Alert archive / Minnesota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 37, NWS Twin Cities, MN

May 21, 2011Hennepin County, Wright County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at May 21, 2011, 6:13 PM CDT for Hennepin County, Wright County, Minnesota. It was in force for 62 min. 7 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: May 21, 2011, 6:13 PM CDT (23:13 UTC)
Expired: May 21, 2011, 7:15 PM CDT
In force: 62 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Hennepin County, MN, Wright County, MN

The radar

The Minneapolis radar (KMPX), 30 km from the middle of the area, began a volume at 23:13 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

Time	Report	Where	Remark
May 21, 6:18 PM CDT	HAIL 0.75	7 Sw Rockford, MN	0.88 HAIL WITH ROTATING WALL CLOUD
May 21, 6:21 PM CDT	HAIL 0.5	4 N Rockford, MN
May 21, 6:25 PM CDT	HAIL 0.25	Corcoran, MN
May 21, 6:25 PM CDT	HAIL 1	Delano, MN	DIME TO QUARTER
May 21, 6:29 PM CDT	FUNNEL CLOUD	Orono, MN	WALL CLOUD
May 21, 6:34 PM CDT	HAIL 0.75	2 Ese Corcoran, MN
May 21, 6:55 PM CDT	FUNNEL CLOUD	Maple Grove, MN	ROTATING WALL CLOUD

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, 11.2 hours before the alert went out and 29 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: 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.

515 
WUUS53 KMPX 212313
SVRMPX
MNC053-171-220015-
/O.NEW.KMPX.SV.W.0037.110521T2313Z-110522T0015Z/

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

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN HENNEPIN COUNTY IN EAST CENTRAL MINNESOTA...
  EASTERN WRIGHT COUNTY IN CENTRAL MINNESOTA...

* UNTIL 715 PM CDT

* AT 608 PM CDT...RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS...
  CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS
  OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM
  WAVERLY TO DELANO TO WAYZATA...AND MOVING NORTHEAST AT 15 MPH.

LOCATIONS IN THE WARNING INCLUDE...
  PLYMOUTH...
  BUFFALO...
  MEDINA...
  LORETTO...
  HAMEL...
  ROCKFORD...
  CORCORAN...
  MAPLE GROVE...
  HANOVER...
  ROGERS...
  ST MICHAEL...
  DAYTON...
  ALBERTVILLE...
  MONTICELLO...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

REPORT ANY SIGNIFICANT WIND OR HAIL DAMAGE TO THE NEAREST LAW
ENFORCEMENT AGENCY...FOR RELAY TO THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 4527 9364 4518 9340 4489 9351 4495 9377
      4497 9377 4497 9389 4504 9409 4532 9388
TIME...MOT...LOC 2313Z 204DEG 12KT 4510 9399 4505 9382
          4500 9349
WIND...HAIL 60MPH 1.00IN

$$

JLT

1 follow-up statement

716 
WWUS53 KMPX 212330
SVSMPX

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

MNC053-171-220015-
/O.CON.KMPX.SV.W.0037.000000T0000Z-110522T0015Z/
WRIGHT MN-HENNEPIN MN-
630 PM CDT SAT MAY 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
HENNEPIN AND EASTERN WRIGHT COUNTIES UNTIL 715 PM CDT...

AT 626 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG
A LINE EXTENDING FROM WAVERLY TO ROCKFORD TO PLYMOUTH...MOVING
NORTHEAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE...
  BUFFALO...CORCORAN...MAPLE GROVE...HANOVER...ST MICHAEL...ROGERS...
  DAYTON...ALBERTVILLE AND GREENFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4527 9364 4518 9340 4499 9349 4497 9377
      4497 9389 4504 9409 4532 9388
TIME...MOT...LOC 2331Z 204DEG 12KT 4516 9396 4510 9379
          4505 9345
WIND...HAIL 60MPH 1.00IN

$$

JLT

The office that day

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

Issued	Product	Office	Counties	Lasted
May 21, 3:20 PM CDT	Special Weather Statement	MPX	Renville	40 min
May 21, 3:57 PM CDT	Special Weather Statement	MPX	McLeod, Meeker, Wright	63 min
May 21, 4:11 PM CDT	Severe Thunderstorm Warning	MPX	McLeod, Meeker, Renville, Sibley, Wright	49 min
May 21, 4:39 PM CDT	Severe Thunderstorm Warning	MPX	McLeod, Meeker, Wright	66 min
May 21, 5:11 PM CDT	Special Weather Statement	MPX	Chippewa, Swift	49 min
May 21, 5:25 PM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Pope, Swift	50 min
May 21, 5:35 PM CDT	Severe Thunderstorm Warning	MPX	Carver, McLeod, Wright	55 min
May 21, 6:37 PM CDT	Tornado Warning	MPX	Hennepin, Isanti	23 min
May 21, 6:54 PM CDT	Special Weather Statement	MPX	Anoka, Sherburne	51 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2011 Every 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.