Alert archive / Indiana / Flash Flood Warnings in 2021

Flash Flood Warning 27, NWS Indianapolis, IN

August 25, 2021Hendricks County, Marion County, Indiana

NWS Indianapolis, IN issued this flash flood warning at Aug 25, 2021, 11:56 AM EDT for Hendricks County, Marion County, Indiana. It was in force for 4 hr. 3 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: Aug 25, 2021, 11:56 AM EDT (15:56 UTC)
Expired: Aug 25, 2021, 4:00 PM EDT
In force: 4 hr
Issued by: NWS Indianapolis, IN
Area: Storm-based polygon
Flood severity: None

Counties Hendricks County, IN, Marion County, IN

The radar

The Indianapolis radar (KIND), 4 km from the middle of the area, began a volume at 15:58 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
Aug 25, 12:04 PM EDT	FLASH FLOOD	1 N Homecroft, IN	FLOODING ALONG MADISON AVENUE BETWEEN I-465 AND GREENWOOD PARK MALL DEEP ENOUGH TO WARRANT TRAFFIC FLOW TO USE LEFT LANE AND SLOW DOWN. RECEIVED VIA TWITTER.
Aug 25, 12:36 PM EDT	HEAVY RAIN 1.1	3 S Brownsburg, IN	AMOUNT TODAY NEAR AVON AND BROWNSBURG BORDER.
Aug 25, 1:13 PM EDT	HEAVY RAIN 4	Plainfield, IN	LOCATION APPROXIMATED.

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

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 3.9 hours before the alert went out and 202 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: 1708 J/kg
Mixed-layer CIN: -135 J/kg
Mixed-layer LCL: 1029 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 132 m²/s²
0-3 km storm-relative helicity: 170 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.9

Open this sounding in Storm Lab

The text

As transmitted.

813 
WGUS53 KIND 251556
FFWIND
INC063-097-252000-
/O.NEW.KIND.FF.W.0027.210825T1556Z-210825T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Indianapolis IN
1156 AM EDT Wed Aug 25 2021

The National Weather Service in Indianapolis has issued a

* Flash Flood Warning for...
  Southeastern Hendricks County in central Indiana...
  Marion County in central Indiana...

* Until 400 PM EDT.

* At 1156 AM EDT, Doppler radar and automated rain gauges indicated 
  slow moving thunderstorms are producing heavy rain across the 
  warned area. Between 1 and 2.5 inches of rain have fallen. The 
  expected rainfall rate is 1 inch in 30 minutes. Additional 
  rainfall amounts of 1 to 2 inches are possible in the warned area. 
  Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  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...
  Indianapolis, Plainfield, Brownsburg, Beech Grove, Speedway, 
  Danville, Southport, Avon, Cumberland, Warren Park, Clermont, 
  Clayton, Homecroft, Indianapolis Int'l Airport, Camby and Monument 
  Circle.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3981 8647 3983 8608 3977 8595 3964 8595
      3963 8655 3970 8656

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1 INCH IN 30 MINUTES

$$

AW

2 follow-up statements

774 
WGUS73 KIND 251714
FFSIND

Flash Flood Statement
National Weather Service Indianapolis IN
114 PM EDT Wed Aug 25 2021

INC063-097-252000-
/O.CON.KIND.FF.W.0027.000000T0000Z-210825T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hendricks IN-Marion IN-
114 PM EDT Wed Aug 25 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 4 PM EDT THIS 
AFTERNOON FOR SOUTHEASTERN HENDRICKS AND MARION COUNTIES...

At 114 PM EDT, the public reported flash flooding due to 
thunderstorms across the warned area. Between 2 and 3 inches of rain 
have fallen.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Public reported.

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...
  Indianapolis, Plainfield, Brownsburg, Beech Grove, Speedway, 
  Danville, Southport, Avon, Cumberland, Warren Park, Clermont, 
  Clayton, Homecroft, Indianapolis Int'l Airport, Camby and Monument 
  Circle.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3981 8647 3983 8608 3977 8595 3964 8595
      3963 8655 3970 8656

FLASH FLOOD...OBSERVED

$$

AW

297 
WGUS73 KIND 251956
FFSIND

Flash Flood Statement
National Weather Service Indianapolis IN
356 PM EDT Wed Aug 25 2021

INC063-097-252006-
/O.EXP.KIND.FF.W.0027.000000T0000Z-210825T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hendricks IN-Marion IN-
356 PM EDT Wed Aug 25 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 4 PM EDT THIS AFTERNOON FOR 
SOUTHEASTERN HENDRICKS AND MARION COUNTIES...

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

LAT...LON 3981 8647 3983 8608 3977 8595 3964 8595
      3963 8655 3970 8656

$$

KH

The office that day

Everything else NWS Indianapolis, IN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 24, 11:54 PM EDT	Special Weather Statement	IND	Fountain, Warren	36 min
Aug 25, 10:58 AM EDT	Special Weather Statement	IND	Marion	32 min
Aug 25, 11:00 AM EDT	Special Weather Statement	IND	Morgan	30 min
Aug 25, 11:10 AM EDT	Areal Flood Warning	IND	Putnam	3 hr
Aug 25, 11:19 AM EDT	Special Weather Statement	IND	Marion	26 min
Aug 25, 11:27 AM EDT	Special Weather Statement	IND	Hendricks	18 min
Aug 25, 11:41 AM EDT	Special Weather Statement	IND	Hendricks	19 min
Aug 25, 11:45 AM EDT	Severe Thunderstorm Warning	IND	Hendricks	30 min
Aug 25, 11:49 AM EDT	Special Weather Statement	IND	Johnson	26 min
Aug 25, 12:05 PM EDT	Severe Thunderstorm Warning	IND	Johnson, Morgan, Shelby	25 min
Aug 25, 12:24 PM EDT	Severe Thunderstorm Warning	IND	Bartholomew, Brown, Johnson, Shelby	36 min
Aug 25, 2:00 PM EDT	Special Weather Statement	IND	Lawrence	30 min
Aug 25, 2:08 PM EDT	Areal Flood Warning	IND	Owen, Putnam	3 hr
Aug 25, 2:29 PM EDT	Special Weather Statement	IND	Lawrence	31 min
Aug 25, 3:03 PM EDT	Special Weather Statement	IND	Martin	27 min
Aug 25, 4:02 PM EDT	Areal Flood Warning	IND	Daviess, Greene, Knox, Sullivan	3 hr
Aug 25, 4:29 PM EDT	Special Weather Statement	IND	Sullivan	31 min

Nearby

Flash Flood Warnings in Indiana, 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.