Alert archive / Minnesota / Tornado Warnings in 2012

Tornado Warning 9, NWS Twin Cities, MN

April 21, 2012Chippewa County, Kandiyohi County, Renville County, Minnesota

NWS Twin Cities, MN issued this tornado warning at Apr 21, 2012, 4:09 PM CDT for Chippewa County, Kandiyohi County, Renville County, Minnesota. It was in force for 36 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
Apr 21, 2012, 4:09 PM CDT (21:09 UTC)
Expired
Apr 21, 2012, 4:45 PM CDT
In force
36 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

Counties Chippewa County, MN, Kandiyohi County, MN, Renville County, MN

The radar

The Minneapolis radar (KMPX), 135 km from the middle of the area, began a volume at 21:11 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

Minneapolis, MN (KMPX), launched 12:00Z, 9.2 hours before the alert went out and 132 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.

093 
WFUS53 KMPX 212109
TORMPX
MNC023-067-129-212145-
/O.NEW.KMPX.TO.W.0009.120421T2109Z-120421T2145Z/

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

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  EAST CENTRAL CHIPPEWA COUNTY IN WEST CENTRAL MINNESOTA...
  SOUTHWESTERN KANDIYOHI COUNTY IN CENTRAL MINNESOTA...
  NORTHWESTERN RENVILLE COUNTY IN CENTRAL MINNESOTA...

* UNTIL 445 PM CDT

* AT 404 PM CDT...RADAR INDICATED A STORM CAPABLE OF PRODUCING A
  TORNADO. THE MOST DANGEROUS PART OF THE STORM WAS NEAR CLARA       
  CITY...OR OVER CLARA CITY...AND MOVING SOUTHEAST AT 25 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  CLARA CITY...
  PRINSBURG...

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 4493 9512 4484 9527 4496 9547 4501 9539
TIME...MOT...LOC 2108Z 301DEG 23KT 4495 9535

$$

CLF
1 follow-up statement
869 
WWUS53 KMPX 212137
SVSMPX

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

MNC023-067-129-212145-
/O.CON.KMPX.TO.W.0009.000000T0000Z-120421T2145Z/
CHIPPEWA MN-KANDIYOHI MN-RENVILLE MN-
437 PM CDT SAT APR 21 2012

...A TORNADO WARNING REMAINS IN EFFECT FOR EXTREME NORTHWESTERN
RENVILLE AND SOUTHWESTERN KANDIYOHI COUNTIES IN CENTRAL MINNESOTA...
AND SOUTHEASTERN CHIPPEWA COUNTY IN WEST CENTRAL MINNESOTA UNTIL 445
PM CDT...

AT 435 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE 
THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS STORM 
WAS LOCATED NEAR PRINSBURG...OR 15 MILES NORTHWEST OF OLIVIA...MOVING
SOUTHEAST AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF EXTREME NORTHWESTERN RENVILLE COUNTY.

LAT...LON 4498 9529 4493 9512 4484 9527 4491 9539
TIME...MOT...LOC 2137Z 310DEG 22KT 4487 9524

$$

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, 3:33 PM CDTTornado WarningMPXRedwood28 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.