Alert archive / New Jersey / Flash Flood Watches in 2013

Flash Flood Watch 6, NWS Philadelphia/Mount Holly

July 23, 20138 counties in Pennsylvania; 13 counties in New Jersey; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flash flood watch at Jul 23, 2013, 3:49 AM EDT for 8 counties in Pennsylvania; 13 counties in New Jersey; New Castle County, Delaware. It took effect at Jul 23, 2013, 6:00 AM EDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Jul 23, 2013, 3:49 AM EDT (07:49 UTC)
In effect from
Jul 23, 2013, 6:00 AM EDT
Expired
Jul 23, 2013, 3:10 PM EDT
In force
9 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None
All 22 counties

New Castle County, DE, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 63 km from the middle of the area, began a volume at 07:50 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

Brookhaven, NY (KOKX), launched 00:00Z, 7.8 hours before the alert went out and 195 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, Brookhaven, NY at 00:00Z on 2013-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 367 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2013-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 square meters per square second.193958Sfc1 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
367 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
876 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

226 
WGUS61 KPHI 230749
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
349 AM EDT TUE JUL 23 2013

...POTENTIAL FOR ADDITIONAL HEAVY SHOWERS AND THUNDERSTORMS
THROUGH TODAY...

.ANOTHER WEATHER DISTURBANCE WILL MOVE ACROSS THE AREA MAINLY
FROM MIDDAY AND INTO THIS EVENING. SHOWERS AND SCATTERED
THUNDERSTORMS ARE EXPECTED TO REDEVELOP, WITH THE POTENTIAL FOR
LOCALLY VERY HEAVY RAIN TO OCCUR.

DEZ001-NJZ001-007>010-012-013-015>020-PAZ060>062-070-071-101>106-
232000-
/O.NEW.KPHI.FF.A.0006.130723T1000Z-130724T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-
WESTERN MONMOUTH-MERCER-SALEM-GLOUCESTER-CAMDEN-
NORTHWESTERN BURLINGTON-OCEAN-BERKS-LEHIGH-NORTHAMPTON-DELAWARE-
PHILADELPHIA-WESTERN CHESTER-EASTERN CHESTER-WESTERN MONTGOMERY-
EASTERN MONTGOMERY-UPPER BUCKS-LOWER BUCKS-
INCLUDING THE CITIES OF...WILMINGTON...NEWTON...WASHINGTON...
MORRISTOWN...FLEMINGTON...SOMERVILLE...NEW BRUNSWICK...FREEHOLD...
TRENTON...PENNSVILLE...GLASSBORO...CAMDEN...CHERRY HILL...
MOORESTOWN...MOUNT HOLLY...JACKSON...READING...ALLENTOWN...
BETHLEHEM...EASTON...MEDIA...PHILADELPHIA...HONEY BROOK...
OXFORD...WEST CHESTER...KENNET SQUARE...COLLEGEVILLE...
POTTSTOWN...NORRISTOWN...LANSDALE...CHALFONT...PERKASIE...
MORRISVILLE...DOYLESTOWN
349 AM EDT TUE JUL 23 2013

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN DELAWARE...NEW 
  JERSEY AND PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS...IN 
  NORTHERN DELAWARE...NEW CASTLE. IN NEW JERSEY...CAMDEN... 
  GLOUCESTER...HUNTERDON...MERCER...MIDDLESEX...MORRIS... 
  NORTHWESTERN BURLINGTON...OCEAN...SALEM...SOMERSET...SUSSEX... 
  WARREN AND WESTERN MONMOUTH. IN PENNSYLVANIA...BERKS... 
  DELAWARE...EASTERN CHESTER...EASTERN MONTGOMERY...LEHIGH... 
  LOWER BUCKS...NORTHAMPTON...PHILADELPHIA...UPPER BUCKS... 
  WESTERN CHESTER AND WESTERN MONTGOMERY. 

* THROUGH THIS EVENING.

* SEVERAL AREAS MONDAY AFTERNOON INTO EARLY THIS MORNING PICKED UP
  VERY HEAVY RAINFALL, ON THE ORDER OF 2 TO 6 INCHES. SOME ADDITIONAL
  SHOWERS AND THUNDERSTORMS ARE EXPECTED TO OCCUR DURING THE
  COURSE OF TODAY, SOME OF WHICH CAN PRODUCE LOCALLY VERY HEAVY
  RAIN IN A SHORT PERIOD OF TIME.
 
* THE SATURATED GROUND COMBINED WITH TIMES OF ADDITIONAL HEAVY
  RAINFALL CAN RESULT IN SOME FLOODING OF ROADWAYS AND IN AREAS OF
  POOR DRAINAGE. IF ADDITIONAL HEAVY RAIN OCCURS OVER AN AREA THAT
  PREVIOUSLY PICKED UP VERY HEAVY RAINFALL, THE THREAT FOR FLASH
  FLOODING WILL INCREASE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$

GORSE
2 follow-up statements
068 
WGUS61 KPHI 231613
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1213 PM EDT TUE JUL 23 2013

...POTENTIAL FOR ADDITIONAL HEAVY SHOWERS AND THUNDERSTORMS
THROUGH TODAY...

.ANOTHER WEATHER DISTURBANCE WILL MOVE ACROSS THE AREA MAINLY
FROM MIDDAY AND INTO THIS EVENING. SHOWERS AND SCATTERED
THUNDERSTORMS ARE EXPECTED TO REDEVELOP...MOSTLY IN NEW JERSEY...
WITH THE POTENTIAL FOR LOCALLY VERY HEAVY RAIN TO OCCUR.

NJZ001-007>009-PAZ060>062-101-103-105-231715-
/O.CAN.KPHI.FF.A.0006.000000T0000Z-130724T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-MORRIS-HUNTERDON-BERKS-LEHIGH-NORTHAMPTON-
WESTERN CHESTER-WESTERN MONTGOMERY-UPPER BUCKS-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...MORRISTOWN...
FLEMINGTON...READING...ALLENTOWN...BETHLEHEM...EASTON...
HONEY BROOK...OXFORD...COLLEGEVILLE...POTTSTOWN...CHALFONT...
PERKASIE
1213 PM EDT TUE JUL 23 2013

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF NEW JERSEY AND PENNSYLVANIA
HAS BEEN CANCELLED. THE PRIMARY THREAT REGION HAS SHIFTED EASTWARD
INTO NEW JERSEY.

$$

DEZ001-NJZ010-012-013-015>020-PAZ070-071-102-104-106-240000-
/O.CON.KPHI.FF.A.0006.000000T0000Z-130724T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-SOMERSET-MIDDLESEX-WESTERN MONMOUTH-MERCER-SALEM-
GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-DELAWARE-
PHILADELPHIA-EASTERN CHESTER-EASTERN MONTGOMERY-LOWER BUCKS-
INCLUDING THE CITIES OF...WILMINGTON...SOMERVILLE...
NEW BRUNSWICK...FREEHOLD...TRENTON...PENNSVILLE...GLASSBORO...
CAMDEN...CHERRY HILL...MOORESTOWN...MOUNT HOLLY...JACKSON...
MEDIA...PHILADELPHIA...WEST CHESTER...KENNET SQUARE...
NORRISTOWN...LANSDALE...MORRISVILLE...DOYLESTOWN
1213 PM EDT TUE JUL 23 2013

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NORTHERN DELAWARE...NEW JERSEY AND SOUTHEAST 
  PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS...IN NORTHERN 
  DELAWARE...NEW CASTLE. IN NEW JERSEY...CAMDEN...GLOUCESTER... 
  MERCER...MIDDLESEX...NORTHWESTERN BURLINGTON...OCEAN...SALEM...
   SOMERSET AND WESTERN MONMOUTH. IN SOUTHEAST PENNSYLVANIA... 
  DELAWARE...EASTERN CHESTER...EASTERN MONTGOMERY...LOWER BUCKS 
  AND PHILADELPHIA. 

* UNTIL 8 PM EDT THIS EVENING

* SCATTERED HEAVY SHOWERS AND THUNDERSTORMS WITH POTENTIAL TO
  PRODUCE 1 TO 2 INCHES OF RAIN IN AN HOUR ARE EXPECTED IN THE
  WATCH AREA THIS AFTERNOON. THE HEAVY SHOWERS SHOULD NOT BE AS
  ORGANIZED AS LAST NIGHT. HOWEVER LAST NIGHTS RAINS MADE THE
  REMAINING AREAS OF THE WATCH MORE VULNERABLE TO EXCESSIVE
  RUNOFF FROM HEAVY RAIN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
757 
WGUS61 KPHI 231910
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
310 PM EDT TUE JUL 23 2013

DEZ001-NJZ010-012-013-015>020-PAZ070-071-102-104-106-232015-
/O.CAN.KPHI.FF.A.0006.000000T0000Z-130724T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-SOMERSET-MIDDLESEX-WESTERN MONMOUTH-MERCER-SALEM-
GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-DELAWARE-
PHILADELPHIA-EASTERN CHESTER-EASTERN MONTGOMERY-LOWER BUCKS-
INCLUDING THE CITIES OF...WILMINGTON...SOMERVILLE...
NEW BRUNSWICK...FREEHOLD...TRENTON...PENNSVILLE...GLASSBORO...
CAMDEN...CHERRY HILL...MOORESTOWN...MOUNT HOLLY...JACKSON...
MEDIA...PHILADELPHIA...WEST CHESTER...KENNET SQUARE...
NORRISTOWN...LANSDALE...MORRISVILLE...DOYLESTOWN
310 PM EDT TUE JUL 23 2013

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN DELAWARE...NEW
JERSEY AND SOUTHEAST PENNSYLVANIA HAS BEEN CANCELLED. 

SCATTERED HEAVY SHOWERS AND THUNDERSTORMS CAN PRODUCE BRIEF STREET
FLOODING BUT MORE WIDESPREAD AND ORGANIZED 1 TO 2 INCH PER HOUR
RAINS ARE NOT ANTICIPATED THIS AFTERNOON.

SHOWERS NOW OCCURRING FROM THE DELAWARE VALLEY ACROSS NEW JERSEY
AND NORTHERN DELAWARE SHOULD BE ENDING FROM WEST TO EAST LATE IN
THE DAY EXCEPT POSSIBLY NOT UNTIL 7 PM ALONG THE NEW JERSEY COAST.

$$

DRAG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 9:19 PM EDTAreal Flood AdvisoryPHICarbon, Monroe3 hr
Jul 22, 9:53 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh3 hr
Jul 22, 11:09 PM EDTAreal Flood AdvisoryPHIBerks, Chester3 hr
Jul 22, 11:39 PM EDTFlash Flood WarningPHIBerks, Lehigh4 hr
Jul 23, 12:11 AM EDTSpecial Weather StatementPHIChester94 min
Jul 23, 12:25 AM EDTFlash Flood WarningPHIChester4 hr
Jul 23, 1:50 AM EDTAreal Flood AdvisoryPHIBucks, Delaware, Montgomery, Philadelphia4 hr
Jul 23, 2:11 AM EDTFlash Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia4 hr
Jul 23, 4:10 PM EDTSpecial Weather StatementPHIBucks, Delaware, Philadelphia2 hr
Jul 22, 9:48 PM EDTAreal Flood AdvisoryPHIMorris4 hr
Jul 23, 2:38 AM EDTSpecial Weather StatementPHIMercer, Middlesex97 min
Jul 23, 4:02 AM EDTAreal Flood AdvisoryPHIBurlington, Monmouth, Ocean4 hr
Jul 23, 9:24 AM EDTAreal Flood WarningPHIBurlington6 hr
Jul 23, 10:32 AM EDTSpecial Weather StatementPHIAtlantic58 min
Jul 23, 11:22 AM EDTSpecial Weather StatementPHIAtlantic, Cumberland53 min
Jul 23, 11:56 AM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Cumberland, Ocean4 hr
Jul 23, 12:03 PM EDTSpecial Weather StatementPHIAtlantic57 min
Jul 23, 12:54 PM EDTSpecial Weather StatementPHIAtlantic66 min
Jul 23, 3:08 PM EDTCoastal Flood AdvisoryPHIAtlantic, Burlington, Cape May, Cumberland, Middlesex, Monmouth and 1 more9 hr
Jul 23, 2:22 AM EDTSpecial Weather StatementPHIKent, Sussex2 hr

Nearby

Flash Flood Watches in New Jersey, 2013Flash Flood Watches in Pennsylvania, 2013Flash Flood Watches in Delaware, 2013Every flash flood watch in 2013

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.