Alert archive / Minnesota / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 704

July 30, 201138 counties in Minnesota; 11 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jul 30, 2011, 1:28 PM CDT for 38 counties in Minnesota; 11 counties in South Dakota. It was in force for 112 min.

The area

The outline as issued.

The facts

Issued
Jul 30, 2011, 1:28 PM CDT (18:28 UTC)
Expired
Jul 30, 2011, 3:20 PM CDT
In force
112 min
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 49 counties

Anoka County, MN, Blue Earth County, MN, Brown County, MN, Carver County, MN, Chippewa County, MN, Chisago County, MN, Cottonwood County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Isanti County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Le Sueur County, MN, Lincoln County, MN, Lyon County, MN, McLeod County, MN, Meeker County, MN, Murray County, MN, Nicollet County, MN, Pipestone County, MN, Pope County, MN, Ramsey County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Steele County, MN, Stevens County, MN, Swift County, MN, Waseca County, MN, Washington County, MN, Watonwan County, MN, Wright County, MN, Yellow Medicine County, MN, Brookings County, SD, Clark County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Kingsbury County, SD, Lake County, SD, Miner County, SD, Moody County, SD

The radar

The Sioux Falls radar (KFSD), 154 km from the middle of the area, began a volume at 18:31 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
30%
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
60%
Six or more combined severe hail and wind reports
80%

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, 6.5 hours before the alert went out and 182 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 2011-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2252 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 2011-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 84 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
2252 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
813 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
84 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 30, 5:47 AM CDTMesoscale DiscussionSPCBig Stone, Brown, Chippewa, Kandiyohi, Lac qui Parle, Lincoln and 9 more88 min
Jul 30, 11:28 AM CDTMesoscale DiscussionSPCAnoka, Benton, Brown, Carver, Chippewa, Chisago and 24 more3 hr
Jul 30, 3:22 PM CDTMesoscale DiscussionSPCBecker, Beltrami, Big Stone, Blue Earth, Brown, Carver and 38 more53 min
Jul 30, 5:31 PM CDTSevere Thunderstorm WatchSPCAitkin, Anoka, Benton, Big Stone, Brown, Carlton and 41 more7 hr
Jul 29, 9:06 PM CDTMesoscale DiscussionSPCCampbell, Corson, Dewey, Haakon, Harding, Hughes and 8 more54 min
Jul 29, 11:52 PM CDTMesoscale DiscussionSPCBrown, Edmunds, McPherson, Marshall83 min

Nearby

Severe Thunderstorm Watches in Minnesota, 2011Severe Thunderstorm Watches in South Dakota, 2011Every severe thunderstorm watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.