Alert archive / Delaware / Flash Flood Warnings in 2008

Flash Flood Warning 15, NWS Philadelphia/Mount Holly

July 6, 2008Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 6, 2008, 1:46 PM EDT for Sussex County, Delaware. It was in force for 5 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: Jul 6, 2008, 1:46 PM EDT (17:46 UTC)
Expired: Jul 6, 2008, 6:53 PM EDT
In force: 5 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), 27 km from the middle of the area, began a volume at 17:48 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, 5.8 hours before the alert went out and 87 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: 957 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 479 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 46 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.

000 
WGUS51 KPHI 061747
FFWPHI
DEC005-062145-
/O.NEW.KPHI.FF.W.0015.080706T1746Z-080706T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
146 PM EDT SUN JUL 6 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 545 PM EDT

* AT 142 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED       
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA. RAINFALL 
  AMOUNTS OF OVER AN INCH HAVE ALREADY FALLEN.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO REHOBOTH
  BEACH...MILTON...LEWES...GEORGETOWN AND ELLENDALE

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

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

LAT...LON 3853 7559 3894 7537 3888 7524 3882 7519
      3880 7515 3879 7511 3881 7509 3880 7507
      3866 7505 3860 7505 3859 7504 3858 7505
      3855 7504 3846 7508
TIME...MOT...LOC 1746Z 180DEG 0KT 3860 7539

$$
 
TFG

4 follow-up statements

000 
WGUS71 KPHI 061835
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
233 PM EDT SUN JUL 6 2008

DEC005-062145-
/O.CON.KPHI.FF.W.0015.000000T0000Z-080706T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX DE-
233 PM EDT SUN JUL 6 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM EDT FOR
SUSSEX COUNTY...

AT 233 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE THUNDERSTORMS PRODUCING FLASH FLOODING OVER THE WARNED AREA.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO REHOBOTH
BEACH...MILTON...LEWES...GEORGETOWN AND ELLENDALE

THE SHEEP PEN DITCH, THE TYNDALL BRANCH AND THE BROAD CREEK IN SOUTH 
CENTRAL DELAWARE HAVE ALL RECEIVED OVER TWO INCHES OF RAIN IN THE 
PAST HOUR AND RAIN IS STILL FALLING AT THE RATE OF OVER AN INCH PER 
HOUR IN THOSE LOCATIONS. THE THUNDERSTORMS ARE SHOWING SIGNS OF 
WEAKENING IN THE COUNTY.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

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. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

LAT...LON 3853 7559 3894 7537 3888 7524 3882 7519
      3880 7515 3879 7511 3881 7509 3880 7507
      3866 7505 3860 7505 3859 7504 3858 7505
      3855 7504 3846 7508
TIME...MOT...LOC 1833Z 180DEG 0KT 3860 7539

$$
 
TFG

000 
WGUS71 KPHI 062011
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
409 PM EDT SUN JUL 6 2008

DEC005-062145-
/O.CON.KPHI.FF.W.0015.000000T0000Z-080706T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX DE-
409 PM EDT SUN JUL 6 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM EDT FOR
SUSSEX COUNTY...

AT 404 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE WEAKER THUNDERSTORMS PRODUCING FLASH FLOODING OVER THE 
WARNED AREA.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO REHOBOTH 
BEACH...MILTON...LEWES...GEORGETOWN AND ELLENDALE. DOPPLER RADAR 
STORM TOTAL ESTIMATES HAVE REACHED BETWEEN 4 AND 5 INCHES IN THE 
AREA BETWEEN MILLSBORO AND SYCAMORE IN SOUTHERN SUSSEX COUNTY WITH 
THE HEAVIEST RAIN IN THE PEPPER BRANCH AND BROAD CREEK BASINS.

ADDITIONAL RAINFALL AMOUNTS OF AROUND AN INCH ARE POSSIBLE IN THE 
WARNED AREA.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

LAT...LON 3853 7559 3894 7537 3888 7525 3882 7519
      3880 7515 3879 7511 3881 7509 3880 7507
      3866 7505 3864 7506 3859 7504 3858 7505
      3855 7504 3846 7508
TIME...MOT...LOC 2009Z 180DEG 0KT 3860 7539

$$

TFG

000 
WGUS51 KPHI 062112
FFWPHI
DEC005-062345-
/O.EXT.KPHI.FF.W.0015.000000T0000Z-080706T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
511 PM EDT SUN JUL 6 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED THE

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

* UNTIL 745 PM EDT

* AT 509 PM...THUNDERSTORMS WERE STILL OCCURRING OVER THE SOUTHERN   
  PART OF THE WARNED AREA WHERE DOPPLER RADAR WAS ESTIMATING BETWEEN
  4 AND 6 INCHES OF RAIN HAS FALLEN SINCE THIS AFTERNOON.
 
* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO GEORGETOWN
 
ADDITIONAL RAINFALL AMOUNTS OF UP TO AN INCH ARE POSSIBLE IN THE 
WARNED AREA.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

LAT...LON 3853 7559 3894 7537 3888 7525 3882 7519
      3880 7515 3879 7511 3881 7509 3880 7507
      3866 7505 3864 7506 3859 7504 3858 7505
      3855 7504 3846 7508
TIME...MOT...LOC 2111Z 180DEG 0KT 3860 7539

$$
 
TFG

000 
WGUS71 KPHI 062253
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
652 PM EDT SUN JUL 6 2008

DEC005-062302-
/O.CAN.KPHI.FF.W.0015.000000T0000Z-080706T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX DE-
652 PM EDT SUN JUL 6 2008

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

NO FLOODING IS CURRENTLY OCCURRING IN THE COUNTY AND NO ADDITIONAL 
HEAVY RAIN SHOULD OCCUR DURING THE NEXT HOUR OR TWO ACROSS THE 
SOUTHERN PART OF THE COUNTY.

LAT...LON 3853 7559 3894 7537 3888 7525 3882 7519
      3880 7515 3879 7511 3881 7509 3880 7507
      3866 7505 3864 7506 3859 7504 3858 7505
      3855 7504 3846 7508
TIME...MOT...LOC 2252Z 180DEG 0KT 3860 7539

$$
 
TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 1:45 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	90 min
Jul 6, 2:41 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	28 min
Jul 6, 2:55 PM EDT	Flash Flood Warning	PHI	Kent, Sussex	2 hr

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.