Alert archive / Missouri / Mesoscale Discussions in 2011

Mesoscale Discussion 2025

August 20, 2011Johnson County, Miami County, Wyandotte County, Kansas; 16 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Aug 20, 2011, 2:28 AM CDT for Johnson County, Miami County, Wyandotte County, Kansas; 16 counties in Missouri. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: Aug 20, 2011, 2:28 AM CDT (07:28 UTC)
Expired: Aug 20, 2011, 3:30 AM CDT
In force: 62 min
Issued by: the Storm Prediction Center

Counties Johnson County, KS, Miami County, KS, Wyandotte County, KS, Bates County, MO, Benton County, MO, Camden County, MO, Cass County, MO, Clay County, MO, Dallas County, MO, Henry County, MO, Hickory County, MO, Jackson County, MO, Johnson County, MO, Lafayette County, MO, Miller County, MO, Morgan County, MO, Pettis County, MO, Platte County, MO, St. Clair County, MO

The radar

The Pleasant Hill radar (KEAX), 40 km from the middle of the area, began a volume at 07:30 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

Topeka, KS (KTOP), launched 00:00Z, 7.5 hours before the alert went out and 158 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: 1999 J/kg
Mixed-layer CIN: -345 J/kg
Mixed-layer LCL: 1353 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 92 m²/s²
0-3 km storm-relative helicity: 287 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

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 19, 11:51 PM CDT	Mesoscale Discussion	SPC	Atchison, Doniphan, Douglas, Franklin, Jackson, Jefferson and 5 more	54 min
Aug 20, 3:56 PM CDT	Mesoscale Discussion	SPC	Barry, Barton, Camden, Cedar, Christian, Dade and 15 more	64 min
Aug 20, 6:04 PM CDT	Severe Thunderstorm Watch	SPC	Barry, Christian, Douglas, Greene, Howell, Lawrence and 8 more	5 hr

Nearby

Mesoscale Discussions in Missouri, 2011 Mesoscale Discussions in Kansas, 2011 Every mesoscale discussion in 2011

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.