Alert archive / Minnesota / Tornado Warnings in 2012

Tornado Warning 23, NWS Twin Cities, MN

May 4, 2012Martin County, Minnesota

NWS Twin Cities, MN issued this tornado warning at May 4, 2012, 3:40 PM CDT for Martin County, Minnesota. It was in force for 50 min. 3 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: May 4, 2012, 3:40 PM CDT (20:40 UTC)
Expired: May 4, 2012, 4:30 PM CDT
In force: 50 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon

County Martin County, MN

The radar

The Minneapolis radar (KMPX), 160 km from the middle of the area, began a volume at 20:40 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
May 4, 3:45 PM CDT	TORNADO	3 N Sherburn, MN
May 4, 3:52 PM CDT	HAIL 1	6 W Sherburn, MN
May 4, 3:57 PM CDT	HAIL 1	2 Sw Sherburn, MN

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

The watch it was issued in

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

Issued	Product	Office	Lasted
May 4, 2:00 PM CDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.7 hours before the alert went out and 158 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: 1101 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: -52 m²/s²
0-3 km storm-relative helicity: 15 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.

068 
WFUS53 KMPX 042040
TORMPX
MNC091-042130-
/O.NEW.KMPX.TO.W.0023.120504T2040Z-120504T2130Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
340 PM CDT FRI MAY 4 2012

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN MARTIN COUNTY IN SOUTH CENTRAL MINNESOTA...

* UNTIL 430 PM CDT

* AT 335 PM CDT...RADAR INDICATED A STORM CAPABLE OF PRODUCING A
  TORNADO. THE MOST DANGEROUS PART OF THE STORM WAS 5 MILES SOUTHWEST
  OF DUNNELL...AND MOVING NORTHEAST AT 30 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  DUNNELL...
  CEYLON...
  SHERBURN...
  WELCOME...
  WILBERT...
  FOXLAKE...

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.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
STURDY SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE NEAREST
DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&&

LAT...LON 4379 9456 4351 9445 4351 9460 4352 9485
      4371 9486
TIME...MOT...LOC 2040Z 240DEG 24KT 4354 9481

$$

BAP

2 follow-up statements

597 
WWUS53 KMPX 042050
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
350 PM CDT FRI MAY 4 2012

MNC091-042130-
/O.CON.KMPX.TO.W.0023.000000T0000Z-120504T2130Z/
MARTIN MN-
350 PM CDT FRI MAY 4 2012

...A TORNADO WARNING REMAINS IN EFFECT FOR WESTERN MARTIN COUNTY
UNTIL 430 PM CDT...

AT 344 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO.  THIS
TORNADO WAS LOCATED 3 MILES NORTH OF SHERBURN AND WAS MOVING 
NORTHEAST AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
  SHERBURN...WELCOME...AND FOXLAKE.

LAT...LON 4379 9456 4351 9445 4351 9460 4352 9485
      4371 9486
TIME...MOT...LOC 2047Z 240DEG 24KT 4359 9479

$$

137 
WWUS53 KMPX 042057
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
357 PM CDT FRI MAY 4 2012

MNC091-042130-
/O.CON.KMPX.TO.W.0023.000000T0000Z-120504T2130Z/
MARTIN MN-
357 PM CDT FRI MAY 4 2012

...A TORNADO WARNING REMAINS IN EFFECT FOR WESTERN MARTIN COUNTY
UNTIL 430 PM CDT...

AT 353 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS STORM
WAS LOCATED NEAR DUNNELL...OR 15 MILES SOUTHWEST OF FAIRMONT...MOVING
NORTHEAST AT 30 MPH.

LOCATIONS IMPACTED INCLUDE...
  CEYLON...SHERBURN...WELCOME...WILBERT AND FOXLAKE.

LAT...LON 4379 9456 4351 9445 4351 9460 4352 9485
      4371 9486
TIME...MOT...LOC 2057Z 240DEG 24KT 4354 9468

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 7:00 PM CDT	Special Weather Statement	MPX	Goodhue	30 min
May 4, 2:07 PM CDT	Special Weather Statement	MPX	Redwood	38 min
May 4, 2:33 PM CDT	Special Weather Statement	MPX	Blue Earth, Martin, Watonwan	57 min
May 4, 3:10 PM CDT	Tornado Warning	MPX	Martin	35 min
May 4, 4:07 PM CDT	Special Weather Statement	MPX	Blue Earth, Waseca, Watonwan	38 min
May 4, 4:22 PM CDT	Severe Thunderstorm Warning	MPX	Faribault, Martin	38 min
May 4, 4:32 PM CDT	Severe Thunderstorm Warning	MPX	Martin	13 min
May 4, 5:00 PM CDT	Special Weather Statement	MPX	Faribault	45 min
May 4, 5:41 PM CDT	Severe Thunderstorm Warning	MPX	Faribault, Freeborn	49 min
May 4, 5:52 PM CDT	Tornado Warning	MPX	Faribault, Freeborn	23 min
May 4, 6:15 PM CDT	Severe Thunderstorm Warning	MPX	Freeborn	45 min
May 4, 6:21 PM CDT	Tornado Warning	MPX	Freeborn	24 min
May 4, 6:24 PM CDT	Areal Flood Advisory	MPX	Blue Earth, Faribault, Martin, Watonwan	3 hr

Nearby

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