Alert archive / Minnesota / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 99, NWS La Crosse, WI

September 4, 2012Houston County, Minnesota

NWS La Crosse, WI issued this severe thunderstorm warning at Sep 4, 2012, 5:50 PM CDT for Houston County, Minnesota. It was in force for 40 min. 2 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
Sep 4, 2012, 5:50 PM CDT (22:50 UTC)
Expired
Sep 4, 2012, 6:30 PM CDT
In force
40 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Hail
1.75 in
Wind
60.0 mph

County Houston County, MN

The radar

The La Crosse radar (KARX), 38 km from the middle of the area, began a volume at 22:50 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
Sep 4, 6:00 PM CDTHAIL 2.5Spring Grove, MN
Sep 4, 6:05 PM CDTHAIL 1Spring Grove, MN

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 4, 3:27 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.8 hours before the alert went out and 214 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 2012-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1446 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 2012-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 172 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
1446 J/kg
Mixed-layer CIN
-171 J/kg
Mixed-layer LCL
1471 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
221 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.8

Open this sounding in Storm Lab

The text

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

741 
WUUS53 KARX 042250
SVRARX
MNC055-042330-
/O.NEW.KARX.SV.W.0099.120904T2250Z-120904T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
550 PM CDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN HOUSTON COUNTY IN SOUTHEAST MINNESOTA...

* UNTIL 630 PM CDT

* AT 545 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM LOCATED NEAR SPRING GROVE...OR 7 MILES
  SOUTHWEST OF CALEDONIA...MOVING EAST AT 25 MPH. THIS STORM CAN
  PRODUCE LARGE DAMAGING HAIL UP TO GOLF BALL SIZE AND DAMAGING WINDS
  IN EXCESS OF 60 MPH. TRAINED WEATHER SPOTTERS HAVE ALREADY REPORTED
  TENNIS BALL SIZE HAIL WITH THIS STORM.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  CALEDONIA AND DUN ROMIN PARK CAMPGROUND AROUND 600 PM...
  EITZEN AROUND 605 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. IF YOU ARE IN THE PATH OF THIS
STORM...PREPARE IMMEDIATELY FOR DESTRUCTIVE HAIL...WHICH CAN
SIGNIFICANTLY DAMAGE ROOFS...WINDOWS...SIDING AND VEHICLES. DAMAGING
WINDS ARE ALSO EXPECTED...WHICH WILL UPROOT TREES AND DOWN POWER
LINES. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS.

&&

LAT...LON 4367 9144 4350 9144 4350 9173 4366 9173
TIME...MOT...LOC 2250Z 266DEG 23KT 4359 9159
WIND...HAIL 60MPH 1.75IN

$$

BAUMGARDT

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 4, 4:39 AM CDTDense Fog AdvisoryARXDodge, Fillmore, Houston, Mower, Olmsted, Wabasha and 1 more4 hr
Sep 4, 4:00 PM CDTSevere Thunderstorm WarningARXWinona30 min
Sep 4, 4:29 PM CDTSevere Thunderstorm WarningARXWinona46 min
Sep 4, 4:53 PM CDTAreal Flood AdvisoryARXWinona97 min
Sep 4, 5:17 PM CDTSevere Thunderstorm WarningARXHouston28 min
Sep 4, 5:29 PM CDTSevere Thunderstorm WarningARXHouston, Winona46 min
Sep 4, 5:38 PM CDTSevere Thunderstorm WarningARXFillmore28 min
Sep 4, 6:14 PM CDTSevere Thunderstorm WarningARXHouston46 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.