Alert archive / Nebraska / Flash Flood Warnings in 2009

Flash Flood Warning 21, NWS Sioux Falls, SD

August 16, 2009Dixon County, Nebraska

NWS Sioux Falls, SD issued this flash flood warning at Aug 16, 2009, 12:29 AM CDT for Dixon County, Nebraska. It was in force for 82 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 16, 2009, 12:29 AM CDT (05:29 UTC)
Expired: Aug 16, 2009, 1:51 AM CDT
In force: 82 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Flood severity: None

County Dixon County, NE

The radar

The Sioux Falls radar (KFSD), 115 km from the middle of the area, began a volume at 05:32 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 16, 12:51 AM CDT	FLASH FLOOD	5 Wsw Martinsburg, NE	WATER STANDING ON HIGHWAY 20 WEST OF ALLEN. UNSURE OF WATER DEPTH.

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, 5.5 hours before the alert went out and 143 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: 1204 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 906 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 137 m²/s²
0-3 km storm-relative helicity: 215 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.

000 
WGUS53 KFSD 160529
FFWFSD
NEC051-160830-
/O.NEW.KFSD.FF.W.0021.090816T0529Z-090816T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1229 AM CDT SUN AUG 16 2009

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DIXON COUNTY IN NORTHEAST NEBRASKA

* UNTIL 330 AM CDT

* AT 1225 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS MOST OF
  DIXON COUNTY. RAINFALL AMOUNTS OF 1 TO 3 INCHES HAVE OCCURRED
  ACROSS THE COUNTY WITH AN ADDITIONAL 1 TO 2 INCHES POSSIBLE
  THROUGH 2 AM.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  PONCA...ALLEN...CONCORD...DIXON...MARTINSBURG...MASKELL...
  NEWCASTLE...PONCA STATE PARK AND WAKEFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

&&

LAT...LON 4226 9702 4271 9702 4276 9701 4276 9698
      4272 9697 4273 9689 4271 9681 4266 9679
      4267 9671 4261 9672 4255 9663 4252 9664
      4252 9672 4225 9673 4225 9694

$$

CJ

1 follow-up statement

000 
WGUS73 KFSD 160651
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
151 AM CDT SUN AUG 16 2009

NEC051-160704-
/O.CAN.KFSD.FF.W.0021.000000T0000Z-090816T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DIXON NE-
151 AM CDT SUN AUG 16 2009

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR DIXON COUNTY IS
CANCELLED...

RAINFALL RATES HAVE DECREASED CONSIDERABLY ACROSS DIXON COUNTY...AS
THE LINE OF STRONGER STORMS HAS SHIFTED EAST INTO IOWA. LIGHT TO 
MODERATE SHOWERS WILL CONTINUE THROUGH THE EARLY MORNING HOURS... 
HOWEVER THE THREAT OF FLASH FLOODING HAS ENDED.

IF FLOODING HAS BEEN OBSERVED...PLEASE REPORT IT TO YOUR LOCAL LAW 
ENFORCEMENT AGENCY.

LAT...LON 4226 9702 4271 9702 4276 9701 4276 9698
      4272 9697 4273 9689 4271 9681 4266 9679
      4267 9671 4261 9672 4255 9663 4252 9664
      4252 9672 4225 9673 4225 9694

$$
 JH

Nearby

Flash Flood Warnings in Nebraska, 2009 Every flash flood warning in 2009

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.