Alert archive / Minnesota / Tornado Warnings in 2011

Tornado Warning 42, NWS Twin Cities, MN

July 30, 2011Isanti County, Kanabec County, Mille Lacs County, Minnesota

NWS Twin Cities, MN issued this tornado warning at Jul 30, 2011, 8:22 PM CDT for Isanti County, Kanabec County, Mille Lacs County, Minnesota. It was in force for 38 min. 4 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
Jul 30, 2011, 8:22 PM CDT (01:22 UTC)
Expired
Jul 30, 2011, 9:00 PM CDT
In force
38 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

Counties Isanti County, MN, Kanabec County, MN, Mille Lacs County, MN

The radar

The Minneapolis radar (KMPX), 95 km from the middle of the area, began a volume at 01:22 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
Jul 30, 8:26 PM CDTTSTM WND DMGBock, MNNUMEROUS TREES DOWN. SOME TREES EXCEED ONE FOOT IN DIAMETER.
Jul 30, 8:26 PM CDTTORNADO6 Nw Dalbo, MNNWS STORM DAMAGE SURVEY TEAM CONFIRMS EF-0 TORNADO. THE TORNADO TOUCHED DOWN IN MILLE LACS COUNTY...ABOUT 6 MILES NORTHWEST OF DALBO...JUST NORTH OF COUNTY ROAD 10. IT THEN PROGRESSED SOUTHEAST INTO ISANTI COUNTY...CROSSING COUNTY ROAD 16 BEFORE TURNING SOUTH
Jul 30, 8:42 PM CDTTSTM WND DMG1 Wnw Dalbo, MNHUNDREDS OF TREES DOWN AROUND THE TOWN.
Jul 30, 8:42 PM CDTHAIL 1.254 Se Bock, 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.

IssuedProductOfficeLasted
Jul 30, 5:31 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 1.4 hours before the alert went out and 95 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 00:00Z on 2011-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2387 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2011-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
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.

400 
WFUS53 KMPX 310122
TORMPX
MNC059-065-095-310200-
/O.NEW.KMPX.TO.W.0042.110731T0122Z-110731T0200Z/

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

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN ISANTI COUNTY IN EAST CENTRAL MINNESOTA...
  SOUTHWESTERN KANABEC COUNTY IN EAST CENTRAL MINNESOTA...
  SOUTH CENTRAL MILLE LACS COUNTY IN EAST CENTRAL MINNESOTA...

* UNTIL 900 PM CDT

* AT 817 PM CDT...RADAR INDICATED A STORM CAPABLE OF PRODUCING A
  TORNADO. THE MOST DANGEROUS PART OF THE STORM WAS NEAR BOCK...OR
  ABOUT 7 MILES NORTHEAST OF PEASE...AND MOVING SOUTHEAST AT 25 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  MILACA...
  LEWIS LAKE...
  DALBO...
  BOCK...

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 4575 9328 4558 9329 4559 9342 4562 9351
      4577 9366 4584 9357
TIME...MOT...LOC 0122Z 314DEG 21KT 4576 9355

$$
1 follow-up statement
926 
WWUS53 KMPX 310144
SVSMPX

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

MNC065-095-310158-
/O.CAN.KMPX.TO.W.0042.000000T0000Z-110731T0200Z/
KANABEC MN-MILLE LACS MN-
844 PM CDT SAT JUL 30 2011

...THE TORNADO WARNING FOR SOUTH CENTRAL MILLE LACS AND SOUTHWESTERN
KANABEC COUNTIES IS CANCELLED...

THE CIRCULATION WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE
WARNED AREA... BUT A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT
DUE TO THE POTENTIAL FOR DAMAGING WINDS AND LARGE HAIL.

LAT...LON 4573 9348 4573 9328 4558 9329 4559 9342
      4562 9351 4563 9352 4573 9351 4574 9349
TIME...MOT...LOC 0143Z 328DEG 17KT 4568 9347

$$

MNC059-310200-
/O.CON.KMPX.TO.W.0042.000000T0000Z-110731T0200Z/
ISANTI MN-
844 PM CDT SAT JUL 30 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHWESTERN ISANTI COUNTY
UNTIL 900 PM CDT...

AT 840 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS STORM
WAS LOCATED NEAR DALBO...OR 10 MILES SOUTHEAST OF MILACA...MOVING
SOUTHEAST AT 20 MPH.

LOCATIONS IMPACTED INCLUDE...
  DALBO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4573 9348 4573 9328 4558 9329 4559 9342
      4562 9351 4563 9352 4573 9351 4574 9349
TIME...MOT...LOC 0143Z 328DEG 17KT 4568 9347

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 7:10 PM CDTTornado WarningMPXTodd50 min
Jul 30, 7:15 PM CDTSevere Thunderstorm WarningMPXDouglas30 min
Jul 30, 7:28 PM CDTAreal Flood AdvisoryMPXTodd3 hr
Jul 30, 7:42 PM CDTSevere Thunderstorm WarningMPXTodd63 min
Jul 30, 7:45 PM CDTSevere Thunderstorm WarningMPXKanabec45 min
Jul 30, 8:01 PM CDTSevere Thunderstorm WarningMPXKanabec, Mille Lacs29 min
Jul 30, 8:15 PM CDTSevere Thunderstorm WarningMPXStearns60 min
Jul 30, 8:18 PM CDTSevere Thunderstorm WarningMPXIsanti, Kanabec, Mille Lacs72 min
Jul 30, 8:50 PM CDTSevere Thunderstorm WarningMPXIsanti55 min
Jul 30, 8:53 PM CDTTornado WarningMPXIsanti35 min
Jul 30, 8:56 PM CDTAreal Flood AdvisoryMPXAnoka, Isanti, Kanabec, Mille Lacs, Sherburne6 hr
Jul 30, 9:07 PM CDTSevere Thunderstorm WarningMPXKandiyohi, Meeker, Stearns38 min
Jul 30, 9:20 PM CDTSevere Thunderstorm WarningMPXAnoka55 min
Jul 30, 9:48 PM CDTSpecial Weather StatementMPXMcLeod, Meeker42 min
Jul 30, 9:50 PM CDTSevere Thunderstorm WarningMPXRamsey, Washington55 min
Jul 30, 9:54 PM CDTAreal Flood AdvisoryMPXAnoka, Dakota, Hennepin, Ramsey, Washington6 hr
Jul 30, 10:21 PM CDTSevere Thunderstorm WarningMPXAnoka39 min
Jul 30, 11:20 PM CDTSpecial Weather StatementMPXLe Sueur40 min
Jul 30, 11:26 PM CDTSevere Thunderstorm WarningMPXLe Sueur, Scott, Sibley31 min
Jul 30, 11:32 PM CDTSpecial Weather StatementMPXGoodhue43 min
Jul 30, 11:55 PM CDTSevere Thunderstorm WarningMPXGoodhue35 min
Jul 31, 4:00 PM CDTHeat AdvisoryMPXAnoka, Blue Earth, Brown, Carver, Chippewa, Dakota and 29 more28 hr

Nearby

Tornado Warnings in Minnesota, 2011Every tornado warning in 2011Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.