Alert archive / Nebraska / Flash Flood Warnings in 2021

Flash Flood Warning 13, NWS Omaha, NE

October 24, 2021Lancaster County, Nebraska

NWS Omaha, NE issued this flash flood warning at Oct 24, 2021, 1:47 PM CDT for Lancaster County, Nebraska. It was in force for 3 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
Oct 24, 2021, 1:47 PM CDT (18:47 UTC)
Expired
Oct 24, 2021, 5:00 PM CDT
In force
3 hr
Issued by
NWS Omaha, NE
Area
Storm-based polygon
Flood severity
None

County Lancaster County, NE

The radar

The Omaha radar (KOAX), 54 km from the middle of the area, began a volume at 18:51 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

TimeReportWhereRemark
Oct 24, 2:31 PM CDTHEAVY RAIN 3.84 E Lincoln, NESTORM TOTAL SO FAR.

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 12:00Z, 6.8 hours before the alert went out and 54 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-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2021-10-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2021-10-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 123 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
435 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
323 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

290 
WGUS53 KOAX 241847
FFWOAX
NEC109-242200-
/O.NEW.KOAX.FF.W.0013.211024T1847Z-211024T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Omaha/Valley NE
147 PM CDT Sun Oct 24 2021

The National Weather Service in Omaha/Valley has issued a

* Flash Flood Warning for...
  Northern Lancaster County in southeastern Nebraska...

* Until 500 PM CDT.

* At 147 PM CDT, trained weather spotters reported thunderstorms 
  producing heavy rain were leading to flash flooding in eastern 
  Lincoln. Between 2 and 3 inches of rain have fallen. Additional 
  rainfall amounts of 1 to 2 inches are possible in the warned area 
  and could lead to more flash flooding.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Trained spotters 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...
  Lincoln and Waverly.

This includes the following streams and drainages...
  Dee Creek, Elk Creek, Antelope Creek, Dead Mans Run, Robinson 
  Branch Salt Creek Tributary, Little Nemaha River, Cardwell Branch, 
  Camp Creek, Camp Creek Tributary, Robinson Branch, Rock Creek, 
  Millville Creek, Stevens Creek Tributary, Ash Hollow Creek, Rock 
  Creek Tributary, Jordan Creek, Middle Creek, Olive Branch, Wahoo 
  Creek, Garr Creek, Beal Slough, Haines Branch, Oak Creek, Stevens 
  Creek, Salt Creek Tributary, Little Salt Creek, Haines Branch 
  Tributary, Hickman Branch Tributary and Hooper Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4074 9646 4069 9666 4077 9680 4085 9683
      4104 9656 4105 9654 4105 9646

FLASH FLOOD...OBSERVED

$$

CA
3 follow-up statements
892 
WGUS73 KOAX 242039
FFSOAX

Flash Flood Statement
National Weather Service Omaha/Valley NE
339 PM CDT Sun Oct 24 2021

NEC109-242200-
/O.CON.KOAX.FF.W.0013.000000T0000Z-211024T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lancaster NE-
339 PM CDT Sun Oct 24 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 5 PM CDT THIS 
AFTERNOON FOR NORTHERN LANCASTER COUNTY...

At 339 PM CDT, trained spotters reported ongoing flooding in eastern 
Lincoln. Between 2.5 and 4 inches of rain have fallen across the 
warned area. Though the heaviest rain has come to an end, light rain 
will continue, along with the threat for flooding.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters 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...
  Lincoln and Waverly.

This includes the following streams and drainages...
  Dee Creek, Elk Creek, Antelope Creek, Dead Mans Run, Robinson 
  Branch Salt Creek Tributary, Little Nemaha River, Cardwell Branch, 
  Camp Creek, Camp Creek Tributary, Robinson Branch, Rock Creek, 
  Millville Creek, Stevens Creek Tributary, Ash Hollow Creek, Rock 
  Creek Tributary, Jordan Creek, Middle Creek, Olive Branch, Wahoo 
  Creek, Garr Creek, Beal Slough, Haines Branch, Oak Creek, Stevens 
  Creek, Salt Creek Tributary, Little Salt Creek, Haines Branch 
  Tributary, Hickman Branch Tributary and Hooper Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4074 9646 4069 9666 4077 9680 4085 9683
      4104 9656 4105 9655 4105 9646

FLASH FLOOD...OBSERVED

$$

CA
547 
WGUS73 KOAX 242124
FFSOAX

Flash Flood Statement
National Weather Service Omaha/Valley NE
424 PM CDT Sun Oct 24 2021

NEC109-242200-
/O.CON.KOAX.FF.W.0013.000000T0000Z-211024T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lancaster NE-
424 PM CDT Sun Oct 24 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 5 PM CDT THIS 
AFTERNOON FOR PARTS OF LANCASTER COUNTY...

At 424 PM CDT, Radar indicated that the heaviest rain was ending. 
Conditions should be improving and the if the trend continues, the 
flash flood warning will be allowed to expire as scheduled at 5 pm.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported flash flooding earlier this
         afternoon.

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...
  Lincoln and Waverly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles. Do not drive into flooded areas.

&&

LAT...LON 4074 9646 4069 9666 4077 9680 4085 9683
      4104 9656 4105 9655 4105 9646

FLASH FLOOD...OBSERVED

$$

Miller
659 
WGUS73 KOAX 242157
FFSOAX

Flash Flood Statement
National Weather Service Omaha/Valley NE
457 PM CDT Sun Oct 24 2021

NEC109-242207-
/O.EXP.KOAX.FF.W.0013.000000T0000Z-211024T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lancaster NE-
457 PM CDT Sun Oct 24 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 5 PM CDT THIS AFTERNOON FOR 
NORTHERN LANCASTER COUNTY...

Heavy rain has ended and water levels should continue to drop. 
Flooding is no longer expected to pose a serious threat. Please 
continue to heed any remaining road closure signs.

LAT...LON 4074 9646 4069 9666 4077 9680 4085 9683
      4104 9656 4105 9655 4105 9646

$$

Miller

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 23, 11:20 PM CDTSpecial Weather StatementOAXJohnson25 min
Oct 23, 11:44 PM CDTSpecial Weather StatementOAXNemaha31 min
Oct 24, 9:41 AM CDTSpecial Weather StatementOAXDodge34 min
Oct 24, 12:33 PM CDTAreal Flood AdvisoryOAXDouglas, Sarpy4 hr
Oct 24, 1:18 PM CDTAreal Flood AdvisoryOAXLancaster3 hr

Nearby

Flash Flood Warnings in Nebraska, 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.