Alert archive / Delaware / Flash Flood Warnings in 2018

Flash Flood Warning 89, NWS Philadelphia/Mount Holly

August 31, 2018Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 31, 2018, 7:37 PM EDT for Kent County, New Castle County, Delaware. It was in force for 4 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
Aug 31, 2018, 7:37 PM EDT (23:37 UTC)
Expired
Aug 31, 2018, 11:30 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Kent County, DE, New Castle County, DE

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.6 hours before the alert went out and 153 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2018-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 425 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2018-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
425 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
930 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

084 
WGUS51 KPHI 312337
FFWPHI
DEC001-003-010330-
/O.NEW.KPHI.FF.W.0089.180831T2337Z-180901T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
737 PM EDT FRI AUG 31 2018

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1130 PM EDT.

* At 736 PM EDT, Doppler radar indicated heavy rain across the 
  warned area. Up to 2 to 3 inches of rain have already fallen. 
  Additional rainfall is moving across the area which is expected to 
  lead to additional Flash flooding.

* Some locations that could experience flooding include...
  Smyrna, Clayton, Cheswold, Hartly, Delaney Corner, Green Spring and
  Kenton.

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.

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 3935 7558 3919 7557 3911 7574 3932 7577
      3935 7576 3936 7576

$$

Robertson
1 follow-up statement
902 
WGUS71 KPHI 010330
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1130 PM EDT FRI AUG 31 2018

DEC001-003-010340-
/O.EXP.KPHI.FF.W.0089.000000T0000Z-180901T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Kent DE-
1130 PM EDT FRI AUG 31 2018

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN NEW CASTLE AND
NORTHWESTERN KENT COUNTIES HAS EXPIRED...

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

LAT...LON 3935 7558 3919 7557 3911 7574 3932 7577
      3935 7576 3936 7576

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 1:37 AM EDTSpecial Weather StatementPHISussex53 min
Aug 31, 10:57 AM EDTAreal Flood AdvisoryPHIKent107 min
Aug 31, 11:31 AM EDTFlash Flood WarningPHIKent11 hr
Aug 31, 11:53 AM EDTSpecial Weather StatementPHIKent37 min
Aug 31, 12:00 PM EDTSevere Thunderstorm WarningPHIKent15 min
Aug 31, 12:15 PM EDTFlash Flood WarningPHIKent, Sussex7 hr
Aug 31, 12:28 PM EDTSpecial Weather StatementPHIKent32 min
Aug 31, 12:35 PM EDTSevere Thunderstorm WarningPHIKent, Sussex40 min
Aug 31, 12:54 PM EDTFlash Flood WarningPHISussex4 hr
Aug 31, 1:09 PM EDTSevere Thunderstorm WarningPHISussex51 min
Aug 31, 1:58 PM EDTSpecial Weather StatementPHISussex32 min
Aug 31, 4:27 PM EDTSpecial Weather StatementPHISussex18 min
Aug 31, 4:32 PM EDTFlash Flood WarningPHISussex4 hr
Aug 31, 4:41 PM EDTAreal Flood AdvisoryPHIKent, New Castle4 hr
Aug 31, 4:42 PM EDTSpecial Weather StatementPHISussex33 min
Aug 31, 5:00 PM EDTFlash Flood WarningPHINew Castle4 hr
Aug 31, 5:14 PM EDTSpecial Weather StatementPHISussex46 min
Aug 31, 5:38 PM EDTAreal Flood AdvisoryPHIKent, New Castle, Sussex4 hr
Aug 31, 5:48 PM EDTFlash Flood WarningPHISussex3 hr
Aug 31, 7:11 PM EDTAreal Flood WarningPHIKent, Sussex4 hr

Nearby

Flash Flood Warnings in Delaware, 2018Every 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.