Alert archive / South Dakota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 260, NWS Sioux Falls, SD

August 11, 2002Aurora County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 11, 2002, 8:53 PM CDT for Aurora County, South Dakota. It was in force for 37 min. 2 reports 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 11, 2002, 8:53 PM CDT (01:53 UTC)
Expired: Aug 11, 2002, 9:30 PM CDT
In force: 37 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), 151 km from the middle of the area, began a volume at 01:55 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 11, 9:16 PM CDT	Thunderstorm Wind 52 E	White Lake, SD
Aug 11, 9:40 PM CDT	Thunderstorm Wind 52 E	Stickney, SD

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

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

Issued	Product	Office	Lasted
Aug 11, 7:00 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 1.9 hours before the alert went out and 130 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: 2317 J/kg
Mixed-layer CIN: -146 J/kg
Mixed-layer LCL: 2063 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 92 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.5

Open this sounding in Storm Lab

The text

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

328 
WUUS53 KFSD 120153
SVRFSD
SDC003-120230-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
853 PM CDT SUN AUG 11 2002

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  AURORA COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 930 PM CDT

* AT 853 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM 16 MILES NORTHWEST OF WHITE LAKE
  TO 19 MILES SOUTHWEST OF WHITE LAKE...OR FROM 22 MILES EAST OF
  CHAMBERLAIN TO 29 MILES SOUTHEAST OF CHAMBERLAIN...MOVING EAST AT
  40 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  PLANKINTON AROUND 910 PM CDT
  STICKNEY AROUND 920 PM CDT

THIS STORM HAS A HISTORY OF PRODUCING DAMAGING WIND. GO INSIDE A
STURDY BUILDING AND STAY AWAY FROM WINDOWS.

LAT...LON 4391 9880 4370 9879 4352 9877 4351 9835
          4372 9834 4392 9835

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 11, 7:55 PM CDT, 58 minutes earlier.

Area forecast discussion, Aug 11, 7:55 PM CDT, 58 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
755 PM CDT SUN AUG 11 2002

UPDATED AROUND 7 PM TO COVER CHANGES TO SEVERE THUNDERSTORM
WATCHES.  ALSO MADE SOME MINOR ADJUSTMENTS TO BACK OFF BEST
THUNDERSTORM CHANCES ACROSS EASTERN COUNTIES.  STILL EXPECTING
CURRENT LINE OF TSRA ACROSS CENTRAL SD TO FORM A COHESIVE LINE WITH
THREAT OF DAMAGING WIND SPREADING EAST ACROSS THE CWA OVERNIGHT.

NO OTHER CHANGES NEEDED AT THIS TIME.

FSD...NONE
 HACKER

In the hours before

Local storm report, Aug 11, 3:09 PM CDT, 5 hours 44 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
309 PM CDT SUN AUG 11 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0340 AM    15 E FAIRFAX              SD   .75 INCH HAIL
08/11/02   GREGORY                        REPORTED BY PUBLIC.

0415 AM    6 SW MITCHELL             SD   .75 INCH HAIL
08/11/02   DAVISON                        REPORTED BY PUBLIC.

Local storm report, Aug 11, 4:37 PM CDT, 4 hours 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
437 PM CDT SUN AUG 11 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0430 AM    5 S WAKONDA               SD   .75 INCH HAIL
08/11/02   CLAY                           REPORTED BY PUBLIC.

Special weather statement, Aug 11, 7:30 PM CDT, 1 hour 23 minutes before

SDZ038-050-052-053-120100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
730 PM CDT SUN AUG 11 2002

...SEVERE THUNDERSTORM WATCH NUMBER 590 FOR GREGORY COUNTY HAS BEEN
REPLACED BY SEVERE THUNDERSTORM WATCH 594...
...SEVERE THUNDERSTORM WATCH 589 EXTENDED BY WATCH NUMBER 594 FOR
JERAULD...BEADLE...AND SANBORN COUNTIES...

THE STORM PREDICTION CENTER HAS ISSUED ANOTHER SEVERE THUNDERSTORM
WATCH...NUMBER 594...UNTIL MIDNIGHT...FOR MUCH OF EASTERN SOUTH
DAKOTA...EXCEPT AREAS ROUGHLY SOUTHEAST OF A LINE FROM BROOKINGS
TO YANKTON.  THIS WATCH REPLACES THE PREVIOUS SEVERE THUNDERSTORM
WATCH NUMBER 590 FOR GREGORY COUNTY...AND EXTENDS THE PREVIOUS WATCH
FOR JERAULD...BEADLE...AND SANBORN COUNTIES.

Local storm report, Aug 11, 8:33 PM CDT, 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
833 PM CDT SUN AUG 11 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0827 PM    (9V9)CHAMBERLAIN ARPT     SD   58 MPH TSTM GUST
08/11/02   BRULE                          ASOS REPORT

Local storm report, Aug 11, 8:49 PM CDT, 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
849 PM CDT SUN AUG 11 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0830 PM    20 NW WESSINGTON SPGS     SD   .88 INCH HAIL
08/11/02   JERAULD                        REPORTED BY PUBLIC.

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 7:58 PM CDT	Severe Thunderstorm Warning	FSD	Beadle, Jerauld	47 min
Aug 11, 8:10 PM CDT	Severe Thunderstorm Warning	FSD	Brule	50 min
Aug 11, 8:28 PM CDT	Severe Thunderstorm Warning	FSD	Gregory	32 min
Aug 11, 8:47 PM CDT	Severe Thunderstorm Warning	FSD	Jerauld	43 min
Aug 11, 8:56 PM CDT	Severe Thunderstorm Warning	FSD	Sanborn	49 min
Aug 11, 9:00 PM CDT	Severe Thunderstorm Warning	FSD	Brule	15 min
Aug 11, 9:05 PM CDT	Severe Thunderstorm Warning	FSD	Beadle	25 min
Aug 11, 9:30 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Davison	30 min
Aug 11, 9:36 PM CDT	Severe Thunderstorm Warning	FSD	Hanson, Miner	24 min
Aug 11, 10:00 PM CDT	Severe Thunderstorm Warning	FSD	Davison, Douglas	30 min
Aug 11, 10:14 PM CDT	Severe Thunderstorm Warning	FSD	Hutchinson	46 min
Aug 11, 10:22 PM CDT	Severe Thunderstorm Warning	FSD	Hanson	53 min
Aug 11, 10:49 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	26 min
Aug 11, 11:17 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	43 min
Aug 12, 12:46 AM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	44 min
Aug 12, 12:53 AM CDT	Severe Thunderstorm Warning	FSD	Clay	37 min
Aug 12, 1:18 AM CDT	Severe Thunderstorm Warning	FSD	Lincoln	42 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2002 Every severe thunderstorm warning in 2002

Sources

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