Alert archive / New Jersey / Flash Flood Watches in 2018

Flash Flood Watch 13, NWS Philadelphia/Mount Holly

August 12, 20184 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 12, 2018, 10:08 PM EDT for 4 states. It took effect at Aug 13, 2018, 5:00 AM EDT. It was in force for 17 hr.

The area

The counties it named.

The facts

Issued
Aug 12, 2018, 10:08 PM EDT (02:08 UTC)
In effect from
Aug 13, 2018, 5:00 AM EDT
Expired
Aug 13, 2018, 10:18 PM EDT
In force
17 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None
All 24 counties

New Castle County, DE, Cecil County, MD, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris 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), 74 km from the middle of the area, began a volume at 02:10 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, 2.1 hours before the alert went out and 202 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 2018-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 940 joules per kilogram.LCLEL10008507005003002001001 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 2018-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 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
940 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
529 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

709 
WGUS61 KPHI 130208
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
1008 PM EDT Sun Aug 12 2018


DEZ001-MDZ008-NJZ001-007>010-012-013-015>019-PAZ054-055-060>062-
070-071-101>106-131015-
/O.NEW.KPHI.FF.A.0013.180813T0900Z-180814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Sussex-Warren-Morris-Hunterdon-Somerset-
Middlesex-Western 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, Elkton, Newton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Freehold, 
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
1008 PM EDT Sun Aug 12 2018

...FLASH FLOOD WATCH IN EFFECT FROM 5 AM EDT MONDAY THROUGH
MONDAY EVENING...

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, Camden, 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. 

* From 5 AM EDT Monday through Monday evening

* Several rounds of heavy showers and thunderstorms are expected 
  to impact the area beginning overnight and continuing through 
  Monday. These storms will be capable of producing very heavy 
  downpours resulting in urban, small stream, and flash flooding, 
  especially where thunderstorms train over the same locations. 

* 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.

&&

$$
3 follow-up statements
682 
WGUS61 KPHI 130730
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
330 AM EDT Mon Aug 13 2018

DEZ001-MDZ008-NJZ001-007>010-012-013-015>019-PAZ054-055-060>062-
070-071-101>106-132200-
/O.CON.KPHI.FF.A.0013.180813T0900Z-180814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Sussex-Warren-Morris-Hunterdon-Somerset-
Middlesex-Western 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, Elkton, Newton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Freehold, 
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
330 AM EDT Mon Aug 13 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING...

The Flash Flood Watch continues for

* The Pennsylvania counties of Carbon, Monroe, Northampton, 
  Lehigh, Berks, Chester, Montgomery, Bucks, Delaware and 
  Philadelphia, for the New Jersey counties of Sussex, Warren, 
  Morris, Hunterdon, Somerset, Middlesex, Mercer, Monmouth, 
  Burlington, Camden, Gloucester and Salem, for New Castle County 
  in Delaware and for Cecil County in Maryland.

* Through this evening

* Several rounds of heavy showers and thunderstorms are expected 
  to impact the area into this evening. The storms will be capable
  of producing very heavy downpours resulting in urban, small 
  stream and 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 streams and creeks. The ground remains 
  fairly saturated due to the recent heavy rainfall.

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.

&&

$$

Iovino
254 
WGUS61 KPHI 131951
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
351 PM EDT Mon Aug 13 2018

DEZ001-MDZ008-NJZ001-007>010-012-013-015>019-PAZ054-055-060>062-
070-071-101>106-140400-
/O.CON.KPHI.FF.A.0013.000000T0000Z-180814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Sussex-Warren-Morris-Hunterdon-Somerset-
Middlesex-Western 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, Elkton, Newton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Freehold, 
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
351 PM EDT Mon Aug 13 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT
TONIGHT...

The Flash Flood Watch continues 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, Camden, 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. 

* Until midnight EDT tonight.

* Additional showers and storms will develop through this evening.
  This activity will be much less organized than the prior round
  of heavy rain that produced flash flooding in northern Delaware,
  eastern Pennsylvania and New Jersey this morning. However, 
  showers and storms late this afternoon and evening will be slow 
  moving and capable of producing very heavy downpours.
 
* Given the saturated soils, elevated streams and ongoing flooding,
  it will not take much rainfall to produce additional urban, 
  small stream and localized flash flooding.

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.

&&

$$
JRK
863 
WGUS61 KPHI 140218
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
1018 PM EDT Mon Aug 13 2018

DEZ001-MDZ008-NJZ001-007>010-012-013-015>019-PAZ054-055-060>062-
070-071-101>106-140330-
/O.CAN.KPHI.FF.A.0013.000000T0000Z-180814T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Sussex-Warren-Morris-Hunterdon-Somerset-
Middlesex-Western 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, Elkton, Newton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Freehold, 
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
1018 PM EDT Mon Aug 13 2018

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of northern Delaware,
northeast Maryland, New Jersey, and Pennsylvania has been
cancelled. The threat of heavy rainfall has diminished, and flash
flooding is no longer expected to be a threat. Please continue to
heed any road closures.

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 6:10 AM EDTAreal Flood AdvisoryPHIBurlington, Ocean4 hr
Aug 13, 8:03 AM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Salem4 hr
Aug 13, 8:30 AM EDTFlash Flood WarningPHIBurlington, Monmouth, Ocean7 hr
Aug 13, 9:14 AM EDTAreal Flood AdvisoryPHIGloucester, Salem4 hr
Aug 13, 9:32 AM EDTSpecial Marine WarningPHI58 min
Aug 13, 10:27 AM EDTFlash Flood WarningPHIBurlington, Camden2 hr
Aug 13, 10:35 AM EDTSpecial Marine WarningPHI85 min
Aug 13, 10:48 AM EDTAreal Flood AdvisoryPHIMiddlesex, Monmouth, Somerset4 hr
Aug 13, 11:38 AM EDTAreal Flood AdvisoryPHIBurlington3 hr
Aug 13, 12:37 PM EDTAreal Flood WarningPHIBurlington, Camden18 hr
Aug 13, 3:19 PM EDTAreal Flood WarningPHIMonmouth, Ocean6 hr
Aug 13, 4:42 AM EDTAreal Flood AdvisoryPHIBerks4 hr
Aug 13, 5:12 AM EDTAreal Flood AdvisoryPHIChester103 min
Aug 13, 6:24 AM EDTAreal Flood AdvisoryPHIBerks, Chester, Delaware, Montgomery4 hr
Aug 13, 6:50 AM EDTFlash Flood WarningPHIBerks, Chester, Delaware, Montgomery6 hr
Aug 13, 8:43 AM EDTFlash Flood WarningPHIBucks, Delaware, Lehigh, Montgomery, Northampton, Philadelphia4 hr
Aug 13, 9:21 AM EDTRiver Flood WarningPHIChester10 hr
Aug 13, 10:40 AM EDTAreal Flood AdvisoryPHICarbon, Monroe, Northampton42 min
Aug 13, 11:05 AM EDTRiver Flood WarningPHIChester, Delaware30 hr
Aug 13, 11:21 AM EDTAreal Flood WarningPHICarbon, Monroe, Northampton4 hr
Aug 13, 12:14 PM EDTRiver Flood WarningPHIBerks, Montgomery23 hr
Aug 13, 12:14 PM EDTRiver Flood WarningPHIMontgomery28 hr
Aug 13, 12:14 PM EDTRiver Flood WarningPHIChester, Montgomery, Philadelphia52 hr
Aug 13, 3:07 PM EDTRiver Flood WarningPHIMontgomery6 hr
Aug 13, 4:57 PM EDTAreal Flood AdvisoryPHICarbon, Monroe, Northampton3 hr
Aug 13, 5:09 PM EDTRiver Flood WarningPHIMontgomery, Philadelphia31 hr
Aug 13, 7:27 PM EDTAreal Flood WarningPHICarbon, Northampton7 hr
Aug 13, 7:42 PM EDTSevere Thunderstorm WarningPHIChester48 min
Aug 13, 6:57 PM EDTSpecial Weather StatementPHICecil, Kent, Queen Anne's, Talbot48 min
Aug 13, 7:17 PM EDTSpecial Weather StatementPHICecil28 min
Aug 13, 8:20 AM EDTRiver Flood WarningPHINew Castle7 hr
Aug 13, 8:28 AM EDTRiver Flood WarningPHINew Castle6 hr
Aug 13, 9:05 AM EDTRiver Flood WarningPHINew Castle6 hr

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.