Alert archive / New Jersey / Flash Flood Watches in 2012

Flash Flood Watch 3, NWS Philadelphia/Mount Holly

August 5, 20126 counties in New Jersey; Carbon County, Monroe County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 5, 2012, 3:49 AM EDT for 6 counties in New Jersey; Carbon County, Monroe County, Northampton County, Pennsylvania. It took effect at Aug 5, 2012, 2:00 PM EDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Aug 5, 2012, 3:49 AM EDT (07:49 UTC)
In effect from
Aug 5, 2012, 2:00 PM EDT
Expired
Aug 5, 2012, 8:12 PM EDT
In force
6 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties Hunterdon County, NJ, Middlesex County, NJ, Morris County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Carbon County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 105 km from the middle of the area, began a volume at 07:53 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 175 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 2012-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1439 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 2012-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
1439 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
740 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
40 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.

405 
WGUS61 KPHI 050749
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
349 AM EDT SUN AUG 5 2012

NJZ001-007>010-012-PAZ054-055-062-052100-
/O.NEW.KPHI.FF.A.0003.120805T1800Z-120806T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-CARBON-MONROE-
NORTHAMPTON-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...MORRISTOWN...
FLEMINGTON...SOMERVILLE...NEW BRUNSWICK...JIM THORPE...
STROUDSBURG...BETHLEHEM...EASTON
349 AM EDT SUN AUG 5 2012

...FLASH FLOOD WATCH IN EFFECT FROM 2 PM EDT THIS AFTERNOON
THROUGH MONDAY MORNING...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF NEW JERSEY AND
  PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS...IN NEW JERSEY... 
  HUNTERDON...MIDDLESEX...MORRIS...SOMERSET...SUSSEX
  AND WARREN. IN PENNSYLVANIA...CARBON...MONROE AND NORTHAMPTON.

* FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY MORNING

* MOIST UNSTABLE AIR FLOWING AHEAD OF AN APPROACHING COLD FRONT
  WILL PRODUCE SHOWERS AND THUNDERSTORMS...MAINLY LATER THIS
  AFTERNOON AND TONIGHT. THE SHOWERS AND THUNDERSTORMS WILL BE
  CAPABLE OF PRODUCE TORRENTIAL RAINS...WITH SOME LOCATIONS
  RECEIVING MORE THAN 2 INCHES OF RAIN IN LESS THAN AN HOUR. THIS
  COULD LEAD TO LOCALIZED FLASH FLOODING.

* THE GREATEST THREAT FOR FLASH FLOODING IS OVER PORTIONS OF
  NORTHWEST NEW JERSEY...GENERALLY LATER THIS AFTERNOON AND
  TONIGHT. 

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.

&&

$$
2 follow-up statements
053 
WGUS61 KPHI 051959
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
359 PM EDT SUN AUG 5 2012

NJZ001-007>010-012-PAZ054-055-062-060400-
/O.CON.KPHI.FF.A.0003.000000T0000Z-120806T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-CARBON-MONROE-
NORTHAMPTON-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...MORRISTOWN...
FLEMINGTON...SOMERVILLE...NEW BRUNSWICK...JIM THORPE...
STROUDSBURG...BETHLEHEM...EASTON
359 PM EDT SUN AUG 5 2012

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH MONDAY MORNING...

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NEW JERSEY AND PENNSYLVANIA...INCLUDING THE 
  FOLLOWING AREAS...IN NEW JERSEY...HUNTERDON...MIDDLESEX... 
  MORRIS...SOMERSET...SUSSEX AND WARREN. IN PENNSYLVANIA... 
  CARBON...MONROE AND NORTHAMPTON. 

* THROUGH MONDAY MORNING

* MOIST UNSTABLE AIR FLOWING AHEAD OF AN APPROACHING COLD FRONT
  WILL PRODUCE MORE HEAVY RAIN SHOWERS AND THUNDERSTORMS THIS
  EVENING. THE SHOWERS AND THUNDERSTORMS WILL BE CAPABLE OF
  PRODUCE TORRENTIAL RAINS...WITH SOME LOCATIONS RECEIVING MORE
  THAN 2 INCHES OF RAIN IN LESS THAN AN HOUR. THIS COULD LEAD TO
  LOCALIZED FLASH FLOODING.

* THE GREATEST THREAT FOR FLASH FLOODING IS OVER PORTIONS OF
  NORTHWEST NEW JERSEY...GENERALLY BETWEEN NOW AND MIDNIGHT. IF
  THE SPOTTY EXCESSIVE AMOUNTS DO NOT OCCUR BY MIDNIGHT
  TONIGHT...THE WATCH WILL PROBABLY BE DISCONTINUED AROUND
  MIDNIGHT.

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.

&&

$$


DRAG
160 
WGUS61 KPHI 060012
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
812 PM EDT SUN AUG 5 2012

NJZ001-007>010-012-PAZ054-055-062-060115-
/O.CAN.KPHI.FF.A.0003.000000T0000Z-120806T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-CARBON-MONROE-
NORTHAMPTON-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...MORRISTOWN...
FLEMINGTON...SOMERVILLE...NEW BRUNSWICK...JIM THORPE...
STROUDSBURG...BETHLEHEM...EASTON
812 PM EDT SUN AUG 5 2012

...FLASH FLOOD WATCH IS CANCELLED...

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

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 1:00 PM EDTSpecial Weather StatementPHIWarren30 min
Aug 5, 1:20 PM EDTSpecial Weather StatementPHISussex85 min
Aug 5, 5:13 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren77 min
Aug 5, 5:22 PM EDTSevere Thunderstorm WarningPHIGloucester, Hunterdon, Salem, Warren68 min
Aug 5, 5:38 PM EDTSevere Thunderstorm WarningPHIGloucester, Salem82 min
Aug 5, 5:52 PM EDTSpecial Marine WarningPHI83 min
Aug 5, 6:16 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 3 more74 min
Aug 5, 6:21 PM EDTSevere Thunderstorm WarningPHICumberland, Salem39 min
Aug 5, 7:09 PM EDTSpecial Weather StatementPHIAtlantic, Cumberland66 min
Aug 5, 7:30 PM EDTSpecial Weather StatementPHIAtlantic, Cumberland, Monmouth, Ocean60 min
Aug 5, 7:38 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth, Ocean67 min
Aug 5, 7:40 PM EDTSpecial Marine WarningPHI95 min
Aug 5, 12:15 PM EDTSpecial Weather StatementPHICarbon, Monroe45 min
Aug 5, 12:29 PM EDTSpecial Weather StatementPHINorthampton31 min
Aug 5, 1:03 PM EDTSpecial Weather StatementPHIMonroe27 min
Aug 5, 4:12 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton78 min
Aug 5, 4:23 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery67 min

Nearby

Flash Flood Watches in New Jersey, 2012Flash Flood Watches in Pennsylvania, 2012Every flash flood watch in 2012

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.