Alert archive / New Jersey / Flash Flood Watches in 2021

Flash Flood Watch 9, NWS New York, NY

September 7, 20215 counties in New Jersey; Orange County, Rockland County, New York

NWS New York, NY issued this flash flood watch at Sep 7, 2021, 3:25 PM EDT for 5 counties in New Jersey; Orange County, Rockland County, New York. It took effect at Sep 8, 2021, 5:00 PM EDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Sep 7, 2021, 3:25 PM EDT (19:25 UTC)
In effect from
Sep 8, 2021, 5:00 PM EDT
Expired
Sep 9, 2021, 2:27 AM EDT
In force
9 hr
Issued by
NWS New York, NY
Flood severity
None

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

The radar

The Brookhaven radar (KOKX), 112 km from the middle of the area, began a volume at 19:23 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, 7.4 hours before the alert went out and 112 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 2021-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1434 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

191 
WGUS61 KOKX 071925
FFAOKX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service New York NY
325 PM EDT Tue Sep 7 2021

NJZ002-004-006-103>108-NYZ067-069-080330-
/O.NEW.KOKX.FF.A.0009.210908T2100Z-210909T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Western Passaic-Eastern Passaic-Hudson-Western Bergen-Eastern Bergen-
Western Essex-Eastern Essex-Western Union-Eastern Union-Orange-
Rockland-
325 PM EDT Tue Sep 7 2021

...FLASH FLOOD WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH LATE 
WEDNESDAY NIGHT...

The National Weather Service in Upton has issued a

* Flash Flood Watch for portions of northeast New Jersey and 
  southeast New York, including the following areas, in northeast 
  New Jersey, Eastern Bergen, Eastern Essex, Eastern Passaic, 
  Eastern Union, Hudson, Western Bergen, Western Essex, Western 
  Passaic and Western Union. In southeast New York, Orange and 
  Rockland.

* From Wednesday afternoon through late Wednesday night.

* A cold frontal passage will produce a round of showers and 
  thunderstorms across the area late Wednesday into Wednesday night. 
  Due to wet antecedent conditions, the area is susceptible to 
  flooding.

* Locally heavy rainfall may produce flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$
5 follow-up statements
637 
WGUS61 KOKX 072359
FFAOKX

Flood Watch
National Weather Service New York NY
759 PM EDT Tue Sep 7 2021

NJZ002-004-006-103>108-NYZ067-069-080800-
/O.CON.KOKX.FF.A.0009.210908T2100Z-210909T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Western Passaic-Eastern Passaic-Hudson-Western Bergen-Eastern Bergen-
Western Essex-Eastern Essex-Western Union-Eastern Union-Orange-
Rockland-
759 PM EDT Tue Sep 7 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM WEDNESDAY AFTERNOON 
THROUGH LATE WEDNESDAY NIGHT...

The Flash Flood Watch continues for

* Portions of northeast New Jersey and southeast New York, including 
  the following areas, in northeast New Jersey, Eastern Bergen, 
  Eastern Essex, Eastern Passaic, Eastern Union, Hudson, Western 
  Bergen, Western Essex, Western Passaic and Western Union. In 
  southeast New York, Orange and Rockland.

* From Wednesday afternoon through late Wednesday night.

* A cold frontal passage will produce a round of showers and 
  thunderstorms across the area late Wednesday into Wednesday night. 
  Due to wet antecedent conditions, the area is susceptible to 
  flooding.

* Locally heavy rainfall may produce flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

DW
203 
WGUS61 KOKX 080721
FFAOKX

Flood Watch
National Weather Service New York NY
321 AM EDT Wed Sep 8 2021

NJZ002-004-006-103>108-NYZ067-069-082100-
/O.CON.KOKX.FF.A.0009.210908T2100Z-210909T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Western Passaic-Eastern Passaic-Hudson-Western Bergen-Eastern Bergen-
Western Essex-Eastern Essex-Western Union-Eastern Union-Orange-
Rockland-
321 AM EDT Wed Sep 8 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM THIS AFTERNOON THROUGH 
LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of northeast New Jersey and southeast New York, including 
  the following areas, in northeast New Jersey, Eastern Bergen, 
  Eastern Essex, Eastern Passaic, Eastern Union, Hudson, Western 
  Bergen, Western Essex, Western Passaic and Western Union. In 
  southeast New York, Orange and Rockland.

* From this afternoon through late tonight.

* A cold frontal passage will produce a round of showers and 
  thunderstorms across the area late Wednesday into late Wednesday 
  night. Due to wet antecedent conditions, the area is susceptible 
  to flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JT
539 
WGUS61 KOKX 081620
FFAOKX

Flood Watch
National Weather Service New York NY
1220 PM EDT Wed Sep 8 2021

NJZ002-004-006-103>108-NYZ067-069-090030-
/O.CON.KOKX.FF.A.0009.210908T2100Z-210909T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Western Passaic-Eastern Passaic-Hudson-Western Bergen-Eastern Bergen-
Western Essex-Eastern Essex-Western Union-Eastern Union-Orange-
Rockland-
1220 PM EDT Wed Sep 8 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 5 PM EDT THIS AFTERNOON 
THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of northeast New Jersey and southeast New York, including 
  the following areas, in northeast New Jersey, Eastern Bergen, 
  Eastern Essex, Eastern Passaic, Eastern Union, Hudson, Western 
  Bergen, Western Essex, Western Passaic and Western Union. In 
  southeast New York, Orange and Rockland.

* From 5 PM EDT this afternoon through late tonight.

* A cold frontal passage will produce a round of showers and 
  thunderstorms late today into tonight. Due to wet antecedent 
  conditions, the area is susceptible to flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Goodman
866 
WGUS61 KOKX 090002
FFAOKX

Flood Watch
National Weather Service New York NY
802 PM EDT Wed Sep 8 2021

NJZ002-004-006-103>108-NYZ067-069-090800-
/O.CON.KOKX.FF.A.0009.000000T0000Z-210909T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Western Passaic-Eastern Passaic-Hudson-Western Bergen-Eastern Bergen-
Western Essex-Eastern Essex-Western Union-Eastern Union-Orange-
Rockland-
802 PM EDT Wed Sep 8 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 4 AM EDT THURSDAY...

The Flash Flood Watch continues for

* Portions of northeast New Jersey and southeast New York, including 
  the following areas, in northeast New Jersey, Eastern Bergen, 
  Eastern Essex, Eastern Passaic, Eastern Union, Hudson, Western 
  Bergen, Western Essex, Western Passaic and Western Union. In 
  southeast New York, Orange and Rockland.

* Until 4 AM EDT Thursday.

* A cold frontal passage will produce a round of showers and 
  thunderstorms tonight through the early morning hours. Due to wet 
  antecedent conditions, the area is susceptible to flooding.

* Locally heavy rainfall may produce flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

DW
572 
WGUS61 KOKX 090627
FFAOKX

Flood Watch
National Weather Service New York NY
227 AM EDT Thu Sep 9 2021

NJZ002-004-006-103>108-NYZ067-069-090730-
/O.CAN.KOKX.FF.A.0009.000000T0000Z-210909T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Western Passaic-Eastern Passaic-Hudson-Western Bergen-Eastern Bergen-
Western Essex-Eastern Essex-Western Union-Eastern Union-Orange-
Rockland-
227 AM EDT Thu Sep 9 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of northeast New Jersey and 
southeast New York, including the following areas, in northeast New 
Jersey, Eastern Bergen, Eastern Essex, Eastern Passaic, Eastern 
Union, Hudson, Western Bergen, Western Essex, Western Passaic and 
Western Union. In southeast New York, Orange and Rockland has been 
cancelled.

Flooding is no longer expected to pose a threat. 

$$

JT

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 3:39 AM EDTSmall Craft AdvisoryOKX6 days
Sep 7, 3:31 PM EDTRip Current StatementOKXKings, Nassau, Queens, Suffolk5 days

Nearby

Flash Flood Watches in New Jersey, 2021Flash Flood Watches in New York, 2021Every flash flood watch 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.