Alert archive / South Dakota / Tornado Warnings in 2007

Tornado Warning 5, NWS Sioux Falls, SD

April 21, 2007Aurora County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Apr 21, 2007, 7:39 PM CDT for Aurora County, South Dakota. It was in force for 36 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: Apr 21, 2007, 7:39 PM CDT (00:39 UTC)
Expired: Apr 21, 2007, 8:15 PM CDT
In force: 36 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

County Aurora County, SD

The radar

The Sioux Falls radar (KFSD), 143 km from the middle of the area, began a volume at 00:41 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
Apr 21, 7:55 PM CDT	TORNADO	5 Ese Plankinton, SD	4-5 BRIEF TOUCHDOWNS

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 21, 2:30 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 0.7 hours before the alert went out and 125 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: 1323 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 965 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: 265 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 4.6

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KFSD 220039
TORFSD
SDC003-220115-
/O.NEW.KFSD.TO.W.0005.070422T0039Z-070422T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
739 PM CDT SAT APR 21 2007

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN AURORA COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 815 PM CDT

* AT 739 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
  PLANKINTON...OR ABOUT 21 MILES WEST OF MITCHELL...MOVING NORTHEAST
  AT 35 MPH.

* THE TORNADO WILL BE NEAR...
  RURAL AURORA COUNTY THROUGH 750 PM CDT

IN ADDITION TO THE THREAT OF A TORNADO...DAMAGING HAIL AND STRONG
WINDS CAN BE EXPECTED. GO TO A SAFE PLACE NOW.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT SATURDAY EVENING
FOR SOUTHEASTERN SOUTH DAKOTA.

LAT...LON 4369 9862 4367 9838 4392 9833 4392 9847

$$

MJF

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 21, 7:08 PM CDT	Severe Thunderstorm Warning	FSD	Brule	42 min
Apr 21, 7:09 PM CDT	Severe Thunderstorm Warning	FSD	Aurora	36 min
Apr 21, 7:20 PM CDT	Severe Thunderstorm Warning	FSD	Beadle	55 min
Apr 21, 7:41 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Gregory	34 min
Apr 21, 7:46 PM CDT	Severe Thunderstorm Warning	FSD	Aurora	29 min
Apr 21, 7:50 PM CDT	Severe Thunderstorm Warning	FSD	Sanborn	40 min
Apr 21, 7:54 PM CDT	Severe Thunderstorm Warning	FSD	Brule	51 min
Apr 21, 7:58 PM CDT	Tornado Warning	FSD	Davison	20 min
Apr 21, 8:07 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Gregory	38 min
Apr 21, 8:18 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Douglas	42 min
Apr 21, 8:25 PM CDT	Severe Thunderstorm Warning	FSD	Beadle, Kingsbury	50 min
Apr 21, 8:25 PM CDT	Tornado Warning	FSD	Aurora	35 min
Apr 21, 8:30 PM CDT	Severe Thunderstorm Warning	FSD	Sanborn	30 min
Apr 21, 8:45 PM CDT	Tornado Warning	FSD	Kingsbury	45 min
Apr 21, 9:06 PM CDT	Severe Thunderstorm Warning	FSD	Brule, Charles Mix	39 min
Apr 21, 9:09 PM CDT	Severe Thunderstorm Warning	FSD	Sanborn	36 min
Apr 21, 9:13 PM CDT	Severe Thunderstorm Warning	FSD	Davison, Hanson	47 min
Apr 21, 9:29 PM CDT	Severe Thunderstorm Warning	FSD	Aurora	46 min
Apr 21, 9:35 PM CDT	Severe Thunderstorm Warning	FSD	Kingsbury, Miner	40 min
Apr 21, 10:35 PM CDT	Severe Thunderstorm Warning	FSD	Brookings	40 min

Nearby

Tornado Warnings in South Dakota, 2007 Every tornado warning in 2007 Tornadoes in 2007

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.