Alert archive / Delaware / Flash Flood Warnings in 2018

Flash Flood Warning 10, NWS Philadelphia/Mount Holly

June 9, 2018Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 9, 2018, 1:25 PM EDT for Sussex County, Delaware. It was in force for 4 hr. 7 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: Jun 9, 2018, 1:25 PM EDT (17:25 UTC)
Expired: Jun 9, 2018, 5:30 PM EDT
In force: 4 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), 35 km from the middle of the area, began a volume at 17:28 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
Jun 9, 2:09 PM EDT	HEAVY RAIN 2.4	Dagsboro, DE	2.40 OF RAIN WAS MEASURED IN ONE HOUR NEAR DAGSBORO. HEAVY RAIN CONTINUES TO FALL
Jun 9, 2:32 PM EDT	HEAVY RAIN 2.66	Williamsville, DE	RAINFALL TOTAL FROM THE LAST HOUR. HEAVY RAIN CONTINUES TO FALL
Jun 9, 2:45 PM EDT	FLASH FLOOD	Bethany Beach, DE	911 CENTER REPORTS NUMEROUS STREETS FLOODED AND VEHICLES IN WATER WITHIN THE LAST 2 HOURS
Jun 9, 2:53 PM EDT	FLASH FLOOD	Fenwick Island, DE	DELDOT REPORTS ALL LANES OF ROUTE 1 CLOSED AT ROUTE 54 DUE TO FLOODING
Jun 9, 4:00 PM EDT	FLASH FLOOD	1 S Dagsboro, DE	SWAMP RD CLOSED BETWEEN RAILROAD AVE AND DUPONT BLVD DUE TO FLASH FLOODING.
Jun 9, 5:00 PM EDT	FLOOD	1 Ese Prince George Acr, DE	ARMORY RD BETWEEN RT 26 AND TOWNSEND RD CLOSED DUE TO FLOODING.
Jun 9, 5:00 PM EDT	FLOOD	1 S Dagsboro, DE	SWAMP RD CLOSED BETWEEN RAILROAD AVE AND DUPONT BLVD DUE TO FLOODING.

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, 5.4 hours before the alert went out and 70 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.

705 
WGUS51 KPHI 091725
FFWPHI
DEC005-092130-
/O.NEW.KPHI.FF.W.0010.180609T1725Z-180609T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly NJ has issued a

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

* Until 530 PM EDT.

* At 124 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is expected to 
  begin shortly in the areas of heaviest rain.

* Some locations that could experience flooding include...
  Georgetown, Millsboro, Selbyville, Dagsboro, Millville, Henlopen
  Acres, Gumboro, Long Neck, Ocean View, Frankford, South Bethany and
  Dewey Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3845 7545 3874 7544 3875 7505 3846 7504
      3845 7505

$$

jjm

1 follow-up statement

824 
WGUS71 KPHI 092005
FFSPHI

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

DEC005-092130-
/O.CON.KPHI.FF.W.0010.000000T0000Z-180609T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex DE-
405 PM EDT SAT JUN 9 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM EDT FOR
SOUTHEASTERN SUSSEX COUNTY...

At 402 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain continuing across the warned area, with over four inches of 
rain reported near Dagsboro. With additional rain moving across 
southern Delaware, flash flooding is expected to continue through 
the afternoon hours. 

Some locations that could experience flooding include... Millsboro, 
Selbyville, Dagsboro, Millville, Gumboro, Long Neck, Ocean View, 
Frankford and South Bethany.

LAT...LON 3846 7545 3865 7544 3867 7505 3846 7504
      3845 7505

$$

jjm

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, 1:35 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, 4:20 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.