Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 1730

August 9, 201221 counties in Illinois; 40 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Aug 9, 2012, 7:10 PM CDT for 21 counties in Illinois; 40 counties in Indiana. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 9, 2012, 7:10 PM CDT (00:10 UTC)
Expired: Aug 9, 2012, 9:15 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 61 counties

Champaign County, IL, Christian County, IL, Clark County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Ford County, IL, Iroquois County, IL, Jasper County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, McLean County, IL, Moultrie County, IL, Piatt County, IL, Shelby County, IL, Vermilion County, IL, Benton County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clay County, IN, Clinton County, IN, Delaware County, IN, Fountain County, IN, Fulton County, IN, Grant County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Johnson County, IN, Madison County, IN, Marion County, IN, Miami County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Newton County, IN, Owen County, IN, Parke County, IN, Pulaski County, IN, Putnam County, IN, Shelby County, IN, Sullivan County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Wabash County, IN, Warren County, IN, White County, IN

The radar

The Indianapolis radar (KIND), 97 km from the middle of the area, began a volume at 00:10 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.

Severe Thunderstorm Watch 569Aug 9, 7:40 PM CDT

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.2 hours before the alert went out and 107 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 680 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 1397 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 33 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

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.

Issued	Product	Office	Counties	Lasted
Aug 9, 7:40 PM CDT	Severe Thunderstorm Watch	SPC	Champaign, Clark, Clay, Coles, Crawford, Cumberland and 17 more	4 hr
Aug 9, 10:02 PM CDT	Severe Thunderstorm Watch	SPC	Ohio	76 min

Nearby

Mesoscale Discussions in Indiana, 2012 Mesoscale Discussions in Illinois, 2012 Every mesoscale discussion in 2012

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.