Alert archive / South Dakota / Tornado Warnings in 2011

Tornado Warning 17, NWS Aberdeen, SD

July 23, 2011McPherson County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Jul 23, 2011, 1:20 AM CDT for McPherson County, South Dakota. It was in force for 25 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: Jul 23, 2011, 1:20 AM CDT (06:20 UTC)
Expired: Jul 23, 2011, 1:45 AM CDT
In force: 25 min
Issued by: NWS Aberdeen, SD
Area: Storm-based polygon

County McPherson County, SD

The radar

The Aberdeen radar (KABR), 66 km from the middle of the area, began a volume at 06:23 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 watch it was issued in

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

Issued	Product	Office	Lasted
Jul 22, 5:35 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 6.3 hours before the alert went out and 119 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: 3084 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1182 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 377 m²/s²
Significant tornado parameter: 3.8
Supercell composite: 27.3

Open this sounding in Storm Lab

The text

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

749 
WFUS53 KABR 230620
TORABR
SDC089-230645-
/O.NEW.KABR.TO.W.0017.110723T0620Z-110723T0645Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ABERDEEN SD
120 AM CDT SAT JUL 23 2011

THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN MCPHERSON COUNTY IN NORTH CENTRAL SOUTH DAKOTA...

* UNTIL 145 AM CDT

* AT 118 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR LONG LAKE...OR 22 MILES EAST OF EUREKA...AND
  MOVING EAST AT 35 MPH.

* THIS TORNADIC STORM WILL BE NEAR...
  SPRING CREEK COLONY AROUND 140 AM CDT...
  LEOLA AROUND 145 AM CDT...

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 4594 9884 4594 9874 4567 9895 4586 9936
      4595 9930 4595 9885
TIME...MOT...LOC 0620Z 292DEG 30KT 4588 9918

$$
TDK

1 follow-up statement

826 
WWUS53 KABR 230645
SVSABR

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
145 AM CDT SAT JUL 23 2011

SDC089-230655-
/O.EXP.KABR.TO.W.0017.000000T0000Z-110723T0645Z/
MCPHERSON SD-
145 AM CDT SAT JUL 23 2011

...THE TORNADO WARNING FOR NORTHEASTERN MCPHERSON COUNTY HAS
EXPIRED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CDT SATURDAY MORNING
FOR NORTH CENTRAL SOUTH DAKOTA. A TORNADO WATCH ALSO REMAINS IN
EFFECT UNTIL 200 AM CDT SATURDAY MORNING FOR WEST CENTRAL MINNESOTA
AND NORTHEAST SOUTH DAKOTA.

LAT...LON 4594 9884 4594 9874 4567 9895 4586 9936
      4595 9930 4595 9885
TIME...MOT...LOC 0620Z 292DEG 30KT 4588 9918

$$
TDK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 7:35 PM CDT	Severe Thunderstorm Warning	ABR	Codington, Deuel, Grant	40 min
Jul 22, 10:50 PM CDT	Severe Thunderstorm Warning	ABR	Corson	55 min
Jul 22, 11:45 PM CDT	Severe Thunderstorm Warning	ABR	Corson	45 min
Jul 23, 12:10 AM CDT	Severe Thunderstorm Warning	ABR	Campbell, Corson, Edmunds, McPherson, Walworth	65 min
Jul 23, 12:48 AM CDT	Severe Thunderstorm Warning	ABR	Corson, Dewey, Edmunds, Faulk, Potter, Walworth	57 min
Jul 23, 1:06 AM CDT	Severe Thunderstorm Warning	ABR	Brown, Edmunds, Faulk, McPherson, Spink	54 min
Jul 23, 2:00 AM CDT	Severe Thunderstorm Warning	ABR	Brown, Day, Marshall	45 min
Jul 23, 2:42 AM CDT	Severe Thunderstorm Warning	ABR	Day, Marshall, Roberts	48 min
Jul 23, 3:36 PM CDT	River Flood Warning	ABR	Codington	23 hr

Nearby

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