Alert archive / Pennsylvania / Flash Flood Watches in 2011

Flash Flood Watch 5, NWS Philadelphia/Mount Holly

August 7, 20115 counties in Pennsylvania; Sussex County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 7, 2011, 6:03 AM EDT for 5 counties in Pennsylvania; Sussex County, Warren County, New Jersey. It took effect at Aug 7, 2011, 10:00 AM EDT. It was in force for 10 hr.

The area

The counties it named.

The facts

Issued
Aug 7, 2011, 6:03 AM EDT (10:03 UTC)
In effect from
Aug 7, 2011, 10:00 AM EDT
Expired
Aug 7, 2011, 8:00 PM EDT
In force
10 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties Sussex County, NJ, Warren County, NJ, Berks County, PA, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 127 km from the middle of the area, began a volume at 10:04 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, 10.1 hours before the alert went out and 210 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 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5 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 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 120 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
5 J/kg
Mixed-layer CIN
-208 J/kg
Mixed-layer LCL
889 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
174 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.

242 
WGUS61 KPHI 071003
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
603 AM EDT SUN AUG 7 2011

...FLASHING FLOODING IS POSSIBLE TODAY INTO THIS EVENING... 

.SCATERED SHOWERS AND THUNDERSTORMS DEVELOPING AHEAD OF A COLD
FRONT MAY PRODUCE HEAVY RAINFALL TODAY AND EARLY THIS EVENING.
PORTIONS OF THE LEHIGH VALLEY...SOUTHERN POCONOS AND NORTHWEST NEW
JERSEY RECEIVED BETWEEN TWO AND ONE-HALF AND SIX AND ONE-HALF
INCHES OF RAIN SATURDAY AFTERNOON INTO EARLY THIS MORNING.
ADDITIONAL RAIN WITH SHOWERS AND THUNDERSTORMS COULD PRODUCE FLASH
FLOODING IN THESE AREAS.

NJZ001-007-PAZ054-055-072030-
/O.CAN.KPHI.FA.A.0009.000000T0000Z-110807T1000Z/
/O.NEW.KPHI.FF.A.0005.110807T1400Z-110808T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-CARBON-MONROE-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...JIM THORPE...
STROUDSBURG
603 AM EDT SUN AUG 7 2011

...FLASH FLOOD WATCH IN EFFECT FROM 10 AM EDT THIS MORNING
THROUGH THIS EVENING...
...FLOOD WATCH IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN NEW JERSEY AND 
  NORTHEAST PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS...IN 
  NORTHERN NEW JERSEY...SUSSEX AND WARREN. IN NORTHEAST 
  PENNSYLVANIA...CARBON AND MONROE. 

* FROM 10 AM EDT THIS MORNING THROUGH THIS EVENING

* THE WATCH AREA RECEIVED BETWEEN ONE AND ONE-HALF AND THREE
  INCHES OF RAIN SATURDAY AFTERNOON INTO EARLY THIS MORNING.
  SCATTERED SHOWERS AND THUNDERSTORMS HAVE THE POTENTIAL TO
  PRODUCE HEAVY RAIN LATER THIS MORNING INTO EARLY THIS EVENING.

* ADDITIONAL RAINFALL IN THESE AREAS COULD PRODUCE FLASH FLOODING.
  THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE THIS
  AFTERNOON AND THIS EVENING.

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.

&&

THE FLOOD WATCH FOR PORTIONS OF NORTHERN NEW JERSEY AND NORTHEAST
PENNSYLVANIA HAS BEEN CANCELLED. THE HEAVIEST RAIN HAS MOVED OUT
OF THE AREA. THERE IS POTENTIAL FOR MORE FLOODING LATER TODAY AND
THIS EVENING.

$$

NJZ008-071115-
/O.CAN.KPHI.FA.A.0009.000000T0000Z-110807T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MORRIS-
INCLUDING THE CITY OF...MORRISTOWN
603 AM EDT SUN AUG 7 2011

...FLOOD WATCH IS CANCELLED...

THE FLOOD WATCH FOR A PORTION OF NORTHERN NEW JERSEY HAS BEEN
CANCELLED. THE HEAVIEST RAIN HAS MOVED OUT OF THE AREA...AND THE
THREAT FOR FLOODING HAS DIMINISHED.

$$

PAZ060>062-072030-
/O.NEW.KPHI.FF.A.0005.110807T1400Z-110808T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BERKS-LEHIGH-NORTHAMPTON-
INCLUDING THE CITIES OF...READING...ALLENTOWN...BETHLEHEM...
EASTON
603 AM EDT SUN AUG 7 2011

...FLASH FLOOD WATCH IN EFFECT FROM 10 AM EDT THIS MORNING
THROUGH THIS EVENING...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

* FLASH FLOOD WATCH FOR A PORTION OF EAST CENTRAL PENNSYLVANIA...
  INCLUDING THE FOLLOWING AREAS...BERKS...LEHIGH AND NORTHAMPTON.

* FROM 10 AM EDT THIS MORNING THROUGH THIS EVENING

* THE WATCH AREA RECEIVED BETWEEN TWO AND ONE-HALF AND SIX AND
  ONE-HALF INCHES OF RAIN SATURDAY AFTERNOON INTO EARLY THIS
  MORNING. SCATTERED SHOWERS AND THUNDERSTORMS HAVE THE POTENTIAL
  TO PRODUCE HEAVY RAIN LATER THIS MORNING INTO EARLY THIS
  EVENING.

* ADDITIONAL RAINFALL IN THESE AREAS COULD PRODUCE FLASH FLOODING.
  THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE THIS
  AFTERNOON AND THIS EVENING.

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.

&&

$$
3 follow-up statements
602 
WGUS61 KPHI 071755
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
155 PM EDT SUN AUG 7 2011

...FLASHING FLOODING IS POSSIBLE TODAY INTO THIS EVENING...

.SCATERED SHOWERS AND THUNDERSTORMS DEVELOPING AHEAD OF A COLD
FRONT MAY PRODUCE HEAVY RAINFALL THIS AFTERNOON AND EARLY THIS
EVENING. PORTIONS OF THE LEHIGH VALLEY...SOUTHERN POCONOS AND
NORTHWEST NEW JERSEY RECEIVED BETWEEN TWO AND ONE-HALF AND SIX AND
ONE-HALF INCHES OF RAIN SATURDAY AFTERNOON INTO EARLY THIS
MORNING. ADDITIONAL RAIN WITH SHOWERS AND THUNDERSTORMS COULD
PRODUCE FLASH FLOODING IN THESE AREAS.

NJZ001-007-PAZ054-055-060>062-080000-
/O.CON.KPHI.FF.A.0005.000000T0000Z-110808T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...JIM THORPE...
STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...EASTON
155 PM EDT SUN AUG 7 2011

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

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NORTHERN NEW JERSEY AND PENNSYLVANIA...INCLUDING 
  THE FOLLOWING AREAS...IN NORTHERN NEW JERSEY...SUSSEX AND 
  WARREN. IN PENNSYLVANIA...BERKS...CARBON...LEHIGH...MONROE AND 
  NORTHAMPTON. 

* UNTIL 8 PM EDT THIS EVENING

* THE WATCH AREA RECEIVED BETWEEN TWO AND ONE-HALF AND SIX AND
  ONE-HALF INCHES OF RAIN SATURDAY AFTERNOON INTO EARLY THIS
  MORNING. SCATTERED SHOWERS AND THUNDERSTORMS HAVE THE POTENTIAL
  TO PRODUCE HEAVY RAIN LATER THIS MORNING INTO EARLY THIS
  EVENING.

* ADDITIONAL RAINFALL IN THESE AREAS COULD PRODUCE FLASH 
  FLOODING. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE 
  THIS AFTERNOON AND THIS EVENING. 

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.

&&

$$
244 
WGUS61 KPHI 071800 CCA
FFAPHI

FLOOD WATCH...CORRECTED
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
159 PM EDT SUN AUG 7 2011

...FLASH FLOODING IS POSSIBLE THIS AFTERNOON INTO THIS EVENING...

.SCATERED SHOWERS AND THUNDERSTORMS DEVELOPING AHEAD OF A COLD
FRONT MAY PRODUCE HEAVY RAINFALL THIS AFTERNOON AND EARLY THIS
EVENING. PORTIONS OF THE LEHIGH VALLEY...SOUTHERN POCONOS AND
NORTHWEST NEW JERSEY RECEIVED BETWEEN TWO AND ONE-HALF AND SIX AND
ONE-HALF INCHES OF RAIN SATURDAY AFTERNOON INTO EARLY THIS
MORNING. ADDITIONAL RAIN WITH SHOWERS AND THUNDERSTORMS COULD
PRODUCE FLASH FLOODING IN THESE AREAS.

NJZ001-007-PAZ054-055-060>062-080000-
/O.COR.KPHI.FF.A.0005.000000T0000Z-110808T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...JIM THORPE...
STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...EASTON
159 PM EDT SUN AUG 7 2011

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

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NORTHERN NEW JERSEY AND PENNSYLVANIA...INCLUDING 
  THE FOLLOWING AREAS...IN NORTHERN NEW JERSEY...SUSSEX AND 
  WARREN. IN PENNSYLVANIA...BERKS...CARBON...LEHIGH...MONROE AND 
  NORTHAMPTON. 

* UNTIL 8 PM EDT THIS EVENING

* THE WATCH AREA RECEIVED BETWEEN TWO AND ONE-HALF AND SIX AND
  ONE-HALF INCHES OF RAIN SATURDAY AFTERNOON INTO EARLY THIS
  MORNING. SCATTERED SHOWERS AND THUNDERSTORMS HAVE THE POTENTIAL
  TO PRODUCE HEAVY RAIN THIS AFTERNOON INTO EARLY THIS EVENING.

* ADDITIONAL RAINFALL IN THESE AREAS COULD PRODUCE FLASH 
  FLOODING. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE 
  THIS AFTERNOON AND THIS EVENING. 

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.

&&

$$
158 
WGUS61 KPHI 080007
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
807 PM EDT SUN AUG 7 2011



NJZ001-007-PAZ054-055-060>062-080115-
/O.EXP.KPHI.FF.A.0005.000000T0000Z-110808T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...JIM THORPE...
STROUDSBURG...READING...ALLENTOWN...BETHLEHEM...EASTON
807 PM EDT SUN AUG 7 2011

...FLASH FLOOD WATCH HAS EXPIRED...

THE FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN NEW JERSEY AND
PENNSYLVANIA HAS EXPIRED. SCATTERED HEAVY SHOWERS OCCURRED TODAY
AND MAY STILL OCCUR UNTIL ABOUT 11 PM. THERE IS VERY LITTLE
CHANCE OF ANY FLOODING EXCEPT POSSIBLY AN ISOLATED INSTANCE OF
VERY BRIEF STREET FLOODING.

$$

DRAG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 8:49 PM EDTFlood WatchPHICarbon, Monroe9 hr
Aug 6, 10:06 PM EDTSpecial Weather StatementPHIBerks84 min
Aug 6, 10:14 PM EDTSpecial Weather StatementPHIPike61 min
Aug 6, 10:33 PM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Northampton6 hr
Aug 7, 12:48 AM EDTSpecial Weather StatementPHIMontgomery57 min
Aug 7, 1:32 AM EDTAreal Flood AdvisoryPHIBerks, Bucks, Chester, Montgomery, Northampton3 hr
Aug 7, 2:29 AM EDTFlash Flood WarningPHIBerks, Lehigh, Northampton3 hr
Aug 7, 3:07 PM EDTSpecial Weather StatementPHIPhiladelphia23 min
Aug 7, 3:48 PM EDTSevere Thunderstorm WarningPHIBucks27 min
Aug 7, 7:20 PM EDTSpecial Weather StatementPHIMonroe40 min
Aug 7, 12:42 AM EDTSpecial Weather StatementPHIMorris63 min
Aug 7, 1:54 AM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Sussex, Warren3 hr
Aug 7, 3:56 AM EDTSpecial Weather StatementPHIHunterdon64 min
Aug 7, 4:45 AM EDTSpecial Weather StatementPHIHunterdon, Somerset60 min
Aug 7, 5:10 AM EDTAreal Flood AdvisoryPHIMorris, Somerset81 min
Aug 7, 5:30 AM EDTSpecial Weather StatementPHIMercer, Middlesex60 min
Aug 7, 3:25 PM EDTSpecial Weather StatementPHIMercer35 min
Aug 7, 3:34 PM EDTSpecial Weather StatementPHIWarren26 min
Aug 7, 4:19 PM EDTSpecial Weather StatementPHIMonmouth41 min
Aug 7, 5:02 PM EDTSpecial Weather StatementPHISussex28 min
Aug 7, 6:49 PM EDTSpecial Weather StatementPHISussex41 min
Aug 7, 7:11 PM EDTSpecial Weather StatementPHISussex49 min
Aug 7, 7:35 PM EDTSpecial Weather StatementPHISussex25 min

Nearby

Flash Flood Watches in Pennsylvania, 2011Flash Flood Watches in New Jersey, 2011Every flash flood watch in 2011

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.