Alert archive / Delaware / Flash Flood Warnings in 2010

Flash Flood Warning 8, NWS Philadelphia/Mount Holly

July 14, 2010New Castle County, Delaware; Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 14, 2010, 2:52 AM EDT for New Castle County, Delaware; Delaware County, Pennsylvania. 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: Jul 14, 2010, 2:52 AM EDT (06:52 UTC)
Expired: Jul 14, 2010, 5:54 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties New Castle County, DE, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 91 km from the middle of the area, began a volume at 06:52 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 6.9 hours before the alert went out and 191 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: 260 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 1054 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 86 m²/s²
0-3 km storm-relative helicity: 124 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

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

648 
WGUS51 KPHI 140652
FFWPHI
DEC003-PAC045-141045-
/O.NEW.KPHI.FF.W.0008.100714T0652Z-100714T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
252 AM EDT WED JUL 14 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITY OF WILMINGTON...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 645 AM EDT

* AT 248 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR 
  INDICATED HEAVY RAIN FALLING NORTHERN DELAWARE AND SOUTHEAST 
  PENNSYLVANIA. MORE SHOWERS AND THUNDERSTORMS WITH VERY HEAVY RAIN 
  WILL MOVE INTO THE AREA THIS MORNING...PRODUCING AN ADDITIONAL 1 
  TO 2 INCHES OF RAIN. 
  
  VERY HEAVY RAIN FELL IN THESE LOCATIONS TUESDAY...AND THE 
  ADDITIONAL HEAVY RAIN WILL RESULT IN FLASH FLOODING. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO NEWTOWN
  SQUARE...GRADYVILLE...ELAM...CONCORDVILLE...CHELSEA...SWARTHMORE...
  NETHER PROVIDENCE TOWNSHIP...LIMA...FOLCROFT...DREXEL HILL...
  CHESTER...BROOMALL...WILMINGTON MANOR...TALLEYVILLE...STANTON...
  PIKE CREEK...NEWPORT...ELSMERE AND ARDEN

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4002 7540 3994 7525 3984 7529 3985 7530
      3984 7537 3980 7542 3979 7542 3976 7547
      3972 7548 3962 7560 3959 7559 3956 7562
      3969 7577

$$

HAYES

1 follow-up statement

717 
WGUS71 KPHI 140954
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
554 AM EDT WED JUL 14 2010

DEC003-PAC045-141003-
/O.CAN.KPHI.FF.W.0008.000000T0000Z-100714T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DELAWARE PA-NEW CASTLE DE-
554 AM EDT WED JUL 14 2010

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHERN NEW CASTLE
AND DELAWARE COUNTIES...

WITH THE HEAVY RAIN NOW NORTH OF THE WARNED AREA, THE FLOOD WARNING 
HAS BEEN CANCELLED.

LAT...LON 4002 7540 3994 7525 3984 7529 3985 7530
      3984 7537 3980 7542 3979 7542 3976 7547
      3972 7548 3962 7560 3959 7559 3956 7562
      3969 7577

$$

KRUZDLO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 13, 9:52 PM EDT	Special Weather Statement	PHI	New Castle	68 min
Jul 13, 10:22 PM EDT	Special Weather Statement	PHI	Kent, Sussex	63 min
Jul 14, 1:44 AM EDT	Special Weather Statement	PHI	New Castle	61 min
Jul 14, 2:40 AM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
Jul 14, 2:58 AM EDT	Special Weather Statement	PHI	Kent	62 min
Jul 14, 10:15 AM EDT	Flash Flood Watch	PHI	New Castle	9 hr
Jul 14, 12:47 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	3 hr
Jul 14, 12:52 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
Jul 14, 2:11 PM EDT	Flash Flood Warning	PHI	New Castle	109 min
Jul 14, 4:03 PM EDT	Areal Flood Warning	PHI	New Castle	79 min
Jul 14, 1:29 AM EDT	Areal Flood Advisory	PHI	Berks	3 hr
Jul 14, 2:32 AM EDT	Flash Flood Warning	PHI	Chester	3 hr
Jul 14, 3:27 AM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	3 hr
Jul 14, 3:46 AM EDT	Flash Flood Warning	PHI	Philadelphia	3 hr
Jul 14, 3:52 AM EDT	Special Weather Statement	PHI	Carbon	53 min
Jul 14, 3:58 AM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery	3 hr
Jul 14, 3:59 AM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jul 14, 6:06 AM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	4 hr
Jul 14, 10:04 AM EDT	Areal Flood Advisory	PHI	Berks	3 hr
Jul 14, 11:11 AM EDT	Flash Flood Warning	PHI	Berks	3 hr
Jul 14, 1:35 PM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	115 min
Jul 14, 2:36 PM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jul 14, 3:12 PM EDT	Flash Flood Warning	PHI	Bucks	63 min

Nearby

Flash Flood Warnings in Delaware, 2010 Flash Flood Warnings in Pennsylvania, 2010 Every flash flood warning in 2010

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.