Alert archive / Delaware / Flash Flood Warnings in 2012

Flash Flood Warning 43, NWS Philadelphia/Mount Holly

September 2, 2012Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 2, 2012, 3:38 PM EDT for Sussex County, Delaware. It was in force for 3 hr. 1 report 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: Sep 2, 2012, 3:38 PM EDT (19:38 UTC)
Expired: Sep 2, 2012, 6:22 PM EDT
In force: 3 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), 29 km from the middle of the area, began a volume at 19:40 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.

What was reported inside it

Time	Report	Where	Remark
Sep 2, 4:25 PM EDT	FLASH FLOOD	Georgetown, DE	YARDS FLOODING.

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, 7.6 hours before the alert went out and 70 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: 448 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 1126 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 41 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.

679 
WGUS51 KPHI 021938
FFWPHI
DEC005-022330-
/O.NEW.KPHI.FF.W.0043.120902T1938Z-120902T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
338 PM EDT SUN SEP 2 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 730 PM EDT...

* AT 330 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
  VERY HEAVY RAIN FROM INTENSIFYING THUNDERSTORMS OVER SOUTHERN
  SUSSEX COUNTY. THESE THUNDERSTORMS ARE DRIFTING TOWARD THE PART
  OF THE COUNTY THAT HAD TORRENTIAL DOWNPOURS LAST WEEKEND.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO LOCATIONS 
  FROM GEORGETOWN SOUTH.

EVENT RAINFALL AMOUNTS OF TWO TO FOUR 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.

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. TURN AROUND...DON'T DROWN! NEVER TRY
TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE
RISING WATER MOVE UP TO HIGHER GROUND.

&&

LAT...LON 3845 7569 3848 7570 3880 7572 3864 7517
      3864 7512 3859 7504 3845 7504

$$

TFG

1 follow-up statement

660 
WGUS71 KPHI 022222
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
622 PM EDT SUN SEP 2 2012

DEC005-022232-
/O.CAN.KPHI.FF.W.0043.000000T0000Z-120902T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX DE-
622 PM EDT SUN SEP 2 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHERN 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 3845 7569 3848 7570 3880 7572 3864 7517
      3864 7512 3859 7504 3845 7504

$$

TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 2, 12:25 AM EDT	Special Weather Statement	PHI	Sussex	95 min
Sep 2, 12:40 PM EDT	Areal Flood Advisory	PHI	New Castle	83 min
Sep 2, 3:00 PM EDT	Areal Flood Advisory	PHI	Sussex	2 hr
Sep 2, 4:51 PM EDT	Areal Flood Advisory	PHI	Sussex	89 min

Nearby

Flash Flood Warnings in Delaware, 2012 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.