Alert archive / Minnesota / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 7, NWS Twin Cities, MN

April 21, 2012Brown County, Redwood County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Apr 21, 2012, 3:22 PM CDT for Brown County, Redwood County, Minnesota. It was in force for 38 min. 2 reports 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, 3:22 PM CDT (20:22 UTC)
Expired: Apr 21, 2012, 4:00 PM CDT
In force: 38 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Brown County, MN, Redwood County, MN

The radar

The Sioux Falls radar (KFSD), 141 km from the middle of the area, began a volume at 20:25 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

Time	Report	Where	Remark
Apr 21, 3:23 PM CDT	TORNADO	6 Nne Walnut Grove, MN	MULTIPLE REPORTS OF FUNNELS WITH BRIEF TOUCHDOWNS OVER 10-15 MINUTES...TIME IS ESTIMATED AS IS LOCATION.
Apr 21, 3:45 PM CDT	TORNADO	7 S Lucan, MN	TIME 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, 8.4 hours before the alert went out and 145 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: 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.

721 
WUUS53 KMPX 212022
SVRMPX
MNC015-127-212100-
/O.NEW.KMPX.SV.W.0007.120421T2022Z-120421T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
322 PM CDT SAT APR 21 2012

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN BROWN COUNTY IN SOUTH CENTRAL MINNESOTA...
  SOUTHERN REDWOOD COUNTY IN SOUTHWEST MINNESOTA...

* UNTIL 400 PM CDT

* AT 318 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM...CAPABLE OF
  PRODUCING QUARTER SIZE HAIL. THIS STORM WAS LOCATED 6 MILES SOUTH
  OF LUCAN...OR ABOUT 21 MILES SOUTHWEST OF REDWOOD FALLS...AND
  MOVING SOUTHEAST AT 25 MPH.

LOCATIONS IN THE WARNING INCLUDE...
  REVERE...
  LAMBERTON...
  SANBORN...
  SPRINGFIELD...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR LARGE
HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS.

REPORT ANY SIGNIFICANT WIND OR HAIL DAMAGE TO THE NEAREST LAW
ENFORCEMENT AGENCY...FOR RELAY TO THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 4411 9511 4419 9512 4418 9536 4424 9556
      4441 9538 4428 9499 4411 9495 4411 9508
TIME...MOT...LOC 2022Z 304DEG 22KT 4431 9538
WIND...HAIL <50MPH 1.00IN

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 21, 1:50 PM CDT	Special Weather Statement	MPX	Stevens	55 min
Apr 21, 2:04 PM CDT	Severe Thunderstorm Warning	MPX	Stevens	14 min
Apr 21, 2:28 PM CDT	Special Weather Statement	MPX	Chippewa, Douglas, Pope, Redwood, Swift	62 min
Apr 21, 3:29 PM CDT	Tornado Warning	MPX	Chippewa, Swift	46 min
Apr 21, 3:33 PM CDT	Tornado Warning	MPX	Redwood	28 min
Apr 21, 4:09 PM CDT	Tornado Warning	MPX	Chippewa, Kandiyohi, Renville	36 min
Apr 21, 4:21 PM CDT	Special Weather Statement	MPX	Pope	39 min
Apr 21, 4:49 PM CDT	Special Weather Statement	MPX	Renville	41 min
Apr 21, 5:01 PM CDT	Tornado Warning	MPX	Martin, Watonwan	44 min
Apr 21, 5:53 PM CDT	Special Weather Statement	MPX	Martin	37 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2012 Every severe thunderstorm warning 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.