Alert archive / Delaware / Flash Flood Warnings in 2023

Flash Flood Warning 22, NWS Philadelphia/Mount Holly

June 27, 2023New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 27, 2023, 2:37 AM EDT for New Castle 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 27, 2023, 2:37 AM EDT (06:37 UTC)
Expired: Jun 27, 2023, 5:55 AM EDT
In force: 3 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), 99 km from the middle of the area, began a volume at 06:41 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 6.6 hours before the alert went out and 175 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: 1362 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 1456 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

044 
WGUS51 KPHI 270637
FFWPHI
DEC003-271045-
/O.NEW.KPHI.FF.W.0022.230627T0637Z-230627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
237 AM EDT Tue Jun 27 2023

The National Weather Service in Mount Holly has issued a

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

* Until 645 AM EDT.

* At 237 AM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 4 inches of rain have fallen. The expected rainfall rate is 
  1 to 2 inches in 1 hour. Additional rainfall amounts of 0.5 to 1 
  inch are possible in the warned area. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  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, Newark, Carneys Point, Elsmere, New Castle, Penns 
  Grove, Delaware City, Newport, Arden, Stanton, Wilmington Manor, 
  and Pike Creek.

This includes the following highways...
	Interstate 95 in Delaware between mile markers 0 and 23.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles. Be especially cautious at night when 
it is harder to recognize the dangers of flooding.

&&

LAT...LON 3946 7577 3972 7579 3972 7577 3978 7574
      3982 7566 3984 7558 3983 7548 3980 7541
      3977 7546 3971 7548 3971 7550 3963 7559
      3958 7558

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

Staarmann

2 follow-up statements

776 
WGUS71 KPHI 270759
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
359 AM EDT Tue Jun 27 2023

DEC003-271045-
/O.CON.KPHI.FF.W.0022.000000T0000Z-230627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-
359 AM EDT Tue Jun 27 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 AM EDT THIS 
MORNING FOR NORTHERN NEW CASTLE COUNTY...

At 359 AM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 2 
and 4 inches of rain have fallen. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

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, Newark, Carneys Point, Elsmere, New Castle, Penns 
  Grove, Delaware City, Newport, Arden, Stanton, Wilmington Manor, 
  and Pike Creek.

This includes the following highways...
	Interstate 95 in Delaware between mile markers 1 and 23.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles. Be especially cautious at night when 
it is harder to recognize the dangers of flooding.

&&

LAT...LON 3946 7577 3972 7579 3972 7577 3978 7574
      3982 7566 3984 7558 3983 7548 3980 7541
      3977 7546 3971 7548 3971 7550 3963 7559
      3958 7558

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Staarmann

448 
WGUS71 KPHI 270955
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
555 AM EDT Tue Jun 27 2023

DEC003-271005-
/O.CAN.KPHI.FF.W.0022.000000T0000Z-230627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-
555 AM EDT Tue Jun 27 2023

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHERN NEW CASTLE COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat this morning. Additional heavy rain is possible again this 
afternoon and evening.

LAT...LON 3946 7577 3972 7579 3972 7577 3978 7574
      3982 7566 3984 7558 3983 7548 3980 7541
      3977 7546 3971 7548 3971 7550 3963 7559
      3958 7558

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 26, 9:19 PM EDT	Special Weather Statement	PHI	New Castle	26 min
Jun 26, 9:25 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	50 min
Jun 26, 9:51 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	54 min
Jun 26, 10:01 PM EDT	Flash Flood Warning	PHI	New Castle	4 hr
Jun 26, 10:33 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	42 min
Jun 26, 10:46 PM EDT	River Flood Warning	PHI	New Castle	5 hr
Jun 26, 10:54 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
Jun 26, 11:09 PM EDT	River Flood Warning	PHI	New Castle	2 hr
Jun 27, 2:09 AM EDT	Special Weather Statement	PHI	New Castle	21 min
Jun 27, 2:29 AM EDT	Special Weather Statement	PHI	New Castle	31 min
Jun 27, 3:02 AM EDT	Flood Watch	PHI	New Castle	46 min
Jun 27, 3:48 AM EDT	Flood Watch	PHI	New Castle	17 hr
Jun 27, 3:05 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	40 min
Jun 27, 3:32 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	3 hr
Jun 27, 3:41 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	22 min
Jun 27, 5:08 PM EDT	Severe Thunderstorm Warning	PHI	Kent	37 min
Jun 27, 5:17 PM EDT	Flash Flood Warning	PHI	New Castle	4 hr
Jun 27, 6:18 PM EDT	Special Weather Statement	PHI	Kent	27 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.