Alert archive / Delaware / Flash Flood Warnings in 2012

Flash Flood Warning 46, NWS Philadelphia/Mount Holly

September 3, 2012New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 3, 2012, 7:31 AM EDT for New Castle County, Delaware. It was in force for 2 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
Sep 3, 2012, 7:31 AM EDT (11:31 UTC)
Expired
Sep 3, 2012, 9:46 AM EDT
In force
2 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), 65 km from the middle of the area, began a volume at 11:32 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, 11.5 hours before the alert went out and 162 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 00:00Z on 2012-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1211 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2012-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.193958Sfc1 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
1211 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
671 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
162 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

568 
WGUS51 KPHI 031131
FFWPHI
DEC003-031430-
/O.NEW.KPHI.FF.W.0046.120903T1131Z-120903T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
731 AM EDT MON SEP 3 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN NEW CASTLE COUNTY...

* UNTIL 1030 AM EDT...

* AT 720 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN OVER SOUTHERN NEW CASTLE COUNTY. RAINFALL          
  ESTIMATES ARE OVER TWO INCHES WITHIN THE LAST HOUR.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO            
  CHAMBERSVILLE...MIDDLETOWN...AND GREEN SPRING.

ADDITIONAL RAINFALL AMOUNTS OF ONE TO TWO INCHES ARE POSSIBLE IN THE 
WARNED AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. 
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE 
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. NEVER ATTEMPT TO CROSS 
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR IN AN 
AUTOMOBILE. TURN AROUND DON'T DROWN!

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE TO THE NATIONAL WEATHER 
SERVICE BY CALLING TOLL FREE...1-877-633-6772.

&&

LAT...LON 3948 7575 3951 7557 3950 7556 3946 7558
      3942 7553 3938 7551 3936 7551 3935 7556
      3934 7555 3931 7559 3931 7563 3929 7567
      3930 7573

$$

ROBERTSON
1 follow-up statement
854 
WGUS71 KPHI 031346
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
946 AM EDT MON SEP 3 2012

DEC003-031356-
/O.CAN.KPHI.FF.W.0046.000000T0000Z-120903T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE DE-
946 AM EDT MON SEP 3 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHERN NEW CASTLE
COUNTY...

THE HEAVY RAIN HAS ENDED ACROSS THE AREA. THEREFORE...THE FLASH 
FLOOD WARNING HAS BEEN CANCELLED. THERE MAY STILL BE AREAS OF HIGH 
WATER ALONG A FEW ROADWAYS AND LOW LYING AREAS...DO NOT DRIVE INTO 
AREAS WHERE WATER COVERS THE ROAD. ADDITIONAL RAIN IS POSSIBLE 
THROUGHOUT TODAY.

LAT...LON 3948 7575 3951 7557 3950 7556 3946 7558
      3942 7553 3938 7551 3936 7551 3935 7556
      3934 7555 3931 7559 3931 7563 3929 7567
      3930 7573

$$

ROBERTSON

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 3, 6:05 AM EDTAreal Flood AdvisoryPHINew Castle3 hr
Sep 3, 8:23 AM EDTFlash Flood WarningPHINew Castle82 min
Sep 3, 1:42 PM EDTSpecial Weather StatementPHISussex93 min
Sep 3, 1:48 PM EDTAreal Flood AdvisoryPHIKent, New Castle3 hr
Sep 3, 1:53 PM EDTAreal Flood AdvisoryPHIKent, New Castle3 hr
Sep 3, 2:19 PM EDTAreal Flood AdvisoryPHISussex114 min
Sep 3, 2:39 PM EDTSpecial Weather StatementPHINew Castle66 min
Sep 3, 2:44 PM EDTAreal Flood AdvisoryPHINew Castle119 min
Sep 3, 3:00 PM EDTFlash Flood WatchPHINew Castle49 hr
Sep 3, 3:14 PM EDTFlash Flood WarningPHIKent, New Castle4 hr
Sep 3, 3:25 PM EDTTornado WarningPHIKent20 min
Sep 3, 3:58 PM EDTAreal Flood AdvisoryPHINew Castle3 hr

Nearby

Flash Flood Warnings in Delaware, 2012Every flash flood warning in 2012

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.