Alert archive / New York / Flash Flood Warnings in 2021

Flash Flood Warning 14, NWS New York, NY

July 9, 2021Nassau County, Suffolk County, Westchester County, New York; Greater Bridgeport Planning Region, Connecticut

NWS New York, NY issued this flash flood warning at Jul 9, 2021, 8:56 AM EDT for Nassau County, Suffolk County, Westchester County, New York; Greater Bridgeport Planning Region, Connecticut. It was in force for 3 hr. 5 reports 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 9, 2021, 8:56 AM EDT (12:56 UTC)
Expired: Jul 9, 2021, 11:33 AM EDT
In force: 3 hr
Issued by: NWS New York, NY
Area: Storm-based polygon
Flood severity: None

Counties Greater Bridgeport Planning Region, CT, Nassau County, NY, Suffolk County, NY, Westchester County, NY

The radar

The Brookhaven radar (KOKX), 62 km from the middle of the area, began a volume at 12:57 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

Time	Report	Where	Remark
Jul 9, 9:06 AM EDT	FLASH FLOOD	Stamford, CT	FIRE UNITS ARE CURRENTLY OPERATING AT NUMEROUS INCIDENTS INVOLVING VEHICLES W/ OCCUPANTS STRANDED IN WATER.
Jul 9, 9:15 AM EDT	FLASH FLOOD	Bayville, NY	SEVERAL ROADS CLOSED AND IMPASSABLE IN BAYVILLE DUE TO FLASH FLOODING.
Jul 9, 10:00 AM EDT	FLASH FLOOD	Glen Cove, NY	POLICE REPORT NUMEROUS FLOODED ROADWAYS THAT ARE IMPASSABLE.
Jul 9, 10:43 AM EDT	FLASH FLOOD	Glen Head, NY	ROUTE 107 IS FLOODED WITH WATER FLOWING ACROSS THE ROAD AND SEVERAL VEHICLES DISABLED.
Jul 9, 10:53 AM EDT	FLASH FLOOD	1 W Matinecock, NY	FLOODING ON VIOLA DRIVE IN GLEN COVE, WATER SEVERAL FEET DEEP.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 0.9 hours before the alert went out and 195 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3 J/kg
Mixed-layer CIN: -156 J/kg
Mixed-layer LCL: 764 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

936 
WGUS51 KOKX 091256
FFWOKX
CTC001-NYC059-103-119-091600-
/O.NEW.KOKX.FF.W.0014.210709T1256Z-210709T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New York NY
856 AM EDT Fri Jul 9 2021

The National Weather Service in Upton has issued a

* Flash Flood Warning for...
  Southern Fairfield County in southern Connecticut...
  Nassau County in southeastern New York...
  Western Suffolk County in southeastern New York...
  Southern Westchester County in southeastern New York...

* Until noon EDT.

* At 856 AM EDT, Doppler radar indicated heavy rain across the 
  warned area. Between 1 and 2 inches of rain have fallen. The 
  expected rainfall rate is 1 inch in 1 hour. Additional rainfall 
  amounts of 1 to 2 inches are possible in the warned area. Flash 
  flooding is already occurring.

  HAZARD...Flash flooding caused by heavy rain.

  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...
  Stamford, Levittown, Freeport, Long Beach, Port Chester, 
  Lindenhurst, Glen Cove, Plainview, Garden City, Massapequa, 
  Lynbrook, Syosset, Mineola, Rye, Westbury, Farmingdale, Oyster 
  Bay, Greenwich, Hempstead and Hicksville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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 4098 7372 4109 7370 4118 7360 4103 7346
      4100 7352 4101 7354 4099 7356 4100 7359
      4098 7359 4097 7362 4098 7365 4093 7367
      4092 7371 4086 7366 4092 7364 4093 7352
      4096 7349 4095 7343 4063 7336 4057 7367

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1 INCH IN 1 HOUR

$$

JM

2 follow-up statements

676 
WGUS71 KOKX 091447
FFSOKX

Flash Flood Statement
National Weather Service New York NY
1047 AM EDT Fri Jul 9 2021

CTC001-NYC059-103-119-091600-
/O.CON.KOKX.FF.W.0014.000000T0000Z-210709T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fairfield CT-Nassau NY-Suffolk NY-Westchester NY-
1047 AM EDT Fri Jul 9 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON EDT TODAY FOR 
SOUTHERN FAIRFIELD, NASSAU, WESTERN SUFFOLK AND SOUTHERN WESTCHESTER 
COUNTIES...

At 1047 AM EDT, Doppler radar indicated heavy rain fell across the 
warned area. Between 2 and 4 inches of rain have fallen over the 
past 3 hours. There will likely be some areas of residual flooding 
remaining. Please continue to heed remaining road closures.

HAZARD...Flash flooding caused by heavy rain.

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...
  Stamford, Levittown, Freeport, Long Beach, Port Chester, 
  Lindenhurst, Glen Cove, Plainview, Garden City, Massapequa, 
  Lynbrook, Syosset, Mineola, Rye, Westbury, Farmingdale, Oyster 
  Bay, Greenwich, Hempstead and Hicksville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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 4098 7372 4109 7370 4118 7360 4103 7346
      4100 7352 4101 7354 4099 7356 4100 7359
      4098 7359 4097 7362 4098 7365 4093 7367
      4092 7371 4086 7366 4092 7364 4093 7352
      4096 7349 4095 7343 4063 7336 4057 7367

FLASH FLOOD...RADAR INDICATED

$$

JM

779 
WGUS71 KOKX 091533
FFSOKX

Flash Flood Statement
National Weather Service New York NY
1133 AM EDT Fri Jul 9 2021

CTC001-NYC059-103-119-091543-
/O.CAN.KOKX.FF.W.0014.000000T0000Z-210709T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fairfield CT-Nassau NY-Suffolk NY-Westchester NY-
1133 AM EDT Fri Jul 9 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN FAIRFIELD, NASSAU, 
WESTERN SUFFOLK AND SOUTHERN WESTCHESTER 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 1200 PM EDT for portions 
of southern Connecticut, northeast New Jersey and southeast New York.

LAT...LON 4098 7372 4109 7370 4118 7360 4103 7346
      4100 7352 4101 7354 4099 7356 4100 7359
      4098 7359 4097 7362 4098 7365 4093 7367
      4092 7371 4086 7366 4092 7364 4093 7352
      4096 7349 4095 7343 4063 7336 4057 7367

$$

JM

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 8:17 PM EDT	Areal Flood Advisory	OKX	Bronx, New York, Westchester	3 hr
Jul 9, 3:15 AM EDT	Areal Flood Advisory	OKX	New York	3 hr
Jul 9, 4:36 AM EDT	Special Marine Warning	OKX		84 min
Jul 9, 5:30 AM EDT	Areal Flood Advisory	OKX	Bronx, Kings, Nassau, New York, Queens, Richmond and 3 more	3 hr
Jul 9, 5:37 AM EDT	Special Marine Warning	OKX		83 min
Jul 9, 5:55 AM EDT	Special Marine Warning	OKX		65 min
Jul 9, 6:15 AM EDT	Special Marine Warning	OKX		90 min
Jul 9, 6:28 AM EDT	Special Marine Warning	OKX		62 min
Jul 9, 6:45 AM EDT	Areal Flood Advisory	OKX	Suffolk	5 hr
Jul 9, 7:09 AM EDT	Areal Flood Advisory	OKX	Putnam, Westchester	3 hr
Jul 9, 7:22 AM EDT	Special Marine Warning	OKX		53 min
Jul 9, 8:29 AM EDT	Areal Flood Advisory	OKX	Bronx, Kings, Nassau, New York, Queens, Richmond and 2 more	61 min
Jul 9, 9:44 AM EDT	Flash Flood Warning	OKX	Suffolk	2 hr
Jul 9, 10:22 AM EDT	Areal Flood Advisory	OKX	Putnam, Westchester	2 hr
Jul 9, 11:39 AM EDT	Special Weather Statement	OKX	Suffolk	111 min
Jul 9, 12:43 PM EDT	Flash Flood Watch	OKX	Suffolk	77 min
Jul 9, 2:09 PM EDT	Small Craft Advisory	OKX		24 hr
Jul 9, 3:34 PM EDT	Rip Current Statement	OKX	Kings, Nassau, Queens, Suffolk	29 hr
Jul 8, 8:13 PM EDT	Special Weather Statement	OKX		47 min
Jul 8, 10:01 PM EDT	Special Weather Statement	OKX		44 min
Jul 9, 5:42 AM EDT	River Flood Warning	OKX	Southeastern Connecticut Planning Region	18 hr
Jul 9, 8:47 AM EDT	Flash Flood Warning	OKX	Greater Bridgeport Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region	4 hr
Jul 9, 9:26 AM EDT	Areal Flood Advisory	OKX	Southeastern Connecticut Planning Region	2 hr
Jul 9, 11:48 AM EDT	Flash Flood Warning	OKX	Southeastern Connecticut Planning Region	3 hr
Jul 9, 1:12 PM EDT	Areal Flood Warning	OKX	Greater Bridgeport Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region	6 hr
Jul 9, 7:12 PM EDT	Areal Flood Advisory	OKX	Greater Bridgeport Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region	5 hr

Nearby

Flash Flood Warnings in New York, 2021 Flash Flood Warnings in Connecticut, 2021 Every 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.