Alert archive / New Jersey / Flash Flood Warnings in 2024

Flash Flood Warning 62, NWS Philadelphia/Mount Holly

August 18, 2024Sussex County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 18, 2024, 5:38 PM EDT for Sussex County, Warren County, 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
Aug 18, 2024, 5:38 PM EDT (21:38 UTC)
Expired
Aug 18, 2024, 9:45 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Sussex County, NJ, Warren County, NJ

The radar

The Philadelphia radar (KDIX), 137 km from the middle of the area, began a volume at 21:38 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 12:00Z, 9.6 hours before the alert went out and 168 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 12:00Z on 2024-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 109 joules per kilogram.LCLLFCEL10008507005003002001001 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, Brookhaven, NY at 12:00Z on 2024-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 187 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
109 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
582 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
187 m²/s²
0-3 km storm-relative helicity
205 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

303 
WGUS51 KPHI 182138
FFWPHI
NJC037-041-190145-
/O.NEW.KPHI.FF.W.0062.240818T2138Z-240819T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
538 PM EDT Sun Aug 18 2024

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Sussex County in northwestern New Jersey...
  Northeastern Warren County in northwestern New Jersey...

* Until 945 PM EDT.

* At 538 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts of 1 to 3 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...
  Newton, Montague, Hopatcong, Franklin, Hamburg, Ogdensburg, 
  Sussex, Branchville, Andover, Pellettown, Crandon Lakes and Lake 
  Mohawk.

This includes Interstate 80 in New Jersey between mile markers 14 
and 21.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4118 7488 4122 7486 4124 7486 4129 7483
      4135 7475 4136 7469 4120 7437 4098 7463
      4096 7466 4090 7487 4093 7494 4105 7502
      4109 7497 4109 7499 4111 7498 4114 7492

FLASH FLOOD...RADAR INDICATED

$$

Hoeflich
2 follow-up statements
669 
WGUS71 KPHI 190042
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
842 PM EDT Sun Aug 18 2024

NJC037-041-190145-
/O.CON.KPHI.FF.W.0062.000000T0000Z-240819T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex NJ-Warren NJ-
842 PM EDT Sun Aug 18 2024

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM EDT THIS 
EVENING FOR SOUTHERN SUSSEX AND NORTHEASTERN WARREN COUNTIES...

At 842 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1.5 and 3 inches of rain have 
fallen. Additional rainfall amounts of 0.5 to 1.5 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...
  Newton, Hopatcong, Franklin, Ogdensburg, Branchville, Andover, 
  Greendell, Five Points, Crandon Lakes, Lake Mohawk, 
  Allamuchy-Panther Valley and Pellettown.

This includes Interstate 80 in New Jersey between mile markers 14 
and 21.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4115 7487 4120 7473 4109 7450 4098 7463
      4096 7466 4090 7487 4093 7494 4105 7502
      4108 7498 4108 7497 4109 7497 4112 7491

FLASH FLOOD...RADAR INDICATED

$$

Hoeflich
264 
WGUS71 KPHI 190135
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
935 PM EDT Sun Aug 18 2024

NJC037-041-190145-
/O.EXP.KPHI.FF.W.0062.000000T0000Z-240819T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex NJ-Warren NJ-
935 PM EDT Sun Aug 18 2024

...FLASH FLOOD WARNING WILL EXPIRE AT 945 PM EDT THIS EVENING FOR 
SOUTHERN SUSSEX AND NORTHEASTERN WARREN COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flood Watch remains in effect until 200 AM EDT for portions of 
northern Delaware, New Jersey, and Pennsylvania.

&&

LAT...LON 4115 7487 4120 7473 4109 7450 4098 7463
      4096 7466 4090 7487 4093 7494 4105 7502
      4108 7498 4108 7497 4109 7497 4112 7491

$$

Hoeflich

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 3:09 AM EDTFlash Flood WarningPHIBurlington, Camden93 min
Aug 18, 4:41 AM EDTFlash Flood WarningPHIBurlington, Camden, Mercer2 hr
Aug 18, 2:17 PM EDTSpecial Marine WarningPHI58 min
Aug 18, 2:42 PM EDTSpecial Marine WarningPHI93 min
Aug 18, 3:55 PM EDTSpecial Marine WarningPHI95 min
Aug 18, 4:04 PM EDTSevere Thunderstorm WarningPHIWarren41 min
Aug 18, 4:41 PM EDTSevere Thunderstorm WarningPHISussex, Warren34 min
Aug 18, 4:56 PM EDTFlash Flood WarningPHIWarren6 hr
Aug 18, 5:10 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Warren29 min
Aug 18, 5:21 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden39 min
Aug 18, 5:31 PM EDTFlash Flood WarningPHIHunterdon, Warren6 hr
Aug 18, 5:47 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex43 min
Aug 18, 5:47 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth58 min
Aug 18, 5:51 PM EDTSevere Thunderstorm WarningPHIMorris, Somerset24 min
Aug 18, 5:59 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex18 min
Aug 18, 6:01 PM EDTFlash Flood WarningPHIHunterdon, Morris, Somerset, Sussex, Warren6 hr
Aug 18, 6:24 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Morris, Somerset66 min
Aug 18, 6:36 PM EDTFlash Flood WarningPHIMorris, Somerset5 hr

Nearby

Flash Flood Warnings in New Jersey, 2024Every flash flood warning in 2024

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.