Alert archive / Delaware / Flash Flood Warnings in 2023

Flash Flood Warning 4, NWS Philadelphia/Mount Holly

June 12, 2023New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 12, 2023, 4:28 PM EDT for New Castle County, Delaware. It was in force for 4 hr. 8 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 12, 2023, 4:28 PM EDT (20:28 UTC)
Expired: Jun 12, 2023, 8:30 PM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County New Castle County, DE

The radar

The Dover AFB radar (KDOX), 98 km from the middle of the area, began a volume at 20:31 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 12, 4:38 PM EDT	RAIN 3.66	2 Sw Glendale, DE	Mesonet station GW1337 BEAR.
Jun 12, 4:40 PM EDT	RAIN 2.08	2 Ene Glasgow, DE	Mesonet station AR962 Newark.
Jun 12, 4:48 PM EDT	RAIN 3.87	2 Sw Glendale, DE	Mesonet station GW1337 BEAR.
Jun 12, 5:00 PM EDT	RAIN 3.24	New Castle County Airpo, DE
Jun 12, 5:29 PM EDT	RAIN 3.9	2 Sw Glendale, DE	Mesonet station GW1337 BEAR.
Jun 12, 5:39 PM EDT	RAIN 3.94	2 Sw Glendale, DE	Mesonet station GW1337 BEAR.
Jun 12, 6:07 PM EDT	FLOOD	Washington Park, DE	Road Closure due to flooding at intersection of Washington Street and W 7th Street in New Castle.
Jun 12, 6:09 PM EDT	RAIN 4.05	2 Sw Glendale, DE	Mesonet station GW1337 BEAR.

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, 8.5 hours before the alert went out and 178 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: 62 J/kg
Mixed-layer CIN: -101 J/kg
Mixed-layer LCL: 756 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 144 m²/s²
0-3 km storm-relative helicity: 144 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

506 
WGUS51 KPHI 122028
FFWPHI
DEC003-130030-
/O.NEW.KPHI.FF.W.0004.230612T2028Z-230613T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
428 PM EDT Mon Jun 12 2023

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern New Castle County in northern Delaware...

* Until 830 PM EDT.

* At 428 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2.5 and 3.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.5 to 1.5 inches 
  are possible in the warned area. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets, and underpasses as well as other
           drainage and low lying areas.

* Some locations that may experience flash flooding include...
  Wilmington, Elsmere, New Castle, Delaware City, Newport, 
  Wilmington Manor, Stanton, Bear, Glasgow, Bellefonte, and Edgemoor.

This includes the following highways...
	Interstate 95 in Delaware between mile markers 6 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3954 7558 3959 7573 3969 7568 3975 7563
      3977 7557 3977 7553 3978 7554 3979 7550
      3978 7549 3977 7548 3963 7557

FLASH FLOOD...RADAR INDICATED

$$

Hoeflich

1 follow-up statement

109 
WGUS71 KPHI 130028
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
828 PM EDT Mon Jun 12 2023

DEC003-130038-
/O.EXP.KPHI.FF.W.0004.000000T0000Z-230613T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-
828 PM EDT Mon Jun 12 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 830 PM EDT THIS EVENING FOR 
NORTHWESTERN NEW CASTLE COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat.

LAT...LON 3954 7558 3959 7573 3969 7568 3975 7563
      3977 7557 3977 7553 3978 7554 3979 7550
      3978 7549 3977 7548 3963 7557

$$

MJL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 12, 3:13 PM EDT	Special Weather Statement	PHI	New Castle	32 min
Jun 12, 4:00 PM EDT	Areal Flood Advisory	PHI	New Castle	4 hr
Jun 12, 5:01 PM EDT	Flash Flood Warning	PHI	New Castle	4 hr

Nearby

Flash Flood Warnings in Delaware, 2023 Every flash flood warning in 2023

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.