Alert archive / Delaware / Flash Flood Warnings in 2018

Flash Flood Warning 13, NWS Philadelphia/Mount Holly

June 9, 2018Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 9, 2018, 4:15 PM EDT for Sussex 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, 4:15 PM EDT (20:15 UTC)
Expired: Jun 9, 2018, 6:48 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 38 km from the middle of the area, began a volume at 20:15 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 66 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.

860 
WGUS51 KPHI 092015
FFWPHI
DEC005-092315-
/O.NEW.KPHI.FF.W.0013.180609T2015Z-180609T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Southwestern Sussex County in southern Delaware...

* Until 715 PM EDT.

* At 414 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across extreme southern Sussex County. Flash flooding 
  is expected in the areas of heaviest rain.

* Some locations that could experience flooding include...
  Laurel, Delmar and Bethel. 

LAT...LON 3846 7569 3858 7570 3857 7541 3845 7541

$$

jjm

1 follow-up statement

109 
WGUS71 KPHI 092248
FFSPHI

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

DEC005-092257-
/O.CAN.KPHI.FF.W.0013.000000T0000Z-180609T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
648 PM EDT SAT JUN 9 2018

...THE FLASH FLOOD WARNING FOR FAR SOUTHWESTERN SUSSEX COUNTY IS
CANCELLED...

The risk of life-threatening flash flooding has decreased since this 
afternoon. However, excessive runoff from the heavy rain that 
already fell and an additional one-half to one inch of rainfall that 
is expected early this evening will cause areal flooding along 
creeks and streams and in poor drainage areas. A Flood Warning has 
been issued to cover this hazard. Please continue to heed any 
remaining road closures.

LAT...LON 3846 7569 3858 7570 3857 7541 3845 7541

$$

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, 4:20 PM EDT	Flash Flood Warning	PHI	Kent	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.