Alert archive / New Jersey / Flash Flood Watches in 2018

Flash Flood Watch 8, NWS Philadelphia/Mount Holly

July 20, 20184 states

NWS Philadelphia/Mount Holly issued this flash flood watch at Jul 20, 2018, 2:44 PM EDT for 4 states. It took effect at Jul 21, 2018, 2:00 PM EDT. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued
Jul 20, 2018, 2:44 PM EDT (18:44 UTC)
In effect from
Jul 21, 2018, 2:00 PM EDT
Expired
Jul 22, 2018, 12:34 AM EDT
In force
11 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None
All 23 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, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Ocean County, NJ, Salem County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 6.7 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, Wallops Is Stn, VA at 12:00Z on 2018-07-20Temperature 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, Wallops Is Stn, VA at 12:00Z on 2018-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1545 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

569 
WGUS61 KPHI 201844
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
244 PM EDT Fri Jul 20 2018

DEZ001>004-MDZ008-012-015-019-020-NJZ015>027-PAZ060-070-071-
101>106-211000-
/O.NEW.KPHI.FF.A.0008.180721T1800Z-180722T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Kent-Inland Sussex-Delaware Beaches-Cecil-Kent MD-
Queen Annes-Talbot-Caroline-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Atlantic Coastal Cape May-Coastal Atlantic-Coastal Ocean-
Southeastern Burlington-Berks-Delaware-Philadelphia-
Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Wilmington, Dover, Georgetown, 
Rehoboth Beach, Elkton, Chestertown, Centreville, Easton, Denton,
Trenton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Jackson, Millville, Hammonton, Cape May Court House,
Ocean City, Atlantic City, Long Beach Island, 
Wharton State Forest, Reading, Media, Philadelphia, Honey Brook, 
Oxford, West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
244 PM EDT Fri Jul 20 2018

...FLASH FLOOD WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
LATE SATURDAY NIGHT...

The National Weather Service in Mount Holly has issued a

* Flash Flood Watch for portions of Delaware, northeast 
  Maryland, New Jersey, and Pennsylvania, including the 
  following areas, in Delaware, Delaware Beaches, Inland Sussex, 
  Kent, and New Castle. In northeast Maryland, Caroline, Cecil, 
  Kent MD, Queen Annes, and Talbot. In New Jersey, Atlantic, 
  Atlantic Coastal Cape May, Camden, Cape May, Coastal Atlantic, 
  Coastal Ocean, Cumberland, Gloucester, Mercer, Northwestern 
  Burlington, Ocean, Salem, and Southeastern Burlington. In 
  Pennsylvania, Berks, Delaware, Eastern Chester, Eastern 
  Montgomery, Lower Bucks, Philadelphia, Upper Bucks, Western 
  Chester, and Western Montgomery. 

* From Saturday afternoon through late Saturday night

* Rain...heavy at times...is expected to overspread the area from
  south to north Saturday afternoon and evening. Rainfall rates
  over one inch per hour are possible.

* Excessive 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. 

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.

&&

$$
4 follow-up statements
039 
WGUS61 KPHI 210744
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
344 AM EDT Sat Jul 21 2018

DEZ001>004-MDZ008-012-015-019-020-NJZ015>027-PAZ060-070-071-
101>106-212100-
/O.CON.KPHI.FF.A.0008.180721T1800Z-180722T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Kent-Inland Sussex-Delaware Beaches-Cecil-Kent MD-
Queen Annes-Talbot-Caroline-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Atlantic Coastal Cape May-Coastal Atlantic-Coastal Ocean-
Southeastern Burlington-Berks-Delaware-Philadelphia-
Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Wilmington, Dover, Georgetown, 
Rehoboth Beach, Elkton, Chestertown, Centreville, Easton, Denton,
Trenton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Jackson, Millville, Hammonton, Cape May Court House,
Ocean City, Atlantic City, Long Beach Island, 
Wharton State Forest, Reading, Media, Philadelphia, Honey Brook, 
Oxford, West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
344 AM EDT Sat Jul 21 2018

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

The Flash Flood Watch continues for

* Northeastern Maryland, Delaware, southeastern Pennsylvania, 
  southern New Jersey and parts of central New Jersey.

* From 2:00 PM this afternoon through late tonight.

* Heavy rain is expected from this afternoon into this evening. 
  Rainfall amounts of 2 to 4 inches are forecast. Much of the rain
  is expected to fall over a period of only a few hours. 

* Excessive rainfall in a short amount of time can lead to flash
  flooding. Urban areas, locations along small streams and creeks,
  and areas of poor drainage are most vulnerable to 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.

&&

$$

Iovino
599 
WGUS61 KPHI 212020
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
420 PM EDT Sat Jul 21 2018

DEZ001>004-MDZ008-012-015-019-020-NJZ015>027-PAZ060-070-071-
101>106-221000-
/O.CON.KPHI.FF.A.0008.000000T0000Z-180722T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Kent-Inland Sussex-Delaware Beaches-Cecil-Kent MD-
Queen Annes-Talbot-Caroline-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Atlantic Coastal Cape May-Coastal Atlantic-Coastal Ocean-
Southeastern Burlington-Berks-Delaware-Philadelphia-
Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Wilmington, Dover, Georgetown, 
Rehoboth Beach, Elkton, Chestertown, Centreville, Easton, Denton,
Trenton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Jackson, Millville, Hammonton, Cape May Court House,
Ocean City, Atlantic City, Long Beach Island, 
Wharton State Forest, Reading, Media, Philadelphia, Honey Brook, 
Oxford, West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
420 PM EDT Sat Jul 21 2018

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

The Flash Flood Watch continues for

* Northeastern Maryland, Delaware, southeastern Pennsylvania,
  southern New Jersey and parts of central New Jersey.

* Through late tonight.

* Moderate to locally heavy rain continues to overspread the area
  late this afternoon. The risk for poor drainage flooding and
  flash flooding increases this evening as a band of heavy
  rainfall lifts northward through the region. Rainfall amounts 
  of around 2 inches are forecast with much of the rain expected 
  to fall over a period of only a few hours this evening. Locally 
  higher amounts of 3 to 4 inches possible, especially across 
  northeastern Maryland and southern Delaware.

* Excessive rainfall in a short amount of time can lead to flash 
  flooding. Urban areas, locations along small streams and 
  creeks, and areas of poor drainage are most vulnerable to 
  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.

&&

$$
685 
WGUS61 KPHI 220144
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
944 PM EDT Sat Jul 21 2018



DEZ001>004-MDZ008-012-015-019-020-NJZ016-021-023-024-220245-
/O.CAN.KPHI.FF.A.0008.000000T0000Z-180722T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Kent-Inland Sussex-Delaware Beaches-Cecil-Kent MD-
Queen Annes-Talbot-Caroline-Salem-Cumberland-Cape May-
Atlantic Coastal Cape May-
Including the cities of Wilmington, Dover, Georgetown, 
Rehoboth Beach, Elkton, Chestertown, Centreville, Easton, Denton,
Pennsville, Millville, Cape May Court House, and Ocean City
944 PM EDT Sat Jul 21 2018

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of Delaware, northeast
Maryland, and southern New Jersey has been cancelled. There will
continue to be some showers affecting the area this evening but
the heaviest and steadiest rain is expected to remain over western
Maryland so the flash flood threat has diminished. 

$$

NJZ015-017>020-022-025>027-PAZ060-070-071-101>106-220945-
/O.CON.KPHI.FF.A.0008.000000T0000Z-180722T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-Atlantic-
Coastal Atlantic-Coastal Ocean-Southeastern Burlington-Berks-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Trenton, Glassboro, Camden, Cherry Hill, 
Moorestown, Mount Holly, Jackson, Hammonton, Atlantic City, 
Long Beach Island, Wharton State Forest, Reading, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
944 PM EDT Sat Jul 21 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 6 AM EDT SUNDAY...

The Flash Flood Watch continues for

* Portions of New Jersey and Pennsylvania, including the 
  following areas, in New Jersey, Atlantic, Camden, Coastal 
  Atlantic, Coastal Ocean, Gloucester, Mercer, Northwestern 
  Burlington, Ocean, and Southeastern Burlington. In 
  Pennsylvania, Berks, Delaware, Eastern Chester, Eastern 
  Montgomery, Lower Bucks, Philadelphia, Upper Bucks, Western 
  Chester, and Western Montgomery. 

* Until 6 AM EDT Sunday

* Rain, moderate to occasionally heavy at times, will continue to
  affect the area through this evening before tapering off late
  tonight. Urban, small stream, and poor drainage flooding will be
  possible with any heavier bands with a lesser threat of more
  localized flash flooding. Total rainfall amounts of around 2
  inches are forecast with locally higher amounts of around 3 
  inches possible in areas that get heavier bands. 

* Excessive rainfall in a short amount of time can lead to flash 
  flooding. Urban areas, locations along small streams and 
  creeks, and areas of poor drainage are most vulnerable to 
  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.

&&

$$

Fitzsimmons
670 
WGUS61 KPHI 220434
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
1234 AM EDT Sun Jul 22 2018

NJZ015-017>020-022-025>027-PAZ060-070-071-101>106-220545-
/O.CAN.KPHI.FF.A.0008.000000T0000Z-180722T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-Atlantic-
Coastal Atlantic-Coastal Ocean-Southeastern Burlington-Berks-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Trenton, Glassboro, Camden, Cherry Hill, 
Moorestown, Mount Holly, Jackson, Hammonton, Atlantic City, 
Long Beach Island, Wharton State Forest, Reading, Media, 
Philadelphia, Honey Brook, Oxford, West Chester, Kennett Square, 
Collegeville, Pottstown, Norristown, Lansdale, Chalfont, 
Perkasie, Morrisville, and Doylestown
1234 AM EDT Sun Jul 22 2018

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of central and southern New 
Jersey, and southeastern Pennsylvania has been cancelled.

Rain showers will end from south to north in the region 
overnight. Additional rainfall should be generally less than a 
half inch and flooding is no longer expected.

$$

Iovino

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 4:00 AM EDTGale WatchPHI24 hr
Jul 20, 4:00 AM EDTSmall Craft AdvisoryPHI30 hr
Jul 20, 4:01 PM EDTGale WarningPHI38 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.