Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 17, NWS New York, NY

July 12, 2021Bergen County, Essex County, Passaic County, New Jersey; Orange County, Rockland County, New York

NWS New York, NY issued this flash flood warning at Jul 12, 2021, 6:09 PM EDT for Bergen County, Essex County, Passaic County, New Jersey; Orange County, Rockland County, New York. It was in force for 3 hr. 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
Jul 12, 2021, 6:09 PM EDT (22:09 UTC)
Expired
Jul 12, 2021, 9:15 PM EDT
In force
3 hr
Issued by
NWS New York, NY
Area
Storm-based polygon
Flood severity
None

Counties Bergen County, NJ, Essex County, NJ, Passaic County, NJ, Orange County, NY, Rockland County, NY

The radar

The Philadelphia radar (KDIX), 120 km from the middle of the area, began a volume at 22:09 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
Jul 12, 7:23 PM EDTFLASH FLOOD1 Nne Wanaque, NJRINGWOOD AVE IMPASSABLE. TWO FEET OF WATER.

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, 10.2 hours before the alert went out and 125 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 2021-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 857 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 2021-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 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
857 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
697 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
114 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.4

Open this sounding in Storm Lab

The text

As transmitted.

438 
WGUS51 KOKX 122209
FFWOKX
NJC003-013-031-NYC071-087-130115-
/O.NEW.KOKX.FF.W.0017.210712T2209Z-210713T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New York NY
609 PM EDT Mon Jul 12 2021

The National Weather Service in Upton has issued a

* Flash Flood Warning for...
  Northern Bergen County in northeastern New Jersey...
  Northern Essex County in northeastern New Jersey...
  Passaic County in northeastern New Jersey...
  South Central Orange County in southeastern New York...
  Rockland County in southeastern New York...

* Until 915 PM EDT.

* At 609 PM 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 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...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Paterson, Passaic, Wayne, Bloomfield, New City, Paramus, West 
  Milford, Ridgewood, Monsey, Nanuet, Ramsey, Ringwood, Pompton 
  Lakes, Suffern, Caldwell, Warwick, Sloatsburg, Hawthorne, Pearl 
  River and Bloomingdale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of urban 
areas, highways, streets and underpasses as well as other drainage 
areas and low lying spots.

&&

LAT...LON 4130 7439 4114 7389 4077 7419 4083 7433
      4086 7432 4087 7434 4091 7433 4090 7428
      4091 7427 4093 7429 4097 7428 4100 7430
      4102 7443 4105 7445 4104 7450 4108 7449
      4109 7450 4120 7437 4125 7446

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

$$

JM
3 follow-up statements
760 
WGUS71 KOKX 122322
FFSOKX

Flash Flood Statement
National Weather Service New York NY
722 PM EDT Mon Jul 12 2021

NJC003-013-031-NYC071-087-130115-
/O.CON.KOKX.FF.W.0017.000000T0000Z-210713T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bergen NJ-Essex NJ-Passaic NJ-Orange NY-Rockland NY-
722 PM EDT Mon Jul 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM EDT THIS 
EVENING FOR NORTHWESTERN BERGEN, NORTHWESTERN ESSEX, PASSAIC, SOUTH 
CENTRAL ORANGE AND ROCKLAND COUNTIES...

At 722 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 2 and 3.5 inches of rain have 
fallen. The expected rainfall rate is 1 to 2 inches in 1 hour. 
Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Paterson, Wayne, Paramus, West Milford, Ridgewood, Monsey, Nanuet, 
  Ramsey, Ringwood, Pompton Lakes, Suffern, Caldwell, Sloatsburg, 
  Hawthorne, Pearl River, Bloomingdale, Fairfield, Greenwood Lake, 
  Upper Greenwood Lake and Fair Lawn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of urban 
areas, highways, streets and underpasses as well as other drainage 
areas and low lying spots.

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 4124 7433 4124 7428 4109 7397 4094 7407
      4083 7423 4083 7433 4086 7432 4087 7434
      4091 7433 4090 7428 4091 7427 4093 7429
      4097 7428 4100 7430 4102 7443 4105 7445
      4104 7450 4107 7449 4109 7450

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

JM
670 
WGUS71 KOKX 130014
FFSOKX

Flash Flood Statement
National Weather Service New York NY
814 PM EDT Mon Jul 12 2021

NJC003-013-031-NYC071-087-130115-
/O.CON.KOKX.FF.W.0017.000000T0000Z-210713T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bergen NJ-Essex NJ-Passaic NJ-Orange NY-Rockland NY-
814 PM EDT Mon Jul 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM EDT THIS 
EVENING FOR NORTHWESTERN BERGEN, NORTHWESTERN ESSEX, PASSAIC, SOUTH 
CENTRAL ORANGE AND ROCKLAND COUNTIES...

At 814 PM EDT, Doppler radar indicated lighter rain showers moving 
across the area, but there are still areas of residual flooding. 
Thunderstorms produced heavy rain across the warned area earlier 
this evening. Between 2 and 4 inches of rain have fallen so far. 
Flash flooding is expected to be ongoing in some areas.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Paterson, Wayne, Paramus, West Milford, Ridgewood, Monsey, Nanuet, 
  Ramsey, Ringwood, Pompton Lakes, Suffern, Caldwell, Sloatsburg, 
  Hawthorne, Pearl River, Bloomingdale, Fairfield, Greenwood Lake, 
  Upper Greenwood Lake and Fair Lawn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of urban 
areas, highways, streets and underpasses as well as other drainage 
areas and low lying spots.

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 4124 7433 4124 7428 4109 7397 4094 7407
      4083 7423 4083 7433 4086 7432 4087 7434
      4091 7433 4090 7428 4091 7427 4093 7429
      4097 7428 4100 7430 4102 7443 4105 7445
      4104 7450 4107 7449 4109 7450

FLASH FLOOD...RADAR INDICATED

$$

JM
800 
WGUS71 KOKX 130117
FFSOKX

Flash Flood Statement
National Weather Service New York NY
917 PM EDT Mon Jul 12 2021

NJC003-013-031-NYC071-087-130127-
/O.EXP.KOKX.FF.W.0017.000000T0000Z-210713T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bergen NJ-Essex NJ-Passaic NJ-Orange NY-Rockland NY-
917 PM EDT Mon Jul 12 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTHWESTERN BERGEN, 
NORTHWESTERN ESSEX, PASSAIC, SOUTH CENTRAL ORANGE AND ROCKLAND 
COUNTIES...

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

A Flash Flood Watch remains in effect until 1000 AM EDT Tuesday for 
portions of southern Connecticut, northeast New Jersey and southeast 
New York.

LAT...LON 4124 7433 4124 7428 4109 7397 4094 7407
      4083 7423 4083 7433 4086 7432 4087 7434
      4091 7433 4090 7428 4091 7427 4093 7429
      4097 7428 4100 7430 4102 7443 4105 7445
      4104 7450 4107 7449 4109 7450

$$

JM

The office that day

Everything else NWS New York, NY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 12, 2:18 AM EDTSpecial Weather StatementOKXHudson42 min
Jul 12, 3:53 PM EDTAreal Flood AdvisoryOKXUnion49 min
Jul 12, 4:18 PM EDTAreal Flood AdvisoryOKXBergen, Hudson52 min
Jul 12, 4:55 PM EDTAreal Flood AdvisoryOKXBergen32 min
Jul 12, 5:38 PM EDTAreal Flood AdvisoryOKXBergen, Essex, Passaic112 min
Jul 12, 5:41 PM EDTSpecial Weather StatementOKXPassaic49 min
Jul 12, 5:51 PM EDTSevere Thunderstorm WarningOKXBergen, Passaic39 min
Jul 12, 6:15 PM EDTTornado WarningOKXBergen, Passaic45 min
Jul 12, 6:58 PM EDTSevere Thunderstorm WarningOKXBergen, Essex, Passaic41 min
Jul 12, 3:37 PM EDTSpecial Marine WarningOKX38 min
Jul 12, 3:45 PM EDTSpecial Weather StatementOKXRichmond30 min
Jul 12, 7:46 PM EDTAreal Flood AdvisoryOKXOrange119 min

Nearby

Flash Flood Warnings in New Jersey, 2021Flash Flood Warnings in New York, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.