Alert archive / Illinois / Mesoscale Discussions in 2018

Mesoscale Discussion 922

June 28, 201853 counties in Illinois; Posey County, Indiana; 9 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2018, 3:34 PM CDT for 53 counties in Illinois; Posey County, Indiana; 9 counties in Missouri. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
Jun 28, 2018, 3:34 PM CDT (20:34 UTC)
Expired
Jun 28, 2018, 5:30 PM CDT
In force
116 min
Issued by
the Storm Prediction Center
All 63 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Fulton County, IL, Gallatin County, IL, Greene County, IL, Hamilton County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Perry County, IL, Piatt County, IL, Pike County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Posey County, IN, City of Saint Louis, MO, Lincoln County, MO, Marion County, MO, Montgomery County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 121 km from the middle of the area, began a volume at 20:33 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, 8.6 hours before the alert went out and 143 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-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2018-06-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2018-06-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
7 J/kg
Mixed-layer CIN
-572 J/kg
Mixed-layer LCL
1140 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
68 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.

IssuedProductOfficeCountiesLasted
Jun 28, 2:00 AM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Clinton, Franklin, Gallatin and 20 more3 hr
Jun 28, 8:43 AM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Clinton, Edwards, Franklin and 24 more62 min
Jun 28, 10:57 AM CDTMesoscale DiscussionSPCAdams, Brown, Hancock, Pike, Scott2 hr
Jun 28, 1:04 PM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 28 more7 hr
Jun 28, 5:33 PM CDTSevere Thunderstorm WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 14 more7 hr
Jun 28, 7:20 AM CDTMesoscale DiscussionSPCAtchison, Holt, Nodaway2 hr

Nearby

Mesoscale Discussions in Illinois, 2018Mesoscale Discussions in Missouri, 2018Mesoscale Discussions in Indiana, 2018Every mesoscale discussion in 2018

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.