Alert archive / Nebraska / Flash Flood Warnings in 2017

Flash Flood Warning 5, NWS Sioux Falls, SD

August 25, 2017Dakota County, Dixon County, Nebraska

NWS Sioux Falls, SD issued this flash flood warning at Aug 25, 2017, 11:08 AM CDT for Dakota County, Dixon County, Nebraska. It was in force for 112 min. 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: Aug 25, 2017, 11:08 AM CDT (16:08 UTC)
Expired: Aug 25, 2017, 1:00 PM CDT
In force: 112 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Flood severity: None

Counties Dakota County, NE, Dixon County, NE

What was reported inside it

Time	Report	Where	Remark
Aug 25, 11:40 AM CDT	FLASH FLOOD	3 Ne Allen, NE	SEVERAL COUNTY ROADS FLOODED IN THE AREA AFTER 4 TO 6 INCHES OF RAIN IN THE PAST 2 TO 3 HOURS.

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

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 4.1 hours before the alert went out and 312 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: 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.

516 
WGUS53 KFSD 251608
FFWFSD
NEC043-051-251800-
/O.NEW.KFSD.FF.W.0005.170825T1608Z-170825T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Sioux Falls SD
1108 AM CDT FRI AUG 25 2017

The National Weather Service in Sioux Falls has issued a

* Flash Flood Warning for...
  Dakota County in northeastern Nebraska...
  South central Dixon County in northeastern Nebraska...

* Until 100 PM CDT

* At 1106 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. One to three inches of rain 
  have already fallen. Flash flooding is expected to begin shortly.

Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area, along with intense rainfall rates that will lead to 
rapid runoff.

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 4249 9691 4247 9650 4228 9645 4228 9673
      4226 9673 4227 9690

$$

Gillispie

2 follow-up statements

081 
WGUS73 KFSD 251646
FFSFSD

Flash Flood Statement
National Weather Service Sioux Falls SD
1146 AM CDT FRI AUG 25 2017

NEC043-051-251800-
/O.CON.KFSD.FF.W.0005.000000T0000Z-170825T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dakota NE-Dixon NE-
1146 AM CDT FRI AUG 25 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 100 PM CDT FOR
DAKOTA AND SOUTH CENTRAL DIXON COUNTIES...

At 1139 AM CDT, local law enforcement reported heavy rain due to a 
thunderstorm between Allen and Waterbury. Four to six inches of rain 
have fallen. Flash flooding is occurring. Several county roads have 
water over them in the Allen and Waterbury areas.

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 4249 9691 4247 9650 4228 9645 4228 9673
      4226 9673 4227 9690

$$

Gillispie

761 
WGUS73 KFSD 251750
FFSFSD

Flash Flood Statement
National Weather Service Sioux Falls SD
1250 PM CDT FRI AUG 25 2017

NEC043-051-251800-
/O.EXP.KFSD.FF.W.0005.000000T0000Z-170825T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dakota NE-Dixon NE-
1250 PM CDT FRI AUG 25 2017

...THE FLASH FLOOD WARNING FOR DAKOTA AND SOUTH CENTRAL DIXON
COUNTIES WILL EXPIRE AT 100 PM CDT...

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

LAT...LON 4249 9691 4247 9650 4228 9645 4228 9673
      4226 9673 4227 9690

$$

Gillispie

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 25, 12:07 PM CDT	Flash Flood Warning	FSD	Dakota, Dixon	113 min

Nearby

Flash Flood Warnings in Nebraska, 2017 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.