Alert archive / Connecticut / Flash Flood Warnings in 2021

Flash Flood Warning 47, NWS New York, NY

September 23, 2021Greater Bridgeport Planning Region, Connecticut

NWS New York, NY issued this flash flood warning at Sep 23, 2021, 11:37 PM EDT for Greater Bridgeport Planning Region, Connecticut. It was in force for 3 hr. 2 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: Sep 23, 2021, 11:37 PM EDT (03:37 UTC)
Expired: Sep 24, 2021, 2:45 AM EDT
In force: 3 hr
Issued by: NWS New York, NY
Area: Storm-based polygon
Flood severity: None

County Greater Bridgeport Planning Region, CT

The radar

The Brookhaven radar (KOKX), 59 km from the middle of the area, began a volume at 03:36 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
Sep 23, 11:55 PM EDT	FLASH FLOOD	2 W Wilton, CT	WILD DUCK ROAD CLOSED DUE TO FLOODING.
Sep 24, 12:25 AM EDT	FLASH FLOOD	2 Nnw Trumbull, CT	WHITNEY AVENUE CLOSED 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 00:00Z, 3.6 hours before the alert went out and 59 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: 742 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 683 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 265 m²/s²
0-3 km storm-relative helicity: 277 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 5.9

Open this sounding in Storm Lab

The text

As transmitted.

696 
WGUS51 KOKX 240337
FFWOKX
CTC001-240645-
/O.NEW.KOKX.FF.W.0047.210924T0337Z-210924T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New York NY
1137 PM EDT Thu Sep 23 2021

The National Weather Service in Upton has issued a

* Flash Flood Warning for...
  Fairfield County in southern Connecticut...

* Until 245 AM EDT.

* At 1137 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 2.5 inches of 
  rain have fallen. The expected rainfall rate is 0.75 to 1 inch in 
  1 hour. 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...
  Bridgeport, Stamford, Norwalk, Danbury, Milford, Shelton, 
  Southbury, New Canaan, Sherman, Newtown, Fairfield, Greenwich, 
  Stratford, Trumbull, Westport, Ridgefield, Darien, Monroe, Bethel 
  and Wilton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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

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 4110 7372 4120 7347 4131 7355 4154 7353
      4156 7346 4149 7344 4151 7339 4149 7337
      4147 7331 4130 7307 4118 7312 4117 7311
      4118 7310 4115 7309 4114 7315 4116 7317
      4110 7325 4112 7330 4107 7335 4098 7364

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...0.75-1 INCH IN 1 HOUR

$$

Fig

1 follow-up statement

102 
WGUS71 KOKX 240637
FFSOKX

Flash Flood Statement
National Weather Service New York NY
237 AM EDT Fri Sep 24 2021

CTC001-240647-
/O.EXP.KOKX.FF.W.0047.000000T0000Z-210924T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fairfield CT-
237 AM EDT Fri Sep 24 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 245 AM EDT EARLY THIS MORNING 
FOR FAIRFIELD COUNTY...

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

LAT...LON 4110 7372 4120 7347 4131 7355 4154 7353
      4156 7346 4149 7344 4151 7339 4149 7337
      4147 7331 4130 7307 4118 7312 4117 7311
      4118 7310 4115 7309 4114 7315 4116 7317
      4110 7325 4112 7330 4107 7335 4098 7364

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 23, 11:53 PM EDT	Areal Flood Advisory	OKX	Greater Bridgeport Planning Region	4 hr
Sep 24, 12:15 AM EDT	Areal Flood Advisory	OKX	Naugatuck Valley Planning Region	5 hr
Sep 24, 8:07 AM EDT	Areal Flood Advisory	OKX	Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region	2 hr
Sep 24, 10:44 AM EDT	Areal Flood Advisory	OKX	Southeastern Connecticut Planning Region	98 min

Nearby

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.