Alert archive / New Jersey / Flash Flood Watches in 2019

Flash Flood Watch 8, NWS Philadelphia/Mount Holly

July 11, 20194 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Jul 11, 2019, 3:44 AM EDT for 4 states. It took effect at Jul 11, 2019, 2:00 PM EDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Jul 11, 2019, 3:44 AM EDT (07:44 UTC)
In effect from
Jul 11, 2019, 2:00 PM EDT
Expired
Jul 11, 2019, 9:41 PM EDT
In force
8 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

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, Morris County, NJ, Salem County, NJ, Somerset County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 71 km from the middle of the area, began a volume at 07:46 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, 7.7 hours before the alert went out and 209 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 2019-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 70 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 2019-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 40 square meters per square second.1939Sfc1 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
70 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
1138 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
40 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

864 
WGUS61 KPHI 110744
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
344 AM EDT Thu Jul 11 2019

DEZ001-MDZ008-NJZ007>010-012-015>019-PAZ060>062-070-071-101>106-
112000-
/O.NEW.KPHI.FF.A.0008.190711T1800Z-190712T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Warren-Morris-Hunterdon-Somerset-Middlesex-
Mercer-Salem-Gloucester-Camden-Northwestern Burlington-Berks-
Lehigh-Northampton-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
Including the cities of Wilmington, Elkton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Trenton, 
Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Reading, Allentown, Bethlehem, Easton, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
344 AM EDT Thu Jul 11 2019

...FLASH FLOOD WATCH IN EFFECT FROM 2 PM EDT THIS AFTERNOON
THROUGH LATE TONIGHT...

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, and Warren. In Pennsylvania, Berks, Delaware, 
  Eastern Chester, Eastern Montgomery, Lehigh, Lower Bucks, 
  Northampton, Philadelphia, Upper Bucks, Western Chester, and 
  Western Montgomery. 

* From 2 PM EDT this afternoon through late tonight

* Showers and thunderstorms this afternoon and tonight will be 
  capable of producing torrential rainfall, with local amounts of 
  1 to 3 inches with locally higher amounts potentially occurring 
  in a short period of time. This could lead to localized flash 
  flooding.

* The risk of flash flooding is highest in urbanized and low- 
  lying areas. Rapid rises on small creeks and streams are 
  possible.

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
2 follow-up statements
173 
WGUS61 KPHI 111851
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
251 PM EDT Thu Jul 11 2019

DEZ001-MDZ008-NJZ007>010-012-015>019-PAZ060>062-070-071-101>106-
120500-
/O.CON.KPHI.FF.A.0008.000000T0000Z-190712T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Warren-Morris-Hunterdon-Somerset-Middlesex-
Mercer-Salem-Gloucester-Camden-Northwestern Burlington-Berks-
Lehigh-Northampton-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
Including the cities of Wilmington, Elkton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Trenton, 
Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Reading, Allentown, Bethlehem, Easton, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
251 PM EDT Thu Jul 11 2019

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

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, and Warren. 
  In Pennsylvania, Berks, Delaware, Eastern Chester, Eastern 
  Montgomery, Lehigh, Lower Bucks, Northampton, Philadelphia, 
  Upper Bucks, Western Chester, and Western Montgomery. 

* Until 1 AM EDT Friday

* Showers and thunderstorms this afternoon and tonight will be
  capable of producing torrential rainfall, with areas of 1 to 3
  inches, with locally higher amounts of 3 to 5 inches possible.
  Very heavy rainfall will occur in a short period of time, which
  could lead to localized flash flooding. 

* The risk of flash flooding is highest in urbanized and low- 
  lying areas. Rapid rises on small creeks and streams are 
  possible. 

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.

&&

$$
308 
WGUS61 KPHI 120141
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
941 PM EDT Thu Jul 11 2019

DEZ001-MDZ008-NJZ007>010-012-015>019-PAZ060>062-070-071-101>106-
120245-
/O.CAN.KPHI.FF.A.0008.000000T0000Z-190712T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Warren-Morris-Hunterdon-Somerset-Middlesex-
Mercer-Salem-Gloucester-Camden-Northwestern Burlington-Berks-
Lehigh-Northampton-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
Including the cities of Wilmington, Elkton, Washington, 
Morristown, Flemington, Somerville, New Brunswick, Trenton, 
Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Reading, Allentown, Bethlehem, Easton, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
941 PM EDT Thu Jul 11 2019

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of northern Delaware,
northeast Maryland, New Jersey, and Pennsylvania has been
cancelled. 

While flooding still continues in some areas due to heavy rain
Thursday afternoon and evening...no addition flooding is expected
to develop since the heavy rain has moved out of the area.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 12:33 PM EDTSpecial Weather StatementPHIChester57 min
Jul 11, 1:23 PM EDTSpecial Weather StatementPHIChester, Delaware52 min
Jul 11, 1:44 PM EDTSevere Thunderstorm WarningPHIDelaware, Montgomery, Philadelphia61 min
Jul 11, 2:41 PM EDTSpecial Weather StatementPHIPhiladelphia64 min
Jul 11, 2:44 PM EDTSpecial Weather StatementPHIBucks, Montgomery61 min
Jul 11, 2:50 PM EDTAreal Flood Advisory EmergencyPHIBerks, Chester, Montgomery4 hr
Jul 11, 3:00 PM EDTFlash Flood WarningPHIBerks, Chester, Montgomery8 hr
Jul 11, 3:13 PM EDTAreal Flood AdvisoryPHIBucks, Carbon, Lehigh, Monroe, Northampton4 hr
Jul 11, 3:33 PM EDTAreal Flood AdvisoryPHINorthampton4 hr
Jul 11, 3:45 PM EDTFlash Flood WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton4 hr
Jul 11, 4:45 PM EDTFlash Flood Warning EmergencyPHIBerks, Montgomery4 hr
Jul 11, 5:12 PM EDTFlash Flood WarningPHIChester4 hr
Jul 11, 5:20 PM EDTFlash Flood WarningPHIBucks, Chester, Montgomery4 hr
Jul 11, 5:33 PM EDTAreal Flood AdvisoryPHIBucks4 hr
Jul 11, 6:14 PM EDTSevere Thunderstorm WarningPHIDelaware, Montgomery, Philadelphia61 min
Jul 11, 6:15 PM EDTFlash Flood WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia4 hr
Jul 11, 6:17 PM EDTAreal Flood AdvisoryPHIBucks4 hr
Jul 11, 6:28 PM EDTRiver Flood WarningPHIMontgomery22 hr
Jul 11, 6:57 PM EDTRiver Flood WarningPHIMontgomery12 hr
Jul 11, 7:03 PM EDTRiver Flood WarningPHIChester, Montgomery, Philadelphia26 hr
Jul 11, 7:19 PM EDTRiver Flood WarningPHIChester7 hr
Jul 11, 7:47 PM EDTFlash Flood WarningPHIBerks, Bucks, Lehigh, Montgomery3 hr
Jul 11, 1:47 PM EDTSpecial Marine WarningPHI28 min
Jul 11, 6:04 PM EDTSpecial Marine WarningPHI86 min
Jul 11, 6:58 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Somerset62 min
Jul 11, 7:22 PM EDTTornado WarningPHIBurlington23 min
Jul 11, 7:27 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 5 more7 hr
Jul 11, 7:44 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Monmouth, Ocean61 min
Jul 11, 5:44 PM EDTSevere Thunderstorm WarningPHIKent, New Castle61 min
Jul 11, 6:39 PM EDTAreal Flood AdvisoryPHIKent, Sussex4 hr
Jul 11, 3:37 PM EDTSpecial Weather StatementPHICecil53 min
Jul 11, 4:55 PM EDTSpecial Weather StatementPHICecil, Kent, Queen Anne's65 min
Jul 11, 5:45 PM EDTAreal Flood AdvisoryPHICecil, Kent, Queen Anne's, Talbot4 hr
Jul 11, 7:36 PM EDTSpecial Weather StatementPHICaroline54 min

Nearby

Flash Flood Watches in New Jersey, 2019Flash Flood Watches in Pennsylvania, 2019Flash Flood Watches in Delaware, 2019Every flash flood watch in 2019

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.