Alert archive / South Dakota / Tornado Warnings in 2011

Tornado Warning 21, NWS Rapid City, SD

August 7, 2011Custer County, South Dakota

NWS Rapid City, SD issued this tornado warning at Aug 7, 2011, 3:56 PM MDT for Custer County, South Dakota. It was in force for 29 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 7, 2011, 3:56 PM MDT (21:56 UTC)
Expired
Aug 7, 2011, 4:25 PM MDT
In force
29 min
Issued by
NWS Rapid City, SD
Area
Storm-based polygon

County Custer County, SD

The radar

The Rapid City radar (KUDX), 54 km from the middle of the area, began a volume at 21:58 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

TimeReportWhereRemark
Aug 7, 4:30 PM MDTHAIL 1.754 S Red Shirt, SD

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.

IssuedProductOfficeLasted
Aug 7, 1:58 PM MDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 9.9 hours before the alert went out and 47 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, Rapid City, SD at 12:00Z on 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 561 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, Rapid City, SD at 12:00Z on 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 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
561 J/kg
Mixed-layer CIN
-335 J/kg
Mixed-layer LCL
1423 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
136 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.

557 
WFUS53 KUNR 072156
TORUNR
SDC033-113-072245-
/O.NEW.KUNR.TO.W.0021.110807T2156Z-110807T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE RAPID CITY SD
356 PM MDT SUN AUG 7 2011

THE NATIONAL WEATHER SERVICE IN RAPID CITY HAS ISSUED A

* TORNADO WARNING FOR...
  EAST CENTRAL CUSTER COUNTY IN SOUTHWESTERN SOUTH DAKOTA...
  NORTHWESTERN SHANNON COUNTY IN SOUTHWESTERN SOUTH DAKOTA...

* UNTIL 445 PM MDT

* AT 353 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 7 MILES EAST OF FAIRBURN...OR 27 MILES EAST OF
  DOWNTOWN CUSTER...AND MOVING SOUTHEAST AT 20 MPH.

* LOCATIONS IMPACTED INCLUDE...
  RED SHIRT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4363 10281 4353 10294 4370 10314 4375 10307
TIME...MOT...LOC 2156Z 309DEG 16KT 4368 10305

$$

TRIMARCHI
2 follow-up statements
743 
WWUS53 KUNR 072216
SVSUNR

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
416 PM MDT SUN AUG 7 2011

SDC033-072223-
/O.CAN.KUNR.TO.W.0021.000000T0000Z-110807T2245Z/
CUSTER SD-
416 PM MDT SUN AUG 7 2011

...THE TORNADO WARNING FOR EAST CENTRAL CUSTER COUNTY IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 4361 10299 4361 10294 4365 10293 4366 10291
      4363 10281 4356 10290 4356 10292
TIME...MOT...LOC 2213Z 307DEG 18KT 4363 10295

$$

SDC113-072245-
/O.CON.KUNR.TO.W.0021.000000T0000Z-110807T2245Z/
SHANNON SD-
416 PM MDT SUN AUG 7 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHWESTERN SHANNON
COUNTY UNTIL 445 PM MDT...

AT 411 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR RED SHIRT...OR 29 MILES NORTHEAST OF DOWNTOWN
HOT SPRINGS...MOVING SOUTHEAST AT 20 MPH.

LOCATIONS IMPACTED INCLUDE...
  RED SHIRT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4361 10299 4361 10294 4365 10293 4366 10291
      4363 10281 4356 10290 4356 10292
TIME...MOT...LOC 2213Z 307DEG 18KT 4363 10295

$$

TRIMARCHI
027 
WWUS53 KUNR 072225
SVSUNR

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RAPID CITY SD
425 PM MDT SUN AUG 7 2011

SDC113-072236-
/O.CAN.KUNR.TO.W.0021.000000T0000Z-110807T2245Z/
SHANNON SD-
425 PM MDT SUN AUG 7 2011

...THE TORNADO WARNING FOR NORTHWESTERN SHANNON COUNTY IS
CANCELLED...

THE TORNADO THREAT HAS DIMINISHED...THEREFORE THE TORNADO WARNING HAS
BEEN CANCELLED. HOWEVER...A SEVERE THUNDERSTORM WARNING REMAINS IN
EFFECT FOR THE AREA.

LAT...LON 4361 10299 4361 10294 4365 10293 4366 10291
      4363 10281 4356 10290 4356 10292
TIME...MOT...LOC 2226Z 307DEG 18KT 4359 10288

$$

TRIMARCHI

The office that day

Everything else NWS Rapid City, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 1:05 PM MDTSevere Thunderstorm WarningUNRPennington55 min
Aug 7, 1:50 PM MDTSevere Thunderstorm WarningUNRPennington55 min
Aug 7, 2:27 PM MDTSevere Thunderstorm WarningUNRPennington63 min
Aug 7, 2:36 PM MDTAreal Flood AdvisoryUNRPennington78 min
Aug 7, 2:53 PM MDTSevere Thunderstorm WarningUNRCuster82 min
Aug 7, 2:57 PM MDTAreal Flood AdvisoryUNRCuster2 hr
Aug 7, 3:39 PM MDTSevere Thunderstorm WarningUNRHaakon66 min
Aug 7, 4:05 PM MDTSevere Thunderstorm WarningUNRCuster, Pennington55 min
Aug 7, 4:19 PM MDTSevere Thunderstorm WarningUNRButte, Lawrence, Meade43 min
Aug 7, 4:28 PM MDTSevere Thunderstorm WarningUNR62 min
Aug 7, 4:31 PM MDTSevere Thunderstorm WarningUNRButte, Harding59 min
Aug 7, 4:33 PM MDTSevere Thunderstorm WarningUNRHaakon57 min
Aug 7, 4:47 PM MDTSevere Thunderstorm WarningUNRJackson58 min
Aug 7, 4:48 PM MDTSevere Thunderstorm WarningUNRLawrence, Meade31 min
Aug 7, 5:05 PM MDTSevere Thunderstorm WarningUNRBennett, Jackson55 min
Aug 7, 5:20 PM MDTSevere Thunderstorm WarningUNRJackson, Mellette55 min
Aug 7, 5:29 PM MDTSevere Thunderstorm WarningUNRButte, Harding, Perkins61 min
Aug 7, 5:37 PM MDTSevere Thunderstorm WarningUNRTodd53 min
Aug 7, 5:49 PM MDTSevere Thunderstorm WarningUNRBennett, Jackson, Mellette, Todd56 min
Aug 7, 5:58 PM MDTSevere Thunderstorm WarningUNRButte, Meade, Perkins62 min

Nearby

Tornado Warnings in South Dakota, 2011Every tornado warning in 2011Tornadoes in 2011

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.