Alert archive / Pennsylvania / Flash Flood Warnings in 2010

Flash Flood Warning 3, NWS Philadelphia/Mount Holly

July 13, 2010Delaware County, Pennsylvania; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 13, 2010, 6:20 AM EDT for Delaware County, Pennsylvania; New Castle County, Delaware. It was in force for 115 min. 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
Jul 13, 2010, 6:20 AM EDT (10:20 UTC)
Expired
Jul 13, 2010, 8:15 AM EDT
In force
115 min
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), 98 km from the middle of the area, began a volume at 10:22 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

TimeReportWhereRemark
Jul 13, 6:30 AM EDTFLOODNewport, DEOLD AIRPORT ROAD FLOODED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 10.3 hours before the alert went out and 187 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-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2010-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 252 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2010-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
252 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
1039 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
197 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

749 
WGUS51 KPHI 131020
FFWPHI
DEC003-PAC045-131215-
/O.NEW.KPHI.FF.W.0003.100713T1020Z-100713T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
620 AM EDT TUE JUL 13 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 815 AM EDT

* AT 618 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA. AS MUCH AS
  2 INCHES OF RAIN HAS FALLEN IN LESS THAN 30 MINUTES NEAR 
  WILMINGTON...AND AN ADDITIONAL INCH OF RAIN IS POSSIBLE.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  GRADYVILLE...ELAM...CONCORDVILLE...CHEYNEY...CHELSEA...ASHLAND...
  NETHER PROVIDENCE TOWNSHIP...LIMA...TALLEYVILLE...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.

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 3984 7566 3984 7560 3987 7562 3989 7558
      3992 7556 3992 7553 3994 7552 3997 7548
      3994 7533 3978 7544 3976 7547 3972 7548
      3965 7556 3968 7571

$$

HAYES
1 follow-up statement
099 
WGUS71 KPHI 131050
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
650 AM EDT TUE JUL 13 2010

DEC003-PAC045-131215-
/O.CON.KPHI.FF.W.0003.000000T0000Z-100713T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DELAWARE PA-NEW CASTLE DE-
650 AM EDT TUE JUL 13 2010

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 AM EDT FOR
NORTHEASTERN NEW CASTLE AND SOUTHERN DELAWARE COUNTIES...

AT 644 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A THUNDERSTORM PRODUCING FLASH FLOODING.  THIS STORM WAS
LOCATED NEAR ARDEN...OR 6 MILES NORTH OF WILMINGTON...MOVING NORTH AT
10 MPH.

SURFACE OBSERVATIONS AND DOPPLER WEATHER INDICATE THAT 2 TO 3 INCHES 
OF RAIN HAS FALLEN IN THE WARNED AREA OVER THE PAST 45 MINUTES. AN 
ADDITIONAL THREE-QUARTERS OF AN INCH OF RAIN IS POSSIBLE ACROSS
NORTHEASTMOST NEW CASTLE COUNTY AND SOUTHERN DELAWARE COUNTY.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ELAM...
CHELSEA...CONCORDVILLE...LIMA...NETHER PROVIDENCE TOWNSHIP AND
GRADYVILLE

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.

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 3984 7566 3984 7560 3987 7562 3989 7558
      3992 7556 3992 7553 3994 7552 3997 7548
      3994 7533 3978 7544 3976 7547 3972 7548
      3965 7556 3968 7571

$$

HAYES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 8:12 PM EDTSpecial Weather StatementPHIChester63 min
Jul 12, 8:40 PM EDTSpecial Weather StatementPHIPhiladelphia65 min
Jul 12, 9:53 PM EDTSpecial Weather StatementPHIBucks, Montgomery67 min
Jul 12, 10:42 PM EDTSpecial Weather StatementPHIBerks63 min
Jul 12, 11:42 PM EDTSpecial Weather StatementPHIBerks, Lehigh63 min
Jul 13, 12:52 AM EDTAreal Flood AdvisoryPHIBerks3 hr
Jul 13, 1:06 AM EDTAreal Flood AdvisoryPHIBerks, Chester, Montgomery3 hr
Jul 13, 4:08 AM EDTAreal Flood AdvisoryPHIBerks115 min
Jul 13, 5:58 AM EDTSpecial Weather StatementPHIDelaware62 min
Jul 13, 6:07 AM EDTAreal Flood AdvisoryPHIChester, Delaware113 min
Jul 13, 7:42 AM EDTAreal Flood AdvisoryPHIBucks, Chester, Delaware, Montgomery, Philadelphia4 hr
Jul 13, 9:17 AM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Philadelphia118 min
Jul 13, 9:31 AM EDTFlash Flood WarningPHIPhiladelphia8 hr
Jul 13, 9:41 AM EDTFlash Flood WarningPHIMontgomery, Philadelphia2 hr
Jul 13, 10:28 AM EDTFlash Flood WarningPHIBucks, Montgomery, Philadelphia3 hr
Jul 13, 10:38 AM EDTAreal Flood AdvisoryPHIBucks3 hr
Jul 13, 2:48 PM EDTFlash Flood WatchPHIDelaware, Philadelphia19 hr
Jul 13, 3:08 PM EDTExcessive Heat WatchPHIDelaware, Philadelphia63 hr
Jul 13, 5:29 PM EDTAreal Flood AdvisoryPHIPhiladelphia117 min
Jul 13, 3:28 AM EDTSpecial Weather StatementPHISussex62 min
Jul 13, 3:33 AM EDTSpecial Weather StatementPHINew Castle57 min
Jul 13, 4:46 AM EDTSpecial Weather StatementPHINew Castle59 min
Jul 13, 4:48 AM EDTSpecial Weather StatementPHIKent57 min
Jul 13, 5:48 AM EDTAreal Flood AdvisoryPHISussex76 min
Jul 13, 6:30 AM EDTTornado WarningPHIKent, New Castle45 min

Nearby

Flash Flood Warnings in Pennsylvania, 2010Flash Flood Warnings in Delaware, 2010Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.