Alert archive / Iowa / Mesoscale Discussions in 2015

Mesoscale Discussion 1084

June 20, 20158 counties in Illinois; 56 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2015, 12:48 PM CDT for 8 counties in Illinois; 56 counties in Iowa. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Jun 20, 2015, 12:48 PM CDT (17:48 UTC)
Expired
Jun 20, 2015, 2:45 PM CDT
In force
117 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 64 counties

Audubon County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cedar County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Clinton County, IA, Crawford County, IA, Dallas County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Henry County, IA, Humboldt County, IA, Ida County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monona County, IA, Muscatine County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Sac County, IA, Scott County, IA, Shelby County, IA, Story County, IA, Tama County, IA, Washington County, IA, Webster County, IA, Wright County, IA, Henderson County, IL, Henry County, IL, Knox County, IL, Mercer County, IL, Rock Island County, IL, Stark County, IL, Warren County, IL, Whiteside County, IL

The radar

The Des Moines radar (KDMX), 68 km from the middle of the area, began a volume at 17:48 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, 5.8 hours before the alert went out and 202 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 2015-06-20Temperature 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, Davenport, at 12:00Z on 2015-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
769 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Jun 20, 3:10 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Fulton, Hancock, Henderson and 6 more2 hr
Jun 20, 3:49 PM CDTTornado WatchSPCAdams, Brown, Cass, Christian, DeWitt, Fulton and 26 more7 hr
Jun 20, 6:33 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Fulton, Hancock, Henderson and 11 more57 min
Jun 20, 2:52 AM CDTMesoscale DiscussionSPCDickinson, Emmet, Lyon, Osceola53 min
Jun 20, 3:18 AM CDTSevere Thunderstorm WatchSPCClay, Dickinson, Emmet, Kossuth, Lyon, O'Brien and 3 more3 hr
Jun 20, 5:11 AM CDTMesoscale DiscussionSPCCerro Gordo, Clay, Emmet, Floyd, Hancock, Humboldt and 5 more64 min

Nearby

Mesoscale Discussions in Iowa, 2015Mesoscale Discussions in Illinois, 2015Every mesoscale discussion in 2015

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.