Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 82, NWS Philadelphia/Mount Holly

September 13, 2021Northampton County, Pennsylvania; Hunterdon County, Morris County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 13, 2021, 9:12 PM EDT for Northampton County, Pennsylvania; Hunterdon County, Morris County, Warren County, New Jersey. It was in force for 114 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 13, 2021, 9:12 PM EDT (01:12 UTC)
Expired
Sep 13, 2021, 11:06 PM EDT
In force
114 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Hunterdon County, NJ, Morris County, NJ, Warren County, NJ, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 100 km from the middle of the area, began a volume at 01:15 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, 1.2 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 00:00Z on 2021-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 90 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 00:00Z on 2021-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 square meters per square second.19395878Sfc1 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
90 J/kg
Mixed-layer CIN
-236 J/kg
Mixed-layer LCL
1411 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

511 
WGUS51 KPHI 140112
FFWPHI
NJC019-027-041-PAC095-140515-
/O.NEW.KPHI.FF.W.0082.210914T0112Z-210914T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
912 PM EDT Mon Sep 13 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southwestern Morris County in northern New Jersey...
  Northeastern Hunterdon County in northwestern New Jersey...
  Central Warren County in northwestern New Jersey...
  Northeastern Northampton County in eastern Pennsylvania...

* Until 115 AM EDT.

* At 912 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. 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...
  Hackettstown, Washington, Belvidere, Peapack And Gladstone, 
  Oxford, Chester, East Bangor, Beatyestown, Great Meadows-Vienna, 
  Brass Castle, Long Valley, and Succasunna-Kenvil.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Motorists should not attempt to drive around barricades or drive 
cars through flooded areas.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Be aware of your surroundings and do not drive on flooded roads.

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 4080 7515 4088 7518 4092 7512 4082 7460
      4074 7466 4073 7467 4073 7469 4073 7471
      4072 7472 4073 7477

FLASH FLOOD...RADAR INDICATED

$$

MPS
1 follow-up statement
066 
WGUS71 KPHI 140306
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1106 PM EDT Mon Sep 13 2021

NJC019-027-041-PAC095-140316-
/O.CAN.KPHI.FF.W.0082.000000T0000Z-210914T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Morris NJ-Warren NJ-Northampton PA-
1106 PM EDT Mon Sep 13 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN MORRIS, 
NORTHEASTERN HUNTERDON, CENTRAL WARREN, AND NORTHEASTERN NORTHAMPTON 
COUNTIES...

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

LAT...LON 4080 7515 4088 7518 4092 7512 4082 7460
      4074 7466 4073 7467 4073 7469 4073 7471
      4072 7472 4073 7477

$$

Iovino

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 13, 8:16 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe44 min
Sep 13, 8:41 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton49 min
Sep 13, 8:51 PM EDTAreal Flood AdvisoryPHICarbon, Monroe108 min
Sep 13, 9:03 PM EDTAreal Flood AdvisoryPHIMonroe, Northampton109 min
Sep 13, 9:21 PM EDTSevere Thunderstorm WarningPHIBucks, Lehigh, Northampton38 min
Sep 13, 9:03 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset, Warren57 min
Sep 13, 9:34 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Morris, Somerset38 min
Sep 13, 9:53 PM EDTSevere Thunderstorm WarningPHIMercer, Middlesex, Monmouth, Somerset52 min
Sep 13, 10:03 PM EDTSpecial Marine WarningPHI57 min

Nearby

Flash Flood Warnings in New Jersey, 2021Flash Flood Warnings in Pennsylvania, 2021Every flash flood warning in 2021

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.