Alert archive / New Jersey / Flood Watches in 2012

Flood Watch 1, NWS Philadelphia/Mount Holly

April 21, 2012Delaware County, Philadelphia County, Pennsylvania; New Castle County, Delaware; 5 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flood watch at Apr 21, 2012, 3:15 PM EDT for Delaware County, Philadelphia County, Pennsylvania; New Castle County, Delaware; 5 counties in New Jersey. It took effect at Apr 22, 2012, 8:00 AM EDT. It was in force for 20 hr.

The area

The counties it named.

The facts

Issued
Apr 21, 2012, 3:15 PM EDT (19:15 UTC)
In effect from
Apr 22, 2012, 8:00 AM EDT
Expired
Apr 23, 2012, 3:37 AM EDT
In force
20 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties New Castle County, DE, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Somerset County, NJ, Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 57 km from the middle of the area, began a volume at 19:17 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, 7.3 hours before the alert went out and 185 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 2012-04-21Temperature 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 2012-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
718 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
49 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.

813 
WGUS61 KPHI 211915
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
315 PM EDT SAT APR 21 2012

DEZ001-NJZ008>010-012-015-PAZ067>071-221000-
/O.NEW.KPHI.FA.A.0001.120422T1200Z-120423T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-MERCER-CHESTER-
MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...MORRISTOWN...FLEMINGTON...
SOMERVILLE...NEW BRUNSWICK...TRENTON...WEST CHESTER...
NORRISTOWN...DOYLESTOWN...MEDIA...PHILADELPHIA
315 PM EDT SAT APR 21 2012

...FLOOD WATCH IN EFFECT FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

* FLOOD WATCH FOR PORTIONS OF NORTHERN DELAWARE...NEW JERSEY AND 
  SOUTHEAST PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS...IN 
  NORTHERN DELAWARE...NEW CASTLE. IN NEW JERSEY...HUNTERDON... 
  MERCER...MIDDLESEX...MORRIS AND SOMERSET. IN SOUTHEAST 
  PENNSYLVANIA...BUCKS...CHESTER...DELAWARE...MONTGOMERY AND 
  PHILADELPHIA. 

* FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT

* HEAVY RAIN IS EXPECTED TO FALL ACROSS THE REGION SUNDAY INTO
  SUNDAY EVENING. EVENT RAINFALL TOTALS OF 2.0 TO 3.5 INCHES ARE
  EXPECTED...WITH THE HIGHEST AMOUNTS ACROSS PORTIONS OF NORTHERN
  NEW JERSEY. EVEN THOUGH WE HAVE DRY DRY LATELY...THIS MUCH RAIN
  COULD RESULT IN FLOODING OF QUICK RESPONDING STREAMS AND SMALL
  RIVERS...SUCH AS THOSE IN NORTHERN DELAWARE AND SOUTHEAST
  PENNSYLVANIA. IN ADDITION...URBAN FLOODING FLOODING IS POSSIBLE.

* AT THIS TIME...MAINSTEM RIVER FLOODING IS NOT EXPECTED.
  HOWEVER...IF MORE THAN 3.5 INCHES OF RAIN FALLS IN THE PASSAIC
  BASIN...MAINSTEM RIVER FLOODING BECOMES POSSIBLE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLOOD WATCH MEANS THERE IS A POTENTIAL FOR FLOODING BASED ON
CURRENT FORECASTS.

YOU SHOULD MONITOR LATER FORECASTS AND BE ALERT FOR POSSIBLE
FLOOD WARNINGS. THOSE LIVING IN AREAS PRONE TO FLOODING SHOULD BE
PREPARED TO TAKE ACTION SHOULD FLOODING DEVELOP.

&&

$$

HAYES
4 follow-up statements
344 
WGUS61 KPHI 220816
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
416 AM EDT SUN APR 22 2012

DEZ001-NJZ008>010-012-015-PAZ067>071-222215-
/O.CON.KPHI.FA.A.0001.120422T1200Z-120423T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-MERCER-CHESTER-
MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...MORRISTOWN...FLEMINGTON...
SOMERVILLE...NEW BRUNSWICK...TRENTON...WEST CHESTER...
NORRISTOWN...DOYLESTOWN...MEDIA...PHILADELPHIA
416 AM EDT SUN APR 22 2012

...FLOOD WATCH REMAINS IN EFFECT FROM 8 AM EDT THIS MORNING
THROUGH LATE TONIGHT...

THE 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...HUNTERDON...MERCER... 
  MIDDLESEX...MORRIS AND SOMERSET. IN SOUTHEAST PENNSYLVANIA... 
  BUCKS...CHESTER...DELAWARE...MONTGOMERY AND PHILADELPHIA. 

* FROM 8 AM EDT THIS MORNING THROUGH LATE TONIGHT

* HEAVY RAIN IS EXPECTED TO FALL ACROSS THE REGION STARTING LATER
  TODAY AND CONTINUING INTO TONIGHT. EVENT RAINFALL TOTALS OF 2.0
  TO 3.5 INCHES ARE EXPECTED...WITH THE HIGHEST AMOUNTS ACROSS
  PORTIONS OF NORTHERN NEW JERSEY. EVEN THOUGH WE HAVE DRY DRY
  LATELY...THIS MUCH RAIN COULD RESULT IN FLOODING OF QUICK
  RESPONDING STREAMS AND SMALL RIVERS...SUCH AS THOSE IN NORTHERN
  DELAWARE AND SOUTHEAST PENNSYLVANIA. IN ADDITION...URBAN
  FLOODING FLOODING IS POSSIBLE.

* AT THIS TIME...MAINSTEM RIVER FLOODING IS NOT EXPECTED. 
  HOWEVER...IF MORE THAN 3.5 INCHES OF RAIN FALLS IN THE PASSAIC 
  BASIN...MAINSTEM RIVER FLOODING BECOMES POSSIBLE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLOOD WATCH MEANS THERE IS A POTENTIAL FOR FLOODING BASED ON
CURRENT FORECASTS.

YOU SHOULD MONITOR LATER FORECASTS AND BE ALERT FOR POSSIBLE
FLOOD WARNINGS. THOSE LIVING IN AREAS PRONE TO FLOODING SHOULD BE
PREPARED TO TAKE ACTION SHOULD FLOODING DEVELOP.

&&

$$
553 
WGUS61 KPHI 220823
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
423 AM EDT SUN APR 22 2012

DEZ001-NJZ008>010-012-015-PAZ067>071-222230-
/O.CON.KPHI.FA.A.0001.120422T1200Z-120423T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-MERCER-CHESTER-
MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...MORRISTOWN...FLEMINGTON...
SOMERVILLE...NEW BRUNSWICK...TRENTON...WEST CHESTER...
NORRISTOWN...DOYLESTOWN...MEDIA...PHILADELPHIA
423 AM EDT SUN APR 22 2012

...FLOOD WATCH REMAINS IN EFFECT FROM 8 AM EDT THIS MORNING
THROUGH LATE TONIGHT...

THE 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...HUNTERDON...MERCER... 
  MIDDLESEX...MORRIS AND SOMERSET. IN SOUTHEAST PENNSYLVANIA... 
  BUCKS...CHESTER...DELAWARE...MONTGOMERY AND PHILADELPHIA. 

* FROM 8 AM EDT THIS MORNING THROUGH LATE TONIGHT

* HEAVY RAIN IS EXPECTED TO FALL ACROSS THE REGION STARTING LATER
  TODAY AND CONTINUING INTO TONIGHT. EVENT RAINFALL TOTALS OF 2.0
  TO 3.5 INCHES ARE EXPECTED...WITH THE HIGHEST AMOUNTS ACROSS
  PORTIONS OF NORTHERN NEW JERSEY. EVEN THOUGH WE HAVE BEEN VERY
  DRY LATELY...THIS MUCH RAIN COULD RESULT IN FLOODING OF QUICK
  RESPONDING STREAMS AND SMALL RIVERS...SUCH AS THOSE IN NORTHERN
  DELAWARE AND SOUTHEAST PENNSYLVANIA. IN ADDITION... URBAN
  FLOODING FLOODING IS POSSIBLE.

* AT THIS TIME...MAINSTEM RIVER FLOODING IS NOT EXPECTED. 
  HOWEVER...IF MORE THAN 3.5 INCHES OF RAIN FALLS IN THE PASSAIC 
  BASIN...MAINSTEM RIVER FLOODING BECOMES POSSIBLE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLOOD WATCH MEANS THERE IS A POTENTIAL FOR FLOODING BASED ON
CURRENT FORECASTS.

YOU SHOULD MONITOR LATER FORECASTS AND BE ALERT FOR POSSIBLE
FLOOD WARNINGS. THOSE LIVING IN AREAS PRONE TO FLOODING SHOULD BE
PREPARED TO TAKE ACTION SHOULD FLOODING DEVELOP.

&&

$$
830 
WGUS61 KPHI 221933
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
333 PM EDT SUN APR 22 2012

DEZ001-NJZ008>010-012-015-PAZ067>071-230800-
/O.CON.KPHI.FA.A.0001.000000T0000Z-120423T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-MERCER-CHESTER-
MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...MORRISTOWN...FLEMINGTON...
SOMERVILLE...NEW BRUNSWICK...TRENTON...WEST CHESTER...
NORRISTOWN...DOYLESTOWN...MEDIA...PHILADELPHIA
333 PM EDT SUN APR 22 2012

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

THE 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...HUNTERDON...MERCER... 
  MIDDLESEX...MORRIS AND SOMERSET. IN SOUTHEAST PENNSYLVANIA... 
  BUCKS...CHESTER...DELAWARE...MONTGOMERY AND PHILADELPHIA. 

* THROUGH LATE TONIGHT

* HEAVY RAIN IS EXPECTED FROM LATE THIS AFTERNOON TO THE EARLY
  PORTION OF MONDAY MORNING. EVENT RAINFALL TOTALS OF 2 TO 3
  INCHES ARE EXPECTED...WITH THE HIGHEST AMOUNTS ACROSS PORTIONS
  OF NORTHERN NEW JERSEY. EVEN THOUGH WE HAVE BEEN VERY DRY
  LATELY...THIS MUCH RAIN COULD RESULT IN FLOODING OF QUICK
  RESPONDING STREAMS AND SMALL RIVERS...SUCH AS THOSE IN NORTHERN
  DELAWARE AND SOUTHEAST PENNSYLVANIA. IN ADDITION...URBAN
  FLOODING FLOODING IS POSSIBLE.

* AT THIS TIME...MAINSTEM RIVER FLOODING IS NOT EXPECTED.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLOOD WATCH MEANS THERE IS A POTENTIAL FOR FLOODING BASED ON
CURRENT FORECASTS.

YOU SHOULD MONITOR LATER FORECASTS AND BE ALERT FOR POSSIBLE
FLOOD WARNINGS. THOSE LIVING IN AREAS PRONE TO FLOODING SHOULD BE
PREPARED TO TAKE ACTION SHOULD FLOODING DEVELOP.

&&

$$
315 
WGUS61 KPHI 230737
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
337 AM EDT MON APR 23 2012

DEZ001-NJZ008>010-012-015-PAZ067>071-230845-
/O.CAN.KPHI.FA.A.0001.000000T0000Z-120423T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEW CASTLE-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-MERCER-CHESTER-
MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA-
INCLUDING THE CITIES OF...WILMINGTON...MORRISTOWN...FLEMINGTON...
SOMERVILLE...NEW BRUNSWICK...TRENTON...WEST CHESTER...
NORRISTOWN...DOYLESTOWN...MEDIA...PHILADELPHIA
337 AM EDT MON APR 23 2012

...FLOOD WATCH IS CANCELLED...

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

THE WIDESPREAD RAIN HAS MOVED NORTH OF THE AREA EARLY THIS MORNING.
WHILE SOME RUNOFF WILL CONTINUE EARLY THIS MORNING, THE THREAT FOR
FLOODING HAS DIMINISHED.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 21, 5:14 PM EDTSpecial Weather StatementPHIBerks61 min
Apr 21, 7:19 PM EDTSpecial Weather StatementPHIChester, Lehigh, Monroe, Montgomery, Northampton116 min
Apr 21, 3:31 AM EDTGale WatchPHI13 hr
Apr 21, 3:31 AM EDTSmall Craft AdvisoryPHI22 hr
Apr 21, 4:04 PM EDTGale WarningPHI36 hr
Apr 21, 6:55 PM EDTSpecial Weather StatementPHISussex65 min

Nearby

Flood Watches in New Jersey, 2012Flood Watches in Pennsylvania, 2012Flood Watches in Delaware, 2012Every 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.