Alert archive / Iowa / Mesoscale Discussions in 2018
Mesoscale Discussion 807
The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2018, 5:13 PM CDT for Mercer County, Rock Island County, Illinois; 37 counties in Iowa. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 20, 2018, 5:13 PM CDT (22:13 UTC)
- Expired
- Jun 20, 2018, 7:15 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 39 counties
Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cedar County, IA, Cerro Gordo County, IA, Delaware County, IA, Des Moines County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Henry County, IA, Humboldt County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Kossuth County, IA, Linn County, IA, Louisa County, IA, Mahaska County, IA, Marshall County, IA, Muscatine County, IA, Palo Alto County, IA, Pocahontas County, IA, Poweshiek County, IA, Scott County, IA, Story County, IA, Tama County, IA, Wapello County, IA, Washington County, IA, Wright County, IA, Mercer County, IL, Rock Island County, IL
The radar
The Des Moines radar (KDMX), 104 km from the middle of the area, began a volume at 22:17 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 nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 10.2 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.
- Mixed-layer CAPE
- 235 J/kg
- Mixed-layer CIN
- -52 J/kg
- Mixed-layer LCL
- 502 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 80 m²/s²
- 0-3 km storm-relative helicity
- 80 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 1:01 PM CDT | Mesoscale Discussion | SPC | Benton, Boone, Dallas, Grundy, Hardin, Iowa and 16 more | 2 hr |
| Jun 20, 3:04 PM CDT | Tornado Watch | SPC | Benton, Black Hawk, Boone, Bremer, Buchanan, Butler and 30 more | 4 hr |
Nearby
Mesoscale Discussions in Iowa, 2018Mesoscale Discussions in Illinois, 2018Every mesoscale discussion in 2018
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.