Alert archive / Nebraska / Flash Flood Warnings in 2021
Flash Flood Warning 11, NWS Omaha, NE
NWS Omaha, NE issued this flash flood warning at Aug 7, 2021, 10:30 PM CDT for Douglas County, Nebraska; Pottawattamie County, Iowa. It was in force for 89 min. 4 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, 10:30 PM CDT (03:30 UTC)
- Expired
- Aug 7, 2021, 11:59 PM CDT
- In force
- 89 min
- Issued by
- NWS Omaha, NE
- Area
- Storm-based polygon
- Emergency
- Flash flood emergency
- Flood severity
- None
Counties Pottawattamie County, IA, Douglas County, NE
The radar
The Omaha radar (KOAX), 39 km from the middle of the area, began a volume at 03:30 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, 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, 10:50 PM CDT | FLASH FLOOD | 4 E Omaha, NE | MAJOR FLASH FLOODING. WATER FLOWING FAST AT A DEPTH OF 2-3 FEET. |
| Aug 7, 11:01 PM CDT | FLASH FLOOD | 4 E Omaha, NE | MANHOLE COVERS BLOWN OFF AND SOME STREET DAMAGE. |
| 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, 3.5 hours before the alert went out and 39 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.
- 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
The text
As transmitted.
298
WGUS53 KOAX 080330
FFWOAX
IAC155-NEC055-080630-
/O.NEW.KOAX.FF.W.0011.210808T0330Z-210808T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Omaha/Valley NE
1030 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...
Southeastern Douglas County in east central Nebraska...
* Until 130 AM CDT.
* At 1030 PM CDT, the public reported thunderstorms producing life
threatening flooding in Downtown Omaha. Between 2 and 3 inches of
rain have fallen. The expected rainfall rate is 1 inch in 3 hours.
Additional rainfall amounts of 1 to 2 inches are possible in the
warned area. Flash flooding is already occurring.
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...
Southeastern Omaha and Council Bluffs.
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 4126 9595 4126 9594 4127 9589 4127 9587
4127 9586 4126 9585 4123 9585 4123 9586
4122 9588 4122 9589 4122 9591 4122 9594
4122 9595 4123 9595 4124 9596 4126 9596
FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...1 INCH IN 3 HOURS
$$
Pearson2 follow-up statements
434
WGUS73 KOAX 080332
FFSOAX
Flash Flood Statement
National Weather Service Omaha/Valley NE
1032 PM CDT Sat Aug 7 2021
IAC155-NEC055-080630-
/O.CON.KOAX.FF.W.0011.000000T0000Z-210808T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pottawattamie IA-Douglas NE-
1032 PM CDT Sat Aug 7 2021
...FLASH FLOOD EMERGENCY FOR DOWNTOWN OMAHA AND COUNCIL BLUFFS...
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 AM CDT SUNDAY FOR
SOUTHWESTERN POTTAWATTAMIE AND SOUTHEASTERN DOUGLAS COUNTIES...
At 1032 PM CDT, the public reported thunderstorms producing heavy
rain in Downtown Omaha. Between 2 and 3 inches of rain have fallen.
The expected rainfall rate is 1 inch in 3 hours. Additional rainfall
amounts of 1 to 2 inches are possible in the warned area. Flash
flooding is already occurring.
This is a FLASH FLOOD EMERGENCY for Downtown Omaha and Council
Bluffs. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER
GROUND NOW!
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Public reported.
IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER
GROUND NOW! Life threatening flash flooding of low water
crossings, small creeks and streams, urban areas,
highways, streets and underpasses.
Some locations that will experience flash flooding include...
Southeastern Omaha and Council Bluffs.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to higher ground now! This is an extremely dangerous and
life-threatening situation. Do not attempt to travel unless you are
fleeing an area subject to flooding or under an evacuation order.
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 4126 9595 4126 9594 4127 9589 4127 9587
4127 9586 4126 9585 4123 9585 4123 9586
4122 9588 4122 9589 4122 9591 4122 9594
4122 9595 4123 9595 4124 9596 4126 9596
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC
EXPECTED RAINFALL...1 INCH IN 3 HOURS
$$
Pearson629
WGUS73 KOAX 080459
FFSOAX
Flash Flood Statement
National Weather Service Omaha/Valley NE
1159 PM CDT Sat Aug 7 2021
IAC155-NEC055-080509-
/O.CAN.KOAX.FF.W.0011.000000T0000Z-210808T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pottawattamie IA-Douglas NE-
1159 PM CDT Sat Aug 7 2021
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN POTTAWATTAMIE
AND SOUTHEASTERN DOUGLAS COUNTIES...
Though this flash flood emergency is being ended, a considerable
flash flood warning remains in effect. Continue to avoid flooded
areas as it will take awhile for the water to completely drain.
LAT...LON 4126 9595 4126 9594 4127 9589 4127 9587
4127 9586 4126 9585 4123 9585 4123 9586
4122 9588 4122 9589 4122 9591 4122 9594
4122 9595 4123 9595 4124 9596 4126 9596
$$
PearsonThe 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 | 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 | 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 | 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 | OAX | Douglas | 40 min |
| Aug 7, 8:55 PM CDT | Severe Thunderstorm Warning | OAX | Butler, Saunders | 35 min |
| Aug 7, 9:05 PM CDT | Flash Flood Warning | OAX | Butler, Colfax, Douglas, Sarpy, Saunders | 4 hr |
| 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 | 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, 10:38 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, 2021Flash Flood Warnings in Iowa, 2021Every 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.