Alert archive / Minnesota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 35, NWS Twin Cities, MN

May 21, 2011Chippewa County, Pope County, Swift County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at May 21, 2011, 5:25 PM CDT for Chippewa County, Pope County, Swift County, Minnesota. It was in force for 50 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
May 21, 2011, 5:25 PM CDT (22:25 UTC)
Expired
May 21, 2011, 6:15 PM CDT
In force
50 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Chippewa County, MN, Pope County, MN, Swift County, MN

The radar

The Minneapolis radar (KMPX), 168 km from the middle of the area, began a volume at 22:27 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
May 21, 5:41 PM CDTHAIL 0.885 S Benson, 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 12:00Z, 10.4 hours before the alert went out and 165 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 2011-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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 2011-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 206 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
2 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
474 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
206 m²/s²
0-3 km storm-relative helicity
240 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.

198 
WUUS53 KMPX 212225
SVRMPX
MNC023-121-151-212315-
/O.NEW.KMPX.SV.W.0035.110521T2225Z-110521T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
525 PM CDT SAT MAY 21 2011

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL CHIPPEWA COUNTY IN WEST CENTRAL MINNESOTA...
  SOUTHWESTERN POPE COUNTY IN WEST CENTRAL MINNESOTA...
  CENTRAL SWIFT COUNTY IN WEST CENTRAL MINNESOTA...

* UNTIL 615 PM CDT

* AT 522 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM...CAPABLE OF
  PRODUCING QUARTER SIZE HAIL. THIS STORM WAS LOCATED 10 MILES
  SOUTHWEST OF DE GRAFF...OR ABOUT 13 MILES SOUTH OF BENSON...AND
  MOVING NORTH AT 30 MPH.

LOCATIONS IN THE WARNING INCLUDE...
  BENSON...
  DE GRAFF...
  CLONTARF...

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 4549 9573 4549 9538 4506 9542 4506 9571
TIME...MOT...LOC 2225Z 178DEG 27KT 4515 9555
WIND...HAIL <50MPH 1.00IN

$$
2 follow-up statements
835 
WWUS53 KMPX 212257
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
557 PM CDT SAT MAY 21 2011

MNC023-121-151-212315-
/O.CON.KMPX.SV.W.0035.000000T0000Z-110521T2315Z/
POPE MN-SWIFT MN-CHIPPEWA MN-
557 PM CDT SAT MAY 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTH CENTRAL
CHIPPEWA...CENTRAL SWIFT AND SOUTHWESTERN POPE COUNTIES IN WEST
CENTRAL MINNESOTA UNTIL 615 PM CDT...

AT 554 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM NEAR
BENSON...MOVING NORTH AT 30 MPH. THIS STORM IS CAPABLE OF PRODUCING
QUARTER SIZE HAIL. 

LOCATIONS IMPACTED INCLUDE...
  CLONTARF AND SWIFT FALLS.

AT 555 PM...NICKEL SIZE HAIL WAS REPORTED WITH THIS STORM IN BENSON. 

LAT...LON 4549 9573 4549 9538 4506 9542 4506 9571
TIME...MOT...LOC 2256Z 178DEG 27KT 4537 9563
WIND...HAIL <50MPH 0.88IN

$$
057 
WWUS53 KMPX 212305
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
605 PM CDT SAT MAY 21 2011

MNC023-212320-
/O.CAN.KMPX.SV.W.0035.000000T0000Z-110521T2315Z/
CHIPPEWA MN-
605 PM CDT SAT MAY 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL CHIPPEWA COUNTY
IN WEST CENTRAL MINNESOTA IS CANCELLED...

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

LAT...LON 4549 9573 4549 9538 4516 9541 4516 9571
TIME...MOT...LOC 2305Z 178DEG 27KT 4542 9565

$$

MNC121-151-212315-
/O.CON.KMPX.SV.W.0035.000000T0000Z-110521T2315Z/
POPE MN-SWIFT MN-
605 PM CDT SAT MAY 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CENTRAL SWIFT
AND SOUTHWESTERN POPE COUNTIES UNTIL 615 PM CDT...

AT 603 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS STORM WAS
LOCATED NEAR CLONTARF...OR 6 MILES NORTH OF BENSON...MOVING NORTH AT
30 MPH.

LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF SOUTHWESTERN POPE COUNTY.

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.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN THE TWIN CITIES.

&&

LAT...LON 4549 9573 4549 9538 4516 9541 4516 9571
TIME...MOT...LOC 2305Z 178DEG 27KT 4542 9565
WIND...HAIL <50MPH 1.00IN

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 3:20 PM CDTSpecial Weather StatementMPXRenville40 min
May 21, 3:57 PM CDTSpecial Weather StatementMPXMcLeod, Meeker, Wright63 min
May 21, 4:11 PM CDTSevere Thunderstorm WarningMPXMcLeod, Meeker, Renville, Sibley, Wright49 min
May 21, 4:39 PM CDTSevere Thunderstorm WarningMPXMcLeod, Meeker, Wright66 min
May 21, 5:11 PM CDTSpecial Weather StatementMPXChippewa, Swift49 min
May 21, 5:35 PM CDTSevere Thunderstorm WarningMPXCarver, McLeod, Wright55 min
May 21, 6:13 PM CDTSevere Thunderstorm WarningMPXHennepin, Wright62 min
May 21, 6:37 PM CDTTornado WarningMPXHennepin, Isanti23 min
May 21, 6:54 PM CDTSpecial Weather StatementMPXAnoka, Sherburne51 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.