Alert archive / Delaware / Flash Flood Warnings in 2009

Flash Flood Warning 37, NWS Philadelphia/Mount Holly

August 12, 2009New Castle County, Delaware; Salem County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 12, 2009, 4:55 PM EDT for New Castle County, Delaware; Salem County, New Jersey. It was in force for 3 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 12, 2009, 4:55 PM EDT (20:55 UTC)
Expired: Aug 12, 2009, 7:28 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties New Castle County, DE, Salem County, NJ

The radar

The Dover AFB radar (KDOX), 93 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 58 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: 402 J/kg
Mixed-layer CIN: -103 J/kg
Mixed-layer LCL: 1048 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 39 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.3

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 122055
FFWPHI
DEC003-NJC033-130100-
/O.NEW.KPHI.FF.W.0037.090812T2055Z-090813T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
455 PM EDT WED AUG 12 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITY OF WILMINGTON...
  NORTHWESTERN SALEM COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 900 PM EDT

* AT 453 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
SLOW MOVING THUNDERSTORMS WITH TORRENTIAL RAIN ACROSS PORTIONS OF 
THE WARNED AREA. RAINFALL AMOUNTS OF ONE TO THREE INCHES ARE 
POSSIBLE WITH RAINFALL RATES APPROACHING SIX INCHES PER HOUR.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PENNS GROVE
  AND CARNEYS POINT

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3979 7542 3978 7542 3977 7540 3972 7537
      3968 7532 3967 7525 3951 7555 3957 7553
      3958 7556 3953 7556 3952 7557 3967 7566

$$

KRUZDLO

1 follow-up statement

000 
WGUS71 KPHI 122328
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
728 PM EDT WED AUG 12 2009

DEC003-NJC033-122338-
/O.CAN.KPHI.FF.W.0037.000000T0000Z-090813T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SALEM NJ-NEW CASTLE DE-
728 PM EDT WED AUG 12 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL NEW
CASTLE AND NORTHWESTERN SALEM COUNTIES...

THE HEAVY RAIN HAS MOVED OUT OF THE AREA. THE FLASH FLOOD WARNING  
HAS BEEN CANCELLED.

LAT...LON 3979 7542 3978 7542 3977 7540 3972 7537
      3968 7532 3967 7525 3951 7555 3957 7553
      3958 7556 3953 7556 3952 7557 3967 7566

$$

KRUZDLO

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 12, 4:16 PM EDT	Areal Flood Advisory	PHI	Kent	3 hr
Aug 12, 4:39 PM EDT	Flash Flood Warning	PHI	Kent, New Castle	3 hr
Aug 12, 5:55 PM EDT	Flash Flood Warning	PHI	New Castle	100 min
Aug 12, 12:04 PM EDT	Areal Flood Advisory	PHI	Mercer	60 min
Aug 12, 12:47 PM EDT	Flash Flood Warning	PHI	Mercer	3 hr
Aug 12, 1:26 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	22 min
Aug 12, 2:55 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	50 min
Aug 12, 3:01 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Cumberland	59 min
Aug 12, 3:17 PM EDT	Flash Flood Warning	PHI	Atlantic, Cumberland	4 hr
Aug 12, 3:29 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester	60 min
Aug 12, 3:32 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Ocean	118 min
Aug 12, 4:01 PM EDT	Flash Flood Warning	PHI	Atlantic, Cape May	3 hr
Aug 12, 4:16 PM EDT	Flash Flood Warning	PHI	Cumberland, Salem	6 hr
Aug 12, 5:13 PM EDT	Areal Flood Advisory	PHI	Cape May, Cumberland	2 hr
Aug 12, 6:03 PM EDT	Areal Flood Advisory	PHI	Sussex	4 hr

Nearby

Flash Flood Warnings in Delaware, 2009 Flash Flood Warnings in New Jersey, 2009 Every flash flood warning in 2009

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.