Alert archive / New Jersey / Flash Flood Watches in 2009

Flash Flood Watch 8, NWS Philadelphia/Mount Holly

August 9, 20094 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 9, 2009, 11:57 AM EDT for 4 states. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued
Aug 9, 2009, 11:57 AM EDT (15:57 UTC)
Expired
Aug 9, 2009, 10:52 PM EDT
In force
11 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None
All 25 counties

New Castle County, DE, Cecil County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland 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, Carbon County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 60 km from the middle of the area, began a volume at 15:59 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 12:00Z, 4.0 hours before the alert went out and 199 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 12:00Z on 2009-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2009-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
897 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
136 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 091557
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1157 AM EDT SUN AUG 9 2009

DEZ001-MDZ008-NJZ001-007>010-012>027-PAZ054-055-060>062-067>071-
100600-
/O.NEW.KPHI.FF.A.0008.090809T1557Z-090810T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-
MIDDLESEX-WESTERN MONMOUTH-EASTERN MONMOUTH-MERCER-SALEM-
GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND-
ATLANTIC-CAPE MAY-ATLANTIC COASTAL CAPE MAY-COASTAL ATLANTIC-
COASTAL OCEAN-SOUTHEASTERN BURLINGTON-CARBON-MONROE-BERKS-LEHIGH-
NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...NEWTON...
WASHINGTON...MORRISTOWN...FLEMINGTON...SOMERVILLE...
NEW BRUNSWICK...FREEHOLD...SANDY HOOK...TRENTON...PENNSVILLE...
GLASSBORO...CAMDEN...CHERRY HILL...MOORESTOWN...MOUNT HOLLY...
JACKSON...MILLVILLE...HAMMONTON...CAPE MAY COURT HOUSE...
OCEAN CITY...ATLANTIC CITY...LONG BEACH ISLAND...
WHARTON STATE FOREST...JIM THORPE...STROUDSBURG...READING...
ALLENTOWN...BETHLEHEM...EASTON...WEST CHESTER...NORRISTOWN...
DOYLESTOWN...MEDIA...PHILADELPHIA
1157 AM EDT SUN AUG 9 2009

...FLASH FLOOD WATCH IN EFFECT THROUGH LATE TONIGHT...

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...ATLANTIC...
 ATLANTIC COASTAL CAPE MAY...CAMDEN...CAPE MAY...COASTAL 
 ATLANTIC...COASTAL OCEAN...CUMBERLAND...EASTERN MONMOUTH...
 GLOUCESTER...HUNTERDON...MERCER...MIDDLESEX...MORRIS...
 NORTHWESTERN BURLINGTON...OCEAN...SALEM...SOMERSET...
 SOUTHEASTERN BURLINGTON...SUSSEX...WARREN AND WESTERN 
 MONMOUTH. IN PENNSYLVANIA...BERKS...BUCKS...CARBON...CHESTER...
 DELAWARE...LEHIGH...MONROE...MONTGOMERY...NORTHAMPTON AND 
 PHILADELPHIA.

* THROUGH LATE TONIGHT

* A VERY MOIST AND UNSTABLE AIRMASS COVERS THE REGION. THIS
  COMBINED WITH A WARM FRONT MOVING NORTH ALONG WITH CONTINUED
  UPPER AIR DISTURBANCES MOVING THROUGH WILL ALLOW SCATTERED
  SHOWERS AND THUNDERSTORMS TO KEEP DEVELOPING THROUGH TONIGHT.
  ANY OF THE SHOWERS AND THUNDERSTORMS COULD CONTAIN TORRENTIAL
  DOWNPOURS WITH POTENTIAL RAINFALL RATES OF 2 INCHES AN HOUR.

* WHERE EVER TORRENTIAL DOWNPOURS DEVELOP, FLASH FLOODING COULD
  ALSO DEVELOP QUICKLY. SMALL STREAMS AND POOR DRAINAGE AREAS WILL
  BE THE MOST SUSCEPTIBLE FOR FLOODING.

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.

&&

$$

RNS
1 follow-up statement
000 
WGUS61 KPHI 100252
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1052 PM EDT SUN AUG 9 2009


DEZ001-MDZ008-NJZ001-007>010-012>027-PAZ054-055-060>062-067>071-
100400-
/O.CAN.KPHI.FF.A.0008.000000T0000Z-090810T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-CECIL-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-
MIDDLESEX-WESTERN MONMOUTH-EASTERN MONMOUTH-MERCER-SALEM-
GLOUCESTER-CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND-
ATLANTIC-CAPE MAY-ATLANTIC COASTAL CAPE MAY-COASTAL ATLANTIC-
COASTAL OCEAN-SOUTHEASTERN BURLINGTON-CARBON-MONROE-BERKS-LEHIGH-
NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...ELKTON...NEWTON...
WASHINGTON...MORRISTOWN...FLEMINGTON...SOMERVILLE...
NEW BRUNSWICK...FREEHOLD...SANDY HOOK...TRENTON...PENNSVILLE...
GLASSBORO...CAMDEN...CHERRY HILL...MOORESTOWN...MOUNT HOLLY...
JACKSON...MILLVILLE...HAMMONTON...CAPE MAY COURT HOUSE...
OCEAN CITY...ATLANTIC CITY...LONG BEACH ISLAND...
WHARTON STATE FOREST...JIM THORPE...STROUDSBURG...READING...
ALLENTOWN...BETHLEHEM...EASTON...WEST CHESTER...NORRISTOWN...
DOYLESTOWN...MEDIA...PHILADELPHIA
1052 PM EDT SUN AUG 9 2009

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN DELAWARE...
NORTHEAST MARYLAND...NEW JERSEY AND PENNSYLVANIA HAS BEEN
CANCELLED. WHILE SOME HEAVY RAIN IS POSSIBLE OVERNIGHT, IT SHOULD
FALL OVER AREAS IN NORTHERN NEW JERSEY THAT DID NOT HAVE HEAVY
RAIN EARLIER TODAY.

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 9:23 AM EDTAreal Flood AdvisoryPHICamden, Gloucester83 min
Aug 9, 10:33 AM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Ocean69 min
Aug 9, 1:56 PM EDTExcessive Heat WarningPHIBurlington, Camden, Gloucester, Mercer30 hr
Aug 9, 1:56 PM EDTHeat AdvisoryPHIAtlantic, Burlington, Cape May, Cumberland, Hunterdon, Middlesex and 6 more30 hr
Aug 9, 6:10 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester, Salem80 min
Aug 9, 6:20 PM EDTSpecial Marine WarningPHI115 min
Aug 9, 6:48 PM EDTSevere Thunderstorm WarningPHIAtlantic, Camden, Cumberland, Gloucester, Salem72 min
Aug 9, 7:21 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Cape May, Cumberland, Ocean69 min
Aug 9, 7:33 PM EDTSpecial Marine WarningPHI87 min
Aug 9, 9:33 AM EDTAreal Flood WarningPHIPhiladelphia51 min
Aug 9, 4:30 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton90 min
Aug 9, 5:17 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery76 min
Aug 9, 5:53 PM EDTSevere Thunderstorm WarningPHIChester82 min
Aug 9, 6:03 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Delaware, Montgomery, Philadelphia117 min
Aug 9, 7:36 PM EDTSevere Thunderstorm WarningPHIKent, Sussex69 min

Nearby

Flash Flood Watches in New Jersey, 2009Flash Flood Watches in Pennsylvania, 2009Flash Flood Watches in Maryland, 2009Every flash flood watch 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.