Alert archive / New Jersey / Flash Flood Warnings in 2022

Flash Flood Warning 11, NWS Philadelphia/Mount Holly

August 20, 2022Morris County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 20, 2022, 5:49 PM EDT for Morris County, New Jersey. It was in force for 114 min. 1 report 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 20, 2022, 5:49 PM EDT (21:49 UTC)
Expired
Aug 20, 2022, 7:43 PM EDT
In force
114 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Morris County, NJ

The radar

The Philadelphia radar (KDIX), 116 km from the middle of the area, began a volume at 21:52 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

TimeReportWhereRemark
Aug 20, 6:32 PM EDTHEAVY RAIN 2.63Butler, NJ

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, 9.8 hours before the alert went out and 124 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 2022-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 557 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 2022-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
557 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
1219 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

206 
WGUS51 KPHI 202149
FFWPHI
NJC027-210200-
/O.NEW.KPHI.FF.W.0011.220820T2149Z-220821T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
549 PM EDT Sat Aug 20 2022

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northeastern Morris County in northern New Jersey...

* Until 1000 PM EDT.

* At 549 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. The expected rainfall rate is 1 to 3 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...
  Kinnelon, Butler, Riverdale, and Pequannock Township.

This includes the following highways...
	Interstate 287 in New Jersey between mile markers 50 and 53.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4096 7428 4094 7439 4098 7444 4101 7439
      4101 7436 4101 7435 4100 7435 4101 7434
      4100 7433 4100 7432 4100 7431 4100 7430
      4099 7429 4098 7430 4098 7428 4097 7428

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

$$

RCM
1 follow-up statement
484 
WGUS71 KPHI 202343
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
743 PM EDT Sat Aug 20 2022

NJC027-202353-
/O.CAN.KPHI.FF.W.0011.000000T0000Z-220821T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Morris NJ-
743 PM EDT Sat Aug 20 2022

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHEASTERN MORRIS COUNTY...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat.

LAT...LON 4096 7428 4094 7439 4098 7444 4101 7439
      4101 7436 4101 7435 4100 7435 4101 7434
      4100 7433 4100 7432 4100 7431 4100 7430
      4099 7429 4098 7430 4098 7428 4097 7428

$$

RCM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 5:13 PM EDTAreal Flood AdvisoryPHIMorris2 hr
Aug 20, 5:16 PM EDTSpecial Weather StatementPHIPassaic29 min
Aug 20, 5:33 PM EDTAreal Flood AdvisoryPHIMorris2 hr
Aug 20, 5:46 PM EDTSpecial Weather StatementPHIPassaic29 min

Nearby

Flash Flood Warnings in New Jersey, 2022Every flash flood warning in 2022

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.