Alert archive / Delaware / Flash Flood Warnings in 2007

Flash Flood Warning 39, NWS Philadelphia/Mount Holly

September 10, 2007Kent County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 10, 2007, 4:55 PM EDT for Kent 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 counties it named.

The facts

Issued: Sep 10, 2007, 4:55 PM EDT (20:55 UTC)
Expired: Sep 10, 2007, 7:00 PM EDT
In force: 2 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Whole counties

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 31 km from the middle of the area, began a volume at 20:55 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.9 hours before the alert went out and 66 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: 1285 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 534 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 26 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.

000 
WGUS51 KPHI 102057
FFWPHI
DEC001-102300-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
455 PM EDT MON SEP 10 2007

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL KENT COUNTY IN CENTRAL DELAWARE...

* UNTIL 700 PM EDT

* AT 450 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM SLOW-MOVING THUNDERSTORMS OVER THE WARNED
  AREA. RADAR ESTIMATED THAT 2 TO 4 INCHES OF RAIN HAS FALLEN WITHIN
  THE PAST HOUR.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MAGNOLIA

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 1.5 INCHES ARE POSSIBLE IN THE 
WARNED AREA.

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.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.

LAT...LON 3909 7552 3907 7541 3901 7540 3904 7554
TIME...MOT...LOC 2055Z 180DEG 0KT 3907 7551

$$

JRP

1 follow-up statement

000 
WGUS71 KPHI 102215
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
615 PM EDT MON SEP 10 2007

DEC001-102225-
KENT DE-
615 PM EDT MON SEP 10 2007

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL KENT
COUNTY...

SHOWERS AND THUNDERSTORMS HAVE MOVED EAST-SOUTHEAST OF THE WARNED 
AREA AND FLASH FLOODING IS NO LONGER A THREAT.

LAT...LON 3909 7552 3907 7541 3901 7540 3904 7554
TIME...MOT...LOC 2213Z 180DEG 0KT 3907 7551

$$

Nearby

Flash Flood Warnings in Delaware, 2007 Every flash flood warning in 2007

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.