Alert archive / Illinois / Mesoscale Discussions in 2016
Mesoscale Discussion 1481
The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2016, 8:41 PM CDT for 20 counties in Illinois; Scott County, Iowa. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- Aug 4, 2016, 8:41 PM CDT (01:41 UTC)
- Expired
- Aug 4, 2016, 9:45 PM CDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 21 counties
Scott County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, Henry County, IL, Kane County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Marshall County, IL, McHenry County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL
The radar
The Quad Cities radar (KDVN), 63 km from the middle of the area, began a volume at 01:41 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 00:00Z, 1.7 hours before the alert went out and 57 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
- 1172 J/kg
- Mixed-layer CIN
- -121 J/kg
- Mixed-layer LCL
- 1357 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 146 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 7.0
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 |
|---|---|---|---|---|
| Aug 4, 7:17 PM CDT | Mesoscale Discussion | SPC | Carroll, Jo Daviess, Stephenson | 88 min |
| Aug 4, 8:59 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Bureau, DeKalb, Henderson, Henry, Kane and 11 more | 3 hr |
| Aug 5, 2:28 PM CDT | Mesoscale Discussion | SPC | Alexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more | 3 hr |
Nearby
Mesoscale Discussions in Illinois, 2016Mesoscale Discussions in Iowa, 2016Every mesoscale discussion in 2016
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.