Alert archive / Minnesota / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 39, NWS Twin Cities, MN

July 21, 2009Benton County, Morrison County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 21, 2009, 1:58 PM CDT for Benton County, Morrison County, Minnesota. It was in force for 47 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
Jul 21, 2009, 1:58 PM CDT (18:58 UTC)
Expired
Jul 21, 2009, 2:45 PM CDT
In force
47 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

Counties Benton County, MN, Morrison County, MN

The radar

The Minneapolis radar (KMPX), 118 km from the middle of the area, began a volume at 18:59 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
Jul 21, 2:10 PM CDTHAIL 11 Sw Little Rock, MNMEASURED IN GRAHAM TOWNSHIP

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, 7.0 hours before the alert went out and 117 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 2009-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 187 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 2009-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 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
187 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
527 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
78 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.

000 
WUUS53 KMPX 211858
SVRMPX
MNC009-097-211945-
/O.NEW.KMPX.SV.W.0039.090721T1858Z-090721T1945Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
158 PM CDT TUE JUL 21 2009

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL MORRISON COUNTY IN CENTRAL MINNESOTA...
  NORTHWESTERN BENTON COUNTY IN CENTRAL MINNESOTA...

* UNTIL 245 PM CDT

* AT 155 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM...CAPABLE OF
  PRODUCING QUARTER SIZE HAIL. THIS STORM WAS LOCATED 3 MILES EAST OF
  ROYALTON...OR ABOUT 12 MILES SOUTHEAST OF LITTLE FALLS...AND MOVING
  EAST AT 15 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  LITTLE ROCK...
  AREAS EAST OF ROYALTON...
  AREAS NORTH OF RICE...

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 4590 9397 4572 9405 4580 9433 4588 9426
TIME...MOT...LOC 1857Z 271DEG 11KT 4583 9421

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 12:51 PM CDTSpecial Weather StatementMPXMorrison39 min
Jul 21, 1:26 PM CDTSpecial Weather StatementMPXMorrison49 min
Jul 21, 2:15 PM CDTSpecial Weather StatementMPXCarver45 min
Jul 21, 2:22 PM CDTSevere Thunderstorm WarningMPXBenton38 min
Jul 21, 2:28 PM CDTSpecial Weather StatementMPXSherburne47 min
Jul 21, 2:43 PM CDTSevere Thunderstorm WarningMPXBlue Earth47 min
Jul 21, 2:53 PM CDTSevere Thunderstorm WarningMPXBenton, Sherburne37 min
Jul 21, 3:19 PM CDTSpecial Weather StatementMPXWashington41 min
Jul 21, 3:24 PM CDTSpecial Weather StatementMPXWright51 min
Jul 21, 3:31 PM CDTSpecial Weather StatementMPXFaribault44 min
Jul 21, 3:43 PM CDTSevere Thunderstorm WarningMPXAnoka, Sherburne, Wright62 min
Jul 21, 3:52 PM CDTSevere Thunderstorm WarningMPXHennepin, Wright53 min
Jul 21, 4:11 PM CDTSevere Thunderstorm WarningMPXAnoka, Hennepin49 min
Jul 21, 4:16 PM CDTSevere Thunderstorm WarningMPXCarver, Hennepin, Wright44 min
Jul 21, 4:19 PM CDTSevere Thunderstorm WarningMPXWashington41 min
Jul 21, 4:36 PM CDTSevere Thunderstorm WarningMPXAnoka24 min
Jul 21, 4:53 PM CDTSevere Thunderstorm WarningMPXCarver, Hennepin36 min
Jul 21, 4:56 PM CDTSevere Thunderstorm WarningMPXLe Sueur, Nicollet, Sibley49 min
Jul 21, 5:02 PM CDTSevere Thunderstorm WarningMPXDakota, Washington43 min
Jul 21, 5:05 PM CDTSevere Thunderstorm WarningMPXRamsey24 min
Jul 21, 5:10 PM CDTAreal Flood AdvisoryMPXWashington2 hr
Jul 21, 5:54 PM CDTSpecial Weather StatementMPXDakota51 min
Jul 21, 6:18 PM CDTSpecial Weather StatementMPXWaseca42 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2009Every severe thunderstorm warning in 2009

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.