Alert archive / Nebraska / Flash Flood Warnings in 2021

Flash Flood Warning 8, NWS Omaha, NE

August 7, 20215 counties in Nebraska; Pottawattamie County, Iowa

NWS Omaha, NE issued this flash flood warning at Aug 7, 2021, 9:05 PM CDT for 5 counties in Nebraska; Pottawattamie County, Iowa. It was in force for 4 hr. 34 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 7, 2021, 9:05 PM CDT (02:05 UTC)
Expired: Aug 8, 2021, 12:51 AM CDT
In force: 4 hr
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Flood severity: None

Counties Pottawattamie County, IA, Butler County, NE, Colfax County, NE, Douglas County, NE, Sarpy County, NE, Saunders County, NE

The radar

The Omaha radar (KOAX), 13 km from the middle of the area, began a volume at 02:07 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 7, 9:12 PM CDT	FLASH FLOOD	1 W Millard, NE	STREET FLOODING REPORTED AT 168TH AND Q STREET.
Aug 7, 9:14 PM CDT	FLASH FLOOD	1 Ssw Gretna, NE	WATER UP TO THE CURBS ALONG HIGHWAY 6.
Aug 7, 9:19 PM CDT	FLASH FLOOD	3 Se Omaha, NE	STREET ROAD FLOODING. VEHICLE STRANDED.
Aug 7, 9:23 PM CDT	HEAVY RAIN 2.08	1 W Millard, NE	MEASURED IN 30 MINUTES.
Aug 7, 9:30 PM CDT	FLASH FLOOD	2 Nne Ralston, NE	TWO CARS STRANDED IN FLOOD WATERS ALONG I80 IN A LOW SPOT.
Aug 7, 9:40 PM CDT	FLASH FLOOD	2 Wnw Offutt Afb, NE	REPORT FROM MPING: STREET/ROAD FLOODING; STREET/ROAD CLOSED; VEHICLES STRANDED.
Aug 7, 9:43 PM CDT	FLASH FLOOD	2 Wnw Offutt Afb, NE	REPORT FROM MPING: STREET/ROAD FLOODING; STREET/ROAD CLOSED; VEHICLES STRANDED.
Aug 7, 9:43 PM CDT	FLASH FLOOD	3 Wsw Bellevue, NE	REPORT FROM MPING: STREET/ROAD FLOODING; STREET/ROAD CLOSED; VEHICLES STRANDED.
Aug 7, 9:46 PM CDT	FLASH FLOOD	3 Se Omaha, NE	FLOODING OVER THE CURBS. ESTIMATED 6 INCHES OF RAIN.
Aug 7, 9:49 PM CDT	FLASH FLOOD	2 N Millard, NE	CAR STRANDED IN FLOOD WATERS.
Aug 7, 9:50 PM CDT	FLASH FLOOD	3 E Omaha, NE	STREET FLOODING WELL OVER THE CURBS.
Aug 7, 9:56 PM CDT	FLASH FLOOD	Council Bluffs, IA	REPORT FROM MPING: STREET/ROAD FLOODING; STREET/ROAD CLOSED; VEHICLES STRANDED.
Aug 7, 9:58 PM CDT	FLASH FLOOD	2 Ene Ralston, NE	STREET FLOODING OVER THE CURBS.
Aug 7, 10:00 PM CDT	FLASH FLOOD	3 E Omaha, NE	CARS COMPLETELY SUBMERGED. OCCUPANTS WERE RESCUED.
Aug 7, 10:04 PM CDT	FLASH FLOOD	4 E Omaha, NE	WATER UP TO 2-3 FEET DEEP AT 11TH AND LEAVENWORTH.
Aug 7, 10:08 PM CDT	FLASH FLOOD	3 Sse Omaha, NE	CAR STRANDED. WATER AT LEAST KNEE DEEP.
Aug 7, 10:10 PM CDT	FLASH FLOOD	3 Ese Omaha, NE	CONSIDERABLE FLASH FLOODING IN THE OMAHA METRO AREA. 6 WATER RESCUES HAVE ALREADY OCCURRED IN SOUTHEASTERN OMAHA SO FAR. SIGNIFICANT STREET FLOODING WITH FLOWING WATER.
Aug 7, 10:14 PM CDT	FLASH FLOOD	1 Nw Council Bluffs, IA	SEVERAL FLOODED ROADS IN THE CITY. A COUPLE OF CARS HAVE BEEN STRANDED.
Aug 7, 10:14 PM CDT	FLASH FLOOD	2 Nnw Council Bluffs, IA	2-4 FEET OF WATER OVER ROADS.
Aug 7, 10:15 PM CDT	FLASH FLOOD	2 Sse Omaha, NE	SEMI TRAILER STORAGE CONTAINER FLOATING IN A PARKING LOT.
Aug 7, 10:19 PM CDT	FLASH FLOOD	4 E Omaha, NE	CARS ARE FLOATING NEAR 11TH AND LEAVENWORTH IN DOWNTOWN OMAHA.
Aug 7, 10:20 PM CDT	FLASH FLOOD	2 Sse Omaha, NE	THREE CARS PILED UP FROM FLOOD WATERS. REPORT FROM TWITTER.
Aug 7, 10:30 PM CDT	FLASH FLOOD	3 Ene Weston, NE	WATER OVER HIGHWAY 92.
Aug 7, 10:38 PM CDT	FLASH FLOOD	4 E Omaha, NE	PEOPLE STRANDED IN AN ELEVATOR IN A PARKING GARAGE DUE TO FLOODING. SIGNIFICANT FLOODING OCCURRING THE DOWNTOWN OMAHA AREA.
Aug 7, 10:42 PM CDT	FLASH FLOOD	2 E Omaha, NE	SADDLE CREEK ROAD IS FLOODED AND CLOSED.
Aug 7, 10:45 PM CDT	FLASH FLOOD	2 N David City, NE	FLOODED ROADS.
Aug 7, 10:50 PM CDT	FLASH FLOOD	4 E Omaha, NE	MAJOR FLASH FLOODING. WATER FLOWING FAST AT A DEPTH OF 2-3 FEET.
Aug 7, 10:52 PM CDT	HEAVY RAIN 5.1	3 Wnw David City, NE	MEASURED RAINFALL.
Aug 7, 10:54 PM CDT	FLASH FLOOD	2 Ese Omaha, NE	CAR STRANDED AT SADDLE CREEK AND LEAVENWORTH. WATER DEPTH TO THE TOP OF THE TIRES.
Aug 7, 11:01 PM CDT	FLASH FLOOD	4 E Omaha, NE	MANHOLE COVERS BLOWN OFF AND SOME STREET DAMAGE.
Aug 7, 11:05 PM CDT	FLASH FLOOD	1 E Council Bluffs, IA	CAR STRANDED.
Aug 7, 11:06 PM CDT	FLASH FLOOD	3 E Omaha, NE	I480 AT EXIT 2B CLOSED DUE TO FLOODING.
Aug 7, 11:38 PM CDT	FLASH FLOOD	3 E Omaha, NE	I480 EASTBOUND CLOSED AT THE HIGHWAY 75 EXIT.
Aug 7, 11:50 PM CDT	FLASH FLOOD	2 Sse Carter Lake, IA	FLOODED BASEMENTS.

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

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.1 hours before the alert went out and 13 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: 2933 J/kg
Mixed-layer CIN: -124 J/kg
Mixed-layer LCL: 1327 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 149 m²/s²
0-3 km storm-relative helicity: 195 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted.

013 
WGUS53 KOAX 080205
FFWOAX
IAC155-NEC023-037-055-153-155-080800-
/O.NEW.KOAX.FF.W.0008.210808T0205Z-210808T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Omaha/Valley NE
905 PM CDT Sat Aug 7 2021

The National Weather Service in Omaha/Valley has issued a

* Flash Flood Warning for...
  Southwestern Pottawattamie County in southwestern Iowa...
  Butler County in east central Nebraska...
  Douglas County in east central Nebraska...
  Sarpy County in east central Nebraska...
  Saunders County in east central Nebraska...
  Southwestern Colfax County in northeastern Nebraska...

* Until 300 AM CDT.

* At 905 PM CDT, Doppler radar and USGS rain gages indicated 
  thunderstorms producing heavy rain across the warned area. Up to 3 
  inches of rain have fallen. The expected rainfall rate is 3 to 4 
  inches in 1 hour. Additional rainfall amounts up 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 and USGS rain gages.

  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...
  Omaha, Council Bluffs, Bellevue, Papillion, La Vista, Ralston, 
  Wahoo, Gretna, David City, Valley, Yutan, Waterloo, Valparaiso, 
  Mead, Bellwood, Rising City, Brainard, Weston, Prague and Elkhorn.

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.

&&

LAT...LON 4138 9737 4138 9725 4140 9725 4134 9636
      4138 9594 4129 9576 4116 9583 4116 9588
      4111 9587 4108 9590 4113 9610 4111 9614
      4107 9616 4105 9662 4107 9737

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...3-4 INCHES IN 1 HOUR

$$

Pearson

2 follow-up statements

546 
WGUS73 KOAX 080225
FFSOAX

Flash Flood Statement
National Weather Service Omaha/Valley NE
925 PM CDT Sat Aug 7 2021

IAC155-NEC023-037-055-153-155-080800-
/O.CON.KOAX.FF.W.0008.000000T0000Z-210808T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pottawattamie IA-Butler NE-Colfax NE-Douglas NE-Sarpy NE-Saunders NE-
925 PM CDT Sat Aug 7 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 3 AM CDT SUNDAY FOR 
SOUTHWESTERN POTTAWATTAMIE, BUTLER, DOUGLAS, SARPY, SAUNDERS AND 
SOUTHWESTERN COLFAX COUNTIES...

At 925 PM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Up to 4 inches of rain have fallen. The 
expected rainfall rate is 3 to 4 inches in 1 hour. Additional 
rainfall amounts up to 3 inches are possible in the warned area. 
Flash flooding is ongoing in several areas. Please do not drive in 
this heavy rain if it can be avoided. There are many reports of cars 
getting stuck.

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...
  Omaha, Council Bluffs, Bellevue, Papillion, La Vista, Ralston, 
  Wahoo, Gretna, David City, Valley, Yutan, Waterloo, Valparaiso, 
  Mead, Bellwood, Rising City, Brainard, Weston, Prague and Elkhorn.

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.

&&

LAT...LON 4138 9737 4138 9725 4140 9725 4134 9636
      4138 9594 4129 9576 4116 9583 4116 9588
      4111 9587 4108 9590 4113 9610 4111 9614
      4107 9616 4105 9662 4107 9737

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...3-4 INCHES IN 1 HOUR

$$

Pearson

531 
WGUS73 KOAX 080551 RRB
FFSOAX

Flash Flood Statement
National Weather Service Omaha/Valley NE
1251 AM CDT Sun Aug 8 2021

IAC155-NEC023-037-055-153-155-080601-
/O.CAN.KOAX.FF.W.0008.000000T0000Z-210808T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pottawattamie IA-Butler NE-Colfax NE-Douglas NE-Sarpy NE-Saunders NE-
1251 AM CDT Sun Aug 8 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN POTTAWATTAMIE, 
BUTLER, DOUGLAS, SARPY, SAUNDERS AND SOUTHWESTERN COLFAX COUNTIES...

Though the heavy rain has ended, please continue to heed remaining 
road closures.

LAT...LON 4138 9737 4138 9725 4140 9725 4134 9636
      4138 9594 4129 9576 4116 9583 4116 9588
      4111 9587 4108 9590 4113 9610 4111 9614
      4107 9616 4105 9662 4107 9737

$$

Pearson

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 7, 7:23 PM CDT	Special Weather Statement	OAX	Platte	52 min
Aug 7, 7:29 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Saunders	46 min
Aug 7, 7:56 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Cass, Douglas, Sarpy, Saunders	49 min
Aug 7, 8:10 PM CDT	Severe Thunderstorm Warning	OAX	Butler	50 min
Aug 7, 8:23 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Cass, Sarpy, Saunders	22 min
Aug 7, 8:29 PM CDT	Severe Thunderstorm Warning	OAX	Saunders	31 min
Aug 7, 8:33 PM CDT	Areal Flood Advisory	OAX	Butler, Colfax, Lancaster, Platte, Saunders, Seward	4 hr
Aug 7, 8:39 PM CDT	Areal Flood Advisory	OAX	Douglas, Sarpy	3 hr
Aug 7, 8:41 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Cass, Douglas, Lancaster, Sarpy, Saunders	49 min
Aug 7, 8:50 PM CDT	Areal Flood Advisory	OAX	Douglas, Sarpy, Saunders	3 hr
Aug 7, 8:50 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OAX	Douglas	40 min
Aug 7, 8:55 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Saunders	35 min
Aug 7, 9:09 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Saline	51 min
Aug 7, 9:24 PM CDT	Severe Thunderstorm Warning	OAX	Douglas, Sarpy, Washington	51 min
Aug 7, 9:35 PM CDT	Flash Flood Warning Considerable damage threat	OAX	Douglas, Sarpy	3 hr
Aug 7, 9:37 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Lancaster, Saunders, Seward	22 min
Aug 7, 9:49 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Johnson, Pawnee	41 min
Aug 7, 9:54 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Lancaster, Saunders	17 min
Aug 7, 9:59 PM CDT	Severe Thunderstorm Warning	OAX	Butler	27 min
Aug 7, 10:25 PM CDT	Flash Flood Warning	OAX	Cass, Lancaster, Otoe, Sarpy, Saunders, Seward	2 hr
Aug 7, 10:30 PM CDT	Flash Flood Warning Emergency	OAX	Douglas	89 min
Aug 7, 10:38 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Otoe	52 min
Aug 7, 11:10 PM CDT	River Flood Warning	OAX	Saunders	13 hr
Aug 8, 12:41 AM CDT	Areal Flood Warning	OAX	Butler, Cass, Colfax, Douglas, Lancaster, Otoe and 4 more	12 hr
Aug 8, 2:37 PM CDT	Heat Advisory	OAX	Butler, Cass, Colfax, Dodge, Douglas, Gage and 13 more	54 hr
Aug 7, 11:25 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Mills, Montgomery, Page	36 min

Nearby

Flash Flood Warnings in Nebraska, 2021 Flash Flood Warnings in Iowa, 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.