Alert archive / Delaware / Flash Flood Warnings in 2018

Flash Flood Warning 14, NWS Philadelphia/Mount Holly

June 9, 2018Kent County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 9, 2018, 4:20 PM EDT for Kent County, Delaware. It was in force for 3 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: Jun 9, 2018, 4:20 PM EDT (20:20 UTC)
Expired: Jun 9, 2018, 7:15 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 43 km from the middle of the area, began a volume at 20:20 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 8.3 hours before the alert went out and 143 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: 733 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 972 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 51 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

132 
WGUS51 KPHI 092020
FFWPHI
DEC001-100015-
/O.NEW.KPHI.FF.W.0014.180609T2020Z-180610T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
420 PM EDT SAT JUN 9 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Kent County in central Delaware...

* Until 815 PM EDT.

* At 417 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain moving into northern Kent County from the north. Some 
  of these thunderstorms have a history of producing rainfall rates 
  greater than one inch per hour. This heavy rain, in addition to 
  the heavy rain which fell over northern Kent County earlier in the 
  afternoon, is expected to produce flash flooding. 

* Some locations that could experience flooding include...
  Dover, Smyrna, Camden, Cheswold, Bowers, Woodside, Viola, Hartly,
  Rising Sun-Lebanon, Hazlettville, Dover Base Housing, Dover
  Speedway, Sandtown, Rising Sun, Wyoming, Felton, Frederica, Kenton,
  Magnolia and Little Creek.

LAT...LON 3931 7542 3931 7541 3932 7538 3930 7540
      3927 7537 3905 7537 3900 7533 3900 7573
      3926 7576

$$

JJM

2 follow-up statements

556 
WGUS71 KPHI 092212
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
612 PM EDT SAT JUN 9 2018

DEC001-100015-
/O.CON.KPHI.FF.W.0014.000000T0000Z-180610T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-
612 PM EDT SAT JUN 9 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM EDT FOR
CENTRAL KENT COUNTY...

At 609 PM EDT, Doppler radar and automated rain gauges indicated up 
to three inches of rain have fallen this afternoon. Although the 
threat of additional heavy rainfall has ended, excessive runoff from 
the earlier thunderstorms will continue early this evening. Flash 
flooding is expected to begin shortly.

Some locations that could experience flooding include...
Dover, Camden, Woodside, Viola, Hartly, Rising Sun-Lebanon, Rising
Sun, Hazlettville, Dover Base Housing, Dover Speedway, Sandtown,
Wyoming, Magnolia, Little Creek, Rodney Village, Kent Acres, Highland
Acres, Woodside East and Riverview.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3921 7537 3910 7537 3900 7564 3900 7573
      3901 7573 3921 7575

$$

JRK

649 
WGUS71 KPHI 092315
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
715 PM EDT SAT JUN 9 2018

DEC001-092325-
/O.CAN.KPHI.FF.W.0014.000000T0000Z-180610T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-
715 PM EDT SAT JUN 9 2018

...THE FLASH FLOOD WARNING FOR CENTRAL KENT COUNTY IS CANCELLED...

The heavy rain has ended and any flood waters have receded. Flooding 
is no longer expected to pose a threat. Please continue to heed any 
remaining road closures.

LAT...LON 3921 7537 3910 7537 3900 7564 3900 7573
      3901 7573 3921 7575

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 9, 12:51 PM EDT	Special Weather Statement	PHI	Sussex	24 min
Jun 9, 1:04 PM EDT	Special Weather Statement	PHI	Kent	56 min
Jun 9, 1:21 PM EDT	Severe Thunderstorm Warning	PHI	Kent	39 min
Jun 9, 1:25 PM EDT	Flash Flood Warning	PHI	Sussex	4 hr
Jun 9, 1:35 PM EDT	Areal Flood Advisory	PHI	Kent	71 min
Jun 9, 1:35 PM EDT	Special Weather Statement	PHI	Sussex	25 min
Jun 9, 2:00 PM EDT	Special Weather Statement	PHI	Sussex	30 min
Jun 9, 2:24 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	51 min
Jun 9, 2:42 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	58 min
Jun 9, 2:48 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	42 min
Jun 9, 2:53 PM EDT	Flash Flood Warning	PHI	Sussex	4 hr
Jun 9, 3:06 PM EDT	Special Weather Statement	PHI	New Castle	24 min
Jun 9, 3:26 PM EDT	Special Weather Statement	PHI	Sussex	34 min
Jun 9, 3:45 PM EDT	Special Weather Statement	PHI	Kent	45 min
Jun 9, 3:47 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	3 hr
Jun 9, 3:53 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	37 min
Jun 9, 4:06 PM EDT	Special Weather Statement	PHI	Sussex	39 min
Jun 9, 4:15 PM EDT	Flash Flood Warning	PHI	Sussex	3 hr
Jun 9, 4:24 PM EDT	Special Weather Statement	PHI	Kent	51 min
Jun 9, 5:31 PM EDT	Special Weather Statement	PHI	Sussex	44 min
Jun 9, 5:44 PM EDT	Areal Flood Warning	PHI	Sussex	4 hr
Jun 9, 6:44 PM EDT	Areal Flood Warning	PHI	Sussex	3 hr

Nearby

Flash Flood Warnings in Delaware, 2018 Every flash flood warning in 2018

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.