Alert archive / Minnesota / Tornado Warnings in 2012

Tornado Warning 8, NWS Twin Cities, MN

April 21, 2012Redwood County, Minnesota

NWS Twin Cities, MN issued this tornado warning at Apr 21, 2012, 3:33 PM CDT for Redwood County, Minnesota. It was in force for 28 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, 2012, 3:33 PM CDT (20:33 UTC)
Expired
Apr 21, 2012, 4:01 PM CDT
In force
28 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

County Redwood County, MN

The radar

The Sioux Falls radar (KFSD), 138 km from the middle of the area, began a volume at 20:34 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
Apr 21, 3:45 PM CDTTORNADO7 S Lucan, MNTIME ESTIMATED BETWEEN 330 AND 400 PM CDT. DAMAGE TO A FLOWER SHOP.

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.6 hours before the alert went out and 149 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, Minneapolis, MN at 12:00Z on 2012-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Minneapolis, MN at 12:00Z on 2012-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1566 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
85 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.

121 
WFUS53 KMPX 212033
TORMPX
MNC127-212115-
/O.NEW.KMPX.TO.W.0008.120421T2033Z-120421T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
333 PM CDT SAT APR 21 2012

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL REDWOOD COUNTY IN SOUTHWEST MINNESOTA...

* UNTIL 415 PM CDT

* AT 332 PM CDT...RADAR INDICATED A STORM CAPABLE OF PRODUCING A
  TORNADO. THE MOST DANGEROUS PART OF THE STORM WAS 5 MILES NORTH OF
  REVERE...AND MOVING SOUTHEAST AT 25 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  REVERE...
  LAMBERTON...
  SANBORN...
  WALNUT GROVE...
  WANDA...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON RADAR...IT MEANS THAT
STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY ALREADY
BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY.

&&

LAT...LON 4437 9534 4429 9510 4419 9512 4418 9536
      4423 9551
TIME...MOT...LOC 2033Z 302DEG 23KT 4428 9536

$$
2 follow-up statements
397 
WWUS53 KMPX 212050
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
350 PM CDT SAT APR 21 2012

MNC127-212115-
/O.CON.KMPX.TO.W.0008.000000T0000Z-120421T2115Z/
REDWOOD MN-
350 PM CDT SAT APR 21 2012

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL REDWOOD
COUNTY UNTIL 415 PM CDT...

AT 346 PM CDT...LOCAL LAW ENFORCEMENT REPORTED SEVERAL FUNNEL CLOUDS
LIFTING UP AND DOWN OVER SOUTHERN REDWOOD COUNTY. THE STORM 
PRODUCING THE FUNNEL CLOUDS WAS LOCATED NEAR LAMBERTON...OR 23 MILES 
SOUTH OF REDWOOD FALLS...MOVING SOUTHEAST AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
  SANBORN.
  LAMBERTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

YOU SHOULD 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 4420 9539 4432 9520 4429 9510 4419 9512
      4418 9536
TIME...MOT...LOC 2048Z 302DEG 23KT 4422 9525

$$
670 
WWUS53 KMPX 212101
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
401 PM CDT SAT APR 21 2012

MNC127-212116-
/O.CAN.KMPX.TO.W.0008.000000T0000Z-120421T2115Z/
REDWOOD MN-
401 PM CDT SAT APR 21 2012

...THE TORNADO WARNING FOR SOUTH CENTRAL REDWOOD COUNTY IS
CANCELLED...

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

LAT...LON 4420 9539 4432 9520 4429 9510 4419 9512
      4418 9536
TIME...MOT...LOC 2101Z 302DEG 23KT 4417 9516

$$

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 1:50 PM CDTSpecial Weather StatementMPXStevens55 min
Apr 21, 2:04 PM CDTSevere Thunderstorm WarningMPXStevens14 min
Apr 21, 2:28 PM CDTSpecial Weather StatementMPXChippewa, Douglas, Pope, Redwood, Swift62 min
Apr 21, 3:22 PM CDTSevere Thunderstorm WarningMPXBrown, Redwood38 min
Apr 21, 3:29 PM CDTTornado WarningMPXChippewa, Swift46 min
Apr 21, 4:09 PM CDTTornado WarningMPXChippewa, Kandiyohi, Renville36 min
Apr 21, 4:21 PM CDTSpecial Weather StatementMPXPope39 min
Apr 21, 4:49 PM CDTSpecial Weather StatementMPXRenville41 min
Apr 21, 5:01 PM CDTTornado WarningMPXMartin, Watonwan44 min
Apr 21, 5:53 PM CDTSpecial Weather StatementMPXMartin37 min

Nearby

Tornado Warnings in Minnesota, 2012Every tornado warning in 2012Tornadoes in 2012

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.