Alert archive / Connecticut / Flash Flood Warnings in 2023

Flash Flood Warning 21, NWS New York, NY

July 10, 2023Southeastern Connecticut Planning Region, Connecticut

NWS New York, NY issued this flash flood warning at Jul 10, 2023, 10:07 AM EDT for Southeastern Connecticut Planning Region, Connecticut. It was in force for 2 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 10, 2023, 10:07 AM EDT (14:07 UTC)
Expired: Jul 10, 2023, 12:15 PM EDT
In force: 2 hr
Issued by: NWS New York, NY
Area: Storm-based polygon
Flood severity: None

County Southeastern Connecticut Planning Region, CT

The radar

The Brookhaven radar (KOKX), 83 km from the middle of the area, began a volume at 14:08 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 10, 10:30 AM EDT	FLASH FLOOD	New London, CT	Three cars submerged near Bank street and Broad street due to flooding.

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, 2.1 hours before the alert went out and 83 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: 820 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 600 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 100 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

As transmitted.

711 
WGUS51 KOKX 101407
FFWOKX
CTC011-101615-
/O.NEW.KOKX.FF.W.0021.230710T1407Z-230710T1615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New York NY
1007 AM EDT Mon Jul 10 2023

The National Weather Service in Upton has issued a

* Flash Flood Warning for...
  South Central New London County in southern Connecticut...

* Until 1215 PM EDT.

* At 1007 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 5 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 3 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...
  New London, Groton, Waterford and Ledyard.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move to higher ground now. Act quickly to protect your life.

&&

LAT...LON 4140 7212 4140 7210 4140 7201 4130 7203
      4130 7206 4130 7207 4130 7208 4130 7209
      4129 7214 4129 7215

FLASH FLOOD...RADAR INDICATED

$$

MET

1 follow-up statement

642 
WGUS71 KOKX 101559
FFSOKX

Flash Flood Statement
National Weather Service New York NY
1159 AM EDT Mon Jul 10 2023

CTC011-101615-
/O.CON.KOKX.FF.W.0021.000000T0000Z-230710T1615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New London CT-
1159 AM EDT Mon Jul 10 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 PM EDT THIS 
AFTERNOON FOR SOUTH CENTRAL NEW LONDON COUNTY...

At 1159 AM EDT, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Between 2 and 5 inches of rain 
have fallen. Flash flooding is ongoing.

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...
  New London, Groton, Waterford and Ledyard.

The heaviest rainfall has moved out of the warning area, and flood 
waters will be receding. The flash flood warning will be allowed to 
expire.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4140 7212 4140 7210 4140 7201 4130 7203
      4130 7206 4130 7207 4130 7208 4130 7209
      4129 7214 4129 7215

FLASH FLOOD...RADAR INDICATED

$$

MET

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 8:27 PM EDT	Severe Thunderstorm Warning	OKX	Greater Bridgeport Planning Region	30 min
Jul 9, 8:56 PM EDT	Special Weather Statement	OKX		49 min
Jul 9, 9:43 PM EDT	Areal Flood Advisory	OKX	Greater Bridgeport Planning Region	2 hr
Jul 9, 10:32 PM EDT	Areal Flood Advisory	OKX	Greater Bridgeport Planning Region	118 min
Jul 9, 11:03 PM EDT	Flash Flood Warning	OKX	Greater Bridgeport Planning Region	5 hr
Jul 10, 5:30 AM EDT	Areal Flood Advisory	OKX	Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region	3 hr
Jul 10, 6:22 AM EDT	Areal Flood Advisory	OKX	Lower Connecticut River Valley Planning Region, Southeastern Connecticut Planning Region	4 hr
Jul 10, 7:13 AM EDT	Special Weather Statement	OKX		47 min
Jul 10, 7:48 AM EDT	Flash Flood Warning	OKX	Lower Connecticut River Valley Planning Region, Southeastern Connecticut Planning Region	70 min
Jul 10, 9:13 AM EDT	Flash Flood Warning	OKX	Southeastern Connecticut Planning Region	3 hr
Jul 10, 10:27 AM EDT	Areal Flood Advisory	OKX	Southeastern Connecticut Planning Region	2 hr

Nearby

Flash Flood Warnings in Connecticut, 2023 Every flash flood warning in 2023

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.