Alert archive / Delaware / Flash Flood Warnings in 2013

Flash Flood Warning 38, NWS Philadelphia/Mount Holly

July 12, 2013Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 12, 2013, 1:24 PM EDT for Sussex County, Delaware. It was in force for 4 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 12, 2013, 1:24 PM EDT (17:24 UTC)
Expired: Jul 12, 2013, 5:15 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), 39 km from the middle of the area, began a volume at 17:25 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.

What was reported inside it

Time	Report	Where	Remark
Jul 12, 2:00 PM EDT	FLASH FLOOD	Williamsville, DE	ROAD CLOSURES DUE TO ROADWAY COLLAPSE ALONG PORTIONS OF LIGHTHOUSE ROAD AND SAND COVE ROAD.
Jul 12, 2:55 PM EDT	FLASH FLOOD	Frankford, DE	6 INCHES OF WATER IN ROADWAYS. WATER RESUCES IN PROGRESS IN MILLVILLE AND OCEANVIEW

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 5.4 hours before the alert went out and 78 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: 522 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 476 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

351 
WGUS51 KPHI 121724
FFWPHI
DEC005-122115-
/O.NEW.KPHI.FF.W.0038.130712T1724Z-130712T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
124 PM EDT FRI JUL 12 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 515 PM EDT...

* AT 117 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAINS FROM A LINE OF SHOWERS AND THUNDERSTORMS OVER     
  NORTHERN KENT COUNTY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED REHOBOTH      
  BEACH, LONG NECK, AND BETHANY BEACH.

NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THAT RAINFALL 
AMOUNTS UP TO 4 INCHES HAVE ACCUMULATED SINCE LATE THIS MORNING. 
MORE RAIN IS EXPECTED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DRIVING INTO FLOOD WATERS COULD COST YOU YOUR LIFE...OR AT THE VERY
LEAST...THOUSANDS OF DOLLARS OF VEHICLE DAMAGE. NEARLY HALF OF ALL
FLASH FLOOD FATALITIES ARE AUTO RELATED. TURN AROUND...DON'T DROWN.

&&

LAT...LON 3845 7524 3846 7525 3879 7524 3879 7508
      3867 7506 3866 7505 3866 7506 3860 7505
      3860 7504 3859 7505 3851 7504 3845 7505

$$

KRUZDLO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 4:08 AM EDT	Flash Flood Watch	PHI	Kent, New Castle, Sussex	17 hr
Jul 12, 7:21 AM EDT	Areal Flood Advisory	PHI	Sussex	10 hr
Jul 12, 9:20 AM EDT	Areal Flood Advisory	PHI	Kent, Sussex	8 hr
Jul 12, 12:15 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	14 hr
Jul 12, 1:18 PM EDT	Flash Flood Warning	PHI	Kent	4 hr
Jul 12, 1:33 PM EDT	Flash Flood Warning	PHI	Sussex	4 hr
Jul 12, 4:00 PM EDT	Areal Flood Advisory	PHI	New Castle	7 hr
Jul 12, 5:18 PM EDT	Areal Flood Advisory	PHI	Sussex	4 hr

Nearby

Flash Flood Warnings in Delaware, 2013 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.