is likely to move back into the warned area 
later this afternoon. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 3880 7571 3900 7573 3919 7537 3905 7537
      3901 7533 3893 7529 3888 7523 3886 7522

$$

MWG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 7, 9:59 AM EDT	Areal Flood Advisory	PHI	Kent, New Castle	3 hr
Aug 7, 10:44 AM EDT	Flash Flood Warning	PHI	Kent	4 hr
Aug 7, 11:41 AM EDT	Areal Flood Advisory	PHI	Kent, Sussex	3 hr
Aug 7, 12:36 PM EDT	Areal Flood Advisory	PHI	Kent	4 hr
Aug 7, 1:47 PM EDT	Special Weather Statement	PHI	Sussex	43 min
Aug 7, 1:58 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	47 min
Aug 7, 2:08 PM EDT	Tornado Warning	PHI	Sussex	37 min
Aug 7, 2:22 PM EDT	Areal Flood Advisory	PHI	Sussex	4 hr
Aug 7, 2:40 PM EDT	Areal Flood Warning	PHI	Kent	6 hr
Aug 7, 2:41 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	34 min
Aug 7, 4:57 PM EDT	Areal Flood Warning	PHI	Sussex	4 hr
Aug 7, 5:25 PM EDT	Areal Flood Warning	PHI	Kent	4 hr

Nearby

Flash Flood Warnings in Delaware, 2017 Every 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.