Alert archive / Delaware / Flash Flood Warnings in 2008

Flash Flood Warning 32, NWS Philadelphia/Mount Holly

August 15, 2008Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 15, 2008, 5:24 PM EDT for Sussex 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: Aug 15, 2008, 5:24 PM EDT (21:24 UTC)
Expired: Aug 15, 2008, 7:49 PM EDT
In force: 2 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), 47 km from the middle of the area, began a volume at 21:26 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, 9.4 hours before the alert went out and 69 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: 1087 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 657 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 50 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 152124
FFWPHI
DEC005-160130-
/O.NEW.KPHI.FF.W.0032.080815T2124Z-080816T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
524 PM EDT FRI AUG 15 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN SUSSEX COUNTY IN SOUTHERN DELAWARE...

* UNTIL 930 PM EDT

* AT 522 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED FLASH
  FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FENWICK
  ISLAND AND BETHANY BEACH

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...
EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER
GROUND.

LAT...LON 3856 7521 3855 7504 3852 7504 3851 7504
      3847 7504 3846 7503 3845 7505 3845 7520

$$

SZATKOWSKI

1 follow-up statement

000 
WGUS71 KPHI 152349
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
749 PM EDT FRI AUG 15 2008

DEC005-152358-
/O.CAN.KPHI.FF.W.0032.000000T0000Z-080816T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX DE-
749 PM EDT FRI AUG 15 2008

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

THE STORMS HAVE MOVED OUT OF THE WARNING AREA AND RAINFALL HAS 
ENDED. 

LAT...LON 3856 7521 3855 7504 3852 7504 3851 7504
      3847 7504 3846 7503 3845 7505 3845 7520

$$

SZATKOWSKI

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 15, 3:11 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	64 min
Aug 15, 3:42 PM EDT	Flash Flood Warning	PHI	Sussex	4 hr
Aug 15, 4:16 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	74 min

Nearby

Flash Flood Warnings in Delaware, 2008 Every flash flood warning in 2008

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.