Alert archive / Iowa / Mesoscale Discussions in 2011

Mesoscale Discussion 1690

July 22, 201167 counties in Iowa; 38 counties in Minnesota; 18 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 22, 2011, 3:00 PM CDT for 67 counties in Iowa; 38 counties in Minnesota; 18 counties in South Dakota. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Jul 22, 2011, 3:00 PM CDT (20:00 UTC)
Expired
Jul 22, 2011, 4:30 PM CDT
In force
90 min
Issued by
the Storm Prediction Center
All 123 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clarke County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Dickinson County, IA, Emmet County, IA, Floyd County, IA, Franklin County, IA, Fremont County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Harrison County, IA, Howard County, IA, Humboldt County, IA, Ida County, IA, Jasper County, IA, Kossuth County, IA, Lyon County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mills County, IA, Mitchell County, IA, Monona County, IA, Montgomery County, IA, O'Brien County, IA, Osceola County, IA, Page County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Ringgold County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Brown County, MN, Carver County, MN, Chippewa County, MN, Cottonwood County, MN, Dakota County, MN, Dodge County, MN, Faribault County, MN, Freeborn County, MN, Goodhue County, MN, Hennepin County, MN, Jackson 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, Mower County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Olmsted County, MN, Pipestone County, MN, Ramsey County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Rock County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Swift County, MN, Waseca County, MN, Watonwan County, MN, Yellow Medicine County, MN, Beadle County, SD, 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, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Spink County, SD, Union County, SD

The radar

The Des Moines radar (KDMX), 149 km from the middle of the area, began a volume at 20:03 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.0 hours before the alert went out and 373 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, Davenport, at 12:00Z on 2011-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2442 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, Davenport, at 12:00Z on 2011-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 140 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
2442 J/kg
Mixed-layer CIN
-94 J/kg
Mixed-layer LCL
1188 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
140 m²/s²
0-3 km storm-relative helicity
168 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 7:09 PM CDTMesoscale DiscussionSPCAdams, Appanoose, Clarke, Davis, Decatur, Des Moines and 18 more96 min
Jul 21, 10:44 PM CDTSevere Thunderstorm WatchSPCFremont, Mills, Montgomery, Page, Pottawattamie89 min
Jul 22, 5:46 PM CDTMesoscale DiscussionSPCBig Stone, Grant, Stevens, Traverse, Wilkin89 min
Jul 22, 6:14 PM CDTTornado WatchSPCBig Stone, Traverse, Wilkin8 hr
Jul 21, 7:10 PM CDTMesoscale DiscussionSPCBennett, Jackson, Jones, Lyman, Mellette, Todd and 1 more95 min
Jul 22, 11:05 AM CDTMesoscale DiscussionSPCCorson, Harding, Perkins55 min
Jul 22, 5:17 PM CDTMesoscale DiscussionSPCButte, Harding, Perkins88 min
Jul 22, 5:35 PM CDTTornado WatchSPCCampbell, Corson, Dewey, Edmunds, Harding, McPherson and 3 more8 hr
Jul 22, 6:22 PM CDTMesoscale DiscussionSPCBrule, Buffalo, Gregory, Lyman, Mellette, Todd and 1 more53 min

Nearby

Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in Minnesota, 2011Mesoscale Discussions in South Dakota, 2011Every mesoscale discussion 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.