Alert archive / South Dakota / Tornado Warnings in 2011

Tornado Warning 19, NWS Sioux Falls, SD

May 11, 2011Lincoln County, Union County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at May 11, 2011, 6:13 PM CDT for Lincoln County, Union County, South Dakota. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 11, 2011, 6:13 PM CDT (23:13 UTC)
Expired
May 11, 2011, 6:45 PM CDT
In force
32 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon

Counties Lincoln County, SD, Union County, SD

The radar

The Sioux Falls radar (KFSD), 58 km from the middle of the area, began a volume at 23:15 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 12:00Z, 11.2 hours before the alert went out and 197 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 12:00Z on 2011-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 909 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 12:00Z on 2011-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939Sfc1 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
909 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
1123 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

915 
WFUS53 KFSD 112313
TORFSD
SDC083-127-112345-
/O.NEW.KFSD.TO.W.0019.110511T2313Z-110511T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
613 PM CDT WED MAY 11 2011

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN LINCOLN COUNTY IN SOUTHEAST SOUTH DAKOTA...
  NORTHEASTERN UNION COUNTY IN SOUTHEAST SOUTH DAKOTA...

* UNTIL 645 PM CDT

* AT 613 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO 3 
MILES NORTH OF HAWARDEN. DOPPLER RADAR SHOWED THIS TORNADO MOVING 
NORTHWEST AT 15 MPH.

* THE TORNADO WILL AFFECT MAINLY RURAL AREAS OF NORTHEASTERN UNION
  AND SOUTHEASTERN LINCOLN COUNTIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A TORNADO IS ON THE GROUND. 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 4303 9655 4314 9676 4324 9662 4307 9648
      4306 9650 4306 9652 4304 9653
TIME...MOT...LOC 2313Z 132DEG 12KT 4308 9654

$$

LAFLIN
2 follow-up statements
593 
WWUS53 KFSD 112328
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
628 PM CDT WED MAY 11 2011

SDC127-112337-
/O.CAN.KFSD.TO.W.0019.000000T0000Z-110511T2345Z/
UNION SD-
628 PM CDT WED MAY 11 2011

...THE TORNADO WARNING FOR NORTHEASTERN UNION COUNTY IS CANCELLED...

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

LAT...LON 4308 9661 4314 9676 4324 9662 4310 9655
TIME...MOT...LOC 2327Z 132DEG 12KT 4311 9659

$$

SDC083-112345-
/O.CON.KFSD.TO.W.0019.000000T0000Z-110511T2345Z/
LINCOLN SD-
628 PM CDT WED MAY 11 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL LINCOLN
COUNTY UNTIL 645 PM CDT...

AT 627 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 6 MILES NORTHEAST OF ALCESTER...OR 9 MILES 
NORTHWEST OF HAWARDEN...MOVING NORTHWEST AT 15 MPH. THIS STORM 
PREVIOUSLY PRODUCED A BRIEF TORNADO 3 MILES NORTH OF HAWARDEN.

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 4308 9661 4314 9676 4324 9662 4310 9655
TIME...MOT...LOC 2327Z 132DEG 12KT 4311 9659

$$

LAFLIN
547 
WWUS53 KFSD 112340
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
640 PM CDT WED MAY 11 2011

SDC083-112350-
/O.EXP.KFSD.TO.W.0019.000000T0000Z-110511T2345Z/
LINCOLN SD-
640 PM CDT WED MAY 11 2011

...THE TORNADO WARNING FOR SOUTH CENTRAL LINCOLN COUNTY WILL EXPIRE
AT 645 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR 
PROPERTY...HOWEVER HAIL IS STILL POSSIBLE WITH THIS THUNDERSTORM.

LAT...LON 4308 9661 4314 9676 4324 9662 4310 9655
TIME...MOT...LOC 2340Z 132DEG 12KT 4314 9663

$$

LAFLIN

The office that day

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

IssuedProductOfficeCountiesLasted
May 11, 4:51 PM CDTSevere Thunderstorm WarningFSDUnion39 min
May 11, 4:55 PM CDTSevere Thunderstorm WarningFSDUnion50 min
May 11, 5:37 PM CDTSevere Thunderstorm WarningFSDClay, Union, Yankton38 min
May 11, 5:42 PM CDTSevere Thunderstorm WarningFSDUnion48 min
May 11, 5:48 PM CDTSevere Thunderstorm WarningFSDLincoln42 min
May 11, 6:06 PM CDTSevere Thunderstorm WarningFSDLincoln24 min
May 11, 6:29 PM CDTSevere Thunderstorm WarningFSDLincoln, Turner, Union31 min
May 11, 6:49 PM CDTSevere Thunderstorm WarningFSDLincoln, Minnehaha, Turner41 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.