Alert archive / Minnesota / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 549

August 1, 201234 counties in Minnesota; Brookings County, Lake County, Moody County, South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Aug 1, 2012, 5:12 PM CDT for 34 counties in Minnesota; Brookings County, Lake County, Moody County, South Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Aug 1, 2012, 5:12 PM CDT (22:12 UTC)
Expired
Aug 1, 2012, 10:25 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 37 counties

Anoka County, MN, Blue Earth County, MN, Brown County, MN, Carver County, MN, Chippewa County, MN, Cottonwood County, MN, Dakota County, MN, Faribault County, MN, Freeborn County, MN, Goodhue County, MN, Hennepin County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Le Sueur County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, McLeod County, MN, Meeker County, MN, Murray County, MN, Nicollet County, MN, Pipestone County, MN, Ramsey County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Waseca County, MN, Washington County, MN, Watonwan County, MN, Wright County, MN, Yellow Medicine County, MN, Brookings County, SD, Lake County, SD, Moody County, SD

The radar

The Sioux Falls radar (KFSD), 145 km from the middle of the area, began a volume at 22:15 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Aug 1, 5:13 PM CDTSevere Thunderstorm WarningFSDLincoln47 min
Aug 1, 5:40 PM CDTSevere Thunderstorm WarningFSDLincoln, Lyon50 min
Aug 1, 6:02 PM CDTSevere Thunderstorm WarningMPXRedwood, Renville, Yellow Medicine58 min
Aug 1, 6:23 PM CDTSevere Thunderstorm WarningFSDLyon26 min
Aug 1, 6:47 PM CDTSevere Thunderstorm WarningMPXBrown, Nicollet, Redwood, Renville, Sibley58 min
Aug 1, 7:08 PM CDTSevere Thunderstorm WarningMPXMcLeod, Renville, Sibley37 min
Aug 1, 8:48 PM CDTSevere Thunderstorm WarningMPXCarver, Hennepin, Scott20 min
Aug 1, 9:19 PM CDTSevere Thunderstorm WarningMPXDakota, Goodhue, Rice41 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.2 hours before the alert went out and 169 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 2012-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 670 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2012-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 246 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
670 J/kg
Mixed-layer CIN
-340 J/kg
Mixed-layer LCL
1367 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
246 m²/s²
0-3 km storm-relative helicity
292 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 1, 1:07 PM CDTMesoscale DiscussionSPCAnoka, Carver, Chisago, Dakota, Goodhue, Hennepin and 6 more23 min
Aug 1, 4:14 PM CDTMesoscale DiscussionSPCAnoka, Benton, Brown, Carver, Chippewa, Chisago and 24 more91 min
Aug 1, 2:53 PM CDTMesoscale DiscussionSPCAurora, Beadle, Bennett, Brule, Buffalo, Charles Mix and 20 more67 min
Aug 1, 3:19 PM CDTSevere Thunderstorm WatchSPCAurora, Beadle, Bennett, Brule, Buffalo, Charles Mix and 28 more6 hr

Nearby

Severe Thunderstorm Watches in Minnesota, 2012Severe Thunderstorm Watches in South Dakota, 2012Every severe thunderstorm watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.