Alert archive / New Jersey / Flash Flood Warnings in 2020

Flash Flood Warning 20, NWS Philadelphia/Mount Holly

July 10, 20205 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 10, 2020, 12:49 PM EDT for 5 counties in New Jersey. It was in force for 4 hr. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 10, 2020, 12:49 PM EDT (16:49 UTC)
Expired: Jul 10, 2020, 4:35 PM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 32 km from the middle of the area, began a volume at 16:51 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.

What was reported inside it

Time	Report	Where	Remark
Jul 10, 1:14 PM EDT	FLASH FLOOD	1 Wsw Wanamassa, NJ	CORRECTS PREVIOUS FLASH FLOOD REPORT FROM 1 WSW WANAMASSA. FLOODING ON ROUTE 66 EAST OF ROUTE 18. ALL LANES CLOSED AND DETOURED.
Jul 10, 1:14 PM EDT	FLASH FLOOD	1 Wsw Wanamassa, NJ	FLOODING ON ROUTE 66 EAST OF ROUTE 66. ALL LANES CLOSED AND DETOURED.
Jul 10, 1:15 PM EDT	FLOOD	2 Nne Farmingdale, NJ	FLOODING ON STATE HIGHWAY 33 WESTBOUND AT STATE HIGHWAY 34. LANE RESTRICTIONS IN PLACE. TIME BASED ON INITIAL DOT REPORT.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 4.8 hours before the alert went out and 160 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 531 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 508 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

399 
WGUS51 KPHI 101649
FFWPHI
NJC021-023-025-029-035-102045-
/O.NEW.KPHI.FF.W.0020.200710T1649Z-200710T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1249 PM EDT Fri Jul 10 2020

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Northeastern Ocean County in southern New Jersey...
  Mercer County in central New Jersey...
  Southern Somerset County in northern New Jersey...
  Monmouth County in central New Jersey...
  Southwestern Middlesex County in northern New Jersey...

* Until 445 PM EDT.

* At 1248 PM EDT, Doppler radar indicated heavy rain falling across
  the warned area. Up to two inches of rain have already fallen.
  Flash flooding is likely.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar indicated.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Some locations that could experience flooding include...
  Trenton, Long Branch, Asbury Park, Lakewood, Howell, Marlboro,
  Manalapan, Ewing, Tinton Falls, Princeton, Jamesburg, Manasquan,
  Hightstown, Point Pleasant Beach, Cranbury, Pennington, Hopewell,
  Allentown, Farmingdale and Roosevelt.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4027 7397 4003 7401 4014 7461 4019 7470
      4016 7471 4016 7472 4018 7475 4022 7477
      4023 7480 4031 7485 4040 7475

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-3 INCHES IN 1 HOUR

$$

Kruzdlo

2 follow-up statements

871 
WGUS71 KPHI 101844
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
244 PM EDT Fri Jul 10 2020

NJC021-023-025-029-035-102045-
/O.CON.KPHI.FF.W.0020.000000T0000Z-200710T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ocean NJ-Mercer NJ-Somerset NJ-Monmouth NJ-Middlesex NJ-
244 PM EDT Fri Jul 10 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM EDT FOR
NORTHEASTERN OCEAN...MERCER...SOUTHERN SOMERSET...MONMOUTH AND
SOUTHWESTERN MIDDLESEX COUNTIES...

At 241 PM EDT, Doppler radar and automated gauges indicated heavy
rain falling across the warned area. Up to three inches of rain have
already fallen. Flash flooding is already occurring.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Radar and automated gauges.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that could experience flooding include...
Trenton, Long Branch, Asbury Park, Lakewood, Howell, Marlboro,
Manalapan, Ewing, Tinton Falls, Princeton, Jamesburg, Manasquan,
Hightstown, Point Pleasant Beach, Cranbury, Pennington, Hopewell,
Allentown, Farmingdale and Roosevelt.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4027 7397 4003 7401 4014 7461 4019 7470
      4016 7471 4016 7472 4018 7475 4022 7477
      4023 7480 4031 7485 4040 7475

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Staarmann

494 
WGUS71 KPHI 102035
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
435 PM EDT Fri Jul 10 2020

NJC021-023-025-029-035-102043-
/O.CAN.KPHI.FF.W.0020.000000T0000Z-200710T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ocean NJ-Mercer NJ-Somerset NJ-Monmouth NJ-Middlesex NJ-
435 PM EDT Fri Jul 10 2020

...THE FLASH FLOOD WARNING FOR NORTHEASTERN OCEAN...MERCER...SOUTHERN
SOMERSET...MONMOUTH AND SOUTHWESTERN MIDDLESEX COUNTIES IS
CANCELLED...

Flooding no longer poses an immediate threat to life and property, 
so this flash flood warning has been cancelled. It has been replaced 
with a flood advisory in order to provide more time for streams and 
low lying areas to drain. 

LAT...LON 4027 7397 4003 7401 4014 7461 4019 7470
      4016 7471 4016 7472 4018 7475 4022 7477
      4023 7480 4031 7485 4040 7475

$$

Miketta

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 10, 6:48 AM EDT	Special Marine Warning	PHI		57 min
Jul 10, 7:11 AM EDT	Special Marine Warning	PHI		94 min
Jul 10, 7:42 AM EDT	Special Marine Warning	PHI		33 min
Jul 10, 8:20 AM EDT	Flash Flood Warning Considerable damage threat	PHI	Cape May	4 hr
Jul 10, 8:34 AM EDT	Special Marine Warning	PHI		30 min
Jul 10, 9:01 AM EDT	Flash Flood Warning	PHI	Atlantic, Cape May	3 hr
Jul 10, 9:13 AM EDT	Special Marine Warning	PHI		21 min
Jul 10, 9:27 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 1 more	4 hr
Jul 10, 10:31 AM EDT	Flash Flood Warning	PHI	Atlantic, Burlington, Ocean	4 hr
Jul 10, 10:35 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Gloucester, Ocean	4 hr
Jul 10, 11:02 AM EDT	Areal Flood Advisory	PHI	Camden, Gloucester, Salem	4 hr
Jul 10, 11:08 AM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Mercer, Monmouth, Ocean	4 hr
Jul 10, 12:35 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth, Ocean, Somerset	3 hr
Jul 10, 12:56 PM EDT	Flash Flood Warning	PHI	Burlington, Camden, Cumberland, Gloucester, Salem	4 hr
Jul 10, 1:15 PM EDT	Flash Flood Warning	PHI	Middlesex, Monmouth, Somerset	4 hr
Jul 10, 1:41 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Somerset	4 hr
Jul 10, 2:08 PM EDT	Areal Flood Advisory	PHI	Morris, Somerset	4 hr
Jul 10, 3:12 PM EDT	Areal Flood Advisory	PHI	Sussex, Warren	4 hr
Jul 10, 4:30 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Ocean	4 hr
Jul 10, 4:48 PM EDT	Areal Flood Warning	PHI	Burlington, Camden, Cumberland, Gloucester, Salem	4 hr
Jul 10, 5:39 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Somerset	4 hr

Nearby

Flash Flood Warnings in New Jersey, 2020 Every flash flood warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.