Alert archive / Iowa / Mesoscale Discussions in 2011

Mesoscale Discussion 394

April 9, 201131 counties in Iowa; Fillmore County, Houston County, Minnesota

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2011, 10:43 PM CDT for 31 counties in Iowa; Fillmore County, Houston County, Minnesota. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
Apr 9, 2011, 10:43 PM CDT (03:43 UTC)
Expired
Apr 9, 2011, 11:45 PM CDT
In force
62 min
Issued by
the Storm Prediction Center
All 33 counties

Allamakee County, IA, Black Hawk County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clay County, IA, Dickinson County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Howard County, IA, Humboldt County, IA, Kossuth County, IA, Mitchell County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Pocahontas County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Fillmore County, MN, Houston County, MN

The radar

The Des Moines radar (KDMX), 140 km from the middle of the area, began a volume at 03:47 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

Minneapolis, MN (KMPX), launched 00:00Z, 3.7 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 00:00Z on 2011-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2011-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 355 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
612 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
355 m²/s²
0-3 km storm-relative helicity
550 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.2

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
Apr 9, 7:42 PM CDTSevere Thunderstorm WatchSPCAllamakee, Chickasaw, Floyd, Howard, Mitchell, Winneshiek7 hr
Apr 9, 9:06 PM CDTMesoscale DiscussionSPCAudubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 31 more54 min
Apr 9, 11:01 PM CDTTornado WatchSPCAllamakee, Bremer, Buena Vista, Butler, Cerro Gordo, Cherokee and 19 more5 hr
Apr 10, 1:26 AM CDTMesoscale DiscussionSPCAllamakee, Buena Vista, Cerro Gordo, Chickasaw, Clay, Dickinson and 14 more64 min
Apr 10, 1:30 PM CDTMesoscale DiscussionSPCAllamakee, Buchanan, Clayton, Delaware, Dubuque, Fayette and 5 more2 hr
Apr 10, 3:19 PM CDTTornado Watch PDSSPCAllamakee, Clayton, Fayette, Howard, Winneshiek7 hr
Apr 10, 5:03 PM CDTMesoscale DiscussionSPCCedar, Clinton, Davis, Delaware, Des Moines, Dubuque and 12 more57 min
Apr 10, 6:05 PM CDTTornado WatchSPCClinton, Des Moines, Jackson, Lee, Louisa, Muscatine and 1 more7 hr
Apr 9, 7:47 PM CDTSevere Thunderstorm WatchSPCCottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more3 hr

Nearby

Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in Minnesota, 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.