Alert archive / New Jersey / Flash Flood Watches in 2020
Flash Flood Watch 7, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 11, 2020, 3:48 PM EDT for 4 states. It took effect at Aug 12, 2020, 11:00 AM EDT. It was in force for 9 hr.
The area
The counties it named.
The facts
- Issued
- Aug 11, 2020, 3:48 PM EDT (19:48 UTC)
- In effect from
- Aug 12, 2020, 11:00 AM EDT
- Expired
- Aug 12, 2020, 8:16 PM EDT
- In force
- 9 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Flood severity
- None
All 28 counties
Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, 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, 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), 74 km from the middle of the area, began a volume at 19:50 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 7.8 hours before the alert went out and 211 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.
- Mixed-layer CAPE
- 344 J/kg
- Mixed-layer CIN
- -59 J/kg
- Mixed-layer LCL
- 1015 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 35 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
481 WGUS61 KPHI 111948 FFAPHI URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Mount Holly NJ 348 PM EDT Tue Aug 11 2020 DEZ001>003-MDZ008-012-015-019-020-NJZ009-015>019-021-PAZ070-071- 101>106-121000- /O.NEW.KPHI.FF.A.0007.200812T1500Z-200813T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot- Caroline-Hunterdon-Mercer-Salem-Gloucester-Camden- Northwestern Burlington-Cumberland-Delaware-Philadelphia- Western Chester-Eastern Chester-Western Montgomery- Eastern Montgomery-Upper Bucks-Lower Bucks- Including the cities of Wilmington, Dover, Georgetown, Elkton, Chestertown, Centreville, Easton, Denton, Flemington, Trenton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Millville, Media, Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, Collegeville, Pottstown, Norristown, Lansdale, Chalfont, Perkasie, Morrisville, and Doylestown 348 PM EDT Tue Aug 11 2020 ...FLASH FLOOD WATCH IN EFFECT FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING... The National Weather Service in Mount Holly has issued a * Flash Flood Watch for portions of Delaware, northeast Maryland, New Jersey, and southeast Pennsylvania, including the following areas, in Delaware, Inland Sussex, Kent, and New Castle. In northeast Maryland, Caroline, Cecil, Kent MD, Queen Annes, and Talbot. In New Jersey, Camden, Cumberland, Gloucester, Hunterdon, Mercer, Northwestern Burlington, and Salem. In southeast Pennsylvania, Delaware, Eastern Chester, Eastern Montgomery, Lower Bucks, Philadelphia, Upper Bucks, Western Chester, and Western Montgomery. * From Wednesday morning through Wednesday evening. * Scattered to widespread thunderstorms are expected on Wednesday, mainly during the afternoon and into the evening. Multiple recent heavy rain events have left many areas more vulnerable than normal to flash flooding, with the ground remaining saturated. Any areas that receive heavy rainfall over a short duration could experience flash flooding. * Areas of flash flooding are expected, especially in urban and flood-prone areas. Small streams and creeks will also be susceptible to flooding, especially those that remain elevated from antecedent 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. && $$ JEO
3 follow-up statements
429 WGUS61 KPHI 120741 FFAPHI URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Mount Holly NJ 341 AM EDT Wed Aug 12 2020 NJZ007-008-010-012-013-PAZ060>062-122100- /O.EXA.KPHI.FF.A.0007.200812T1500Z-200813T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Warren-Morris-Somerset-Middlesex-Western Monmouth-Berks-Lehigh- Northampton- Including the cities of Washington, Morristown, Somerville, New Brunswick, Freehold, Reading, Allentown, Bethlehem, and Easton 341 AM EDT Wed Aug 12 2020 ...FLASH FLOOD WATCH IN EFFECT FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING... The National Weather Service in Mount Holly has expanded the * Flash Flood Watch for much of southeastern Pennsylvania and central and northern New Jersey. * From 11 AM EDT this morning through this evening * Very slow moving showers and thunderstorms primarily this afternoon and evening will be capable of heavy rain leading to flash flooding. * Multiple recent heavy rain events have left many areas more vulnerable than normal to flash flooding, with the ground remaining saturated. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flash Flood Watch means that there is the potential for flash flooding which can be life-threatening. Heavy rain is expected to occur over a short period of time. Rapidly rising flood waters may quickly inundate roadways and areas of poor drainage. Streams and creeks could leave their banks, flooding nearby properties. Please monitor the forecast, especially if you live in a location that is prone to flooding. Be prepared to take action if a flash flood warning is issued for your area. && $$ DEZ001>003-MDZ008-012-015-019-020-NJZ009-015>019-021-PAZ070-071- 101>106-122100- /O.CON.KPHI.FF.A.0007.200812T1500Z-200813T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot- Caroline-Hunterdon-Mercer-Salem-Gloucester-Camden- Northwestern Burlington-Cumberland-Delaware-Philadelphia- Western Chester-Eastern Chester-Western Montgomery- Eastern Montgomery-Upper Bucks-Lower Bucks- Including the cities of Wilmington, Dover, Georgetown, Elkton, Chestertown, Centreville, Easton, Denton, Flemington, Trenton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Millville, Media, Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, Collegeville, Pottstown, Norristown, Lansdale, Chalfont, Perkasie, Morrisville, and Doylestown 341 AM EDT Wed Aug 12 2020 ...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 11 AM EDT THIS MORNING THROUGH THIS EVENING... The Flash Flood Watch continues for * Delaware, northeastern Maryland, much of southeastern Pennsylvania, and southwestern, central, and northern New Jersey. * From 11 AM EDT this morning through this evening * Very slow moving showers and thunderstorms primarily this afternoon and evening will be capable of heavy rain leading to flash flooding. * Multiple recent heavy rain events have left many areas more vulnerable than normal to flash flooding, with the ground remaining saturated. 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. && $$ Johnson
561 WGUS61 KPHI 121923 FFAPHI Flood Watch National Weather Service Mount Holly NJ 323 PM EDT Wed Aug 12 2020 NJZ007>010-012-013-015-PAZ060>062-105-106-122030- /O.CAN.KPHI.FF.A.0007.000000T0000Z-200813T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Warren-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth- Mercer-Berks-Lehigh-Northampton-Upper Bucks-Lower Bucks- Including the cities of Washington, Morristown, Flemington, Somerville, New Brunswick, Freehold, Trenton, Reading, Allentown, Bethlehem, Easton, Chalfont, Perkasie, Morrisville, and Doylestown 323 PM EDT Wed Aug 12 2020 ...FLASH FLOOD WATCH IS CANCELLED... The Flash Flood Watch for portions of New Jersey and Pennsylvania has been cancelled. Heavy rain is no longer expected to pose a threat to these areas. $$ DEZ001>003-MDZ008-012-015-019-020-NJZ016>019-021-PAZ070-071- 101>104-130300- /O.CON.KPHI.FF.A.0007.000000T0000Z-200813T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot- Caroline-Salem-Gloucester-Camden-Northwestern Burlington- Cumberland-Delaware-Philadelphia-Western Chester-Eastern Chester- Western Montgomery-Eastern Montgomery- Including the cities of Wilmington, Dover, Georgetown, Elkton, Chestertown, Centreville, Easton, Denton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Millville, Media, Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, Collegeville, Pottstown, Norristown, and Lansdale 323 PM EDT Wed Aug 12 2020 ...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 11 PM EDT THIS EVENING... The Flash Flood Watch continues for * Portions of Delaware, northeast Maryland, southern New Jersey, and southeast Pennsylvania, including the following areas, in Delaware, Inland Sussex, Kent, and New Castle. In northeast Maryland, Caroline, Cecil, Kent MD, Queen Annes, and Talbot. In southern New Jersey, Camden, Cumberland, Gloucester, Northwestern Burlington, and Salem. In southeast Pennsylvania, Delaware, Eastern Chester, Eastern Montgomery, Philadelphia, Western Chester, and Western Montgomery. * Until 11 PM EDT this evening. * Very slow moving showers and thunderstorms primarily this afternoon and evening will continue to be capable of heavy rain leading to flash flooding. * Multiple recent heavy rain events have left many areas more vulnerable than normal to flash flooding, with the ground remaining saturated. 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. && $$ JEO
339 WGUS61 KPHI 130016 FFAPHI Flood Watch National Weather Service Mount Holly NJ 816 PM EDT Wed Aug 12 2020 DEZ001>003-MDZ008-012-015-019-020-NJZ016>019-021-PAZ070-071- 101>104-130130- /O.CAN.KPHI.FF.A.0007.000000T0000Z-200813T0300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot- Caroline-Salem-Gloucester-Camden-Northwestern Burlington- Cumberland-Delaware-Philadelphia-Western Chester-Eastern Chester- Western Montgomery-Eastern Montgomery- Including the cities of Wilmington, Dover, Georgetown, Elkton, Chestertown, Centreville, Easton, Denton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Millville, Media, Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, Collegeville, Pottstown, Norristown, and Lansdale 816 PM EDT Wed Aug 12 2020 ...FLASH FLOOD WATCH IS CANCELLED... The Flash Flood Watch for portions of Delaware, northeast Maryland, southern New Jersey, and southeast Pennsylvania has been cancelled. Showers and thunderstorms producing heavy rain and flash flooding has ended. Therefore, the Flash Flood Watch has been cancelled. $$ MPS
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 4:22 AM EDT | Marine Dense Fog Advisory | PHI | 10 hr | |
| Aug 11, 1:20 PM EDT | Areal Flood Advisory | PHI | Burlington | 115 min |
| Aug 11, 2:27 PM EDT | Areal Flood Advisory | PHI | Monmouth, Ocean | 3 hr |
| Aug 11, 2:42 PM EDT | Special Weather Statement | PHI | Monmouth | 48 min |
| Aug 11, 2:45 PM EDT | Severe Thunderstorm Warning | PHI | Monmouth | 30 min |
Nearby
Flash Flood Watches in New Jersey, 2020Flash Flood Watches in Pennsylvania, 2020Flash Flood Watches in Maryland, 2020Every flash flood watch in 2020
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.