Alert archive / New Jersey / Flash Flood Watches in 2007

Flash Flood Watch 2, NWS Philadelphia/Mount Holly

August 20, 20074 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 20, 2007, 3:32 PM EDT for 4 states. It took effect at Aug 21, 2007, 5:00 AM EDT. It was in force for 10 hr.

The area

The counties it named.

The facts

Issued
Aug 20, 2007, 3:32 PM EDT (19:32 UTC)
In effect from
Aug 21, 2007, 5:00 AM EDT
Expired
Aug 21, 2007, 2:47 PM EDT
In force
10 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties New Castle County, DE, Cecil County, MD, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Carbon County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 76 km from the middle of the area, began a volume at 19:33 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, 7.5 hours before the alert went out and 125 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, Phillips Aaf/Abe, MD at 12:00Z on 2007-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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, Phillips Aaf/Abe, MD at 12:00Z on 2007-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
464 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
251 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WGUS61 KPHI 201932
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
332 PM EDT MON AUG 20 2007

...A FLASH FLOOD WATCH HAS BEEN ISSUED FROM LATE TONIGHT THROUGH
TUESDAY EVENING...

.A VERY MOIST AIR MASS PUSHING EAST FROM THE OHIO VALLEY WILL BE
LIFTED OVER A STATIONARY FRONTAL BOUNDARY TO OUR SOUTHWEST. THIS
WILL PRODUCE PERIODS OF MODERATE TO AT TIMES HEAVY RAIN WITH A
FEW EMBEDDED THUNDERSTORMS.

DEZ001-MDZ008-NJZ001-007>010-012-015>019-PAZ054-055-060>062-
067>071-211000-
/O.NEW.KPHI.FF.A.0002.070821T0900Z-070822T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-
MIDDLESEX-MERCER-SALEM-GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-
CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-
DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...NEWTON...
WASHINGTON...MORRISTOWN...FLEMINGTON...SOMERVILLE...
NEW BRUNSWICK...TRENTON...PENNSVILLE...GLASSBORO...CAMDEN...
CHERRY HILL...MOORESTOWN...MOUNT HOLLY...JIM THORPE...
STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...EASTON...
WEST CHESTER...NORRISTOWN...DOYLESTOWN...MEDIA
332 PM EDT MON AUG 20 2007

...FLASH FLOOD WATCH IN EFFECT FROM LATE TONIGHT THROUGH TUESDAY
EVENING...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN DELAWARE...
  NORTHEAST MARYLAND...NEW JERSEY AND PENNSYLVANIA...INCLUDING 
  THE FOLLOWING AREAS...IN NORTHERN DELAWARE...NEW CASTLE. IN 
  NORTHEAST MARYLAND...CECIL. IN NEW JERSEY...CAMDEN...
  GLOUCESTER...HUNTERDON...MERCER...MIDDLESEX...MORRIS...
  NORTHWESTERN BURLINGTON...SALEM...SOMERSET...SUSSEX AND 
  WARREN. IN PENNSYLVANIA...BERKS...BUCKS...CARBON...CHESTER...
  DELAWARE...LEHIGH...MONROE...MONTGOMERY...NORTHAMPTON AND 
  PHILADELPHIA.

* FROM LATE TONIGHT THROUGH TUESDAY EVENING

* A FRONTAL BOUNDARY STALLED TO OUR SOUTHWEST WILL PROVIDE AN AVENUE
  FOR WEATHER DISTURBANCES TO TRACK ALONG. THIS WILL CONTINUE TO
  OCCUR TONIGHT AND DURING THE DAY TUESDAY IN THE FORM OF A COUPLE
  OF ROUNDS OF RAIN AND POSSIBLY A FEW THUNDERSTORMS. THE RAIN MAY
  FALL HEAVY AT TIMES TONIGHT AND ESPECIALLY DURING THE DAY
  TUESDAY.

TIMES OF HEAVIER RAIN MAY AFFECT TUESDAY MORNINGS COMMUTE.
ADDITIONAL RAINFALL AMOUNTS ARE ANTICIPATED TO BE 1 TO 2 INCHES
WITH LOCALLY 3 INCHES POSSIBLE. THIS AMOUNT OF RAIN, ESPECIALLY IF
IT FALLS IN A RELATIVELY SHORT PERIOD OF TIME COUPLED WITH THE
RAINFALL THAT HAS ALREADY OCCURRED IN MOST AREAS, COULD CAUSE SOME
FLOODING OF STREETS AND POOR DRAINAGE AREAS AND SOME SMALL STREAMS.
DO NOT DRIVE THROUGH FLOODED ROADS, AS THE WATER MAY BE DEEPER
THAN YOU THINK IT IS. SOME ADDITIONAL RAINFALL IS ANTICIPATED FOR
WEDNESDAY.

A FLASH FLOOD WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR
LOCALLY HEAVY RAINFALL, WHICH MAY 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.

ONE WAY TO KEEP ABREAST OF EXISTING AND FORECASTED WATER
CONDITIONS ON WATERWAYS THROUGHOUT THE REGION IS TO MONITOR THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ AVAILABLE ON OUR
HOMEPAGE AT WWW.WEATHER.GOV/PHI. JUST CLICK THE AHPS ICON ON THE
LEFT HAND MENU.

$$

GORSE/EBERWINE
3 follow-up statements
000 
WGUS61 KPHI 210056
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
856 PM EDT MON AUG 20 2007

...A FLASH FLOOD WATCH HAS BEEN ISSUED FROM LATE TONIGHT THROUGH
TUESDAY EVENING...

.A VERY MOIST AIR MASS PUSHING EAST FROM THE OHIO VALLEY WILL BE
LIFTED OVER A STATIONARY FRONTAL BOUNDARY TO OUR SOUTHWEST. THIS
OVERRUNNING WILL PRODUCE PERIODS OF MODERATE TO AT TIMES HEAVY
RAIN WITH A FEW EMBEDDED THUNDERSTORMS.

DEZ001-MDZ008-NJZ001-007>010-012-015>019-PAZ054-055-060>062-
067>071-211100-
/O.CON.KPHI.FF.A.0002.070821T0900Z-070822T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-
MIDDLESEX-MERCER-SALEM-GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-
CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-
DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...NEWTON...
WASHINGTON...MORRISTOWN...FLEMINGTON...SOMERVILLE...
NEW BRUNSWICK...TRENTON...PENNSVILLE...GLASSBORO...CAMDEN...
CHERRY HILL...MOORESTOWN...MOUNT HOLLY...JIM THORPE...
STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...EASTON...
WEST CHESTER...NORRISTOWN...DOYLESTOWN...MEDIA
856 PM EDT MON AUG 20 2007

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 5 AM EDT TUESDAY
THROUGH TUESDAY EVENING...

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NORTHERN DELAWARE...NORTHEAST MARYLAND...NEW 
  JERSEY AND PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS...IN 
  NORTHERN DELAWARE...NEW CASTLE. IN NORTHEAST MARYLAND...CECIL. 
  IN NEW JERSEY...CAMDEN...GLOUCESTER...HUNTERDON...MERCER...
  MIDDLESEX...MORRIS...NORTHWESTERN BURLINGTON...SALEM...
  SOMERSET...SUSSEX AND WARREN. IN PENNSYLVANIA...BERKS...
  BUCKS...CARBON...CHESTER...DELAWARE...LEHIGH...MONROE...
  MONTGOMERY...NORTHAMPTON AND PHILADELPHIA.

* FROM 5 AM EDT TUESDAY THROUGH TUESDAY EVENING

* A FRONTAL BOUNDARY STALLED TO OUR SOUTHWEST WILL PROVIDE AN 
  AVENUE FOR WEATHER DISTURBANCES TO TRACK ALONG. THIS WILL 
  CONTINUE TO OCCUR TONIGHT AND DURING THE DAY TUESDAY IN THE 
  FORM OF A COUPLE OF ROUNDS OF RAIN AND POSSIBLY A FEW 
  THUNDERSTORMS. THE RAIN MAY FALL HEAVY AT TIMES TONIGHT AND 
  ESPECIALLY DURING THE DAY TUESDAY. 

TIMES OF HEAVIER RAIN MAY AFFECT TUESDAY MORNINGS COMMUTE.
ADDITIONAL RAINFALL AMOUNTS ARE ANTICIPATED TO BE 1 TO 2 INCHES
WITH LOCALLY 3 INCHES POSSIBLE. THIS AMOUNT OF RAIN... ESPECIALLY
IF IT FALLS IN A RELATIVELY SHORT PERIOD OF TIME COUPLED WITH THE
RAINFALL THAT HAS ALREADY OCCURRED IN MOST AREAS... COULD CAUSE
SOME FLOODING OF STREETS AND POOR DRAINAGE AREAS AND SOME SMALL
STREAMS. DO NOT DRIVE THROUGH FLOODED ROADS... AS THE WATER MAY BE
DEEPER THAN YOU THINK IT IS. SOME ADDITIONAL RAINFALL IS
ANTICIPATED FOR WEDNESDAY.

A FLASH FLOOD WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR
LOCALLY HEAVY RAINFALL... WHICH MAY 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.

ONE WAY TO KEEP ABREAST OF EXISTING AND FORECASTED WATER
CONDITIONS ON WATERWAYS THROUGHOUT THE REGION IS TO MONITOR THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ AVAILABLE ON OUR
HOMEPAGE AT WWW.WEATHER.GOV/PHI. JUST CLICK THE AHPS ICON ON THE
LEFT HAND MENU.

$$

GORSE/EBERWINE/MIKETTA
000 
WGUS61 KPHI 210731
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
331 AM EDT TUE AUG 21 2007


DEZ001-MDZ008-NJZ001-007>010-012-015>019-PAZ054-055-060>062-
067>071-211600-
/O.CON.KPHI.FF.A.0002.070821T0900Z-070822T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-
MIDDLESEX-MERCER-SALEM-GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-
CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-
DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...NEWTON...
WASHINGTON...MORRISTOWN...FLEMINGTON...SOMERVILLE...
NEW BRUNSWICK...TRENTON...PENNSVILLE...GLASSBORO...CAMDEN...
CHERRY HILL...MOORESTOWN...MOUNT HOLLY...JIM THORPE...
STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...EASTON...
WEST CHESTER...NORRISTOWN...DOYLESTOWN...MEDIA
331 AM EDT TUE AUG 21 2007

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

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NORTHERN DELAWARE...NORTHEAST MARYLAND...NEW 
  JERSEY AND PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS...IN 
  NORTHERN DELAWARE...NEW CASTLE. IN NORTHEAST MARYLAND...CECIL. 
  IN NEW JERSEY...CAMDEN...GLOUCESTER...HUNTERDON...MERCER...
  MIDDLESEX...MORRIS...NORTHWESTERN BURLINGTON...SALEM...
  SOMERSET...SUSSEX AND WARREN. IN PENNSYLVANIA...BERKS...
  BUCKS...CARBON...CHESTER...DELAWARE...LEHIGH...MONROE...
  MONTGOMERY...NORTHAMPTON AND PHILADELPHIA.

* THROUGH THIS EVENING

* A FRONTAL BOUNDARY STALLED TO OUR SOUTH WILL PROVIDE AN AVENUE
  FOR WEATHER DISTURBANCES TO TRACK ALONG. THIS WILL CONTINUE TO
  THROUGH THE DAY TODAY IN THE FORM OF A COUPLE OF ROUNDS OF RAIN
  AND POSSIBLY A FEW THUNDERSTORMS FROM AROUND PHILADELPHIA SOUTH.
  THE RAIN MAY FALL HEAVY AT TIMES TODAY.

TIMES OF HEAVIER RAIN WILL AFFECT THIS MORNINGS COMMUTE. ADDITIONAL
RAINFALL AMOUNTS ARE ANTICIPATED TO BE 1 TO 2 INCHES WITH LOCALLY
3 INCHES POSSIBLE. THIS AMOUNT OF RAIN...ESPECIALLY IF IT FALLS IN
A RELATIVELY SHORT PERIOD OF TIME COUPLED WITH THE RAINFALL THAT
HAS ALREADY OCCURRED IN MOST AREAS...COULD CAUSE SOME FLOODING OF
STREETS AND POOR DRAINAGE AREAS AND SOME SMALL STREAMS. DO NOT
DRIVE THROUGH FLOODED ROADS...AS THE WATER MAY BE DEEPER THAN YOU
THINK IT IS. AREAS THAT HAVE RECEIVED THE HEAVIEST RAIN SO FAR
INCLUDE BERKS, BUCKS, MONTGOMERY AND PHILADELPHIA COUNTIES IN
PENNSYLVANIA AND BURLINGTON AND CAMDEN COUNTIES IN NEW JERSEY. THE
HEAVIEST RAIN WILL BE OVER BY THE EVENING COMMUTE, BUT RUNOFF
PROBLEMS COULD LINGER THROUGH THE EVENING.

A FLASH FLOOD WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR
LOCALLY HEAVY RAINFALL... WHICH MAY 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.

ONE WAY TO KEEP ABREAST OF EXISTING AND FORECASTED WATER
CONDITIONS ON WATERWAYS THROUGHOUT THE REGION IS TO MONITOR THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ AVAILABLE ON OUR
HOMEPAGE AT WWW.WEATHER.GOV/PHI. JUST CLICK THE AHPS ICON ON THE
LEFT HAND MENU.

$$

TFG
000 
WGUS61 KPHI 211847
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
247 PM EDT TUE AUG 21 2007

DEZ001-MDZ008-NJZ001-007>010-012-015>019-PAZ054-055-060>062-
067>071-212000-
/O.CAN.KPHI.FF.A.0002.000000T0000Z-070822T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-
MIDDLESEX-MERCER-SALEM-GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-
CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-
DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...NEWTON...
WASHINGTON...MORRISTOWN...FLEMINGTON...SOMERVILLE...
NEW BRUNSWICK...TRENTON...PENNSVILLE...GLASSBORO...CAMDEN...
CHERRY HILL...MOORESTOWN...MOUNT HOLLY...JIM THORPE...
STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...EASTON...
WEST CHESTER...NORRISTOWN...DOYLESTOWN...MEDIA
247 PM EDT TUE AUG 21 2007

...FLASH FLOOD WATCH IS CANCELLED...

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

WHILE THERE CAN BE SOME LOCALIZED PONDING OF WATER ON ROADWAYS,
THE THREAT FOR WIDESPREAD FLOODING HAS ENDED. IF LOCALIZED
FLOODING DOES OCCUR, THIS WILL BE HANDLED BY AN ADVISORY OR
WARNING FOR THAT SPECIFIC AREA.

$$

GORSE/EBERWINE

Nearby

Flash Flood Watches in New Jersey, 2007Flash Flood Watches in Pennsylvania, 2007Flash Flood Watches in Delaware, 2007Every flash flood watch 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.