Alert archive / Minnesota / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 6, NWS Twin Cities, MN

April 21, 2012Stevens County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Apr 21, 2012, 2:04 PM CDT for Stevens County, Minnesota. It was in force for 14 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
Apr 21, 2012, 2:04 PM CDT (19:04 UTC)
Expired
Apr 21, 2012, 2:18 PM CDT
In force
14 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Stevens County, MN

The radar

The Aberdeen radar (KABR), 186 km from the middle of the area, began a volume at 19:06 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
Apr 21, 2:11 PM CDTHAIL 0.5Donnelly, MN

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 7.1 hours before the alert went out and 203 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, Aberdeen, SD at 12:00Z on 2012-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 12:00Z on 2012-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 297 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
728 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
297 m²/s²
0-3 km storm-relative helicity
400 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.

820 
WUUS53 KMPX 211904
SVRMPX
MNC149-211945-
/O.NEW.KMPX.SV.W.0006.120421T1904Z-120421T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
204 PM CDT SAT APR 21 2012

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN STEVENS COUNTY IN WEST CENTRAL MINNESOTA...

* UNTIL 245 PM CDT

* AT 202 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM...CAPABLE OF
  PRODUCING QUARTER SIZE HAIL. THIS STORM WAS LOCATED NEAR
  DONNELLY...OR ABOUT 11 MILES NORTHWEST OF MORRIS...AND MOVING EAST
  AT 15 MPH.

LOCATIONS IN THE WARNING INCLUDE...
  MORRIS...
  DONNELLY...

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.

SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE
WARNING. PREPARE TO MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE
SUCH AS A BASEMENT OR SMALL INTERIOR ROOM IF A TORNADO IS SPOTTED.

&&

LAT...LON 4563 9624 4577 9613 4572 9577 4552 9581
TIME...MOT...LOC 1904Z 286DEG 14KT 4569 9608
WIND...HAIL <50MPH 1.00IN

$$
1 follow-up statement
980 
WWUS53 KMPX 211918
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
218 PM CDT SAT APR 21 2012

MNC149-211933-
/O.CAN.KMPX.SV.W.0006.000000T0000Z-120421T1945Z/
STEVENS MN-
218 PM CDT SAT APR 21 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN STEVENS COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR 
PROPERTY...HOWEVER HEAVY RAIN AND SMALL HAIL ARE STILL POSSIBLE WITH 
THIS THUNDERSTORM.

LAT...LON 4563 9624 4577 9613 4572 9577 4552 9581
TIME...MOT...LOC 1918Z 286DEG 14KT 4567 9601

$$
DWE

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 21, 1:50 PM CDTSpecial Weather StatementMPXStevens55 min
Apr 21, 2:28 PM CDTSpecial Weather StatementMPXChippewa, Douglas, Pope, Redwood, Swift62 min
Apr 21, 3:22 PM CDTSevere Thunderstorm WarningMPXBrown, Redwood38 min
Apr 21, 3:29 PM CDTTornado WarningMPXChippewa, Swift46 min
Apr 21, 3:33 PM CDTTornado WarningMPXRedwood28 min
Apr 21, 4:09 PM CDTTornado WarningMPXChippewa, Kandiyohi, Renville36 min
Apr 21, 4:21 PM CDTSpecial Weather StatementMPXPope39 min
Apr 21, 4:49 PM CDTSpecial Weather StatementMPXRenville41 min
Apr 21, 5:01 PM CDTTornado WarningMPXMartin, Watonwan44 min
Apr 21, 5:53 PM CDTSpecial Weather StatementMPXMartin37 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2012Every severe thunderstorm warning in 2012

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.