Alert archive / Illinois / Mesoscale Discussions in 2020

Mesoscale Discussion 803

June 3, 202021 counties in Illinois; 16 counties in Iowa; 11 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jun 3, 2020, 6:37 PM CDT for 21 counties in Illinois; 16 counties in Iowa; 11 counties in Missouri. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued: Jun 3, 2020, 6:37 PM CDT (23:37 UTC)
Expired: Jun 3, 2020, 8:30 PM CDT
In force: 113 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 245

All 48 counties

Appanoose County, IA, Davis County, IA, Des Moines County, IA, Henry County, IA, Jefferson County, IA, Keokuk County, IA, Lee County, IA, Louisa County, IA, Lucas County, IA, Mahaska County, IA, Monroe County, IA, Muscatine County, IA, Van Buren County, IA, Wapello County, IA, Washington County, IA, Wayne County, IA, Adams County, IL, Brown County, IL, Cass County, IL, Fulton County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Knox County, IL, Logan County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Mercer County, IL, Morgan County, IL, Peoria County, IL, Rock Island County, IL, Sangamon County, IL, Schuyler County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Adair County, MO, Clark County, MO, Knox County, MO, Lewis County, MO, Macon County, MO, Marion County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO

The radar

The Quad Cities radar (KDVN), 134 km from the middle of the area, began a volume at 23:37 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

Davenport, (KDVN), launched 12:00Z, 11.6 hours before the alert went out and 139 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: 529 J/kg
Mixed-layer CIN: -163 J/kg
Mixed-layer LCL: 1033 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 116 m²/s²
0-3 km storm-relative helicity: 140 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

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
Jun 3, 9:52 AM CDT	Mesoscale Discussion	SPC	Adams, Brown, Cass, Fulton, Hancock, Henderson and 11 more	113 min
Jun 3, 1:45 PM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Cass, Christian and 33 more	2 hr
Jun 3, 3:52 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Bond, Brown, Calhoun, Clinton, Fayette and 12 more	6 hr
Jun 3, 4:56 AM CDT	Mesoscale Discussion	SPC	Adair, Adams, Benton, Cedar, Clarke, Clinton and 22 more	3 hr

Nearby

Mesoscale Discussions in Illinois, 2020 Mesoscale Discussions in Iowa, 2020 Mesoscale Discussions in Missouri, 2020 Every mesoscale discussion in 2020

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.