Alert archive / New Jersey / Flash Flood Warnings in 2020

Flash Flood Warning 64, NWS Philadelphia/Mount Holly

August 13, 2020Cape May County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 13, 2020, 4:52 PM EDT for Cape May County, New Jersey. It was in force for 113 min. 2 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: Aug 13, 2020, 4:52 PM EDT (20:52 UTC)
Expired: Aug 13, 2020, 6:45 PM EDT
In force: 113 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Cape May County, NJ

The radar

The Dover AFB radar (KDOX), 71 km from the middle of the area, began a volume at 20:53 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
Aug 13, 5:00 PM EDT	HEAVY RAIN 3	Goshen, NJ	3 INCHES OF RAIN IN ONE HOUR ENDING AT 5 PM.
Aug 13, 5:09 PM EDT	HEAVY RAIN 3.26	Goshen, NJ	CORRECTS PREVIOUS HEAVY RAIN REPORT FROM GOSHEN. 3.26 INCHES OF RAIN IN ONE HOUR ENDING AT 5:09 PM.

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 8.9 hours before the alert went out and 153 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: 1152 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 760 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: -19 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

301 
WGUS51 KPHI 132052
FFWPHI
NJC009-132245-
/O.NEW.KPHI.FF.W.0064.200813T2052Z-200813T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
452 PM EDT Thu Aug 13 2020

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Cape May County in southern New Jersey...

* Until 645 PM EDT.

* At 452 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

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

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.

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 3890 7493 3899 7512 3920 7499 3918 7491
      3923 7492 3923 7490 3932 7486 3930 7476
      3931 7471 3929 7470 3930 7465 3931 7468
      3931 7469 3933 7470 3932 7469 3930 7462
      3931 7455

FLASH FLOOD...RADAR INDICATED

$$

JJM

1 follow-up statement

719 
WGUS71 KPHI 132240
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
640 PM EDT Thu Aug 13 2020

NJC009-132250-
/O.EXP.KPHI.FF.W.0064.000000T0000Z-200813T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cape May NJ-
640 PM EDT Thu Aug 13 2020

...THE FLASH FLOOD WARNING FOR CAPE MAY COUNTY WILL EXPIRE AT 645 PM
EDT...

Flooding is no longer expected to pose a threat. Please continue to
heed any remaining road closures.

LAT...LON 3890 7493 3899 7512 3920 7499 3918 7491
      3923 7492 3923 7490 3932 7486 3930 7476
      3931 7471 3929 7470 3930 7465 3931 7468
      3931 7469 3933 7470 3932 7469 3930 7462
      3931 7455

$$

JJM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 13, 3:02 AM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 7 more	17 hr
Aug 13, 7:47 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Somerset	118 min
Aug 13, 8:37 AM EDT	Flash Flood Warning	PHI	Hunterdon, Mercer, Middlesex, Somerset	3 hr
Aug 13, 9:36 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Middlesex, Morris, Somerset	114 min
Aug 13, 10:01 AM EDT	Flash Flood Warning	PHI	Middlesex, Morris, Somerset	3 hr
Aug 13, 1:06 PM EDT	Special Weather Statement	PHI	Ocean	39 min
Aug 13, 1:30 PM EDT	Special Weather Statement	PHI	Cumberland	45 min
Aug 13, 1:56 PM EDT	Areal Flood Advisory	PHI	Atlantic, Cape May, Cumberland	2 hr
Aug 13, 1:58 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Ocean	2 hr
Aug 13, 2:44 PM EDT	Areal Flood Advisory	PHI	Atlantic	2 hr
Aug 13, 3:54 PM EDT	Special Weather Statement	PHI	Cape May	36 min
Aug 13, 4:01 PM EDT	Areal Flood Advisory	PHI	Cape May	2 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.