Alert archive / Delaware / Flash Flood Warnings in 2013

Flash Flood Warning 52, NWS Philadelphia/Mount Holly

August 9, 2013Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 9, 2013, 7:40 PM EDT for Sussex 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 9, 2013, 7:40 PM EDT (23:40 UTC)
Expired
Aug 9, 2013, 11:30 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), 31 km from the middle of the area, began a volume at 23:40 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.7 hours before the alert went out and 76 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, Wallops Is Stn, VA at 12:00Z on 2013-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 295 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, Wallops Is Stn, VA at 12:00Z on 2013-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 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
295 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
1059 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

558 
WGUS51 KPHI 092340
FFWPHI
DEC005-100330-
/O.NEW.KPHI.FF.W.0052.130809T2340Z-130810T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
740 PM EDT FRI AUG 9 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SUSSEX COUNTY...

* UNTIL 1130 PM EDT...

* AT 734 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  OVER TWO INCHES OF RAIN HAS FALLEN IN CENTRAL DELAWARE NEAR        
  GEORGETOWN IN LESS THAN ONE HOUR. ADDITIONAL RAIN IS EXPECTED FOR  
  THE NEXT HOUR OR SO...WHICH COULD RESULT IN FLOODING OF LOW LYING  
  AREAS.

* LOCATIONS IN THE WARNING INCLUDE GEORGETOWN AND SEAFORD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
NEVER ATTEMPT TO CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN 
DEPTH BY FOOT OR IN AN AUTOMOBILE. TURN AROUND DON'T DROWN!

&&

LAT...LON 3846 7569 3876 7570 3876 7508 3868 7506
      3863 7506 3863 7505 3860 7506 3860 7505
      3859 7506 3845 7504

$$

FORECASTER:JJM
1 follow-up statement
290 
WGUS71 KPHI 100156
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
956 PM EDT FRI AUG 9 2013

DEC005-100207-
/O.CAN.KPHI.FF.W.0052.000000T0000Z-130810T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX DE-
956 PM EDT FRI AUG 9 2013

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SUSSEX COUNTY...

THE WATERS FROM THE EARLIER HEAVY RAINS ARE RECEDING AND FLOOD WATERS
NO LONGER POSE A THREAT TO LIFE OR PROPERTY. THEREFORE...THE FLASH
FLOOD WARNING HAS BEEN CANCELLED.

LAT...LON 3846 7569 3876 7570 3876 7508 3868 7506
      3863 7506 3863 7505 3860 7506 3860 7505
      3859 7506 3845 7504

$$

FORECASTER:JJM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 7:03 PM EDTSpecial Weather StatementPHISussex57 min

Nearby

Flash Flood Warnings in Delaware, 2013Every flash flood warning in 2013

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.