Alert archive / Illinois / Mesoscale Discussions in 2017

Mesoscale Discussion 1619

September 4, 201734 counties in Illinois; Vermillion County, Indiana; 4 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Sep 4, 2017, 6:05 PM CDT for 34 counties in Illinois; Vermillion County, Indiana; 4 counties in Missouri. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Sep 4, 2017, 6:05 PM CDT (23:05 UTC)
Expired: Sep 4, 2017, 8:00 PM CDT
In force: 115 min
Issued by: the Storm Prediction Center

All 39 counties

Bond County, IL, Calhoun County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jasper County, IL, Jersey County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Richland County, IL, Saint Clair County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL, Vermilion County, IL, Vermillion County, IN, City of Saint Louis, MO, Jefferson County, MO, Saint Charles County, MO, Saint Louis County, MO

The radar

The Lincoln radar (KILX), 90 km from the middle of the area, began a volume at 23:07 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

Lincoln, IL (KILX), launched 12:00Z, 11.1 hours before the alert went out and 118 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1674 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 220 m²/s²
0-3 km storm-relative helicity: 241 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Sep 4, 2:17 PM CDT	Mesoscale Discussion	SPC	Champaign, Douglas, Edgar, Ford, Iroquois, Vermilion	118 min
Sep 4, 3:43 PM CDT	Mesoscale Discussion	SPC	Champaign, Christian, DeWitt, Douglas, Ford, Greene and 16 more	2 hr
Sep 4, 4:00 PM CDT	Severe Thunderstorm Watch	SPC	Bond, Calhoun, Champaign, Christian, Clark, Clay and 29 more	6 hr
Sep 4, 3:32 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Allen, Blackford, Boone, Carroll, Cass and 38 more	6 hr
Sep 4, 5:50 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Boone, Carroll, Cass and 30 more	115 min

Nearby

Mesoscale Discussions in Illinois, 2017 Mesoscale Discussions in Missouri, 2017 Mesoscale Discussions in Indiana, 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.