Alert archive / Minnesota / Tornado Warnings in 2011

Tornado Warning 43, NWS Twin Cities, MN

July 30, 2011Isanti County, Minnesota

NWS Twin Cities, MN issued this tornado warning at Jul 30, 2011, 8:53 PM CDT for Isanti County, Minnesota. It was in force for 35 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 30, 2011, 8:53 PM CDT (01:53 UTC)
Expired: Jul 30, 2011, 9:28 PM CDT
In force: 35 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon

County Isanti County, MN

The radar

The Minneapolis radar (KMPX), 76 km from the middle of the area, began a volume at 01:54 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 30, 5:31 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 1.9 hours before the alert went out and 76 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: 2387 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 1239 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 176 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 8.4

Open this sounding in Storm Lab

The text

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

223 
WFUS53 KMPX 310153
TORMPX
MNC059-310245-
/O.NEW.KMPX.TO.W.0043.110731T0153Z-110731T0245Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
853 PM CDT SAT JUL 30 2011

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN ISANTI COUNTY IN EAST CENTRAL MINNESOTA...

* UNTIL 945 PM CDT

* AT 849 PM CDT...RADAR WAS TRACKING A SEVERE STORM WITH STRONG
  ROTATION. THE MOST DANGEROUS PART OF THE STORM WAS 14 MILES
  NORTHWEST OF ISANTI...OR ABOUT 2 MILES SOUTH OF DALBO...AND MOVING
  SOUTHEAST AT 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  BODUM...
  ISANTI...
  ATHENS...

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.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

&&

LAT...LON 4541 9308 4542 9347 4562 9349 4565 9335
TIME...MOT...LOC 0153Z 326DEG 19KT 4564 9340

$$

2 follow-up statements

211 
WWUS53 KMPX 310208
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
908 PM CDT SAT JUL 30 2011

MNC059-310245-
/O.CON.KMPX.TO.W.0043.000000T0000Z-110731T0245Z/
ISANTI MN-
908 PM CDT SAT JUL 30 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHERN ISANTI
COUNTY UNTIL 945 PM CDT...

AT 903 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS STORM
WAS LOCATED NEAR ISANTI...OR NEAR CAMBRIDGE...MOVING SOUTHEAST AT 30
MPH.

LOCATIONS IMPACTED INCLUDE...
  BODUM...ISANTI AND ATHENS.

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.

TORNADOES ARE DIFFICULT TO SEE AT NIGHT. TAKE COVER NOW.

&&

LAT...LON 4559 9328 4542 9309 4541 9317 4542 9338
      4557 9342
TIME...MOT...LOC 0208Z 327DEG 24KT 4551 9330

$$

138 
WWUS53 KMPX 310228
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
928 PM CDT SAT JUL 30 2011

MNC059-310243-
/O.CAN.KMPX.TO.W.0043.000000T0000Z-110731T0245Z/
ISANTI MN-
928 PM CDT SAT JUL 30 2011

...THE TORNADO WARNING FOR SOUTHERN ISANTI COUNTY IS
CANCELLED...

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR THE
AREA UNTIL 945 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS LOST SIGNS OF STRONGER
ROTATION... AND STRONG WINDS AND LARGE HAIL NOW APPEAR TO BE THE 
PRIMARY SEVERE WEATHER THREATS... ALONG WITH HEAVY DOWNPOURS AND
POSSIBLE LOCALIZED FLOODING.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1 AM CDT.

LAT...LON 4559 9328 4542 9309 4541 9317 4542 9338
      4557 9342
TIME...MOT...LOC 0228Z 327DEG 24KT 4540 9320

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 7:10 PM CDT	Tornado Warning	MPX	Todd	50 min
Jul 30, 7:15 PM CDT	Severe Thunderstorm Warning	MPX	Douglas	30 min
Jul 30, 7:28 PM CDT	Areal Flood Advisory	MPX	Todd	3 hr
Jul 30, 7:42 PM CDT	Severe Thunderstorm Warning	MPX	Todd	63 min
Jul 30, 7:45 PM CDT	Severe Thunderstorm Warning	MPX	Kanabec	45 min
Jul 30, 8:01 PM CDT	Severe Thunderstorm Warning	MPX	Kanabec, Mille Lacs	29 min
Jul 30, 8:15 PM CDT	Severe Thunderstorm Warning	MPX	Stearns	60 min
Jul 30, 8:18 PM CDT	Severe Thunderstorm Warning	MPX	Isanti, Kanabec, Mille Lacs	72 min
Jul 30, 8:22 PM CDT	Tornado Warning	MPX	Isanti, Kanabec, Mille Lacs	38 min
Jul 30, 8:50 PM CDT	Severe Thunderstorm Warning	MPX	Isanti	55 min
Jul 30, 8:56 PM CDT	Areal Flood Advisory	MPX	Anoka, Isanti, Kanabec, Mille Lacs, Sherburne	6 hr
Jul 30, 9:07 PM CDT	Severe Thunderstorm Warning	MPX	Kandiyohi, Meeker, Stearns	38 min
Jul 30, 9:20 PM CDT	Severe Thunderstorm Warning	MPX	Anoka	55 min
Jul 30, 9:48 PM CDT	Special Weather Statement	MPX	McLeod, Meeker	42 min
Jul 30, 9:50 PM CDT	Severe Thunderstorm Warning	MPX	Ramsey, Washington	55 min
Jul 30, 9:54 PM CDT	Areal Flood Advisory	MPX	Anoka, Dakota, Hennepin, Ramsey, Washington	6 hr
Jul 30, 10:21 PM CDT	Severe Thunderstorm Warning	MPX	Anoka	39 min
Jul 30, 11:20 PM CDT	Special Weather Statement	MPX	Le Sueur	40 min
Jul 30, 11:26 PM CDT	Severe Thunderstorm Warning	MPX	Le Sueur, Scott, Sibley	31 min
Jul 30, 11:32 PM CDT	Special Weather Statement	MPX	Goodhue	43 min
Jul 30, 11:55 PM CDT	Severe Thunderstorm Warning	MPX	Goodhue	35 min
Jul 31, 4:00 PM CDT	Heat Advisory	MPX	Anoka, Blue Earth, Brown, Carver, Chippewa, Dakota and 29 more	28 hr

Nearby

Tornado Warnings in Minnesota, 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.