Alert archive / New Jersey / Flash Flood Warnings in 2023

Flash Flood Warning 62, NWS Philadelphia/Mount Holly

July 16, 20234 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 16, 2023, 5:26 AM EDT for 4 counties in New Jersey. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 16, 2023, 5:26 AM EDT (09:26 UTC)
Expired
Jul 16, 2023, 9:30 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Hunterdon County, NJ, Morris County, NJ, Sussex County, NJ, Warren County, NJ

The radar

The Philadelphia radar (KDIX), 111 km from the middle of the area, began a volume at 09:30 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, 9.4 hours before the alert went out and 146 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 2023-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1061 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2023-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 square meters per square second.193958Sfc1 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
1061 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
624 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
29 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.0

Open this sounding in Storm Lab

The text

As transmitted.

269 
WGUS51 KPHI 160926
FFWPHI
NJC019-027-037-041-161330-
/O.NEW.KPHI.FF.W.0062.230716T0926Z-230716T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
526 AM EDT Sun Jul 16 2023

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Central Morris County in northern New Jersey...
  Northeastern Hunterdon County in northwestern New Jersey...
  Southeastern Sussex County in northwestern New Jersey...
  East Central Warren County in northwestern New Jersey...

* Until 930 AM EDT.

* At 526 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 1.5 inches of 
  rain have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts of 1 to 2 inches are possible in 
  the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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 may experience flash flooding include...
  Dover, Hopatcong, Hackettstown, Wharton, Rockaway, Mount 
  Arlington, Franklin, Mendham, High Bridge, Stanhope, Netcong, and 
  Clinton.

This includes the following highways...
	Interstate 78 in New Jersey between mile markers 17 and 21.
	Interstate 80 in New Jersey between mile markers 17 and 39.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4090 7491 4122 7440 4120 7437 4109 7450
      4108 7449 4103 7450 4105 7445 4104 7443
      4102 7443 4103 7442 4101 7439 4076 7459
      4072 7473 4072 7472 4071 7472 4060 7490
      4074 7493

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

SFJ
2 follow-up statements
600 
WGUS71 KPHI 161011
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
611 AM EDT Sun Jul 16 2023

NJC019-027-037-041-161330-
/O.CON.KPHI.FF.W.0062.000000T0000Z-230716T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Morris NJ-Sussex NJ-Warren NJ-
611 AM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 AM EDT THIS 
MORNING FOR CENTRAL MORRIS, NORTHEASTERN HUNTERDON, SOUTHEASTERN 
SUSSEX, AND EAST CENTRAL WARREN COUNTIES...

At 611 AM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 2 inches of rain have 
fallen. The expected rainfall rate is 0.5 to 1 inch in 1 hour. 
Additional rainfall amounts of 0.5 to 1 inch are possible in the 
warned area. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

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 may experience flash flooding include...
  Dover, Hopatcong, Hackettstown, Wharton, Rockaway, Mount 
  Arlington, Franklin, Mendham, High Bridge, Stanhope, Netcong, and 
  Clinton.

This includes the following highways...
	Interstate 78 in New Jersey between mile markers 17 and 21.
	Interstate 80 in New Jersey between mile markers 17 and 39.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4090 7491 4122 7440 4120 7437 4109 7450
      4108 7449 4103 7450 4105 7445 4104 7443
      4102 7443 4103 7442 4101 7439 4076 7459
      4072 7473 4072 7472 4071 7472 4060 7490
      4074 7493

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...0.5-1 INCH IN 1 HOUR

$$

SFJ
558 
WGUS71 KPHI 161327
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
927 AM EDT Sun Jul 16 2023

NJC019-027-037-041-161337-
/O.EXP.KPHI.FF.W.0062.000000T0000Z-230716T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Morris NJ-Sussex NJ-Warren NJ-
927 AM EDT Sun Jul 16 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 930 AM EDT THIS MORNING FOR 
CENTRAL MORRIS, NORTHEASTERN HUNTERDON, SOUTHEASTERN SUSSEX, AND 
EAST CENTRAL WARREN COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat.

A Flood Watch remains in effect until 1200 AM EDT Monday for 
portions of northern Delaware...New Jersey...and Pennsylvania.

LAT...LON 4090 7491 4122 7440 4120 7437 4109 7450
      4108 7449 4103 7450 4105 7445 4104 7443
      4102 7443 4103 7442 4101 7439 4076 7459
      4072 7473 4072 7472 4071 7472 4060 7490
      4074 7493

$$

MJL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 2:22 AM EDTSpecial Marine WarningPHI53 min
Jul 16, 2:47 AM EDTSpecial Weather StatementPHIGloucester, Salem28 min
Jul 16, 3:08 AM EDTSpecial Marine WarningPHI42 min
Jul 16, 3:40 AM EDTFlash Flood WarningPHISussex, Warren7 hr
Jul 16, 4:05 AM EDTFlash Flood WarningPHIHunterdon, Warren6 hr
Jul 16, 4:14 AM EDTSpecial Weather StatementPHIHunterdon31 min
Jul 16, 4:38 AM EDTTornado WarningPHIHunterdon, Somerset37 min
Jul 16, 4:50 AM EDTSpecial Weather StatementPHIBurlington, Ocean25 min
Jul 16, 5:07 AM EDTTornado WarningPHIHunterdon, Morris, Somerset38 min
Jul 16, 5:13 AM EDTFlash Flood WarningPHISussex, Warren4 hr
Jul 16, 5:16 AM EDTSpecial Weather StatementPHIOcean29 min
Jul 16, 5:31 AM EDTTornado WarningPHIMorris, Somerset, Sussex29 min
Jul 16, 5:44 AM EDTSpecial Marine WarningPHI61 min
Jul 16, 5:45 AM EDTSpecial Weather StatementPHIMonmouth30 min
Jul 16, 5:58 AM EDTTornado WarningPHIMorris32 min
Jul 16, 7:52 AM EDTSpecial Marine WarningPHI53 min
Jul 16, 8:40 AM EDTSpecial Marine WarningPHI47 min
Jul 16, 10:54 AM EDTAreal Flood WarningPHIWarren5 hr
Jul 16, 11:08 AM EDTFlash Flood WarningPHIGloucester, Salem3 hr
Jul 16, 11:36 AM EDTFlash Flood WarningPHIMiddlesex, Somerset3 hr
Jul 16, 12:22 PM EDTAreal Flood AdvisoryPHIMercer3 hr
Jul 16, 12:26 PM EDTAreal Flood AdvisoryPHIBurlington, Camden3 hr
Jul 16, 1:47 PM EDTAreal Flood AdvisoryPHIGloucester, Salem80 min
Jul 16, 1:50 PM EDTSpecial Marine WarningPHI85 min
Jul 16, 2:20 PM EDTAreal Flood AdvisoryPHIMiddlesex, Somerset72 min
Jul 16, 2:42 PM EDTSpecial Weather StatementPHICape May48 min
Jul 16, 3:09 PM EDTSpecial Marine WarningPHI51 min
Jul 16, 6:17 PM EDTAreal Flood WarningPHIWarren10 hr
Jul 16, 6:19 PM EDTAreal Flood WarningPHIWarren10 hr

Nearby

Flash Flood Warnings in New Jersey, 2023Every flash flood warning in 2023

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.