Alert archive / New York / Flash Flood Watches in 2021

Flash Flood Watch 5, NWS New York, NY

July 16, 20215 counties in New Jersey; 10 counties in New York; Greater Bridgeport Planning Region, Connecticut

NWS New York, NY issued this flash flood watch at Jul 16, 2021, 2:43 PM EDT for 5 counties in New Jersey; 10 counties in New York; Greater Bridgeport Planning Region, Connecticut. It took effect at Jul 17, 2021, 2:00 PM EDT. It was in force for 13 hr.

The area

The counties it named.

The facts

Issued
Jul 16, 2021, 2:43 PM EDT (18:43 UTC)
In effect from
Jul 17, 2021, 2:00 PM EDT
Expired
Jul 18, 2021, 3:18 AM EDT
In force
13 hr
Issued by
NWS New York, NY
Flood severity
None

Counties Greater Bridgeport Planning Region, CT, Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Passaic County, NJ, Union County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Westchester County, NY

The radar

The Brookhaven radar (KOKX), 93 km from the middle of the area, began a volume at 18:43 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, 6.7 hours before the alert went out and 93 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 2021-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1044 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 2021-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.1939Sfc1 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
1044 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
994 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

945 
WGUS61 KOKX 161843
FFAOKX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service New York NY
243 PM EDT Fri Jul 16 2021

CTZ005-009-NJZ002-004-006-103>108-NYZ067>075-176>179-171000-
/O.NEW.KOKX.FF.A.0005.210717T1800Z-210718T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Fairfield-Southern Fairfield-Western Passaic-Eastern
Passaic-Hudson-Western Bergen-Eastern Bergen-Western Essex-Eastern
Essex-Western Union-Eastern Union-Orange-Putnam-Rockland-Northern
Westchester-Southern Westchester-New York (Manhattan)-Bronx-Richmond
(Staten Island)-Kings (Brooklyn)-Northern Queens-Northern Nassau-
Southern Queens-Southern Nassau-
243 PM EDT Fri Jul 16 2021

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

The National Weather Service in Upton has issued a

* Flash Flood Watch for portions of southern Connecticut, northeast 
  New Jersey and southeast New York, including the following areas, 
  in southern Connecticut, Northern Fairfield and Southern 
  Fairfield. 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, 
  Bronx, Kings (Brooklyn), New York (Manhattan), Northern Nassau, 
  Northern Queens, Northern Westchester, Orange, Putnam, Richmond 
  (Staten Island), Rockland, Southern Nassau, Southern Queens and 
  Southern Westchester.

* From Saturday afternoon through late Saturday night.

* Showers and thunderstorms are expected to impact the area ahead of 
  a slow moving cold front. The rain will fall across areas with 
  abnormally wet antecedent conditions due to recent heavy rain, 
  leading to an increased potential for flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

MD
4 follow-up statements
051 
WGUS61 KOKX 170729
FFAOKX

Flood Watch
National Weather Service New York NY
329 AM EDT Sat Jul 17 2021

CTZ005-009-NJZ002-004-006-103>108-NYZ067>075-176>179-172030-
/O.CON.KOKX.FF.A.0005.210717T1800Z-210718T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Fairfield-Southern Fairfield-Western Passaic-Eastern
Passaic-Hudson-Western Bergen-Eastern Bergen-Western Essex-Eastern
Essex-Western Union-Eastern Union-Orange-Putnam-Rockland-Northern
Westchester-Southern Westchester-New York (Manhattan)-Bronx-Richmond
(Staten Island)-Kings (Brooklyn)-Northern Queens-Northern Nassau-
Southern Queens-Southern Nassau-
329 AM EDT Sat Jul 17 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 2 PM EDT THIS AFTERNOON 
THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of southern Connecticut, northeast New Jersey and 
  southeast New York, including the following areas, in southern 
  Connecticut, Northern Fairfield and Southern Fairfield. 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, Bronx, 
  Kings (Brooklyn), New York (Manhattan), Northern Nassau, Northern 
  Queens, Northern Westchester, Orange, Putnam, Richmond (Staten 
  Island), Rockland, Southern Nassau, Southern Queens and Southern 
  Westchester.

* From 2 PM EDT this afternoon through late tonight.

* Showers and thunderstorms are expected to impact the area ahead of 
  a slow moving cold front. The rain will fall across areas with 
  abnormally wet antecedent conditions due to recent heavy rain, 
  leading to an increased potential for flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$
695 
WGUS61 KOKX 172004
FFAOKX

Flood Watch
National Weather Service New York NY
404 PM EDT Sat Jul 17 2021

CTZ005-009-NJZ002-004-006-103>108-NYZ067>075-176>179-180415-
/O.CON.KOKX.FF.A.0005.000000T0000Z-210718T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Fairfield-Southern Fairfield-Western Passaic-Eastern
Passaic-Hudson-Western Bergen-Eastern Bergen-Western Essex-Eastern
Essex-Western Union-Eastern Union-Orange-Putnam-Rockland-Northern
Westchester-Southern Westchester-New York (Manhattan)-Bronx-Richmond
(Staten Island)-Kings (Brooklyn)-Northern Queens-Northern Nassau-
Southern Queens-Southern Nassau-
404 PM EDT Sat Jul 17 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of southern Connecticut, northeast New Jersey and 
  southeast New York, including the following areas, in southern 
  Connecticut, Northern Fairfield and Southern Fairfield. 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, Bronx, 
  Kings (Brooklyn), New York (Manhattan), Northern Nassau, Northern 
  Queens, Northern Westchester, Orange, Putnam, Richmond (Staten 
  Island), Rockland, Southern Nassau, Southern Queens and Southern 
  Westchester.

* Through late tonight.

* Showers and thunderstorms are expected to impact the area ahead of 
  a slow moving cold front. The rain will fall across areas with 
  abnormally wet antecedent conditions due to recent heavy rain, 
  leading to an increased potential for flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

JM
386 
WGUS61 KOKX 180331
FFAOKX

Flood Watch
National Weather Service New York NY
1131 PM EDT Sat Jul 17 2021

CTZ005-009-NJZ002-004-006-103>108-NYZ067>075-176>179-181000-
/O.CON.KOKX.FF.A.0005.000000T0000Z-210718T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Fairfield-Southern Fairfield-Western Passaic-Eastern
Passaic-Hudson-Western Bergen-Eastern Bergen-Western Essex-Eastern
Essex-Western Union-Eastern Union-Orange-Putnam-Rockland-Northern
Westchester-Southern Westchester-New York (Manhattan)-Bronx-Richmond
(Staten Island)-Kings (Brooklyn)-Northern Queens-Northern Nassau-
Southern Queens-Southern Nassau-
1131 PM EDT Sat Jul 17 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 6 AM EDT SUNDAY...

The Flash Flood Watch continues for

* Portions of southern Connecticut, northeast New Jersey and 
  southeast New York, including the following areas, in southern 
  Connecticut, Northern Fairfield and Southern Fairfield. 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, Bronx, 
  Kings (Brooklyn), New York (Manhattan), Northern Nassau, Northern 
  Queens, Northern Westchester, Orange, Putnam, Richmond (Staten 
  Island), Rockland, Southern Nassau, Southern Queens and Southern 
  Westchester.

* Until 6 AM EDT Sunday.

* Showers and thunderstorms are expected to impact the area ahead of 
  a slow moving cold front. The rain will fall across areas with 
  abnormally wet antecedent conditions due to recent heavy rain, 
  leading to an increased potential for flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$
295 
WGUS61 KOKX 180718
FFAOKX

Flood Watch
National Weather Service New York NY
318 AM EDT Sun Jul 18 2021

CTZ005-009-NJZ002-004-006-103>108-NYZ067>075-176>179-180830-
/O.CAN.KOKX.FF.A.0005.000000T0000Z-210718T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Fairfield-Southern Fairfield-Western Passaic-Eastern
Passaic-Hudson-Western Bergen-Eastern Bergen-Western Essex-Eastern
Essex-Western Union-Eastern Union-Orange-Putnam-Rockland-Northern
Westchester-Southern Westchester-New York (Manhattan)-Bronx-Richmond
(Staten Island)-Kings (Brooklyn)-Northern Queens-Northern Nassau-
Southern Queens-Southern Nassau-
318 AM EDT Sun Jul 18 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of southern Connecticut, 
northeast New Jersey and southeast New York, including the following 
areas, in southern Connecticut, Northern Fairfield and Southern 
Fairfield. 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, 
Bronx, Kings (Brooklyn), New York (Manhattan), Northern Nassau, 
Northern Queens, Northern Westchester, Orange, Putnam, Richmond 
(Staten Island), Rockland, Southern Nassau, Southern Queens and 
Southern Westchester has been cancelled.

The Flood Watch is cancelled. Flooding is no longer expected to pose 
a threat.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 3:08 PM EDTAreal Flood AdvisoryOKXOrange112 min
Jul 16, 3:48 PM EDTSpecial Weather StatementOKXOrange42 min
Jul 16, 4:24 PM EDTSpecial Weather StatementOKXOrange51 min
Jul 16, 4:34 PM EDTAreal Flood AdvisoryOKXOrange116 min
Jul 16, 5:26 PM EDTSevere Thunderstorm WarningOKXSoutheastern Connecticut Planning Region49 min
Jul 16, 5:32 PM EDTSpecial Weather StatementOKX43 min
Jul 16, 6:04 PM EDTSpecial Weather StatementOKX41 min

Nearby

Flash Flood Watches in New York, 2021Flash Flood Watches in New Jersey, 2021Flash Flood Watches in Connecticut, 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.