Alert archive / Minnesota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 237, NWS Twin Cities, MN

August 6, 20114 counties in Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 6, 2011, 9:45 PM CDT for 4 counties in Minnesota. It was in force for 45 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 6, 2011, 9:45 PM CDT (02:45 UTC)
Expired
Aug 6, 2011, 10:30 PM CDT
In force
45 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Dakota County, MN, Le Sueur County, MN, Rice County, MN, Scott County, MN

The radar

The Minneapolis radar (KMPX), 41 km from the middle of the area, began a volume at 02:45 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 6, 10:05 PM CDTHAIL 0.88New Market, MN

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 00:00Z, 2.8 hours before the alert went out and 42 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 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 931 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 00:00Z on 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
931 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
1415 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

926 
WUUS53 KMPX 070245
SVRMPX
MNC037-079-131-139-070330-
/O.NEW.KMPX.SV.W.0237.110807T0245Z-110807T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
945 PM CDT SAT AUG 6 2011

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN DAKOTA COUNTY IN EAST CENTRAL MINNESOTA...
  NORTHEASTERN LE SUEUR COUNTY IN SOUTH CENTRAL MINNESOTA...
  NORTHERN RICE COUNTY IN SOUTH CENTRAL MINNESOTA...
  SOUTHEASTERN SCOTT COUNTY IN EAST CENTRAL MINNESOTA...

* UNTIL 1030 PM CDT

* AT 940 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM...CAPABLE OF
  PRODUCING QUARTER SIZE HAIL. THIS STORM WAS LOCATED NEAR NEW
  PRAGUE...OR ABOUT 20 MILES NORTHEAST OF LE SUEUR...AND MOVING
  SOUTHEAST AT 35 MPH.

LOCATIONS IN THE WARNING INCLUDE...
  NEW PRAGUE...
  VESELI...
  NEW MARKET...
  LONSDALE...
  ELKO...
  WEBSTER...
  DUNDAS...
  NORTHFIELD...

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.

&&

LAT...LON 4456 9368 4471 9354 4448 9303 4446 9304
      4429 9320
TIME...MOT...LOC 0245Z 305DEG 29KT 4458 9349
WIND...HAIL <50MPH 1.00IN

$$
1 follow-up statement
351 
WWUS53 KMPX 070311
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1011 PM CDT SAT AUG 6 2011

MNC079-070326-
/O.CAN.KMPX.SV.W.0237.000000T0000Z-110807T0330Z/
LE SUEUR MN-
1011 PM CDT SAT AUG 6 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LE SUEUR COUNTY
IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 4449 9342 4461 9332 4448 9303 4446 9304
      4433 9316
TIME...MOT...LOC 0311Z 288DEG 26KT 4453 9324

$$

MNC037-131-139-070330-
/O.CON.KMPX.SV.W.0237.000000T0000Z-110807T0330Z/
DAKOTA MN-RICE MN-SCOTT MN-
1011 PM CDT SAT AUG 6 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
SCOTT...NORTHEASTERN RICE AND SOUTHWESTERN DAKOTA COUNTIES UNTIL 1030
PM CDT...

AT 1008 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS STORM WAS
LOCATED NEAR ELKO...OR 17 MILES NORTH OF FARIBAULT...MOVING EAST AT
30 MPH.

LOCATIONS IMPACTED INCLUDE...
  DUNDAS...NORTHFIELD AND BRIDGEWATER.

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 4449 9342 4461 9332 4448 9303 4446 9304
      4433 9316
TIME...MOT...LOC 0311Z 288DEG 26KT 4453 9324
WIND...HAIL <50MPH 1.00IN

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 7:12 PM CDTSevere Thunderstorm WarningMPXMeeker, Stearns, Wright33 min
Aug 6, 7:16 PM CDTSpecial Weather StatementMPXMeeker44 min
Aug 6, 8:13 PM CDTSpecial Weather StatementMPXMcLeod47 min
Aug 6, 8:17 PM CDTSevere Thunderstorm WarningMPXMcLeod, Meeker, Wright43 min
Aug 6, 8:46 PM CDTSevere Thunderstorm WarningMPXCarver, McLeod, Sibley44 min
Aug 6, 10:32 PM CDTSpecial Weather StatementMPXSteele43 min
Aug 7, 7:27 AM CDTRiver Flood WarningMPXTodd5 days

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.