Alert archive / Nebraska / Flash Flood Warnings in 2017

Flash Flood Warning 6, NWS Sioux Falls, SD

August 25, 2017Dakota County, Dixon County, Nebraska; Union County, South Dakota

NWS Sioux Falls, SD issued this flash flood warning at Aug 25, 2017, 12:07 PM CDT for Dakota County, Dixon County, Nebraska; Union County, South Dakota. It was in force for 113 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 25, 2017, 12:07 PM CDT (17:07 UTC)
Expired
Aug 25, 2017, 2:00 PM CDT
In force
113 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Flood severity
None

Counties Dakota County, NE, Dixon County, NE, Union County, SD

The radar

The Sioux Falls radar (KFSD), 109 km from the middle of the area, began a volume at 17:09 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.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 5.1 hours before the alert went out and 288 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, Aberdeen, SD at 12:00Z on 2017-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Aberdeen, SD at 12:00Z on 2017-08-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
742 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

510 
WGUS53 KFSD 251707
FFWFSD
NEC043-051-SDC127-251900-
/O.NEW.KFSD.FF.W.0006.170825T1707Z-170825T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Sioux Falls SD
1207 PM CDT FRI AUG 25 2017

The National Weather Service in Sioux Falls has issued a

* Flash Flood Warning for...
  Northwestern Dakota County in northeastern Nebraska...
  Central Dixon County in northeastern Nebraska...
  Southwestern Union County in southeastern South Dakota...

* Until 200 PM CDT

* At 1206 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. One to two inches of rain have 
  already fallen. Flash flooding is expected to begin shortly.

Additional rainfall amounts of one to three inches are possible in 
the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4270 9662 4247 9650 4249 9691 4270 9691

$$

Gillispie
1 follow-up statement
138 
WGUS73 KFSD 251825
FFSFSD

Flash Flood Statement
National Weather Service Sioux Falls SD
125 PM CDT FRI AUG 25 2017

NEC043-051-SDC127-251834-
/O.CAN.KFSD.FF.W.0006.000000T0000Z-170825T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dakota NE-Dixon NE-Union SD-
125 PM CDT FRI AUG 25 2017

...THE FLASH FLOOD WARNING FOR NORTHWESTERN DAKOTA...CENTRAL DIXON
AND SOUTHWESTERN UNION COUNTIES IS CANCELLED...

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

LAT...LON 4270 9662 4247 9650 4249 9691 4270 9691

$$

Gillispie

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 25, 11:08 AM CDTFlash Flood WarningFSDDakota, Dixon112 min
Aug 25, 5:32 PM CDTSevere Thunderstorm WarningFSDBrule58 min
Aug 25, 5:42 PM CDTSevere Thunderstorm WarningFSDBrule, Charles Mix, Gregory63 min
Aug 25, 6:36 PM CDTSevere Thunderstorm WarningFSDBeadle, Kingsbury, Miner, Sanborn39 min
Aug 25, 6:48 PM CDTSevere Thunderstorm WarningFSDAurora, Davison, Jerauld, Sanborn57 min

Nearby

Flash Flood Warnings in Nebraska, 2017Flash Flood Warnings in South Dakota, 2017Every flash flood warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.