Alert archive / Indiana / Mesoscale Discussions in 2017

Mesoscale Discussion 1257

July 7, 201720 counties in Illinois; 29 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Jul 7, 2017, 12:19 PM CDT for 20 counties in Illinois; 29 counties in Indiana. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: Jul 7, 2017, 12:19 PM CDT (17:19 UTC)
Expired: Jul 7, 2017, 1:15 PM CDT
In force: 56 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 49 counties

Champaign County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Ford County, IL, Iroquois County, IL, Jasper County, IL, Kankakee County, IL, Lawrence County, IL, Livingston County, IL, Moultrie County, IL, Piatt County, IL, Richland County, IL, Vermilion County, IL, Wayne County, IL, Benton County, IN, Boone County, IN, Carroll County, IN, Clay County, IN, Clinton County, IN, Daviess County, IN, Fountain County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Jasper County, IN, Johnson County, IN, Knox County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Newton County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Sullivan County, IN, Tippecanoe County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN, White County, IN

The radar

The Indianapolis radar (KIND), 129 km from the middle of the area, began a volume at 17:19 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, 5.3 hours before the alert went out and 79 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: 1263 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 1203 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 7, 12:45 PM CDT	Severe Thunderstorm Watch	SPC	Ford, Iroquois, Kankakee, Vermilion	7 hr
Jul 7, 7:51 AM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Boone, Carroll, Cass and 25 more	114 min
Jul 7, 8:46 AM CDT	Severe Thunderstorm Watch	SPC	Adams, Allen, Blackford, Cass, DeKalb, Delaware and 20 more	7 hr
Jul 7, 10:22 AM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Cass, DeKalb, Delaware and 17 more	53 min
Jul 7, 2:54 PM CDT	Mesoscale Discussion	SPC	Bartholomew, Brown, Clark, Dearborn, Decatur, Fayette and 19 more	96 min
Jul 7, 3:24 PM CDT	Severe Thunderstorm Watch	SPC	Clark, Dearborn, Fayette, Floyd, Franklin, Harrison and 8 more	7 hr
Jul 7, 5:34 PM CDT	Mesoscale Discussion	SPC	Clark, Floyd, Jackson, Jefferson, Jennings, Lawrence and 6 more	86 min

Nearby

Mesoscale Discussions in Indiana, 2017 Mesoscale Discussions in Illinois, 2017 Every mesoscale discussion in 2017

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.