Alert archive / Minnesota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 227, NWS Twin Cities, MN

August 2, 20114 counties in Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 2, 2011, 8:05 AM CDT for 4 counties in Minnesota. It was in force for 55 min. 1 report 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
Aug 2, 2011, 8:05 AM CDT (13:05 UTC)
Expired
Aug 2, 2011, 9:00 AM CDT
In force
55 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

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

The radar

The Minneapolis radar (KMPX), 103 km from the middle of the area, began a volume at 13:06 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
Aug 2, 8:30 AM CDTTSTM WND DMGN Glendorado, MNA FEW 6-10 INCH DIAMETER TREES DOWN

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
Aug 2, 5:23 AM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 1.1 hours before the alert went out and 103 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 2011-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2133 joules per kilogram.LCLLFCEL10008507005003002001001 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 2011-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 233 square meters per square second.193958Sfc1 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
2133 J/kg
Mixed-layer CIN
-209 J/kg
Mixed-layer LCL
850 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
233 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

441 
WUUS53 KMPX 021305
SVRMPX
MNC009-059-065-095-021400-
/O.NEW.KMPX.SV.W.0227.110802T1305Z-110802T1400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
805 AM CDT TUE AUG 2 2011

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN BENTON COUNTY IN CENTRAL MINNESOTA...
  NORTHERN ISANTI COUNTY IN EAST CENTRAL MINNESOTA...
  SOUTHERN KANABEC COUNTY IN EAST CENTRAL MINNESOTA...
  SOUTHERN MILLE LACS COUNTY IN EAST CENTRAL MINNESOTA...

* UNTIL 900 AM CDT

* AT 801 AM CDT...RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS...
  CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THESE
  STORMS WERE LOCATED ALONG A LINE EXTENDING FROM LITTLE ROCK TO 6
  MILES SOUTH OF PARENT...AND MOVING EAST AT 45 MPH.

LOCATIONS IN THE WARNING INCLUDE...
  PRINCETON...
  MILACA...
  MORA...
  RONNEBY...
  GLENDORADO...
  FORESTON...
  PEASE...
  DALBO...
  OGILVIE...
  LEWIS LAKE...
  GRANDY...
  STANCHFIELD...
  BRAHAM...
  GRASSTON...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR
DAMAGING WINDS IN EXCESS OF 60 MPH. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.

WIND DAMAGE WITH THIS STORM WILL OCCUR WELL AHEAD OF ANY RAIN OR
LIGHTNING. DO NOT WAIT FOR THE SOUND OF THUNDER BEFORE TAKING COVER.
SEEK SHELTER IMMEDIATELY INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS.

&&

LAT...LON 4590 9314 4557 9314 4557 9388 4582 9395
      4582 9377 4584 9376
TIME...MOT...LOC 1306Z 266DEG 40KT 4580 9408 4555 9393
WIND...HAIL 60MPH <.75IN

$$
1 follow-up statement
973 
WWUS53 KMPX 021350
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
850 AM CDT TUE AUG 2 2011

MNC009-065-095-021405-
/O.CAN.KMPX.SV.W.0227.000000T0000Z-110802T1400Z/
BENTON MN-KANABEC MN-MILLE LACS MN-
850 AM CDT TUE AUG 2 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN MILLE LACS...SOUTHERN
KANABEC AND EASTERN BENTON COUNTIES IS CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED AND 
MOVED OUT OF THE WARNED AREA.

LAT...LON 4573 9348 4573 9315 4572 9314 4557 9314
      4557 9351 4573 9351 4574 9349
TIME...MOT...LOC 1350Z 266DEG 40KT 4568 9342 4558 9323

$$

MNC059-021400-
/O.CON.KMPX.SV.W.0227.000000T0000Z-110802T1400Z/
ISANTI MN-
850 AM CDT TUE AUG 2 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN
ISANTI COUNTY UNTIL 900 AM CDT...

AT 847 AM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF
60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM DALBO
TO CAMBRIDGE...MOVING EAST AT 45 MPH.

LOCATIONS IMPACTED INCLUDE...
  GRANDY...STANCHFIELD AND BRAHAM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...LARGE HAIL...AND DEADLY LIGHTNING. FOR YOUR PROTECTION MOVE TO
AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS.

&&

LAT...LON 4573 9348 4573 9315 4572 9314 4557 9314
      4557 9351 4573 9351 4574 9349
TIME...MOT...LOC 1350Z 266DEG 40KT 4568 9342 4558 9323
WIND...HAIL 60MPH <.75IN

$$

RAH

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 12:00 AM CDTRiver Flood WarningMPXTodd57 hr
Aug 2, 5:26 AM CDTSevere Thunderstorm WarningMPXChippewa, Lac qui Parle, Swift, Yellow Medicine64 min
Aug 2, 6:06 AM CDTSpecial Weather StatementMPXPope, Stevens54 min
Aug 2, 6:41 AM CDTSevere Thunderstorm WarningMPXKandiyohi, Pope, Stearns, Swift51 min
Aug 2, 6:56 AM CDTSevere Thunderstorm WarningMPXChippewa, Kandiyohi, Meeker, Swift64 min
Aug 2, 7:23 AM CDTSevere Thunderstorm WarningMPXMeeker, Sherburne, Stearns, Wright67 min
Aug 2, 7:24 AM CDTSpecial Weather StatementMPXBenton, Carver, Isanti, McLeod, Sherburne, Sibley and 1 more36 min
Aug 2, 7:39 AM CDTSevere Thunderstorm WarningMPXBenton, Stearns51 min
Aug 2, 7:57 AM CDTSevere Thunderstorm WarningMPXAnoka, Hennepin, Isanti, Ramsey, Sherburne, Wright48 min
Aug 2, 8:31 AM CDTSevere Thunderstorm WarningMPXAnoka, Chisago, Isanti, Washington74 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2011Every severe thunderstorm warning 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.