Alert archive / New Jersey / Flash Flood Watches in 2018

Flash Flood Watch 12, NWS Philadelphia/Mount Holly

August 11, 20184 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 11, 2018, 3:24 AM EDT for 4 states. It was in force for 20 hr.

The area

The counties it named.

The facts

Issued
Aug 11, 2018, 3:24 AM EDT (07:24 UTC)
Expired
Aug 11, 2018, 11:25 PM EDT
In force
20 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None
All 30 counties

Kent County, DE, New Castle County, DE, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Atlantic County, NJ, Burlington County, NJ, Camden 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, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 07:26 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, 7.4 hours before the alert went out and 212 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 2018-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 155 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 2018-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
155 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
1448 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

856 
WGUS61 KPHI 110724
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
324 AM EDT Sat Aug 11 2018

DEZ001-NJZ001-007>010-012>019-PAZ054-055-060>062-070-071-101>106-
111700-
/O.NEW.KPHI.FF.A.0012.180811T0724Z-180812T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Eastern Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Wilmington, Newton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Freehold, 
Sandy Hook, Trenton, Pennsville, Glassboro, Camden, Cherry Hill, 
Moorestown, Mount Holly, Jim Thorpe, Stroudsburg, Reading, 
Allentown, Bethlehem, Easton, Media, Philadelphia, Honey Brook, 
Oxford, West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
324 AM EDT Sat Aug 11 2018

...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, New 
  Jersey, and Pennsylvania, including the following areas, in 
  northern Delaware, New Castle. In New Jersey, Camden, Eastern 
  Monmouth, Gloucester, Hunterdon, Mercer, Middlesex, Morris, 
  Northwestern Burlington, Salem, Somerset, Sussex, Warren, and 
  Western Monmouth. In Pennsylvania, Berks, Carbon, Delaware, 
  Eastern Chester, Eastern Montgomery, Lehigh, Lower Bucks, 
  Monroe, Northampton, Philadelphia, Upper Bucks, Western 
  Chester, and Western Montgomery. 

* Through late tonight

* Showers and thunderstorms producing heavy downpours will develop
  this morning and continue through tonight. The trend appears for
  there to be one round early this morning, followed by a
  potential lull in the heavy rain from late morning through early
  afternoon. Another round of slow moving showers and
  thunderstorms will develop this afternoon through this evening.
  Although rainfall amounts area wide will generally average less
  than one inch, there is the potential for locally heavy rainfall
  of 2 to 3 inches, possibly more, where thunderstorms train over
  the same location. The main area of risk for the potential
  flooding will be along and north of the I-95 urban corridor. 

* Heavy rainfall within a short period of time can lead to 
  rapidly rising water and flash flooding, particularly in urban 
  areas, and along small creeks and streams. The ground remains 
  fairly saturated due to recent heavy rains over the past several
  weeks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that there is the potential for flash
flooding which can be life-threatening. Heavy rain is expected to
occur over a short period of time. Rapidly rising flood waters
may quickly inundate roadways and areas of poor drainage. Streams
and creeks could leave their banks, flooding nearby properties.

Please monitor the forecast, especially if you live in a location
that is prone to flooding. Be prepared to take action if a flash 
flood warning is issued for your area.

&&

$$

MPS
3 follow-up statements
921 
WGUS61 KPHI 111443
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
1043 AM EDT Sat Aug 11 2018

DEZ002-MDZ008-012-015-NJZ020>022-025>027-120500-
/O.EXA.KPHI.FF.A.0012.000000T0000Z-180812T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent-Cecil-Kent MD-Queen Annes-Ocean-Cumberland-Atlantic-
Coastal Atlantic-Coastal Ocean-Southeastern Burlington-
Including the cities of Dover, Elkton, Chestertown, Centreville, 
Jackson, Millville, Hammonton, Atlantic City, Long Beach Island, 
and Wharton State Forest
1043 AM EDT Sat Aug 11 2018

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

The National Weather Service in Mount Holly has expanded the

* Flash Flood Watch to include portions of central Delaware, 
  northeast Maryland, and southern New Jersey, including the 
  following areas, in central Delaware, Kent. In northeast 
  Maryland, Cecil, Kent MD, and Queen Annes. In southern New 
  Jersey, Atlantic, Coastal Atlantic, Coastal Ocean, Cumberland, 
  Ocean, and Southeastern Burlington. 

* Through late tonight

* Showers and thunderstorms producing heavy downpours will develop
  again this afternoon and continue through tonight. Although
  rainfall amounts area wide will generally average less than one
  inch, there is the potential for locally heavy rainfall of 2 to
  3 inches, possibly more, where thunderstorms train over the same
  location.

* Heavy rainfall within a short period of time can lead to 
  rapidly rising water and flash flooding, particularly in urban 
  areas, and along small creeks and streams. The ground remains 
  fairly saturated due to recent heavy rains over the past 
  several weeks. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that there is the potential for flash
flooding which can be life-threatening. Heavy rain is expected to
occur over a short period of time. Rapidly rising flood waters
may quickly inundate roadways and areas of poor drainage. Streams
and creeks could leave their banks, flooding nearby properties.

Please monitor the forecast, especially if you live in a location
that is prone to flooding. Be prepared to take action if a flash
flood warning is issued for your area.

&&

$$

DEZ001-NJZ001-007>010-012>019-PAZ054-055-060>062-070-071-101>106-
120500-
/O.CON.KPHI.FF.A.0012.000000T0000Z-180812T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Eastern Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Wilmington, Newton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Freehold, 
Sandy Hook, Trenton, Pennsville, Glassboro, Camden, Cherry Hill, 
Moorestown, Mount Holly, Jim Thorpe, Stroudsburg, Reading, 
Allentown, Bethlehem, Easton, Media, Philadelphia, Honey Brook, 
Oxford, West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
1043 AM EDT Sat Aug 11 2018

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

The Flash Flood Watch continues for

* Portions of northern Delaware, New Jersey, and Pennsylvania, 
  including the following areas, in northern Delaware, New 
  Castle. In New Jersey, Camden, Eastern Monmouth, Gloucester, 
  Hunterdon, Mercer, Middlesex, Morris, Northwestern Burlington, 
  Salem, Somerset, Sussex, Warren, and Western Monmouth. In 
  Pennsylvania, Berks, Carbon, Delaware, Eastern Chester, 
  Eastern Montgomery, Lehigh, Lower Bucks, Monroe, Northampton, 
  Philadelphia, Upper Bucks, Western Chester, and Western 
  Montgomery. 

* Through late tonight

* Showers and thunderstorms producing heavy downpours will develop
  again this afternoon and continue through tonight. Although
  rainfall amounts area wide will generally average less than one
  inch, there is the potential for locally heavy rainfall of 2 to
  3 inches, possibly more, where thunderstorms train over the same
  location.

* Heavy rainfall within a short period of time can lead to 
  rapidly rising water and flash flooding, particularly in urban 
  areas, and along small creeks and streams. The ground remains 
  fairly saturated due to recent heavy rains over the past 
  several weeks. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that there is the potential for flash
flooding which can be life-threatening. Heavy rain is expected to
occur over a short period of time. Rapidly rising flood waters
may quickly inundate roadways and areas of poor drainage. Streams
and creeks could leave their banks, flooding nearby properties.

Please monitor the forecast, especially if you live in a location
that is prone to flooding. Be prepared to take action if a flash
flood warning is issued for your area.

&&

$$
282 
WGUS61 KPHI 120137
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
937 PM EDT Sat Aug 11 2018



NJZ001-007>010-012-015-PAZ054-055-060>062-070-071-101>106-120245-
/O.CAN.KPHI.FF.A.0012.000000T0000Z-180812T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Mercer-Carbon-
Monroe-Berks-Lehigh-Northampton-Delaware-Philadelphia-
Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Newton, Washington, Morristown, 
Flemington, Somerville, New Brunswick, Trenton, Jim Thorpe, 
Stroudsburg, Reading, Allentown, Bethlehem, Easton, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
937 PM EDT Sat Aug 11 2018

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of New Jersey and Pennsylvania
has been cancelled. The heaviest rain has pushed south and east of
this area so no additional flash flooding is expected tonight. 
However areas of lingering standing water along with high stream 
flows can be expected into tonight for areas that experienced 
flash flooding earlier today. 


$$

DEZ001-002-MDZ008-012-015-NJZ013-014-016>022-025>027-120500-
/O.CON.KPHI.FF.A.0012.000000T0000Z-180812T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Kent-Cecil-Kent MD-Queen Annes-Western Monmouth-
Eastern Monmouth-Salem-Gloucester-Camden-Northwestern Burlington-
Ocean-Cumberland-Atlantic-Coastal Atlantic-Coastal Ocean-
Southeastern Burlington-
Including the cities of Wilmington, Dover, Elkton, Chestertown, 
Centreville, Freehold, Sandy Hook, Pennsville, Glassboro, Camden,
Cherry Hill, Moorestown, Mount Holly, Jackson, Millville, 
Hammonton, Atlantic City, Long Beach Island, 
and Wharton State Forest
937 PM EDT Sat Aug 11 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 1 AM EDT SUNDAY...

The Flash Flood Watch continues for

* Portions of Delaware, northeast Maryland, and New Jersey, 
  including the following areas, in Delaware, Kent and New 
  Castle. In northeast Maryland, Cecil, Kent MD, and Queen 
  Annes. In New Jersey, Atlantic, Camden, Coastal Atlantic, 
  Coastal Ocean, Cumberland, Eastern Monmouth, Gloucester, 
  Northwestern Burlington, Ocean, Salem, Southeastern 
  Burlington, and Western Monmouth. 

* Until 1 AM EDT Sunday

* Showers and thunderstorms producing heavy downpours will
  continue to affect the area this evening before moving out west
  to east after midnight. Rainfall rates may exceed over 2 inches
  per hour in the heaviest storms leading to flash flooding. 


* Heavy rainfall within a short period of time can lead to 
  rapidly rising water and flash flooding, particularly in urban 
  areas, and along small creeks and streams. The ground remains 
  fairly saturated due to recent heavy rains over the past 
  several weeks. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that there is the potential for flash
flooding which can be life-threatening. Heavy rain is expected to
occur over a short period of time. Rapidly rising flood waters
may quickly inundate roadways and areas of poor drainage. Streams
and creeks could leave their banks, flooding nearby properties.

Please monitor the forecast, especially if you live in a location
that is prone to flooding. Be prepared to take action if a flash
flood warning is issued for your area.

&&

$$

Fitzsimmons
945 
WGUS61 KPHI 120325
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
1125 PM EDT Sat Aug 11 2018

DEZ001-002-MDZ008-012-015-NJZ013-014-016>022-025>027-120430-
/O.CAN.KPHI.FF.A.0012.000000T0000Z-180812T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Kent-Cecil-Kent MD-Queen Annes-Western Monmouth-
Eastern Monmouth-Salem-Gloucester-Camden-Northwestern Burlington-
Ocean-Cumberland-Atlantic-Coastal Atlantic-Coastal Ocean-
Southeastern Burlington-
Including the cities of Wilmington, Dover, Elkton, Chestertown, 
Centreville, Freehold, Sandy Hook, Pennsville, Glassboro, Camden,
Cherry Hill, Moorestown, Mount Holly, Jackson, Millville, 
Hammonton, Atlantic City, Long Beach Island, 
and Wharton State Forest
1125 PM EDT Sat Aug 11 2018

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of Delaware, northeast
Maryland, and New Jersey has been cancelled. The heaviest rainfall
has ended, and flash flooding is no longer expected to be a threat
tonight.

More chances for showers and storms exist Sunday through much of
next week.

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 4:19 PM EDTAreal Flood AdvisoryPHICecil3 hr
Aug 11, 4:19 PM EDTSevere Thunderstorm WarningPHICecil29 min
Aug 11, 5:20 PM EDTAreal Flood AdvisoryPHICecil, Kent, Queen Anne's4 hr
Aug 11, 5:24 PM EDTSpecial Weather StatementPHICecil36 min
Aug 11, 6:08 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's52 min
Aug 11, 6:12 PM EDTFlash Flood WarningPHICecil, Kent, Queen Anne's3 hr
Aug 11, 6:45 PM EDTFlash Flood WarningPHICaroline, Queen Anne's, Talbot5 hr
Aug 11, 6:55 PM EDTSevere Thunderstorm WarningPHICaroline, Queen Anne's, Talbot50 min
Aug 11, 7:42 PM EDTSpecial Weather StatementPHICaroline, Queen Anne's, Talbot48 min
Aug 11, 2:25 AM EDTSpecial Weather StatementPHIBerks65 min
Aug 11, 3:26 AM EDTSpecial Weather StatementPHIBerks64 min
Aug 11, 4:17 AM EDTAreal Flood AdvisoryPHIBerks4 hr
Aug 11, 4:26 AM EDTCoastal Flood AdvisoryPHIBucks, Delaware, Philadelphia24 hr
Aug 11, 5:19 AM EDTFlash Flood WarningPHIBerks3 hr
Aug 11, 5:27 AM EDTAreal Flood AdvisoryPHINorthampton4 hr
Aug 11, 6:06 AM EDTAreal Flood AdvisoryPHIBucks, Northampton6 hr
Aug 11, 6:31 AM EDTAreal Flood AdvisoryPHIBucks7 hr
Aug 11, 12:16 PM EDTSpecial Weather StatementPHIChester29 min
Aug 11, 12:48 PM EDTAreal Flood AdvisoryPHIChester3 hr
Aug 11, 1:20 PM EDTAreal Flood AdvisoryPHIChester, Montgomery3 hr
Aug 11, 1:33 PM EDTFlash Flood WarningPHIChester, Montgomery4 hr
Aug 11, 1:40 PM EDTFlash Flood WarningPHIChester4 hr
Aug 11, 1:48 PM EDTFlash Flood WarningPHIDelaware, Philadelphia4 hr
Aug 11, 1:51 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia39 min
Aug 11, 2:00 PM EDTFlash Flood WarningPHIBucks, Lehigh, Northampton9 hr
Aug 11, 2:14 PM EDTFlash Flood WarningPHIBucks3 hr
Aug 11, 2:26 PM EDTSpecial Weather StatementPHIBucks, Philadelphia34 min
Aug 11, 2:42 PM EDTSpecial Weather StatementPHIBucks33 min
Aug 11, 3:06 PM EDTFlash Flood WarningPHINorthampton4 hr
Aug 11, 3:50 PM EDTAreal Flood AdvisoryPHIBerks, Montgomery115 min
Aug 11, 4:47 PM EDTSpecial Weather StatementPHIMontgomery28 min
Aug 11, 4:52 PM EDTAreal Flood AdvisoryPHICarbon, Lehigh2 hr
Aug 11, 5:36 PM EDTAreal Flood WarningPHIBucks4 hr
Aug 11, 5:58 PM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia5 hr
Aug 11, 6:13 PM EDTSpecial Weather StatementPHIChester32 min
Aug 11, 7:16 AM EDTFlash Flood WarningPHIMiddlesex, Somerset4 hr
Aug 11, 10:49 AM EDTAreal Flood AdvisoryPHIMiddlesex, Somerset3 hr
Aug 11, 11:29 AM EDTAreal Flood AdvisoryPHIAtlantic4 hr
Aug 11, 11:46 AM EDTSpecial Marine WarningPHI119 min
Aug 11, 11:55 AM EDTSpecial Weather StatementPHIBurlington35 min
Aug 11, 12:27 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Ocean4 hr
Aug 11, 12:39 PM EDTSpecial Weather StatementPHIOcean36 min
Aug 11, 12:55 PM EDTSpecial Marine WarningPHI65 min
Aug 11, 1:07 PM EDTFlash Flood WarningPHIAtlantic, Cape May4 hr
Aug 11, 1:26 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 1:42 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 2:05 PM EDTSpecial Weather StatementPHICape May25 min
Aug 11, 2:06 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester3 hr
Aug 11, 2:19 PM EDTSpecial Marine WarningPHI86 min
Aug 11, 2:20 PM EDTAreal Flood AdvisoryPHICape May, Cumberland3 hr
Aug 11, 2:30 PM EDTFlash Flood WarningPHIHunterdon, Morris, Warren3 hr
Aug 11, 2:46 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset3 hr
Aug 11, 2:58 PM EDTSpecial Weather StatementPHICumberland47 min
Aug 11, 3:13 PM EDTSpecial Weather StatementPHIHunterdon47 min
Aug 11, 3:23 PM EDTAreal Flood AdvisoryPHIMorris, Sussex3 hr
Aug 11, 3:24 PM EDTSpecial Weather StatementPHIAtlantic, Cumberland51 min
Aug 11, 3:32 PM EDTFlash Flood WarningPHIAtlantic3 hr
Aug 11, 3:47 PM EDTFlash Flood WarningPHIMorris3 hr
Aug 11, 4:11 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 4:28 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 5:00 PM EDTAreal Flood AdvisoryPHIGloucester, Salem3 hr
Aug 11, 5:26 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Warren4 hr
Aug 11, 6:11 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 7:35 PM EDTAreal Flood AdvisoryPHIAtlantic, Cumberland3 hr
Aug 11, 7:46 PM EDTRiver Flood WarningPHIEssex, Morris, Passaic4 days
Aug 11, 1:23 PM EDTSevere Thunderstorm WarningPHISussex37 min

Nearby

Flash Flood Watches in New Jersey, 2018Flash Flood Watches in Pennsylvania, 2018Flash Flood Watches in Maryland, 2018Every flash flood watch in 2018

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.