Alert archive / Nebraska / Flash Flood Warnings in 2015

Flash Flood Warning 18, NWS Sioux Falls, SD

September 23, 2015Dixon County, Nebraska

NWS Sioux Falls, SD issued this flash flood warning at Sep 23, 2015, 1:45 AM CDT for Dixon County, Nebraska. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 23, 2015, 1:45 AM CDT (06:45 UTC)
Expired
Sep 23, 2015, 4:45 AM CDT
In force
3 hr
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Flood severity
None

County Dixon County, NE

The radar

The Sioux Falls radar (KFSD), 123 km from the middle of the area, began a volume at 06:47 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

Omaha, NE (KOAX), launched 00:00Z, 6.8 hours before the alert went out and 140 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 00:00Z on 2015-09-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 504 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2015-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 square meters per square second.193958Sfc1 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
504 J/kg
Mixed-layer CIN
-241 J/kg
Mixed-layer LCL
1351 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
370 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

295 
WGUS53 KFSD 230645
FFWFSD
NEC051-230945-
/O.NEW.KFSD.FF.W.0018.150923T0645Z-150923T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
145 AM CDT WED SEP 23 2015

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN DIXON COUNTY IN NORTHEASTERN NEBRASKA...

* UNTIL 445 AM CDT
    
* AT 142 AM CDT...DOPPLER RADAR INDICATED A LINE OF SLOW MOVING 
  THUNDERSTORMS PRODUCING HEAVY RAIN ACROSS THE WARNED AREA. RADAR 
  INDICATES UP TO THREE INCHES OF RAIN HAVE ALREADY FALLEN WITH UP 
  TO AN ADDITIONAL 2 INCHES OF RAIN POSSIBLE THROUGH THE NEXT FEW 
  HOURS. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  WAKEFIELD...CONCORD AND DIXON IN DIXON COUNTY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

&&

LAT...LON 4266 9701 4264 9686 4226 9686 4227 9702

$$

HANKO
2 follow-up statements
278 
WGUS73 KFSD 230814
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
314 AM CDT WED SEP 23 2015

NEC051-230945-
/O.CON.KFSD.FF.W.0018.000000T0000Z-150923T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DIXON NE-
314 AM CDT WED SEP 23 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 AM CDT FOR
SOUTHWESTERN DIXON COUNTY...

AT 312 AM CDT...DOPPLER RADAR CONTINUED TO INDICATED A LINE OF SLOW 
MOVING THUNDERSTORMS PRODUCING HEAVY RAIN ACROSS THE WARNED AREA. 
RADAR ESTIMATES AS MUCH AS 7 INCHES HAS FALLEN IN PORTIONS OF THE 
WARNING AREA WITH AN ADDITIONAL 1 TO 2 INCHES POSSIBLE IN THE NEXT 
HOUR OR SO. 

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... 
WAKEFIELD...CONCORD AND DIXON IN DIXON COUNTY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 4266 9701 4264 9686 4226 9686 4227 9702

$$

HANKO
135 
WGUS73 KFSD 230937
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
437 AM CDT WED SEP 23 2015

NEC051-230947-
/O.EXP.KFSD.FF.W.0018.000000T0000Z-150923T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DIXON NE-
437 AM CDT WED SEP 23 2015

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN DIXON COUNTY WILL EXPIRE
AT 445 AM CDT...

THE HEAVY RAIN HAS ENDED...AND FLOODING IS NO LONGER EXPECTED TO POSE
A THREAT.

LAT...LON 4266 9701 4264 9686 4226 9686 4227 9702

$$

HANKO

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 23, 4:14 AM CDTFlash Flood WatchFSDDakota, Dixon27 hr

Nearby

Flash Flood Warnings in Nebraska, 2015Every flash flood warning in 2015

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.