Alert archive / Illinois / Mesoscale Discussions in 2009
Mesoscale Discussion 899
The Storm Prediction Center issued this mesoscale discussion at May 30, 2009, 2:44 PM CDT for 22 counties in Illinois. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- May 30, 2009, 2:44 PM CDT (19:44 UTC)
- Expired
- May 30, 2009, 4:15 PM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
All 22 counties
Cass County, IL, Champaign County, IL, Christian County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Effingham County, IL, Fayette County, IL, Fulton County, IL, Logan County, IL, Macon County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Sangamon County, IL, Schuyler County, IL, Shelby County, IL, Tazewell County, IL
The radar
The Lincoln radar (KILX), 6 km from the middle of the area, began a volume at 19:48 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
Lincoln, IL (KILX), launched 12:00Z, 7.7 hours before the alert went out and 65 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2479 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- -37 m²/s²
- 0-3 km storm-relative helicity
- 222 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 30, 3:49 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Christian, Clark, Clay, Clinton, Coles and 20 more | 11 hr |
| May 30, 6:01 PM CDT | Mesoscale Discussion | SPC | Bond, Cass, Champaign, Christian, Clark, Clay and 40 more | 59 min |
Nearby
Mesoscale Discussions in Illinois, 2009Every mesoscale discussion in 2009
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.